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Learn more about some of the types of brain tumors and neurological conditions treated at the Gerald J. Glasser Brain Tumor Center.

Brain Tumors and Related Conditions Treated

Glioblastoma Multiforme (GBM)

A tumor that arises from glial cells (from the Greek for “glue”), or supportive tissue, of the brain is called a “glioma.” One type of glioma is the astrocytoma. Astrocytomas are named after astrocytes, the star-shaped cells from which they grow. Astrocytomas are histologically graded by their rate of growth (mitotic activity) and nuclear atypia on a scale from Grade I to IV. The terms “malignant glioma” and “high-grade glioma” include grade III and Grade IV gliomas.  Glioblastoma multiforme (GBM) is the highest-grade glioma (synonymous with Grade IV glioma) tumor and is the most malignant form of astrocytoma. GBMs are the most common adult primary brain tumors, and make up approximately half of all astrocytomas. They can occur at any age, but are more common in older patients.

Symptoms
Symptoms, such as headache and nausea, usually are the result of increased intracranial pressure caused by the mass of the tumor in the brain or from a backup of the cerebrospinal fluid that surrounds the brain and spinal cord. As a brain tumor grows, it may interfere with the normal functions of the brain. The glial cells are widely distributed throughout the central nervous system, so these tumors can occur in a wide variety of locations, and therefore can cause a wide variety of other symptoms. Depending on the location, gliomas may cause seizures, weakness or numbness in the arms or legs, impairments in language function, blurred vision, changes in personality, cognitive impairments and memory loss. Some GBMs may reach a fairly large size before they begin to cause noticeable symptoms.

Diagnosis
These tumors are diagnosed with a neurological examination followed by imaging studies of the brain, usually a computed tomography (CT) or magnetic resonance imaging (MRI) scan. The scan is usually performed with a contrast dye that makes the border and details of the tumor more visible in relation to the surrounding normal brain. The scan provides detail information regarding the exact size, location and probable type of tumor. However, only examination of a patient’s tumor tissue under a microscope can confirm an exact diagnosis. This tissue is usually obtained with either a biopsy or removal of the tumor. In a biopsy, GBM can be characterized by the presence of necrosis, or cell death, which is not present in anaplastic astrocytomas. In some cases, neurosurgeons may employ a stereotactic MRI scan. In this study, a high-resolution contrast MRI is performed and a three-dimensional brain model is constructed using a computer system that is used to perform minimally invasive surgery and allow for volumetric three-dimensional removal of the tumor, which maximizes the degree of tumor removal.

Treatment
In general, the initial treatment of a glioblastoma is surgical resection of the tumor. With modern techniques, surgery which consists of a craniotomy (making an opening in the skull) is generally safe and allows the team at the Brain Tumor Center to obtain tumor tissue for accurate microscopic diagnosis and treatment planning. With stereotactic volumetric techniques a tumor surgeon can often achieve a gross or near total removal of the tumor when evaluated with an MRI scan after surgery. Removing the tumor tends to reduce the symptoms caused by the presence of the tumor. In some patients with medical conditions that don't allow for surgery or in patients with concerns about the location of the tumor, a biopsy may be done in place of the surgery. 

In some cases, depending on the location of the tumor, the neurosurgeon may employ advanced techniques that enable safe removal of a tumor even in eloquent parts of the brain. Some of these techniques include functional brain mapping to identify the location of movement, sensation and language centers in the brain. This is performed with intraoperative electrical stimulation of the brain, functional MRI scans and occasionally by performing the surgery awake in order to monitor and evaluate these functions during the operation. With stereotactic image-guided techniques the surgeon uses an MRI based 3D model of the patients brain – much like a GPS system - to safely remove as much of the tumor as possible. High-powered microscopes are also used to help the neurosurgeon better see the tumor and ultrasonic aspirators are sometimes used to help remove the tumor. 

After surgery, each patient is reviewed at our Multi-Disciplinary Tumor Board with an expert team of neuro-oncologists, medical oncologists, neuro-pathologists, neuro-radiologists and neurosurgeons. Together the tumor board recommends the best treatment options for each patient, incorporating ongoing national clinical trials and the latest treatment protocols. Usually, because the tentacle-like cells of an astrocytoma grow into the surrounding tissue, these tumors require additional treatment around the margins with image guided conformal radiation and/or systemic chemotherapy or targeted biological therapy after surgery. Stereotactic radiosurgery also may be used in some cases of tumor recurrence or to target focal areas of recurrence following chemotherapy. Stereotactic radiosurgery (SRS) and Fractionated stereotactic radiosurgery (FSRS) are special forms of precisely focused, high-dose radiation for delivery to a small, localized tumor as a single dose treatment or fractionated treatment over four to five days. 

Research
New therapies, such as immunotherapy, vaccine therapy, gene therapy, and new biologically targeted chemotherapies are being examined. Clinical trials are open for both patients with newly-diagnosed and those with recurrent tumors. These trials test the safety and effectiveness of treatments that have shown promise in earlier phase trials or in laboratory studies. For patients, they provide access to therapies that would otherwise be unavailable. All clinical trials are overseen by government and hospital boards and subject to rigorous regulation and oversight.

Molecular markers have been increasingly used to complement the microscopic diagnosis of gliomas. The promoter methylation of the O6-methyguanine methyltransferase (MGMT) gene and the presence of IDH1 (Isocitrate dehydrogenase) and some IDH2 gene mutations can predict a person’s response to certain chemotherapeutic agents. Gene expression profiling is beginning to be used for evaluating the efficacy of new-targeted molecular drugs. Incorporating molecular techniques into patient’s tumor analysis will allow for the promise of personalized medicine by targeted cancer drugs.

Anaplastic Astrocytomas

Anaplastic astrocytomas are one of two primary forms of high-grade (malignant) glioma. A tumor that arises from glial cells (from the Greek for “glue”), or supportive tissue, of the brain is called a “glioma.” One type of glioma is the astrocytoma. Astrocytomas are named after astrocytes, the star-shaped cells from which they grow. Astrocytomas are histologically graded by their rate of growth (mitotic activity) and nuclear atypia on a scale from Grade I to IV. The terms “malignant glioma” and “high-grade glioma” include grade III and Grade IV gliomas.  Anaplastic astrocytomas (synonymous with Grade III glioma) comprise approximately 30 percent of all astrocytomas. High-grade astrocytomas can occur at any age, but they are more common in older patients. 

Symptoms
Symptoms, such as headache and nausea, usually are the result of increased intracranial pressure caused by the mass of the tumor in the brain or from a backup of the cerebrospinal fluid that surrounds the brain and spinal cord. As a brain tumor grows, it may interfere with the normal functions of the brain. The glial cells are widely distributed throughout the central nervous system, so these tumors can occur in a wide variety of locations, and therefore can cause a wide variety of other symptoms. Depending on the location, gliomas may cause headaches, nausea, seizures, weakness or numbness in the arms or legs, impairments in language function, blurred vision, changes in personality, cognitive impairments and memory loss. Some anaplastic astrocytomas may reach a fairly large size before they begin to cause noticeable symptoms.

Diagnosis
These tumors are diagnosed with a neurological examination followed by imaging studies of the brain, usually a computed tomography (CT) or magnetic resonance imaging (MRI) scan. The scan is usually performed with a contrast dye that makes the border and details of the tumor more visible in relation to the surrounding normal brain. The scan provides detail information regarding the exact size, location and probable type of tumor. However, only examination of a patient’s tumor tissue under a microscope can confirm an exact diagnosis. This tissue is usually obtained with either a biopsy or removal of the tumor. In some cases, neurosurgeons may employ a stereotactic MRI scan. In this study, a high-resolution contrast MRI is performed and a three-dimensional brain model is constructed using a computer system that is used to perform minimally invasive surgery and allow for volumetric three-dimensional removal of the tumor, which maximizes the degree of tumor removal.

Treatment
In general, the initial treatment of anaplastic astrocytoma is surgical resection of the tumor. With modern techniques, surgery for a craniotomy (making an opening in the skull) is generally safe and allows the team at the Brain Tumor Center to obtain tumor tissue for accurate microscopic diagnosis and treatment planning. With stereotactic volumetric techniques a tumor surgeon can often achieve a gross or near total removal of the tumor when evaluated with an MRI scan after surgery. Removing the tumor tends to reduce the symptoms caused by the presence of the tumor. In some patients with medical conditions that don't allow for surgery or in patients with concerns about the location of the tumor, a biopsy may be done in place of the surgery.

 In some cases, depending on the location of the tumor, the neurosurgeon may employ advanced techniques that enable safe removal of a tumor even in eloquent parts of the brain. Some of these techniques include functional brain mapping to identify the location of movement, sensation and language centers in the brain. This is performed with intraoperative electrical stimulation of the brain, functional MRI scans and occasionally by performing the surgery awake in order to monitor and evaluate these functions during the operation. With stereotactic image-guided techniques the surgeon uses an MRI based 3D model of the patients brain – much like a GPS system - to safely remove as much of the tumor as possible. High-powered microscopes are also used to help the neurosurgeon better see the tumor and ultrasonic aspirators are sometimes used to help remove the tumor. 

After surgery, each patient is reviewed at our Multi-Disciplinary Tumor Board with an expert team of neuro-oncologists, medical oncologists, neuro-pathologists, neuro-radiologists and neurosurgeons. Together the tumor board recommends the best treatment options for each patient, incorporating ongoing national clinical trials and the latest treatment protocols. Usually, because the tentacle-like cells of an astrocytoma grow into the surrounding tissue, these tumors require additional treatment around the margins with image guided conformal radiation and/or systemic chemotherapy or targeted biological therapy after surgery. Stereotactic radiosurgery also may be used in some cases of tumor recurrence or to target focal areas of recurrence following chemotherapy. Stereotactic radiosurgery (SRS) and Fractionated stereotactic radiosurgery (FSRS) are special forms of precisely focused, high-dose radiation for delivery to a small, localized tumor as a single dose treatment or fractionated treatment over four to five days. 

Research
New therapies, such as immunotherapy, vaccine therapy, gene therapy, and new biologically targeted chemotherapies are being examined. Clinical trials are open for both patients with newly-diagnosed and those with recurrent tumors. These trials test the safety and effectiveness of treatments that have shown promise in earlier phase trials or in laboratory studies. For patients, they provide access to therapies that would otherwise be unavailable. All clinical trials are overseen by government and hospital boards and subject to rigorous regulation and oversight.

Molecular markers have been increasingly used to complement the microscopic diagnosis of gliomas. The promoter methylation of the O6-methyguanine methyltransferase (MGMT) gene and the presence of IDH1 (Isocitrate dehydrogenase) and some IDH2 gene mutations can predict a person’s response to certain chemotherapeutic agents. Gene expression profiling is beginning to be used for evaluating the efficacy of new-targeted molecular drugs. Incorporating molecular techniques into patient’s tumor analysis will allow for the promise of personalized medicine by targeted cancer drugs.

Meningiomas

Meningiomas are typically benign, slow-growing tumors that arise from the meninges. The meninges are a protective membrane surrounding the brain and spinal cord. These tumors do not arise from the brain itself but instead grow inward from the meninges exerting pressure on the brain or spinal cord. Occasionally meningiomas will grow outwards into the skull, causing it to thicken. Although most meningiomas are benign slow growing tumors, higher-grade (Atypical and Malignant) meningiomas can occur in a small minority of patients. Meningiomas, in general, are relatively common tumors, making up about 30% percent of all primary brain tumors, and can occur anywhere on the meninges. The tumors can occur in anyone, but they appear to be most common in middle-aged women.

It is common to name meningiomas based on the location of the tumor in relation to the overlying skull. For example a simple convexity meningioma lies under the side of the skull whereas a parasagittal meningioma is located near the sagittal sinus, a major blood vessel at the top of the cerebral hemispheres. Some meningiomas grow at the bottom of the skull and are called skull base meningiomas with specific names related to the adjacent bony structure. These tumors can cause problems even though they are benign because of pressure exerted on the surrounding nerves and brain. 

Symptoms
Meningiomas are usually slow growing and, therefore, may grow to a large size before causing symptoms.  The symptoms of a meningioma are caused by the pressure the growing tumor exerts on surrounding brain. These tumors can occur in a variety of places and therefore cause a wide range of symptoms, although they tend to occur in specific regions around the brain. Depending on the location of the mass, meningiomas may cause headaches, nausea, seizures, weakness or numbness in the limbs or face, visual problems, and gradual changes in mood or personality. The symptoms tend to increase in severity as the tumor grows.

