ACOUSTIC NEUROMA - SCHWANNOMA, NEURINOMA, NEUROFIBROMA

Summary:

These tumours arise from the Schwann cells, which insulate the 8th cranial nerve. These tumours can vary in size from very small to very large. Since these tumours grow slowly, symptoms may be slow to develop and the patient may delay seeking medical help.
Symptoms can include hearing loss, visual disturbances, dizziness, difficulty swallowing, or infrequently, facial numbness or weakness. In most cases, these tumours can be completely removed by surgery. Specialized radiation therapy may also be indicated. After treatment, the patient may have permanent or temporary damage to his/her facial nerve. Some centers have specialized programs to deal with facial weakness. Inquire about this. Traveling to another centre for rehabilitation may be a consideration. Hearing loss may be permanent.

The Acoustic Neuroma Association of Canada can be contacted for further in-depth information as well as support. They can be reached at 1-800-561-ANAC (2622) or their website is www.anac.ca

ASTROCYTOMA

Summary:

These tumours arise from cells called astrocytes. This is the supportive tissue of the brain. Astrocytomas are graded from I to IV (1 to 4) depending on how the tumour looks to the pathologist. Grade I tumours are slightly abnormal whereas Grade IV tumours are very abnormal in appearance.

Anaplastic Astrocytoma (Grade III)
The cells of these tumours are moderately fast growing and less well defined than an astrocytoma (Grade I or II). These higher-grade tumours are malignant and treatment is usually more aggressive than that for lower grade tumours. Patients are often diagnosed in adulthood, with diagnoses peaking in their forties. These tumours are diffuse and infiltrating to the surrounding tissue, and the tentacle-like projections of these astrocytomas make them harder to remove. Treatment involves removal of as much tumour as safely possible plus radiation and chemotherapy.

Cerebellar Pilocytic Astrocytoma (Grade I)
These tumours are astrocytomas found in the cerebellum. This is the part of the brain that controls balance. Most of these tumours are considered benign. First symptoms of these tumours are usually headache, vomiting or an unsteady gait. They occur equally between the sexes and at all ages in children, although they are unusual in infants. Approximately two-thirds of these tumours are cystic (have a fluid cyst associated with a solid mass) in nature. These tumours are very rare in adults.

The management of astrocytoma may involve treating hydrocephalus. This is usually accomplished pre-operatively with steroids (dexamethasone, or the more common trade name of Decadron), which frequently relieve symptoms in 24-48 hours. A second approach to hydrocephalus infrequently requires the placement of a shunt.

The goal of treatment of a cerebellar pilocytic astrocytoma is complete surgical removal. This is achieved in a large majority of cases and no further treatment is necessary. If total removal is not possible (for example it may have grown into the brain stem) radiation therapy may be necessary. The role of chemotherapy is changing in these tumours. Some response has now been found to chemotherapeutic agents. Pilocytic astrocytomas can occur in other parts of the brain and their treatment is usually surgery, and radiation therapy if necessary.

Glioblastoma Multiforme (Grade IV)
These tumours may contain various cell types, hence the name "multiforme". The most common cell types are astrocytes. Most of these tumours occur in the cerebral hemispheres and often involve the corpus callosum. The cells of these tumours grow quickly, are not well defined, and they may frequently spread throughout the brain. The most common symptoms are due to increased pressure in the brain and can include headache, vomiting, drowsiness and nausea. Presentation of this tumour is often within the 4th to the 7th decade of life. This tumour type represents 12-15% of all intracranial tumours.

Surgery may be performed to remove as much tumour as possible. Radiation and chemotherapy are often then used to control growth of the tumour. Recent studies have shown promise in the use of radiation and chemotherapy (specifically Temozolomide®) at the same time to improve quality of life and increase survival.

Astrocytoma (Grade II)
These are astrocytomas that are usually located in the hemispheres of the brain. First symptoms of these tumours usually include seizures, nausea, vomiting, headache and difficulties with vision. This type of tumour is most commonly diagnosed in patients who are 20 to 45 years of age. Grade 2 astrocytomas make up about 25% of all gliomas.