Diagnosis
These tumors are diagnosed with a neurological examination followed by imaging studies of the brain, usually a computed tomography (CT) or magnetic resonance imaging (MRI) scan. The scan is usually performed with a contrast dye that makes the border and details of the tumor more visible in relation to the surrounding normal brain. The scan provides detail information regarding the exact size, location and other structures involved by the tumor. Neurosurgeons will often employ a stereotactic MRI scan. In this study, a high-resolution contrast MRI is performed and a three-dimensional brain model is constructed using a computer system that is used to perform minimally invasive surgery and allow for volumetric three-dimensional removal of the tumor, which maximizes the degree of tumor removal. An angiogram, which allows physicians to visualize the blood vessels in the area, may also be used for embolization of a very vascular tumor and closing off its blood supply. Only examination of a patient’s tumor tissue under a microscope can confirm an exact diagnosis. This tissue is usually obtained with a biopsy or tumor resection. 

Treatment
If a particular meningioma is small and does not cause any symptoms, it may be observed over time rather than treated immediately. In this situation surveillance MRI scans will be recommended to monitor the stability of the tumor over time. In cases in which treatment is necessary, surgery is usually the primary form of treatment for a meningioma. Because most meningiomas are benign, and rarely invade the surrounding brain tissue, complete resection often results in a cure. Prior to surgery, some patients can benefit from embolization of the blood supply to a meningioma which can make complete removal easier for the surgeon. Usually surgery is performed with a frameless stereotactic navigation system in which a high-resolution MRI is used to construct a 3-dimensional brain model – much like a GPS system - that allows for minimally invasive surgery. High-powered microscopes are also used to help the neurosurgeon better see the tumor and ultrasonic aspirators are sometimes used to help remove the tumor. Some tumors, however, may be difficult to remove completely, especially those that occur near important structures at the base of the skull. After surgery, the tumor tissue is microscopically examined to establish an accurate diagnosis, assess the risk of recurrence and dictate the next step in treatment. 

Conventional external beam radiation therapy may be used as a follow-up treatment, especially for malignant or atypical tumors that have recurred. In addition, non-invasive, stereotactic radiosurgery (CyberKnife) may be used as either primary or adjunct treatment for small or residual tumors in difficult to reach locations or in patients that cannot undergo surgery. Stereotactic Radiosurgery uses numerous finely focused beams of radiation to accurately target the tumor and while minimizing the effects to any surrounding tissue. The target tumor is usually outlined on a 3-Dimensional model of the brain by the neurosurgeon and the radiation oncologist prior to the procedure.

After surgery, each patient is reviewed at our Multi-Disciplinary Tumor Board with an expert team of neuro-oncologists, medical oncologists, neuro-pathologists, neuro-radiologists and neurosurgeons. Together the tumor board recommends the best treatment options for each patient, incorporating ongoing national clinical trials and the latest treatment protocols.

Metastatic Brain Tumors

A metastatic brain tumor is formed by cancer cells originating from a primary cancer elsewhere in the body and then subsequently spread to the brain. Sometimes this results in a single tumor and sometimes this can result in multiple brain metastases. In most situations, the primary cancer is diagnosed before it spreads to the brain, but in some cases the brain tumors are found at the same time or before the primary cancer is discovered. 

Cancers of the lung, breast, skin, and kidneys are the most common cause of metastatic brain tumors. These tumors are usually found on an MRI scan of the brain which is obtained because the patient experiences neurological symptoms. Occasionally the tumors are discovered incidentally and there is no known history of a primary systemic cancer. Increasingly, cancer patients offered new therapies are required to undergo brain imaging, part of what is termed radiologic staging, that may incidentally discover brain metastases.

Metastatic brain tumors and their symptoms are generally treatable. Longer survival, improved quality of life and stabilization of neurocognitive functioning for patients with brain metastasis are the most important goals of treatment. Improvements on all these fronts have been witnessed over the past decade.

Symptoms 
The symptoms of a metastatic brain tumor depend on its location and size. As a brain tumor grows, it may interfere with the normal functions of the brain and depending on the location may cause headaches, nausea, seizures, weakness or numbness in the limbs or face, visual problems, and gradual changes in mood or personality. The symptoms tend to increase in severity as the tumor grows in size. Headache and nausea, usually are the result of increased intracranial pressure caused by the mass of the tumor in the brain or from a backup of the cerebrospinal fluid that surrounds the brain and spinal cord. 

Diagnosis
These tumors are diagnosed with a neurological examination followed by imaging studies of the brain, usually a computed tomography (CT) or magnetic resonance imaging (MRI) scan. Sometimes a brain scan is part of the initial screening process when the primary cancer is diagnosed or is obtained if a patient begins to have symptoms of a brain or spinal tumor. The scan is usually performed with a contrast dye that makes the border and details of the tumor more visible in relation to the surrounding normal brain. The scan provides detail information regarding the exact number, size and location of the tumor. Neurosurgeons will often employ a stereotactic MRI scan. In this study, a high-resolution contrast MRI is performed and a three-dimensional brain model is constructed using a computer system that is used to perform minimally invasive surgery or Stereotactic Radiosurgery (CyberKnife).

Although the MRI scans provide a probable diagnosis, only examination of a patient’s tumor tissue under a microscope can confirm an exact diagnosis. This tissue is usually obtained with a biopsy or tumor resection if indicated. If a metastatic tumor is diagnosed before the primary cancer site is found, tests to locate the primary site will follow. These tests may include blood tests, a chest, abdominal and pelvic CT, a body PET scan, or other tests as needed. The pathology report of tissue collected during surgery can also help the doctor determine possible sites of the primary cancer if testing fails to do so.

Treatment
Treatment for a metastatic brain tumor involves the close cooperation of an oncologist, radiation oncologist and neurosurgeon. The neurosurgeon will look at the scans to determine if the tumor(s) can be surgically removed, or if other treatment options are more reasonable. Depending on the patient’s overall health, the number of metastatic tumors, and their location and size, metastatic brain tumors may be treated with one or a combination of techniques. Treatment decisions will take into account not only long-term survival possibilities, but quality of life during and after treatment, as well as cognition concerns. 

Minimally invasive stereotactic surgery is preferred when a symptomatic or large solitary tumor can be completely removed without causing any neurological damage. Usually surgery is performed with a frameless stereotactic navigation system in which a high-resolution MRI is used to construct a 3-dimensional brain model – much like a GPS system - that allows for minimally invasive volumetric brain surgery. In some cases, depending on the location of the tumor, the neurosurgeon may employ advanced techniques that enable safe removal of a tumor even in eloquent parts of the brain. Some of these techniques include functional brain mapping to identify the location of movement, sensation and language centers in the brain. This is performed with intraoperative electrical stimulation of the brain, functional MRI scans and occasionally by performing the surgery awake in order to monitor and evaluate these functions during the operation. 

Stereotactic Radiosurgery (CyberKnife) radiosurgery uses a single, high dose of radiation to stop a metastatic tumor from growing, and is, alone, very effective in controlling individual small metastatic tumors. Stereotactic Radiosurgery uses numerous finely focused beams of radiation to accurately target the tumor and while minimizing the effects to any surrounding tissue. The target tumor is usually outlined on a 3-Dimensional model of the brain by the neurosurgeon and the radiation oncologist prior to the procedure.

Whole brain radiation is used if multiple metastatic brain tumors are present and the patient is not a candidate for stereotactic radiosurgery or open surgery. In general, surgical resection of a metastatic tumor is followed with either Stereotactic Radiosurgery or whole brain radiation to prevent tumor recurrence following surgical resection. Systemic chemotherapy and immunotherapy use medications to kill cancer cells and enlist the body’s immune system in fighting the disease. 

After surgery, each patient is reviewed at our Multi-Disciplinary Tumor Board with an expert team of neuro-oncologists, medical oncologists, neuro-pathologists, neuro-radiologists and neurosurgeons. Together the tumor board recommends the best treatment options for each patient, incorporating ongoing national clinical trials and the latest treatment protocols.

Astrocytomas and Low Grade Gliomas

Astrocytomas are tumors that are believed to arise from precursors of astrocytes – supportive cells of the brain named for their star-like shape. Astrocytomas are the most common of the primary brain tumors. Astrocytomas are histologically graded by their rate of growth (mitotic activity) and nuclear atypia on a scale from Grade I to IV. Grades I and II astrocytomas are the slowest growing tumors, and are also called “low-grade” astrocytomas. Their symptoms develop over an extended period of time. Representing approximately 10 to 15 percent of all gliomas, they generally are found in young patients and have a more favorable prognosis. Unfortunately, low-grade astrocytomas also occur less frequently than their malignant, high-grade counterparts. Low-grade astrocytomas can be further sub-grouped into three tumor types: pilocytic astrocytomas, pleomorphic xanthoastrocytomas, and diffuse astrocytomas (which are by far the most common).

Symptoms
The initial symptoms of brain tumors, such as headache and nausea, usually are the result of increased intracranial pressure caused by the bulk of the tumor or a backup of the cerebrospinal fluid that surrounds the brain and spinal cord. Astrocytic cells are widely distributed throughout the central nervous system, so these tumors can occur in a wide variety of locations, and therefore can cause a wide variety of other symptoms. Depending on the location of the mass, low-grade astrocytomas may cause seizures, weakness or numbness in the limbs, impairments in language function, blurred or double vision, gradual changes in mood or personality, and memory loss.

Diagnosis
Imaging studies are an important component of the diagnosis of low-grade astrocytomas . Currently, magnetic resonance imaging (MRI) is the best available imaging modality. Computed tomography (CT) scans also are used. CT and MR scans show the presence of this tumor, which typically does not “enhance” when an intravenous contrast dye is given. In some cases, neurological surgeons may employ an MRI scan with frameless stereotactic guidance for preoperative planning purposes. For this study, a high resolution contrast MRI is performed, sometimes requiring that special markers (called fiducials) be placed on the patient’s scalp. The MRI scan is processed by a computer, and a three dimensional brain model is constructed. This can be used in the operating room to minimize the size of the surgical exposure, maximize tumor removal, and minimize injury to the surrounding brain.

Treatment
Surgery for low-grade gliomas involves obtaining tumor tissue by either biopsy or resection for a careful analysis and pathological diagnosis. Usually surgery is performed with a frameless stereotactic navigation system in which a high-resolution MRI is used to construct a 3-dimensional brain model – much like a GPS system - that allows for minimally invasive volumetric brain surgery. In some cases, depending on the location of the tumor, the neurosurgeon may employ advanced techniques that enable safe removal of a tumor even in eloquent parts of the brain. Some of these techniques include functional brain mapping to identify the location of movement, sensation and language centers in the brain. This is performed with intraoperative electrical stimulation of the brain, functional MRI scans and occasionally by performing the surgery awake in order to monitor and evaluate these functions during the operation. These techniques allow the surgeon to safely remove the maximum amount of tumor tissue without causing neurological harm to the patient. With contemporary surgical techniques a significant, near-total or gross total resection can be achieved in an increasing number of patients. 

When a tumor is removed, it can be examined under a microscope to provide an accurate diagnosis so the next steps in treatment, which may include radiation therapy or chemotherapy, can be determined. For some Grade I gliomas (e.g. pilocytic astrocytomas) with sharply defined boundaries, gross total surgical removal can confer a cure. However, surgery alone will not provide a cure for other Low Grade gliomas and diffuse astrocytomas where the tumor usually has already grown tiny microscopic tentacles that spread into the surrounding brain tissue. Those tentacles cannot always be seen by the neurosurgeon. They also intermingle with brain cells that are performing their normal important functions. As a result, “complete” safe tumor removal may not be possible. The extent of surgery depends on the location of the tumor, the patient’s symptoms and personal preferences.

The choice of treatment after surgical resection usually factors in the exact tumor subtype and grade, the molecular profile of the tumor (which can predict responsiveness to chemotherapy) and the extent of resection. There is no single approach that can be recommended for all patients. More insights may come from further studies looking at whether a tumor’s chemical and molecular makeup helps to predict whether one type of treatment will be more effective than another. For example, the promoter methylation of the O6-methyguanine methyltransferase (MGMT) gene and the presence of IDH1 (Isocitrate dehydrogenase) and some IDH2 gene mutations can predict a person’s response to certain chemotherapeutic agents. Incorporating molecular techniques into patient’s tumor analysis will allow for the promise of personalized medicine by targeted cancer drugs. 

After surgery, each patient is reviewed at our Multi-Disciplinary Tumor Board with an expert team of neuro-oncologists, medical oncologists, neuro-pathologists, neuro-radiologists and neurosurgeons. Together the tumor board recommends the best treatment options for each patient, incorporating ongoing national clinical trials and the latest treatment protocols.

Olfactory Groove and Sphenoid Wing Meningiomas

Meningiomas are typically benign, slow-growing tumors that arise from the meninges. The meninges are a protective membrane surrounding the brain and spinal cord. These tumors do not arise from the brain itself but instead grow inward from the meninges displacing the brain or spinal cord.

Although most meningiomas are benign slow growing tumors, higher-grade (Atypical and Malignant) meningiomas can occur in a small minority of patients. Meningiomas, in general, are relatively common tumors, making up about 30% percent of all primary brain tumors, and can occur anywhere on the meninges. The tumors can occur in anyone, but they appear to be most common in middle-aged women.

It is common to name meningiomas based on the location of the tumor in relation to the overlying skull. Olfactory groove meningiomas grow next to the nerves that run between the brain and the nose, the nerves that allow you to smell. They can become large without causing significant neurologic deficits or evidence of increased intracranial pressure. Loss of smell can often be the only symptom. Other neurological symptoms are often uncommon until the tumor has reached a large size. 

Meningiomas of the sphenoid wing form on the skull just behind the eyes and are traditionally divided into three types: lateral, middle, and medial (clinoidal). Lateral sphenoid wing meningiomas involve the sphenoid ridge and the surrounding frontal and temporal lobes. Medial sphenoid ridge (clinoidal) meningiomas, often compress the optic nerve and can involve the carotid artery and cavernous sinus to cause double vision and numbness of the face.

Symptoms
Meningiomas are usually slow growing and, therefore, may grow to a large size before causing symptoms.  The symptoms of a meningioma are caused by the pressure the growing tumor exerts on surrounding brain or nerves. Depending on the location of the mass, meningiomas may cause headaches, seizures, weakness or numbness in the limbs or face, visual problems, and gradual changes in mood or personality. The symptoms tend to increase in severity as the tumor grows in size.

Olfactory groove meningiomas often lead to the loss of the sense of smell. If they grow large enough, they can also compress the optic nerves to the eyes and surrounding brain, causing visual symptoms, headaches, seizures and personality changes. Sphenoid wing meningiomas can cause visual problems, including loss of peripheral vision and even unilateral monocular blindness. In addition, they can cause facial numbness, double vision, headaches and seizures.

Diagnosis
These tumors are diagnosed with a neurological examination followed by imaging studies of the brain, usually a computed tomography (CT) or magnetic resonance imaging (MRI) scan. The scan is usually performed with a contrast dye that makes the border and details of the tumor more visible in relation to the surrounding normal brain. The scan also provides detail information regarding the exact size, location and other structures involved by the tumor. An angiogram, which allows physicians to visualize the blood vessels in the area, may also be used for embolization of a very vascular tumor and closing off its blood supply. Only examination of a patient’s tumor tissue under a microscope can confirm an exact diagnosis. This tissue is usually obtained with tumor resection.

Treatment
If a particular meningioma is small and does not cause any symptoms, it may be observed over time rather than treated immediately. In this situation surveillance MRI scans will be recommended to monitor the stability of the tumor over time. In cases in which treatment is necessary, surgery is usually the primary form of treatment for a meningioma. Because most meningiomas are benign, and rarely invade the surrounding brain tissue, complete resection often results in a cure. 

With contemporary microsurgical and skull base techniques, many of these tumors now can be removed. Prior to surgery, some patients can benefit from embolization of the blood supply to a meningioma which can make complete removal easier for the surgeon. Usually surgery is performed with a frameless stereotactic navigation system in which a high-resolution MRI is used to construct a three-dimensional brain model that allows for minimally invasive surgery. While every effort is aimed at total removal, certain tumors present a formidable technical challenge because they adhere to vital neural and vascular structures at the base of the brain. After surgery, the tumor tissue is microscopically examined to establish an accurate diagnosis, assess the risk of recurrence and dictate the next step in treatment. 

Conventional external beam radiation therapy may be used as a follow-up treatment, especially for malignant or atypical tumors that have recurred. In addition, non-invasive, stereotactic radiosurgery (CyberKnife) may be used as either primary or adjunct treatment for small or residual tumors in difficult to reach locations or in patients that cannot undergo surgery. Stereotactic Radiosurgery uses numerous finely focused beams of radiation to accurately target the tumor and while minimizing the effects to any surrounding tissue. The target tumor is usually outlined on a 3-Dimensional model of the brain by the neurosurgeon and the radiation oncologist prior to the procedure.

After surgery, each patient is reviewed at our Multi-Disciplinary Tumor Board with an expert team of neuro-oncologists, medical oncologists, neuro-pathologists, neuro-radiologists and neurosurgeons. Together the tumor board recommends the best treatment options for each patient, incorporating ongoing national clinical trials and the latest treatment protocols.

Pituitary and Parasellar Tumors

The pituitary gland sits in a small bony pocket (called the sella turcica) at the base of the skull just behind the nose. The pituitary gland is known as the “master gland” because it helps control the secretion of hormones from a number of other endocrine glands in the body. The pituitary gland secretes growth hormone (GH), prolactin (PRL), and adrenocorticotropin hormone (ACTH), which serve a variety of essential hormonal and metabolic functions. The hypothalamus, a part of the brain near the pituitary, signals the pituitary gland to secrete more or less hormones depending on the needs of the body. A stem-like stalk connects the pituitary gland to the hypothalamus and it is through this stalk that the hypothalamus sends signals to control the activity of the pituitary gland.

Most pituitary gland tumors, called pituitary adenomas, are benign slow growing tumors that develop in the anterior part of the gland. Pituitary adenomas are relatively common and are very treatable. Some tumors can be treated with medications while others require surgery or radiation. Because the pituitary gland is important in the function of other glands in the body, treating a pituitary tumor requires an active coordinated multidisciplinary health care approach.

Other tumors that appear in this area, called the sellar/parasellar region, include craniopharyngiomas, germ cell tumors, and epidermoid cysts, which are tumors that arise from developmental cells; meningiomas, tumors of the protective covering of the brain; gliomas, tumors that arise from the supporting cells in the brain; and metastatic tumors that originate in another part of the body and spread to the brain.

Symptoms
Many pituitary adenomas are fairly small and do not lead to any symptoms. When symptoms do arise from a pituitary tumor they are caused by two mechanisms: hormonal changes caused by the tumor and the growth of the tumor. Excess hormone production can lead to the lack of a menstrual period (amenorrhea) and infertility, production of breast milk without pregnancy (galactorrhea), excess or abnormal growth (acromegaly),

Cushing’s syndrome with high blood pressure and unusual changes in the skin and body, or a hyperactive thyroid. Tumors that produce hormones, known as functioning tumors, often cause symptoms when they are very small (microadenomas- less than 1 cm in diameter).

Once a pituitary tumor enlarges and it can also disrupt the remainder of the healthy pituitary gland, causing a lack of certain hormones leading to fatigue, weakness, growth problems and excessive thirst and urination. As a pituitary tumor or parasellar tumor enlarges it can lead to symptoms from direct pressure against the optic nerves. These larger pituitary tumors, known as macroadenomas (>1 cm), are usually not hormonally active and may grow outside of the sella turcica and compress the surrounding structures. These tumors can cause headaches, nausea, vomiting, and when they compress the optic chiasm can cause vision loss.

Diagnosis
The diagnosis of pituitary and parasellar tumors is based on your symptoms, physical exam and specialized testing including an endocrine and ophthalmic assessment. For an endocrine assessment, special blood tests determine your hormone levels and whether the pituitary gland is the source of any excess hormone.

Sometimes, a scan of the chest or abdomen is needed to verify that the hormone imbalances are caused by the pituitary gland. An ophthalmologist may examine your eyes and perform a visual field test to determine if the tumor is affecting your visual acuity or impairs your peripheral vision.

Imaging studies are also an important component of the diagnosis of pituitary and parasellar tumors. Magnetic resonance imaging (MRI) and Computed tomography (CT) scans are often used. The scan is usually performed with a contrast dye that makes the border and details of the tumor more visible in relation to the surrounding normal brain. The scan also provides detail information regarding the exact size, location and other structures involved by the tumor. In some cases, neurological surgeons may employ an MRI or CT scan with frameless stereotactic guidance for preoperative planning purposes. For this study, a high-resolution contrast MRI or CT is performed and then processed by a computer to create a three-dimensional model of the brain and skull base. This can be used in the operating room when performing endoscopic minimally invasive pituitary or parasellar tumor surgery.

Special tests such as MRA and angiography are sometimes used for parasellar tumors to help your medical team better see a growth or abnormality and identify its blood supply. Minimally invasive endoscopic surgery for pituitary tumors are usually performed through the sinuses with an endoscope together with an ENT surgeon that specializes in skull base surgery. The ENT specialist may evaluate your particular anatomy before surgery and perform endoscopy of the sinuses. Only examination of a patient’s tumor tissue under a microscope can confirm an exact diagnosis. This tissue is usually obtained with tumor resection.

Treatment
Treatment for a pituitary or parasellar tumor depends on its hormonal activity, size and location of the tumor. The goals of treatment can vary from person to person depending on the age and overall health of the patient and their particular symptoms or hormone levels. Some small benign tumors without any symptoms or hormonal imbalances may be simply observed over time and only treated if the tumor grows over the period of observation. Certain tumors such as prolactin producing tumors could

be treated with medications alone. In this situation, the drugs reduce the size of the tumor and are often prescribed long term with the help of your
endocrinologist. Sometimes medications are used for hormone secreting tumors if hormone levels do not fully normalize after surgical resection.

Surgical removal of the pituitary or parasellar tumor may be recommended depending on its size, effect on surrounding structures such as the optic nerves, or its hormone secreting status.  The goal is to remove as much tumor as safely possible and preferably minimally invasively. The development of endoscopic minimally-invasive skull base techniques has made surgical treatment of pituitary adenomas and parasellar tumors safer and more effective.

This type of surgery avoids any skin incisions or openings of the outside of the skull. An ENT surgeon usually helps approach the tumor through the nose (endonasal) and natural sinuses and together with the neurosurgeon they remove the tumor through a thin tube with a light source at the end called an endoscope. Endoscopic techniques continue to evolve and requires careful analysis by your surgeon to determine if you are a candidate.

While every effort is aimed at total removal, certain tumors present a formidable technical challenge because they adhere to vital neural and vascular structures at the base of the brain. After surgery, the tumor tissue is microscopically examined to establish an accurate diagnosis, assess the risk of recurrence and dictate the next step in treatment.

In addition to surgery, non-invasive, stereotactic radiosurgery (CyberKnife) may be used as either primary or adjunct treatment for small or residual tumors in difficult to reach locations or in patients that cannot undergo surgery. Stereotactic Radiosurgery uses numerous finely focused beams of radiation to accurately target the tumor and while minimizing the effects to any surrounding tissue. The target tumor is usually outlined on a 3-Dimensional model of the brain by the neurosurgeon and the radiation oncologist prior to the procedure.

Ependymoma

Ependymomas are glial tumors (glial cells are the supporting cells of the brain and spinal cord and ependymal cells are a subtype of glial cells) that originate from the ependymal cells that line ventricles of the brain and central canal of the spinal cord The ventricles and central canal are naturally occurring cavities within the brain where cerebrospinal fluid is normally produced. Ependymomas usually arise from the ependymal tissue on the floor of the 4th ventricle in children or in the spinal cord in adults. They can also arise in a variety of other locations throughout the brain and spine. Ependymomas often lead to obstruction of the cerebrospinal fluid flow within the brain because of their intimate relationship with the ventricles, central canal and spinal fluid.

Ependymomas are sub-divided and pathologically graded into four major types: subependymomas and myxopapillary ependymomas (grade I), and ependymomas (grade II) and anaplastic ependymomas (grade III). The grade is based on how much the cells look like normal ependymal cells, although various grading systems exist. The cells of a grade I ependymal tumor look somewhat unusual, and those of a grade III tumor appear pleomorphic and more invasive to the surrounding tissue.