Surgical removal is the method of treatment for these astrocytomas. Radiation may also be necessary if the tumour is in an area of the brain responsible for such functions as speech, understanding or movement and if it cannot be easily surgically removed. Chemotherapy may be a consideration. A significant proportion of astrocytomas, over time, may alter their cell structure and become more aggressive (eg. anaplastic astrocytoma and glioblastoma multiforme).

Pilocytic Astrocytoma (Grade I)
These tumours tend to be classified as a low-grade astrocytoma because they do not spread from their original site. They are generally considered to be benign tumours and can often be removed by surgery depending on their location. Pilocytic astrocytomas are often found in the optic chiasm, optic nerves, thalamus as well as the cerebellum.

Pleomorphic Xanthoastrocytoma (Grade II)
This tumour usually occurs in adolescents and presents with seizures. It has been important to recognize this tumour type since the prognosis of this type of astrocytoma is very good. Pleomorphic Xanthoastrocytomas are a rare form of astrocytomas and represents less than 1% of all intracranial tumours. This tumour is usually treated with surgical removal and the role for radiation therapy and chemotherapy has not been defined

CHONDROMA

Summary:

CHONDROSARCOMA

Summary:

Chondrosarcomas are bone tumours composed of cartilage and are the malignant form of chondromas. Although these tumours are still relatively slow growing, they often develop at the base of the skull or in the sphenoid bone and are invasive to the surrounding tissue, making surgical removal difficult.

CRANIOPHARYNGIOMA

Summary:

These slow growing tumours account for approximately nine percent (9%) of all pediatric brain tumours and usually occur in children between 5 and 10 years of age. Rarely, they occur in adults. These tumours arise from cells along the pituitary stalk and may grow upwards and involve the hypothalamus, optic nerve pathways and the third ventricle. These tumours are cystic in nature and usually benign. At diagnosis, there may be signs of increased pressure in the brain (third ventricle blocked), visual loss (either decreased vision or visual field problems) and hormone difficulties (growth delay, thyroid deficiency, sexual delay).
Complete removal of this tumour is possible if it is in a favorable location. Otherwise, radiation therapy may be used. Long-term follow-up will be necessary by an endocrinologist (a physician who studies the hormone systems of the body). Lifelong hormone replacement may be necessary. Neuropsychological testing and follow-up are advisable. Problems with emotions and behaviour may need to be monitored.

CYST

Summary:

Cysts are abnormal accumulations of fluid enclosed in a lining. They may contain blood, tissue or tumour cells. There are specific cysts that are named for their type of tissue and their content.

Arachnoid Cyst
Arachnoid cysts are congenital in origin and may occur anywhere in the brain. In children, they most commonly arise in the back of the brain and in the region of the third ventricle. They are cerebrospinal fluid (CSF)-filled cysts that are lined with the arachnoid membrane (one of the three meningeal coverings). Some arachnoid cysts are self-contained, while others may be connected by a passageway with the ventricles or subarachnoid space. The entrapped fluid may block the CSF pathways, producing hydrocephalus.

Colloid Cyst
These cysts usually occur in the third ventricle and can cause hydrocephalus. They contain embryonic tissue (tissue formed before birth). Treatment includes surgery and sometimes shunting.

Dermoid and Epidermoid Cyst
These cysts develop from congenital tissue (formed before birth). Epidermoid cysts contain keratin, cellular debris and cholesterol. Dermoid cysts contain hair and sebaceous (sweat) glands. These masses occur in central areas of the brain such as the hypothalamic region, the vermis of the cerebellum and the pineal region. The bones of the skull (not involving the brain itself) and the spine may also be involved. These cysts are treated with surgery and complete removal is usually possible.

Hamartoma
This is an aggregation (or clumping) of a particular normal tissue or cell types in areas in which they are not typically found. It is not considered to be fast-growing or malignant and is presumed to be congenital (existing before birth).
The tissues included in the mass are normal but may be highly disorganized. Many of these tumours present with seizures and hydrocephalus. Treatment is usually surgical, although in the majority of cases, the tumour cannot be completely removed. These tumours have a tendency to grow during childhood and infrequently grow after puberty.

Rathke Cleft Cyst (Rathke Pouch Cyst)
During development, the pituitary gland develops from two components. The anterior portion develops from the roof of the mouth, and the posterior portion from the brain itself.

Occasionally, non-malignant cysts develop from the fragments of tissue that initially had lined the mouth. These cysts have no solid component and are fluid filled sacs with a very specialized lining that secretes fluid. These cysts are always in the area of the pituitary gland and can be large. Treatment is surgical removal. At times a shunting procedure may be necessary.

Teratoma
This is a congenital tumour, which is made up of elements from the three primary cell layers: Ectoderm (skin and nervous system), Mesoderm (muscle, bone and cartilage) and Endoderm (gut lining). These are the earliest cell types in development. It is most commonly a tumour of the pineal gland or lower spinal cord in the central nervous system, but may be found near the base of the brain near the pituitary gland, or the base of the third ventricle. Treatment is usually surgery.

DNT

See YSEMBRYOPLASTIC NEUROEPITHELIAL TUMOUR

EPENDYMOMA

Summary:

These tumours arise from the cells lining the ventricles (hollow channels) of the brain (most commonly the fourth ventricle). As these tumours grow and fill the ventricle, they obstruct the flow of cerebrospinal fluid (CSF) through the brain. These tumours appear more commonly among younger children. There are a number of variants of ependymoma and an anaplastic (fast growing) ependymoma is sometimes found.
Hydrocephalus, caused by the blocking of the flow of cerebrospinal fluid, may make shunting necessary. Total surgical removal is not always possible, and treatment is individualized depending on the type of ependymoma or variant identified. Treatment for fast growing tumours will include radiation (occasionally also given to the spine) and chemotherapy.

EPENDYMOBLASTOMA

Summary:

These tumours may also arise from ependymal cells and appear to be tumours that begin before the cells have reached a more mature or functional stage of development. Symptoms of these tumours include headache, nausea, vomiting, balance problems and visual disturbances.

GANGLIOGLIOMA

Summary:

Gangliogliomas are generally slow growing tumours and may occur anywhere in the brain although the temporal lobe and cerebellar hemispheres are the most common sites. They are benign tumours that arise from ganglia-type cells. Treatment is usually total removal by surgery. On occasion, radiation therapy is used.

GERM CELL TUMOUR

Summary:

Germ cell tumours arise in the pineal region of the brain.

The pineal gland is located centrally in the brain and is an out-pouching of the third ventricle. Hydrocephalus is usually a presenting symptom as the cerebrospinal fluid pathway may be blocked. The optic (vision) pathways may also be involved and there may be double vision. Surgery is sometimes possible or a biopsy may be performed to obtain a diagnosis. Some of these tumours are sensitive to radiation. A shunt may be necessary to treat the hydrocephalus, although hydrocephalus may be initially controlled by the use of steroids. Some germ cell tumours may be treated with chemotherapy.
There are four categories of pineal region tumours:
 

1. Germ cell tumours:

- fast growing:

i. choriocarcinoma
ii. embryonal carcinoma
iii. endodermal sinus tumour

- not as fast growing:

i. germinoma

- slow growing:

i. dermoid cyst
ii. epidermoid cyst
iii. teratoma
iv. yolk sac tumour (Endodermal Sinus Tumour)

2. Pineal cell tumours:

- fast growing:

i. pinealoblastoma

- slow growing:

i. pinealocytoma

These tumours arise from the actual pineal cells of the pineal gland itself. If the cells are dividing quickly, they are considered pinealoblastomas, whereas those tumours with slow growing cells are called pinealomas. Treatment is usually biopsy, or if small, surgical removal. Radiation therapy follows and some centres are using chemotherapy.

3. Glial cell tumours:

Any glial tumour, both slow and fast growing, can be found in the pineal region. These are discussed earlier in this chapter (e.g. astrocytomas).