Subependymomas usually occur along the walls of a ventricle and are slow
growing and considered to be low-grade or grade I tumors. Myxopapillary ependymomas tend to occur in the lower part of the spinal cord near the conus medullaris, which is essentially the tail end of the spinal cord. This part of the spinal cord is important in controlling bowel and bladder function as well as some lower extremity function. Both of these ependymoma subtypes are slow growing and are considered to be low-grade or grade I tumors.

Ependymomas are the most common ependymal tumors and are considered grade II tumors. These tumors are usually located along or adjacent to the ventricular system and often in the 4th ventricle near the brain stem and the upper portions of the spinal cord. These tumors can often lead to hydrocephalus where there is a backup of the spinal fluid within the ventricles of the brain.

Anaplastic ependymomas are high-grade tumors (grade III) and tend to be faster growing than the lower grade ependymal tumors. Similar to grade-II ependymomas, these are often located along or adjacent to the ventricular system and often in the 4th ventricle near the brain stem and the upper portions of the spinal cord.

Symptoms
The initial symptoms of brain tumors, such as headache and nausea, usually are the result of increased intracranial pressure caused by the bulk of the tumor or a backup of the cerebrospinal fluid that surrounds the brain and spinal cord. Ependymal cells are widely distributed throughout the central nervous system, so these tumors can occur in a variety of locations and can cause a wide variety of other symptoms. Depending on the location of the mass they may cause seizures, gait difficulties, balance problems, neck pain, double vision and weakness or numbness in the limbs. Some tumors located in the spinal cord can cause difficulty with bladder or bowel control.

Diagnosis
These tumors are diagnosed with a neurological examination followed by imaging studies of the brain, usually a computed tomography (CT) or magnetic resonance imaging (MRI) scan. The scan is usually performed with a contrast dye that makes the border and details of the tumor more visible in relation to the surrounding normal brain. The scan provides detail information regarding the exact size, location and probable type of tumor. However, only examination of a patient’s tumor tissue under a microscope can confirm an exact diagnosis. This tissue is usually obtained with either a biopsy or removal of the tumor.

In some cases, neurosurgeons may employ a stereotactic MRI scan. In this study, a high-resolution contrast MRI is performed and a three-dimensional brain model is constructed using a computer system that is used to perform minimally invasive surgery and allow for volumetric three-dimensional removal of the tumor, which maximizes the degree of tumor removal.

Some ependymomas can spread through the cerebrospinal fluid and in order to detect this a spinal MRI scan and a lumbar puncture (spinal tap) may need to be performed. The fluid obtained during the spinal tap can be tested for the presence of tumor cells. These results often guide any subsequent treatment.

Treatment
In general, the initial treatment of a ependymoma is surgical resection of as much of the tumor as possible. With modern techniques, surgery for a craniotomy (making an opening in the skull) is generally safe and allows the team at the Brain Tumor Center to obtain tumor tissue for accurate microscopic diagnosis and treatment planning. Depending on the location of the tumor the surgeon can often achieve a gross or near total removal of the tumor when evaluated with an MRI scan after surgery. Removing the tumor and reliving any hydrocephalus tends to reduce the symptoms caused by the presence of the tumor. In some cases, depending on the location of the ependymoma, the neurosurgeon may employ techniques that enable safe removal of a tumor even along the brain stem.

Some of these techniques include intra-operative neuro-monitoring, where the function of the nerves that emanate out of the brain stem or spinal cord are monitored throughout the operation in order to make sure vital brainstem and spinal cord functions are not disrupted. In other locations of the brain the surgeon may employ stereotactic image-guided techniques where the surgeon uses an MRI based 3D model of the patient’s brain – much like a GPS system - to safely remove as much of the tumor as possible.

High-powered microscopes are also used to help the neurosurgeon better see the tumor and ultrasonic aspirators are sometimes used to help remove the tumor.

Most grade I tumors do not recur after complete surgical removal. Grades II and III tumors need additional treatment and have a higher likelihood of recurring. Radiation therapy is sometimes recommended for older children and adults following surgery if all visible tumor wasn’t removed and in some cases even after complete resection. If the tumor is localized, radiation therapy is usually given just to that area of the brain. If the tumor has spread to the spinal fluid, radiation is usually also given to the entire brain and spine in addition to where the tumor started.

After surgery, each patient is reviewed at our Multi-Disciplinary Tumor Board with an expert team of neuro-oncologists, medical oncologists, neuro-pathologists, neuro-radiologists and neurosurgeons. Together the tumor board recommends the best treatment options for each patient, incorporating ongoing national clinical trials and the latest treatment protocols. 

Oligodendroglioma & Oligoastrocytomas (Mixed Gliomas)

Oligodendrogliomas and oligoastrocytomas (mixed gliomas) are a type of glial cell tumor arising from oligodendrocytes and/or astrocytes. Tumors that arise from glial (from the Greek for “glue”) cells, or supportive tissue, of the brain are called “gliomas.” One type of glioma is the oligodendroglioma, which arise from oligodendrocytes, glial cells that form insulation around neurons, that helps them conduct electrical impulses. Another type of glioma is the astrocytoma, named after astrocytes, the star-shaped glial cells from which they grow.

These tumors are often found in young and middle aged adults and often present with a seizure. Oligodendrogliomas have a characteristic fried egg-shaped cell appearance compared to the star like appearance of astrocytes on microscopic inspection and are considered a unique type of glioma.  They often contain areas of calcification and are believed to be slow growing tumors. 

Some oligodendrogliomas contain abnormal genetic material. Deletions or absence of chromosomes 1p and 19q are frequently seen in oligodendroglioma and oligoastrocytoma tumors. Combined deletion of 1p and 19q is a predictor
of prognosis and may predict response to treatment. Oligodendrogliomas are histologically graded by their rate of growth (mitotic activity) and nuclear atypia and usually are low-grade (grade II)
 or high-grade (grade III also called anaplastic) tumors. Grade II tumors are considered low-grade tumors, which generally grow at a slower rate than grade III tumors. Grade II tumors may evolve over time into grade III tumors. Grade III tumors are anaplastic. “Anaplastic” tumors are malignant tumors.

Sometimes a glioma may contain a combination of cell types including oligodendroglioma and astrocytic cells. These mixed gliomas are often called oligoastrocytomas and their behavior is usually tends be based more on the grade of the tumor than the individual cell type. 

Symptoms
Symptoms, such as headache and nausea, usually are the result of increased intracranial pressure caused by the mass of the tumor in the brain or from a backup of the cerebrospinal fluid that surrounds the brain and spinal cord. As a brain tumor grows, it may interfere with the normal functions of the brain. The glial cells are widely distributed throughout the central nervous system, so these tumors can occur in a wide variety of locations, and therefore can cause a wide variety of other symptoms. Depending on the location, gliomas may cause headaches, nausea, seizures, weakness or numbness in the arms or legs, impairments in language function, blurred vision, changes in personality, cognitive impairments and memory loss. Some oligodendrogliomas and mixed gliomas may reach a fairly large size before they begin to cause noticeable symptoms and oligodendrogliomas are more often associated with the onset of seizures. 

Diagnosis
These tumors are diagnosed with a neurological examination followed by imaging studies of the brain, usually a computed tomography (CT) or magnetic resonance imaging (MRI) scan. The scan is usually performed with a contrast dye that makes the border and details of the tumor more visible in relation to the surrounding normal brain. The scan provides detail information regarding the exact size, location and probable type of tumor. Many oligodendrogliomas will demonstrate some degree of hardening or calcification on imaging studies. However, only examination of a patient’s tumor tissue under a microscope can confirm an exact diagnosis. This tissue is usually obtained with either a biopsy or removal of the tumor. In some cases, neurosurgeons may employ a stereotactic MRI scan. In this study, a high-resolution contrast MRI is performed and a three-dimensional brain model is constructed using a computer system that is used to perform minimally invasive surgery and allow for volumetric three-dimensional removal of the tumor, which maximizes the degree of tumor removal.

Treatment

In general, the initial treatment of oligodendrogliomas and oligoastrocytomas (mixed gliomas) is surgical resection of the tumor. With modern techniques, surgery for a craniotomy (making an opening in the skull) is generally safe and allows the team at the Brain Tumor Center to obtain tumor tissue for accurate microscopic diagnosis and treatment planning. With stereotactic volumetric techniques a tumor surgeon can often achieve a gross or near total removal of the tumor when evaluated with an MRI scan after surgery. Removing the tumor tends to reduce the symptoms caused by the presence of the tumor. In some patients with medical conditions that don't allow for surgery or in patients with concerns about the location of the tumor, a biopsy may be done in place of the surgery. 

In some cases, depending on the location of the tumor, the neurosurgeon may employ advanced techniques that enable safe removal of a tumor even in eloquent parts of the brain. Some of these techniques include functional brain mapping to identify the location of movement, sensation and language centers in the brain. This is performed with intraoperative electrical stimulation of the brain, functional MRI scans and occasionally by performing the surgery awake in order to monitor and evaluate these functions during the operation. With stereotactic image-guided techniques the surgeon uses an MRI based 3D model of the patients brain – much like a GPS system - to safely remove as much of the tumor as possible. High-powered microscopes are also used to help the neurosurgeon better see the tumor and ultrasonic aspirators are sometimes used to help remove the tumor.

Recently, the role of chemotherapy as an important treatment for some oligodendrogliomas has been established. Biopsied or resected oligodendrogliomas and oligoastrocytomas (mixed gliomas) are be tested by neuropathologists for 1p and 19q chromosomal deletions because those deletions confer increased sensitivity to some types of chemotherapy. Depending on the extent of tumor resection, the grade of the tumor when evaluated by the pathologist and the presence of chromosomal co-deletions, chemotherapy and/or radiation may be suggested after surgery to prevent any future recurrence or to treat any residual tumor cells. For most low-grade oligodendrogliomas and oligoastrocytomas (mixed gliomas) that on MRI scan appear to have been completely resected with surgery, close observation with serial follow-up MRI scans is often recommended. If there is residual remaining tumor after surgery, radiation treatment is often recommended however the optimal timing of radiation is still being determined and often takes into consideration the status of any chromosomal deletions within the tumor. For anaplastic oligodendrogliomas and oligoastrocytomas (mixed gliomas) a combination of radiation and chemotherapy is often recommended. 

After surgery, each patient is reviewed at our Multi-Disciplinary Tumor Board with an expert team of neuro-oncologists, medical oncologists, neuro-pathologists, neuro-radiologists and neurosurgeons. Together the tumor board recommends the best treatment options for each patient, incorporating ongoing national clinical trials and the latest treatment protocols.

Colloid Cyst

Colloid cysts are benign tumors that typically grow along the roof of the third ventricle. Although they are often labeled as tumors, colloid cysts actually are thought to arise during embryonic development. The cyst, which contains a thick gelatinous fluid, can grow in size, and in this location can block the normal flow cerebrospinal fluid. As the fluid builds up in the ventricles (hydrocephalus), increased pressure on the surrounding brain causes headaches. Other symptoms may include confusion, difficulty walking, and brief interruption of consciousness. These cysts can often quietly sit in the brain, not making their presence known for many years into adulthood when they finally reach a large enough size to cause symptoms. 

Symptoms
Symptoms, such as headache and nausea, usually are the result of increased intracranial pressure caused by the blockage of normal cerebrospinal fluid flow through the brain ventricular system. As the fluid and pressure buildup in the ventricles increases these tumors can lead to confusion, short-term memory difficulties, difficulty walking, and sudden deterioration with an abrupt loss of consciousness. 

Diagnosis
These tumors are diagnosed with a neurological history and examination followed by imaging studies of the brain, usually a computed tomography (CT) or magnetic resonance imaging (MRI) scan. The scan provides detail information regarding the exact size and location of the Colloid Cyst and identifies the presence of any associated hydrocephalus. In some cases, neurosurgeons may employ a stereotactic MRI scan. In this study, a high-resolution contrast MRI is performed and a three-dimensional brain model is constructed using a computer system that is used to perform minimally invasive surgery and allow for endoscopic removal of the tumor. 

Treatment
Small colloid cysts without any hydrocephalus or any symptoms can be observed over time with periodic imaging studies. For symptomatic colloid cysts the definitive treatment is with surgical removal. Surgical removal van be performed using microsurgical techniques with an approach to the ventricular system through which the tumor is removed. With the advent of minimally invasive endoscopic techniques, most colloid cysts are now being removed endoscopically. The endoscopic procedure involves making a small incision behind the hairline where a small access hole is made to the brain. Through the access port, a rigid fiberoptic camera is inserted into the ventricle and the colloid cyst is removed using specialized instruments that pass through channels in the endoscope. The cyst is coagulated and the contents are aspirated through a suction catheter. The cyst wall is removed and the attachment is dissected free all through the endoscope. This technique is significantly less invasive and disruptive of the surrounding brain. Following surgical removal most patients are monitored with annual surveillance MRI scans to make sure there is no evidence of tumor recurrence. Aside from removal of the tumor no other treatment is typically necessary.

Craniopharyngiomas

Craniopharyngiomas are slow growing benign tumors that arise from small nests of cells located along the pituitary stalk, which connects the pituitary gland to the hypothalamus in the brain. Craniopharyngiomas comprise 2 to 5 percent of all brain tumors and present in two age groups: children up to the age 16 with a second peak in incidence in adults over the age of 45 y/o. These tumors are thought to arise from epithelial cells derived from Rathke’s pouch, the embryonic precursor to the anterior pituitary. 

Adamantinomatous craniopharyngioma occurs in children and tends to be a more cystic tumor than the papillary craniopharyngioma is a more solid tumor and occurs more frequently in adults. By virtue of their origin within the sella and parasellar region craniopharyngiomas grow near the pituitary gland and often involve pituitary stalk, third ventricle, hypothalamus, and optic nerves. While they are benign tumors, these localized tumors may reach a large size before they are diagnosed. 

Symptoms
The symptoms of a craniopharyngioma are caused by compression the growing tumor exerts on surrounding brain structures in the sella and parasellar region. Compression of the pituitary stalk may result in pituitary hormone deficiency that contributes to developmental delay, short stature, obesity, and a range of other hormonal problems including the inability to regulate water balance. Compression of the optic nerves may lead to visual deficits, usually a bitemporal hemianopsia. Larger tumors can cause headache and nausea because of increased intracranial pressure caused by the mass of the tumor in the brain or from a backup of the cerebrospinal fluid that surrounds the brain and spinal cord.

Diagnosis
The diagnosis of a craniopharyngioma is based on your symptoms, physical exam and specialized testing including an endocrine and ophthalmic assessment. For an endocrine assessment, special blood tests determine your hormone levels. An ophthalmologist may examine your eyes and perform a visual field test to determine if the tumor is affecting your visual acuity or impairs your peripheral vision.

Imaging studies are also an important component of the diagnosis of craniopharyngiomas. Magnetic resonance imaging (MRI) and Computed tomography (CT) scans are often used. The scan is usually performed with a contrast dye that makes the border and details of the tumor more visible in relation to the surrounding normal brain. The scan also provides detail information regarding the exact size, location and other structures involved by the tumor. In some cases, neurological surgeons may employ an MRI or CT scan with frameless stereotactic guidance for preoperative planning purposes. For this study, a high-resolution contrast MRI or CT is performed and then processed by a computer to create a three-dimensional model of the brain and skull base. This can be used in the operating room when performing endoscopic minimally invasive skull base surgery. 

Minimally invasive endoscopic surgery for craniopharyngiomas are usually performed through the sinuses with an endoscope together with an ENT surgeon that specializes in skull base surgery. The ENT specialist may evaluate your particular anatomy before surgery and perform endoscopy of the sinuses. 

Treatment
The initial treatment for a craniopharyngioma usually is surgery to remove as much of the tumor as safely possible. Surgery to remove these tumors can be performed using endoscopic or minimally-invasive skull base techniques or with Traditional or open skull base techniques depending on the exact location and extent of your particular tumor. Because craniopharyngiomas can be adherent to structures within the suprasellar space at the skull base complete resection is often difficult. If hydrocephalus is present because of the tumor, a shunt may be placed during surgery to help drain excess cerebrospinal fluid away from the brain. Even in cases of total resection, these tumors have a tendency towards recurrence, therefore surveillance repeat MRI or CT scans are conducted for a period of time following initial treatment. 

Radiation therapy may be used as a follow-up treatment after surgery, especially in cases with residual tumor. In children younger than age 3, radiation therapy may be delayed by the
 use of surgery or hormone therapies. In addition, non-invasive, stereotactic radiosurgery (CyberKnife) may be used as adjunct treatment for small or residual tumors in difficult to reach locations or in patients that have had recurrence. Stereotactic Radiosurgery uses numerous finely focused beams of radiation to accurately target the tumor and while minimizing the effects to any surrounding tissue. The target tumor is usually outlined on a 3-Dimensional model of the brain by the neurosurgeon and the radiation oncologist prior to the procedure.

After surgery, each patient is reviewed at our Multi-Disciplinary Tumor Board with an expert team of neuro-oncologists, medical oncologists, neuro-pathologists, neuro-radiologists and neurosurgeons. Together the tumor board recommends the best treatment options for each patient, incorporating ongoing national clinical trials and the latest treatment protocols.

Rathke’s Cleft Cyst

Rathke’s cleft cyst is a benign congenital fluid filled cyst that is found between the anterior and posterior parts of the pituitary gland. Symptomatic Rathke cleft cysts are fairly rare and make up less than 1 percent of all brain tumors. Rathke’s cleft cysts are thought to arise when Rathke’s pouch, the embryonic precursor to the anterior pituitary, does not develop properly. Small asymptomatic cysts are very common and frequently detected incidentally on an MRI study. Rathke cleft cysts only rarely cause problems during childhood and are not usually diagnosed until adulthood. Symptomatic Rathke’s cleft cysts typically cause various problems with the pituitary gland's normal function and compress the optic nerves to leading visual disturbances especially peripheral vision loss. 

Symptoms
The symptoms of a Rathke’s cleft cyst are usually caused by compression of the surrounding pituitary gland and optic nerves above in the suprasellar space. Compression of the pituitary stalk may result in pituitary hormone deficiency that contributes to developmental delay, short stature, obesity, and a range of other hormonal problems. Compression of the optic nerves may lead to visual deficits, usually a bitemporal hemianopsia. Without treatment, Rathke’s cleft cysts can continue to cause problems with pituitary gland function and issues with weight, hormones, and vision. Larger cysts can cause headache and nausea because of backup of the cerebrospinal fluid that surrounds the brain and spinal cord. 

Diagnosis
The diagnosis of a Rathke’s cleft cyst is based on your symptoms, physical exam and specialized testing including an endocrine and ophthalmic assessment. For an endocrine assessment, special blood tests determine your hormone levels. An ophthalmologist may examine your eyes and perform a visual field test to determine if the cyst is affecting your visual acuity or impairs your peripheral vision.

Imaging studies are also an important component of the diagnosis of Rathke’s cleft cyst. Magnetic resonance imaging (MRI) and Computed tomography (CT) scans are often used. The scan is usually performed with a contrast dye that makes the border and details of the cyst more visible in relation to the surrounding normal brain. The scan also provides detail information regarding the exact size, location and other structures involved by the cyst. In some cases, neurological surgeons may employ an MRI or CT scan with frameless stereotactic guidance for preoperative planning purposes. For this study, a high-resolution contrast MRI or CT is performed and then processed by a computer to create a three-dimensional model of the brain and skull base. This can be used in the operating room when performing endoscopic minimally invasive skull base surgery. 

Treatment
Most small and non-symptomatic Rathke’s cleft cysts can be observed over time with surveillance MRI scans and do not require any treatment. Larger Rathke’s cleft cysts that lead to significant symptoms usually require surgery to drain the cyst. This can usually be done without damaging the normal pituitary gland. The cyst walls are not usually excised as they are adherent to important brain structures and removal would cause unnecessary harm. Surgery for drainage of Rathke’s cleft cysts is usually performed with an endoscope through the sinuses using minimally invasive endoscopic skull base techniques together with an ENT surgeon that specializes in skull base surgery. The neurosurgeon and ENT specialist may evaluate your particular anatomy before surgery and perform endoscopy of the sinuses. 

 

Trigeminal Neuralgia

Trigeminal neuralgia (or tic douloureux) is one of the most common treatable craniofacial pain syndromes. Trigeminal neuralgia is a neuropathic syndrome characterized by episodes of severe agonizing facial pain originating from the trigeminal nerve, which supplies sensation to the face and mouth. Although it can happen at any age, it is more commonly seen in people over the age of 50. The trigeminal nerve has three major branches including the ophthalmic nerve (V1), maxillary nerve (V2) and the mandibular nerve (V3). The ophthalmic (V1) division supplies sensation to the eye, forehead and bridge of the nose. The maxillary (V2) division supplies sensory innervation to the upper lip, palate, upper teeth, gums, and the inner cheek below the eye. The mandibular (V3) division provides sensation to the jaw, lower teeth, gums, lower lip, and side of the tongue. The pain from trigeminal neuralgia may involve one, two or all three divisions of the trigeminal nerve, but most commonly involves the middle (Maxillary nerve V2) and lower (mandibular V3) branches. 

Trigeminal neuralgia is caused by damage to the outer covering of the trigeminal nerve, which carries sensory information from the face to the brain. Damage to the outer nerve covering (the myelin sheath) leads to erratic and hyperactive transmission of nerve signals. This can lead to attacks of pain caused by the misdirection of signals sub-serving normal painless sensation. This type of damage to the nerve is usually the result of microvascular compression, where a small blood vessel along the surface of the nerve compresses the nerve as it enters the brainstem. Usually the compression is caused by the superior cerebellar artery, but it can also be caused by other arteries and veins surrounding the brainstem. Occasionally, some patients will have a small tumor that compresses the nerve and causes the symptoms of trigeminal neuralgia. A small fraction of patients with trigeminal neuralgia have multiple sclerosis which causes plaques within the nervous system. The cause of trigeminal neuralgia in these patients is the presence of a plaque within the brain along the sensory pathways of the trigeminal nerve. In some other patients the cause for the neuralgia cannot be clearly identified. 

Symptoms
The typical (type I) pain from trigeminal neuralgia is classically described as “stabbing,” or “electrical shock-like” in nature. Episodes are typically sudden, brief bursts of facial pain often triggered by light touch around the mouth and face. Sensory stimuli that often trigger the pain can include talking, brushing the teeth, eating, cold or a light breeze may trigger the pain. The pain is usually a sharp electric like pain that can also occur spontaneously without a “trigger”. The symptoms typically occur on one side of the face, but in rare cases may be bilateral. Patients can have periods of remission with pain-free intervals that last for minutes to weeks, but true long-term remission without treatment is rare. The attacks will often cease during sleep but often occur upon arising in the morning. 

Some patients develop atypical symptoms in addition to the classic trigeminal neuralgia symptoms. The atypical (type II) symptoms often include a more constant pain that is not triggered by touch and is associated with a more dull or burning sensation. This constellation of very specific symptoms often provides the diagnosis of trigeminal neuralgia.

Diagnosis
Trigeminal neuralgia is diagnosed almost exclusively based on history, symptomatology and neurological examination. Your surgeon will ask very specific symptoms regarding your symptoms and medication history to help support the diagnosis and recommend the best treatment option. Imaging studies of the brain, usually a computed tomography (CT) or magnetic resonance imaging (MRI) scan are also usually performed to support the diagnosis. These imaging studies are obtained to exclude the possibility of a small tumor or multiple sclerosis which would dictate a different course of treatment. The scan is usually performed with a contrast dye that makes the border and details of any tumor or abnormality more visible in relation to the surrounding normal brain. 

In addition to the standard MRI scan, a special high resolution MRI scan is obtained with very thin slices that can directly visualize the trigeminal nerve and identify the presence of a compressive vessel. However, many people without symptoms of trigeminal neuralgia will also have a vessel near the brainstem; therefore, these imaging findings must be interpreted very carefully with consideration of the patient’s particular symptoms and history including history of prior medical or surgical treatments. 

Treatment
The primary initial treatment of trigeminal neuralgia is usually pharmacological. In some patients, the pain is mild and can subside without any treatment, but in most patients with bothersome pain medical management is recommended. Patients often obtain relief, at least initially, with the anticonvulsant medication carbamazepine (Tegretol®) or oxcarbazepine (Trileptal®). When first diagnosed, these drugs are often highly effective in treating the pain of trigeminal neuralgia. These medications sometimes have side effects, including lethargy, balance difficulties, low sodium, skin rash and bone marrow suppression. If these medications are ineffective or have intolerable side effects, a variety of other medications may be used (e.g. Pregabalin --Lyrica®, Lamotrigine -- Lamictal®, Phenytoin – Dilantin® and topiramate -- Topomax®); however, these second line medications are often not as effective in relieving the pain of trigeminal neuralgia and are usually given in addition to carbamazepine or oxcarbazepine. 