GLIOBLASTOMA MULTIFORME (GBM)

See Astrocytoma

GLIOMA

Summary:

Glioma - These tumours arise from glial cells. There are three types of glial cells: astrocytes, oligodendrocytes and ependymal cells. The following types of gliomas refer to their location within the brain.

Glioma, Brain Stem
Brain stem gliomas are astrocytomas that usually start in the pons.

Ten to twenty-five percent (10%-25%) of pediatric brain tumours will be brain stem gliomas. These gliomas only make up 2-3% of all intracranial tumours in adults, and are more likely to be low grade and remain localized.

These tumours occur equally between sexes and most often occur between the ages of 5-10 years. Brain stem gliomas are located in an area of the brain and spinal cord that is responsible for many vital body functions. These include vision, balance, strength, gagging, coughing and swallowing.

Because of the location of these tumours, surgery is rarely an option (except for biopsy and draining of cyst). Radiation to the mass is the usual method of treatment. Some centres may add chemotherapy before or after radiation treatment. These are generally considered tumours of childhood.

Glioma, Butterfly
When a glioma spreads across the corpus callosum into both hemispheres, it often has the appearance of a butterfly on a CT or MRI scan and is given the general term "butterfly glioma".

Glioma, Optic Nerve
Optic nerve gliomas are located along the optic nerves, the optic chiasm and the hypothalamus. (See Visual Changes, Chapter 7) These tumours are usually slow growing (astrocytomas). Symptoms will vary depending on location but may include decreased vision, double vision and papilledema (swelling of the optic nerve). If vision has been lost, surgery may be considered. If visual function remains, there will be careful follow-up with imaging studies done at regular intervals. Radiation therapy may be an option. For tumours that involve the hypothalamus and the third ventricle, there may be signs of hydrocephalus as well as hormone imbalance.

Surgical treatment of hydrocephalus may be considered. Some tumours located here respond well to chemotherapy and it may be considered. These tumours are usually associated with Neurofibromatosis Type 1 (a type of genetic disorder that affects the skin and nervous system).

Glioma, Mixed
You may hear this term used. A tumour may be composed of two or more cell types (as seen under the microscope). These tumours are classified into oligo-astrocytoma in which the two predominant cells identified are the oligodendroglial cells and astrocytoma cells. In this tumour, both of these cell groups appear to be "tumour-like". At times, malignant features are identified. In this situation, the tumour is identified as an anaplastic (malignant) oligo-astrocytoma.

These tumours are treated based on the more prominent cell group identified. Treatment may depend on the size, location, and the diagnosis. The presence of specific genetic changes may be very useful in categorizing these tumours. The prognosis of these tumours may be more determined by the characteristics and numbers of astrocytic cells present.

Glioma, Multicentric
You may hear this term applied to glial tumours that, on investigational studies, appear to be located in two widely separated parts of the brain (eg. left frontal and right temporal). The multiple locations of these tumours usually make complete surgical resection very difficult.

These tumours may be treated with radiation therapy and chemotherapy depending on the exact tumour type.

Oligodendroglioma
These tumours are slow growing and can be low grade (grade II) or high-grade (grade III). The mass usually appears calcified (calcium deposits) on imaging (CT scan or MRI scan) showing that it has been there for many years. Some of these tumours are malignant when first diagnosed and are referred to as anaplastic (malignant) oligodendrogliomas. These tumours arise from the oligodendroglial cells, which make up the myelin that insulates nerve fibres. More than 60% of oligodendrogliomas are found in the frontal lobe.

Symptoms of these tumours may include seizures, headache and vision problems. Treatment usually involves surgical removal along with a course of chemotherapy and/or radiation therapy if sub-totally (incompletely) removed. These tumours are often chemo-sensitive and recent advances in genetic testing are helping to determine the appropriate treatment path for these tumours. Specific changes in chromosomes 1 and 19 are found in about 50% of these tumours and influence the treatment period.

HEMANGIOBLASTOMA

Summary:

These tumours may develop from and are composed of blood vessels. These tumours occur most frequently in the cerebellum but can be elsewhere in the brain or spinal cord. These tumours grow slowly and symptoms depend on location. Treatment includes surgery and possibly radiation. These tumours may run in families.