Surgical treatment for trigeminal neuralgia is considered if medical management has been exhausted and is no longer effective or if the side effects of medications are excessive or disabling. Fortunately, several surgical options are available and range from non-invasive radiosurgical procedures, to minimally invasive percutaneous procedures to microsurgical decompression of the nerve. 

Stereotactic radiosurgery (CyberKnife) >>
Stereotactic radiosurgery (CyberKnife) is performed on an outpatient basis and is a collaboration between the neurosurgeon and the radiation oncologist. The trigeminal nerve is identified on the special high resolution MRI scan during the treatment planning. The treatment itself is painless and usually takes approximately one hour. There is usually no need for any anesthesia and no skin incisions required to perform the procedure. The pain relief with stereotactic radiosurgery generally occurs gradually over the course of 2 – 6 weeks time but may take several months to reach the maximum degree of effectiveness. The results with stereotactic radiosurgery are long lasting and the procedure can be repeated in the case of recurrence if more than six months has passed. 

Percutaneous glycerol rhizolysis is a minimally invasive procedure during which a small needle is inserted into the cheek and using x-ray guidance the needle is guided through a small foramen (foramen ovale) at the bottom of the skull where the mandibular division of the trigeminal nerve (V3) exits.  The needle is advanced above the foramen into a small pocket at the bottom of the skull called meckel’s cave where the trigeminal ganglion is located. Once the location of the needle is confirmed with contrast dye on x-ray, glycerol is injected into meckel’s cave which bathes the spinal fluid around the nerve. The glycerol achieves the therapeutic effect by disrupting the insulation around the trigeminal nerve fibers and consequently disrupting the transmission of painful sensory signals to the brain. The procedure is performed with light sedation and local anesthesia and most people are able to go home a few hours after the procedure. Pain relief from glycerol rhizolysis is usually immediate and the procedure can be repeated if there is any recurrence of trigeminal neuralgia symptoms. There is often a small degree of facial numbness following the procedure that often subsides or becomes less bothersome after several weeks. 

Microvascular decompression
is the most definitive and first-choice treatment option for patients that are able to undergo general anesthesia and is the procedure that offers the highest likelihood of long-term pain relief. During a microvascular decompression a small opening is made behind the ear through the mastoid bone and the trigeminal nerve is directly inspected under an operating microscope. Using microsurgical techniques, the surgeon identifies the vessel along the surface of the trigeminal nerve that is causing compression and carefully releases the artery and moves it away from the nerve. The nerve is circumferentially inspected to identify any other compressing blood vessels and sometimes an endoscope is used to provide better visualization in areas that can’t be seen through the microscope. To prevent the artery from compressing the nerve again in the future, the surgeon places a soft Teflon cushion along the nerve, between the nerve and the artery, that is left in place.  

During a microvascular decompression we usually monitor the functions of other nearby nerves to make sure they are not interfered with; including the nerves for hearing which are right next to the trigeminal nerve. The procedure is also performed with stereotactic image guidance which allows the surgeon to plan out the smallest possible opening into the skull with a GPS type navigation device using a high resolution MRI scan. Patients usually are admitted to the hospital for two days after surgery for observation before being sent home. Patients then return to the office one week after surgery and can resume most normal activities after the office visit. Most patients will have immediate pain relief after surgery and remain with substantially reduced or absent facial pain for years afterwards. 

Pineal Region Tumors (Germ cell tumors & Pineal parenchymal tumors)

Pineal region tumors represent a heterogeneous group of lesions that arise in the region of the pineal gland, which is located behind the third ventricle at the top of the brainstem. The pineal gland produces several hormones including melatonin that regulates sleep-wake cycles. There are two primary categories of tumors that arise in the pineal region: germ cell tumors and pineal parenchymal tumors.  In addition to these, the pineal region contains a variety of other cell types that are also found throughout the brain and tumors originating from these cells can also arise in the pineal region including: astrocytomas, meningiomas, ependymomas, metastatic brain tumors and epidermoid or dermoid cysts. 

Germ cell tumors: These tumors commonly occur in the pineal region but can also near the pituitary gland in the suprasellar space. Germ cell tumors are thought to arise from the abnormal migration of cells in embryonic development during pregnancy. These tumors are not related to the pineal gland itself and can be benign (teratomas, dermoid and epidermoid tumors), malignant (germinomas, choriocarcinomas, endodermal sinus tumors and embryonal cell tumors) or mixed tumor types. These tumors are generally rare and usually manifest in patients by adolescence. Sometimes, biochemical markers in the blood and cerebrospinal fluid can differentiate the various tumor subtypes. This information is usually considered with imaging test results and biopsy to provide an accurate diagnosis and treatment plan.

Pineal parenchymal tumors: These tumors arise directly from pineocytes, cells of the pineal gland itself. These rare tumors can occur at any age and can be benign (Pineocytomas), malignant (Pineoblastomas) or have intermediate grade differentiation- meaning they share features of both malignant and benign tumors. Surgical biopsy results as well as imaging studies are used to provide an accurate diagnosis and assess the malignancy of these tumors in order to formulate a comprehensive treatment plan.

Symptoms

Symptoms, such as headache, nausea and vomiting, usually are the result of increased intracranial pressure from a backup of the cerebrospinal fluid that surrounds the brain and spinal cord. The backup of cerebrospinal fluid, called hydrocephalus, is very common with pineal tumors because they are located at the back of the third ventricle and block fluid flow into the sylvian aqueduct.  As a pineal region tumor grows, it may interfere with the normal functions of the surrounding brain. In the pineal region, compression of the upper brainstem may lead to disruption of certain eye movements, including the inability to look up which is part of Parinaud’s syndrome. Other symptoms can include uncoordinated body movements and an unsteady gait. 

Diagnosis
Pineal region tumors are diagnosed with a neurological examination followed by imaging studies of the brain, usually a computed tomography (CT) or magnetic resonance imaging (MRI) scan. The scan is usually performed with a contrast dye that makes the border and details of the tumor more visible in relation to the surrounding normal brain. The scan provides detail information regarding the presence of hydrocephalus, the exact size, location and probable type of tumor. However, only examination of a patient’s tumor tissue under a microscope can confirm an exact diagnosis. This tissue is usually obtained with either a biopsy or removal of the tumor. In some cases, neurosurgeons may employ a stereotactic MRI scan. In this study, a high-resolution contrast MRI is performed and a three-dimensional brain model is constructed using a computer system that is used to perform minimally invasive surgery and allow for volumetric three-dimensional removal of the tumor, which maximizes the degree of tumor removal. Depending on the type of tumor, an MRI entire spine and/or a lumbar puncture to sample cerebrospinal fluid may be performed to evaluate for the presence of any disseminated tumor cells within the spine and spinal fluid. This can play a role in determining the entire course of treatment after any surgery. 

Treatment

In general the initial treatment for a pineal region tumor is usually surgical removal of the tumor. With modern techniques, surgery for a pineal region tumor is generally safe and allows the team at the Brain Tumor Center to obtain tumor tissue for accurate microscopic diagnosis and treatment planning. A number of surgical approaches to the pineal region exist which are tailored to the individual patient’s tumor and symptoms. Modern anesthetic and surgical advances allow for relatively safe surgery without the risks that were often associated with these procedures in the past. The use of microsurgical technique, intra-operative stereotactic navigation and endoscopic technology the likelihood of a complete removal is maximized and greater than ever before. If hydrocephalus is present, an endoscopic third ventriculostomy can often be performed to bypass the obstruction in the flow of cerebrospinal fluid. This is often preferred over the placement of a permanent shunt system (a tube with a regulating valve that allows spinal fluid to flow into the abdominal cavity), which is the alternative treatment for hydrocephalus. The endoscopic procedure avoids the potential risks associated with inserting a permanent shunt device and, often times, a minimally invasive biopsy of the tumor can be obtained during the same procedure.  

For some benign tumors, complete resection is curative and is not followed by any other treatment. These patients are often observed with surveillance MRI studies to make sure there is no tumor recurrence. In other cases, such as with malignant tumors or tumors with intermediate differentiation surgery is often followed by chemotherapy or radiation therapy. In these cases maximal safe tumor removal is thought to improve the long-term outcome and response to treatment. Germinomas, for example, are particularly sensitive to radiation therapy while chemotherapy plays an important role in the other pineal region tumor types. Stereotactic radiosurgery, which involves delivery of a highly focused beam of radiation to the tumor that leaves the surrounding brain unaffected, can also be used in small tumors. After surgery, each patient is reviewed at our Multi-Disciplinary Tumor Board with an expert team of neuro-oncologists, medical oncologists, neuro-pathologists, neuro-radiologists and neurosurgeons. Together the tumor board recommends the best treatment options for each patient, incorporating ongoing national clinical trials and the latest treatment protocols.

Cholesteatoma

Cholesteatoma is a benign growth that consists of a buildup of squamous epithelial skin cells that grow into the middle ear and mastoid bone. These are benign conditions and are not tumors but can grow with time causing problems because of erosion of the bones inside and surrounding the ear and the base of the skull. These lesions generally grow slowly as the more and more layers of old skin cells and their secretions are deposited within the bone of the ear and skull base. The destruction of the bones of the middle ear will often lead to hearing loss and can rarely extend into the skull base where they can exert pressure onto the brain. 

Cholesteatoma usually occur because of poor eustachian tube function and repeated infections in the middle ear. The eustachian tube allows air from the ear to communicate to the nose. When the eustachian tube is blocked because of allergy, anatomic predisposition, or infections a small vacuum can develop which brings in the epithelial skin cells that lead to formation of a Cholesteatoma.

Symptoms
Most patients with a cholesteatoma will have fluid discharge from the affected ear, have a sense of fullness in the ear and this is often accompanied with some hearing loss. Less common symptoms of a cholesteatoma include earache, ringing in the ear, gait imbalance, facial weakness or asymmetry and headache. 

Diagnosis
Cholesteatoma is usually diagnosed with physical examination by an otolaryngologist (ENT specialist). Oftentimes a hearing test will be also administered to determine the extent of any possible hearing loss and to evaluate the extent of destruction the cholesteatoma has caused. A balance test may also be administered to determine the involvement of the bones in the inner ear and skull base that contain the balance organs. An imaging study of the skull base, usually a high resolution CT scan with 3-Dimensional reconstructions will often be obtained to understand the extent of bony destruction and involvement by the Cholesteatoma. 

Treatment
Initial treatment for a cholesteatoma may consist of a careful cleaning of the ear, antibiotics, and ear drops to help bring any infection under control. A large cholesteatoma usually requires surgery to prevent any further extension of the lesion into critical regions of the skull base. Surgical removal of the cholesteatoma helps to clear any infection and create a dry ear. Sometimes, depending on the extent of destruction, it is possible to attempt reconstruction of the damaged middle ear bones in an effort to improve hearing. If the cholesteatoma has significant extension into the bones of the skull base, including the petrous apex, the lesion might not be adequately drained through a standard outpatient procedure performed through the mastoid bone. Instead, it may require a lateral skull base approach or an endoscopic skull base approach where the lesion is accessed minimally invasively through the nose.

Skull Base Encephalocele and Meningocele

An encephalocele is a rare condition in which there is a small gap within the bones of the skull through which the coverings of the brain, cerebrospinal fluid and sometimes brain tissue can protrude in a small sac-like structure. Encephaloceles can occur in a variety of locations throughout the skull including the base of the skull. They usually arise secondary to an abnormality during fetal development, which results in a small groove along the middle of the skull. Skull base encephaloceles can be located along the forehead, nose or within the sinuses. Some encephaloceles can be large deformities that are immediately visible but others can be very small and go undetected especially when in the nose or sinus cavities. 

Although encephaloceles are generally congenital lesions in children, they can also occur in adults as the result of trauma or prior surgery along the skull base where the paper thin bones between the sinus cavities and the skull are disrupted allowing an encephalocele to form. Encephaloceles are also associated with hydrocephalus (the buildup of cerebrospinal fluid within the brain) and with pseudotumor cerebri a condition where the pressures within the skull and brain are abnormally elevated for reasons that are not entirely well understood.  

Symptoms
The symptoms of a skull base encephalocele are usually related to the drainage of cerebrospinal fluid through the brain coverings that have been pushed through the bony defect. The coverings of the brain in an encephalocele often become very thin and can develop tears that lead clear drainage from the nostril. Typically the drainage is worsened with straining, bending or exercise. Infection may also develop within the cerebrospinal fluid leading to meningitis. The over drainage of spinal fluid through the encephalocele can also lead to positional headaches.

Diagnosis
The diagnosis of an skull base encephalocele is based on your symptoms, physical exam and specialized imaging studies of the brain and skull base. A high resolution CT scan with 3-Dimensional reconstructions will often be obtained to understand the extent of bony destruction and involvement by the encephalocele. The scans also provides detail information regarding the exact size, location and other structures involved by the encephalocele. The scan is often performed with a contrast dye to help identify the presence of any major arteries that could herniate through into the encephalocele. The MRI scan can also help identify the presence of any hydrocephalus, infection or any other anomalies of the brain that can be associated with an encephalocele.

In some cases, otolaryngologists and neurological surgeons may employ a MRI or CT scan for frameless stereotactic guidance. The high-resolution CT scan is processed by a computer to create a 3-Dimensional model of the skull base that can be used in the operating room when performing endoscopic minimally invasive skull base surgery. 

Treatment
The primary treatment for a symptomatic skull base encephalocele is surgical repair of the skull defect, reduction of the encephalocele into the skull cavity and repair of the coverings of the brain to eliminate the cerebrospinal fluid leak. Depending on the size, extent and involvement of associated structures by the encephalocele surgical repair can be performed with either traditional open skull base techniques or with minimally invasive endoscopic techniques performed through the nose. Patients that are candidates for minimally invasive endoscopic techniques often experience fewer or no incisions, decreased pain and a shorter length of hospital stay.  

Esthesioneuroblastoma (Olfactory Neuroblastoma)

Esthesioneuroblastoma also known as Olfactory Neuroblastoma, is malignant tumor of the upper nasal cavity and anterior skull base. It is believed to arise from the olfactory neuroepithelium (the nerves that provide the sensation for smell) that lines the cribriform plate. The cribriform plate (from the Latin for “sieve”) is a horizontal segment of bone that is part of the ethmoid bone within the roof of the nose and has numerous holes through which olfactory nerve filaments pass.

These tumors often grow along the roof of the nose and involve the bones of the base of the skull. Sometimes these tumors can extend into the orbit or into the skull cavity causing ocular and neurological symptoms. They can occur at any age but have a tendency to occur in teenagers and the sixth decade of life.

Symptoms
The symptoms of an esthesioneuroblastoma can vary depending on the exact structures that are involved by the tumor. Most patients with esthesioneuroblastoma present with symptoms of nasal obstruction (inability to breath through the involved nostril), nasal bleeding, decreased sense of smell, and facial pain. Sometimes these tumors can extend into the orbit and lead to vision changes including double vision, vision loss and bulging of the eye. If there is significant extension into the cranial cavity and involvement of the brain, patients may develop headaches, nausea and vomiting.

Diagnosis
The diagnosis of an esthesioneuroblastoma is initially based on a complete history, physical examination. An ENT specialist will often perform nasal endoscopy to evaluate the nasal passages, location of the tumor and can often obtain a biopsy of the lesion immediately. Obtaining the biopsy is important for early diagnosis so that a comprehensive treatment plan can be established. 

Specialized imaging studies of the brain and skull base are also important in establishing the diagnosis and determining the extent of the tumor. A high resolution CT scan with 3-Dimensional reconstructions will often be obtained to understand the extent of skull base involvement, the exact size, location and other structures involved by the esthesioneuroblastoma. The scan is usually performed with a contrast dye that makes the border and details of the tumor more visible in relation to the surrounding normal brain. In some cases, otolaryngologists and neurological surgeons may employ a MRI or CT scan for frameless stereotactic guidance. The high-resolution CT or MRI scan is processed by a computer to create a 3-Dimensional model of the skull base that can be used in the operating room when performing endoscopic minimally invasive skull base surgery. 

Treatment
Treatment for esthesioneuroblastoma often requires the input of a multidisciplinary group of experts including ophthalmologists, oncologists, radiation oncologists, neurosurgeons and otolaryngologists.  Initial treatment is usually surgical resection of the tumor followed by radiotherapy. Treatment depends on the degree of local involvement by the tumor and the presence of any distant metastatic disease. 

The traditional surgical approach to these tumors involves a combined craniofacial resection of the tumor, during which the tumor is removed en-block together with the tumor involved surrounding structures. More recently, minimally invasive endoscopic techniques performed through the nose have been utilized in the management of these tumors. Endoscopic techniques allow access to regions that are sometimes difficult to access with open surgery. Patients that are candidates for minimally invasive endoscopic techniques often experience fewer or no incisions, are able to avoid any disfiguring facial incisions, decreased pain and a shorter length of hospital stay. Endoscopic techniques have now been shown to have comparable success rates but fewer complications compared with traditional craniofacial resection.

After surgery, radiation therapies may include intensity modulated radiation therapy (IMRT) and stereotactic radiosurgery. These technologies allow effective treatment of the cancer while limiting the amount of radiation to important normal tissues such as the eyes, optic nerves, brain, brain stem and spinal cord. 

Epidermoid and Dermoid Tumor

Epidermoid and dermoid tumors, also referred to as epidermoid or dermoid cysts are slow growing benign lesions that result form an error of cell migration during embryonic development. These lesions develop when cells in the developing embryo that were destined for the skin, hair or nail tissue become entrapped in the developing brain or spinal cord. These trapped cells ultimately produce what is called an inclusion cyst and the cyst contents can vary depending on the exact cell type that was trapped. The distinction between epidermoid and dermoid cysts is that epidermoid cysts do not contain hair or sebaceous glands. Rarely these cysts can spontaneously release their contents into the brain or cerebrospinal fluid causing a form of chemical meningitis. 

Epidermoid cysts are benign masses, frequently located off to the side of the brain or skull such as the cerebellopontine angle (an area along the side of the brainstem), near the pituitary gland, or within the skull. Dermoid cysts tend to me more midline in location but are relatively rare in the brain and instead occur more frequently in the spine, face or scalp. These tumors also are referred to as germ cell tumors because the original skin layer within the embryo that these trapped cells originated from is known as a germ layer.

Symptoms
Intracranial Epidermoid and dermoid tumors are usually slow growing and, therefore, may grow to a large size before causing symptoms.  The symptoms of an intracranial epidermoid and dermoid are caused by the pressure the growing tumor exerts on surrounding brain and can vary depending on location. These tumors can occur in a variety of places and therefore cause a wide range of symptoms, although they tend to occur in specific regions around the brain. Depending on the location of the mass, epidermoid and dermoid tumors may cause headaches, nausea, seizures, vision loss, facial pain, weakness or numbness in the limbs or face, and gradual changes in mood or personality. The symptoms tend to increase in severity as the tumor grows in size. If the cyst ruptures and spill its contents, it can cause repeated bouts of severe meningitis, with symptoms including fever, headache, and neck stiffness.

Diagnosis
These tumors are diagnosed with a neurological examination followed by imaging studies of the brain, usually a computed tomography (CT) or magnetic resonance imaging (MRI) scan. The scan is often performed with a contrast dye to make the border and details of the tumor more visible in relation to the surrounding normal brain. However, these tumors are often indistinct from the surrounding brain and a specialized MRI sequence (diffusion imaging) has to be performed in order truly visualize the tumor. The MRI scan provides detail information regarding the exact size, location and other structures involved by the tumor. Only examination of a patient’s tumor tissue under a microscope can confirm an exact diagnosis. This tissue is usually obtained with a biopsy or tumor resection. 

Treatment
The primary treatment for symptomatic dermoid or epidermoid cysts is surgical removal. In general the goals of surgical removal are to remove the cyst contents but to also remove the cyst lining if safely possible. Chemotherapy and radiation generally do not play a significant role in the treatment of these lesions. Depending on the location of the tumor, surgical removal can include minimally invasive techniques including endoscopic transnasal approaches or open skull base approaches. In general, surgery for these tumors is performed with an intraoperative neuro-navigation system that localizes the exact position of the lesion and depending on the location of the tumor, neuro-monitoring, especially of the cranial nerves is performed. 

Chordomas (Skull Base and Spinal Column)

Chordomas are tumors that tend to arise within the spine (especially the sacrum) or within the base of the skull. These tumors develop from remnants of the notochord, an embryonic structure that is involved in development of the bony skull and spine. The notochord eventually forms the central parts of the spinal intervertebral disks. These tumors are usually slow-growing, but they may invade nearby structures, tend to recur after treatment and can destroy surrounding bone and tissue. 

Symptoms
Chordomas are usually slow growing and, therefore, may grow to a large size before causing symptoms.  The pressure that a growing tumor exerts on the surrounding brain or cranial nerves usually causes the symptoms of a chordoma. With a skull base chordoma, symptoms usually develop with compression of the brainstem or cranial nerves. These symptoms can include headaches, weakness or numbness in the limbs or face, double vision and hearing loss. The symptoms tend to increase in severity as the tumor grows in size. With chordomas arising in the spine, symptoms can include tingling, numbness or weakness in the arms or legs and loss of bladder or bowel control.

Diagnosis
The diagnosis of a chordoma is based on your symptoms, physical exam and specialized imaging studies of the brain and skull base or of the spinal column. A high resolution CT scan with 3-Dimensional reconstructions will often be obtained to understand the extent of bony destruction and involvement by the chordoma. The scan also provides detail information regarding the exact size, location and other structures involved by the chordoma. The scan is often performed with a contrast dye to help identify the relationship of any major arteries to the chordoma and to make the border of the tumor more visible in relation to the surrounding normal anatomy. The MRI scan can also help identify the extent of any compression of the brain, cranial nerves or spinal cord. In some cases, otolaryngologists and neurological surgeons may employ an MRI or CT scan for frameless stereotactic guidance. The high-resolution CT scan is processed by a computer to create a 3-Dimensional model of the skull base that can be used in the operating room when performing endoscopic minimally invasive skull base surgery. In some cases of a spinal column chordoma, a needle biopsy of the tumor will be performed to confirm the diagnosis. In these circumstances, the surgical team is often ready to perform an operation soon afterwards in order to prevent spread of any of the tumor cells. 

Treatment
The initial treatment for a chordomas is usually surgery to remove as much of the tumor as safely possible. Surgery to remove skull base chordomas can be performed using endoscopic or minimally-invasive skull base techniques or with Traditional or open skull base techniques depending on the exact location and extent of your particular tumor. Surgery for removal of spinal column chordoma is usually performed open surgical en bloc resection of the tumor. Depending on the location of the tumor, en bloc resection may not always be possible without the risks if serious neurological or vascular complications. Even in cases of total resection, these tumors have a tendency towards recurrence, therefore surveillance repeat MRI or CT scans are conducted for a period of time following initial treatment. Depending on the particular location of the tumor, surgery may involve a team of physicians including, neurosurgery, ENT surgery, plastic surgery, urology and vascular surgery.

Following surgery, radiation therapy may be used as a follow-up treatment, especially in cases with residual tumor. In addition, non-invasive, stereotactic radiosurgery (CyberKnife) or proton beam irradiation may be used as adjunct treatment. Stereotactic Radiosurgery uses numerous finely focused beams of radiation to accurately target the tumor and while minimizing the effects to any surrounding tissue. The target tumor is usually outlined on a 3-Dimensional model of the brain by the neurosurgeon and the radiation oncologist prior to the procedure.

After surgery, each patient is reviewed at our Multi-Disciplinary Tumor Board with an expert team of neuro-oncologists, medical oncologists, neuro-pathologists, neuro-radiologists and neurosurgeons. Together the tumor board recommends the best treatment options for each patient, incorporating ongoing national clinical trials and the latest treatment protocols.

Juvenile Nasopharyngeal Angiofibroma (JNA)

JNA is a benign tumor of the nasal cavity that is exclusively found in adolescent boys and young men. These tumors are typically benign, non-cancerous, but they can grow rapidly to a large size and extend from the nasal cavity into the skull base making surgical resection more difficult. These tumors are typically highly vascular lesions with a robust blood supply sometimes necessitating embolization prior to any surgery. These tumors generally have a good prognosis because of their overall benign nature. 

Symptoms
Most patients with JNA present with symptoms of nasal obstruction (inability to breath through the involved nostril), profuse nasal bleeding, and sometimes, facial pain and numbness. Blockage of the Eustachian tube by the tumor or swelling related to the tumor can lead to fluid in the middle ear and unilateral hearing loss. Sometimes these tumors can extend into the superior orbital fissure and lead to vision changes including double vision, vision loss and bulging of the eye. If there is significant extension into the cranial cavity and involvement of the brain, patients may develop headaches, nausea and vomiting.

Diagnosis
In addition to classic clinical symptoms, diagnosis of a JNA is often made on nasal endoscopy.  The tumor appears as a hemorrhagic or pulsatile mass protruding from the lateral nasal wall in the region of the sphenopalatine artery.  The tumor is almost always one sided, but large tumors can cross the midline.  Imaging of the tumor usually involves CT scan, MRI, MRA, and sometimes angiography with plans for pre-operative embolization.  Tissue diagnosis is made at the time of surgery, as these are very vascular tumors that are not biopsied in an office setting.

Treatment
Treatment typically involves surgical resection.  Today many tumors can be resected endoscopically without any facial incisions.  In rare instances, combined open and endoscopic techniques are employed when the tumor has extensive skull base or orbital involvement.   Sometimes pre-operative angiography with embolization is utilized in conjunction with surgical resection.

Acoustic Neuroma

An acoustic neuroma, known as a vestibular schwannoma, is a benign (non-cancerous) growth that arises on the eighth cranial nerve leading from the brain to the inner ear. The acoustic (eighth cranial) nerve includes branches that mediate the sense of balance and head position (the vestibular nerve), as well as hearing (the cochlear nerve). Acoustic neuromas are benign tumors that arise from the vestibular portion of the acoustic nerve. The eighth nerve, along with the facial or seventh cranial nerve, sit next to each other as they leave the brain stem and enter the skull through a small bony canal called the internal auditory meatus (IAC). Surrounding each nerve fiber are Schwann cells that form a layer of insulation and acoustic neuromas arise from these cells and are also known as vestibular schwannomas. Acoustic neuromas usually grow slowly over a period of years.  

Symptoms
Early symptoms are easy to overlook and include one sided hearing loss often accompanied by ringing in the ears (tinnitus) which result from compression of the eight nerve. The loss of hearing is usually subtle and worsens slowly, but sometimes sudden loss of hearing can occur. Some patients also describe a sense of fullness in the affected ear. Loss of balance and vertigo are also common symptoms since the tumor originates from the balance portion of the eighth nerve. In some patients the balance system on the other side compensates for this they don’t notice ant balance loss. If the tumor enlarges it can compress the surrounding brain stem in the cerebellopontine angle and cause hydrocephalus, fluid buildup in the brain, headaches, facial numbness, facial weakness, double vision and swallowing difficulties.

Treatment
If acoustic neuroma, vestibular schwannoma, is small and does not cause any symptoms, it can often be observed over time rather than treated immediately. In cases in which treatment is necessary, micro-surgical removal through a variety of skull base techniques has been a long standing therapeutic option. Because these tumors are benign complete surgical removal often results in a long term cure. The development of focused radiation techniques, also called stereotactic radiosurgery (CyberKnife Radiosurgery), which involves the use of a highly focused beam of radiation to target the tumor, now provides an option that does not require open surgery and poses less threat to functional areas of the brain.  CyberKnife stereotactic radiosurgery is usually used for smaller but can also be used to treat any residual tumor after microsurgery. 

Choosing the best treatment is a decision that must be made by both the patient and the physician after careful review of the size of the tumor and its location as well as the patients symptoms. Because of the complexity and rarity of these tumors, treatment with either observation, surgery, or radiosurgery should be done by doctors and hospitals with extensive experience in the total management of these tumors.  The teams concentrated experience is what leads the best possible outcomes for patients with acoustic neuromas.

Observation
Often times acoustic neuromas are discovered incidentally and when small in size on an MRI scan and cause no symptoms at all. When considering the slow rate of growth in an otherwise benign tumor, careful observation with surveillance MRI scans is often the best management. This helps determine the rate of growth in the tumor, if any, and help plan for any interventions if needed. Observation helps avoid treatment of a tumor that is not causing any harm and avoids any potential treatment related complications. The decision to pursue observation also takes into consideration the status of hearing in the other ear for the patient. On the other hand, if the tumor grows over time treatment may become necessary.

Microsurgical removal of acoustic neuromas
Several different skull base approaches have evolved for the removal of acoustic neuromas. These microsurgical approaches include the translabyrinthine, retrosigmoid and middle fossa approach. The approach is tailored to each individual patient based on factors such as tumor size, location, and hearing status. These microsurgical approaches are designed to minimize manipulation of the surrounding brain by removal of some of the bone at the base of the skull and inner ear. Some approaches facilitate identification and protection of the facial nerve early in the operation prior to removal of any the tumor. Other approaches allow for a greater chance of hearing preservation with in patients with smaller tumors and good hearing prior to surgery. Regardless of which approach is used, during surgery a stimulating probe is used to monitor the function of the facial and auditory nerves. 

The surgical team usually includes a neurosurgeon and a neurotologist and they together with the patient decide on the best particular approach for a patient. One of the primary goals of surgery, aside from removal of the tumor, is the maintenance of facial nerve function, followed by preservation of hearing when possible and complete tumor removal. Total tumor removal carries a higher risk of hearing and facial nerve problems.  

Stereotactic Radiosurgery (CyberKnife) treatment for acoustic neuroma 
Stereotactic radiosurgery is a minimally-invasive form of focused radiation that is often used to arrest or control the growth of an acoustic neuroma. Stereotactic radiation delivery utilizes high resolution MRI scans to target the tumor with pinpoint radiation while minimizing injury to surrounding nerves and brain tissue. This technique is performed as an outpatient and does not require the use of any anesthesia. The technology involves accurately delivering multiple tiny beams of radiation that intersect at the tumor. This results in a high dose of radiation to the tumor and very little to any surrounding brain structures.

A computer workstation is used to create a 3D model of the tumor and surrounding brain structures and a team of radiation physicists, neurosurgeons and radiation oncologists create a treatment plan that maximizes the tumor dose and minimize radiation to surrounding normal tissues. The patients head is stabilized with a fitted mask shield and treatments generally last 30-60 minutes.
 
Radiation delivery to the tumor cells causes DNA damage rendering them unable to divide and reproduce.  The benefits of radiation are not immediate but occur gradually over time.  Gradually the tumor may stop growing and in some cases may shrink in size. Patients that undergo radiosurgery for their acoustic neuroma need to maintain a schedule of follow-up annual MRI scans to make sure the remain is well controlled. Radiosurgery is usually performed by a team including a neurosurgeon, neurotologist and radiation oncologist. In some cases the tumor can continue to grow despite radiosurgery and require microsurgery for removal.

Skull Base Tumors and conditions

Skull base surgery refers to surgical techniques required to obtain access to the floor of the cranial cavity. Due to the complexity of this region, the
neurosurgeon often works in conjunction with ear, nose, and throat (ENT), or plastic surgeons when performing skull base surgery because of the close
proximity of the face and neck to the skull base. Advances in microsurgical
techniques, understanding of the skull base anatomy, improvements in
neuroimaging, endoscopy, and stereotactic radiosurgery have allowed such
lesions to be successfully treated.

Anatomy of the skull base
The skull base is composed of the bones and cartilage that form the face and cranium which surrounds the bottom of the brain. The bones of the skull base also form the eye socket, rood of the nasal cavity, some of the sinuses, and the inner ear. Contained within this region are major blood vessels that supply the brain with essential nutrients and important nerves with their exiting pathways. The floor of the skull is divided into three regions from front to back: the anterior, the middle, and the posterior compartments. The anterior compartment is the region above a person’s eyes and some of the sinuses, the middle compartment is the region behind the eyes and centered around the pituitary gland, an organ required for proper hormonal function. The posterior compartment contains the brainstem and the cerebellum and is centered around the inner ear and the connection of the brain to the spinal column. The brainstem is the connection between the brain and spinal cord, containing the origin of nerves involved in the control of breathing, blood pressure, eye movements, swallowing, etc. 

Symptoms
The symptoms and presentation of patients with tumors and conditions of the skull base is highly variable because of the many important structures contained in this area. These symptoms occur due to direct compression of important nerves by a tumor or blood vessels or by blocking the normal flow of fluid around the brain. Tumors of the anterior compartment may produce headache, sinus congestion, or vision changes. Those of the middle compartment may produce endocrine dysfunction or vision changes. Those of the posterior compartment can produce neck pain, dizziness, tinnitus, hearing loss, and difficulties with swallowing and talking.

Diagnosis
The diagnosis of growths or abnormalities that may require skull base surgery is based on your symptoms and a physical exam. Imaging studies are an important component of the diagnosis of skull base conditions because this area cannot be seen directly. Brain imaging studies such as magnetic resonance imaging (MRI) and Computed tomography (CT) scans are often used. In some cases, neurological surgeons may employ an MRI or CT scan with frameless stereotactic guidance for preoperative planning purposes. For this study, a high-resolution contrast MRI or CT is performed and then processed by a computer to create a three-dimensional model of the brain and skull base. This can be used in the operating room when performing endoscopic minimally invasive skull base surgery. Special tests such as PET scan, MRA and angiography are sometimes used to help your medical team better see a growth or abnormality and identify its blood supply. If the conditions involves the sinuses or if surgery will traverse the sinuses endoscopy of the sinuses may be performed before surgery by the ENT specialist to evaluate your particular anatomy. Other tests such as balance, vision, and hearing evaluations may also be checked.

Types of skull base surgery
Skull base surgery can be done in two main ways. Although the preferred method is endoscopic, open surgery is also an option, depending on the type of growth that needs to be removed and its location:

Endoscopic or minimally-invasive skull base surgery
An ENT surgeon usually helps approach the tumor through the nose (endonasal) and natural sinuses and together with the neurosurgeon they remove the tumor through a thin tube with a light source at the end called an endoscope. Endoscopic techniques continue to evolve and requires careful analysis by your surgeon to determine if you are a candidate. 

Traditional or open skull base surgery
This type of surgery generally requires an incision behind the hairline and opening of the skull. Advances in neuro-anesthesia and microsurgical techniques (typically an operating microscope is used) have made this surgery safer and less invasive. In this type of surgery, bone surrounding the skull base is removed so that the surgeon can access the skull base with minimal to no brain retraction at all which leads to better outcomes. The bone that is removed is reconstructed at the end of the operation. In some cases this surgery is performed with minimally invasive techniques and combined with an endoscope, which allows for smaller incisions and even surgery through an eye-brow or eyelid incision.

Surgery for skull base tumors and conditions

The management of skull base tumors and conditions often requires consideration of several factors including the patient’s symptoms, growth of a lesion over time, the suspected pathology and potential for post-operative chemotherapy or radiation. Depending on the particular location and structures involved specialists in ENT, ophthalmology, radiation oncology and medical oncology may need to be involved. Some patients are candidates for non-invasive stereotactic radiosurgery and other patients may benefit from either open or endoscopic surgery. 

The diversity of skull base tumors and conditions are vast, and they may arise from various sources including the brain, the lining of the brain, the bones making up the skull base, or metastases. Although these tumors and conditions have unique individual characteristics, they may present in a similar fashion due to involvement of similar nervous structures. They can be grouped according to the area of the skull base from which they arise:

Tumors and conditions occurring in the anterior compartment include:

  • meningiomas
  • esthesioneuroblastomas (olfactory neuroblastoma)
  • orbital gliomas
  • nasopharyngeal carcinomas
  • juvenile nasopharyngeal angiofibroma
  • encephaloceles

Those occurring in the middle compartment include:

  • meningiomas
  • pituitary adenomas
  • Rathke’s cleft cysts
  • craniopharyngiomas
  • schwannomas
  • cholesteatoma
  • encephaloceles

Those of the posterior compartment include:

  • acoustic neuromas
  • schwannomas
  • epidermoid tumors
  • chordomas
  • chondrosarcomas
  • Glomus tumors
  • Trigeminal neuralgia
  • Hemi-facial spasm

At the Gerald J. Glasser Brain Tumor Center we provide comprehensive multi-disciplinary care for a variety of skull base conditions. Both non-operative, operative and post-operative care is provided with experts in the area of neurosurgery but also in neurophysiology, neurology, plastic surgery, ENT, neurological oncology, radiation oncology, and intensive care nursing. 


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