Von Hippel-Lindau Disease
This is a genetically dominant disorder. Hemangioblastomas, often in the cerebellum, are the most common brain tumours associated with this disease. Hemangioblastomas are associated with the retina of the eye and, if not treated, can lead to blindness. Treatment is usually surgery for the brain tumour.

Laser coagulation can be used for retinal lesions. Malignant kidney tumours are common in this disorder. Other types of abnormal tumours are also common.

To learn more about this disorder, contact the Canadian VHL Family Alliance at 1-800-767-4845 or http://vhlcanada.ca

HYDROCEPHALUS

Summary:

The condition hydrocephalus may occur when there is a blockage in the pathways through which the cerebrospinal (CSF) fluid normally travels. It may also arise from an over-production of CSF or a difficulty in absorbing the CSF that is produced. Because the brain is enclosed within the bony skull, the extra CSF, trapped by blocked pathways, has no escape. This extra CSF within the brain will produce increased pressure symptoms: headaches, vomiting, drowsiness and in some cases, confusion.

Brain tumours may block the channels of cerebrospinal fluid within the brain. Rare tumours involving the ventricles may affect the production and absorption of the fluid. Spinal cord tumours may block the CSF as it travels around the spinal cord. A surgical procedure of shunting extra CSF may be necessary.
 

LIPOMA

Summary:

This is a mass, which is made up of normal adipose (fatty) tissue and is usually situated just below the skin. Lipomas may be watched over time to see if they grow. Surgical removal may be indicated but location of the mass has to be considered. Lipomas are common in the spinal cord associated with congenital malformations. Rarely, lipomas can be found in the corpus callosum.

LYMPHOMA

Summary:

Lymphomas arise from specialized cells of the lymphatic system and occur both in the brain and spinal cord. The incidence is increased in patients after organ transplantation and patients whose immune system is depressed (e.g. AIDS). These tumours are frequently responsive to steroid medication. Surgery and radiation may be indicated along with chemotherapy. Lymphomas starting elsewhere in the body may spread to the brain or spinal fluid and it is not unusual for this tumour to be found in multiple places.
To learn more about Lymphoma, contact Lymphoma Foundation Canada at 1-866-204-0233 or www.lymphoma.ca

LEUKEMIA

Summary:

Leukemia is a cancer of the blood cells. Acute Lymphoblastic Leukemia (ALL) involves the blood forming cells called the lymphocytes. Acute Nonlymphoblastic Leukemia (ANLL) refers to fast dividing blood cells arising from any blood cells other than the lymphocytes.

Treatment is a combination of chemotherapy drugs with or without radiation treatment. It will continue for 2 to 3 years depending on age, sex, white blood cell count at diagnosis as well as other variables.

Occasionally, a person at high risk with leukemia may require radiation to the head and spinal cord. Radiation is used because drugs commonly used for chemotherapy cannot get through the blood-brain barrier into the brain and kill tumour cells in this location. Very rarely do some leukemia cells make it into the brain and it is expected that they will be killed by the radiation therapy.
Alternately, instead of radiation therapy, sometimes chemotherapy drugs are injected directly into the cerebrospinal fluid, either by lumbar puncture or through an Ommaya Reservoir into the lateral ventricle, to help prevent the spread of leukemia into the brain or spinal fluid.

It is possible that a tumour may form in the brain from the leukemia cells, or much more commonly, that the cells will grow in the cerebrospinal fluid that circulates in the ventricles and around the brain. This is called carcinomatous meningitis.

If a patient has previously received radiation therapy, he/she cannot receive it again without significant risk of harming healthy cells. In this case, it is possible that an Ommaya Reservoir will be put in place by a neurosurgeon. Through this reservoir, chemotherapy can be administered directly into the CSF around and in the brain (and thereby bypassing the blood brain barrier).

Occasionally, patients with leukemia or other solid tumours may develop peculiar lesions involving the brain. An example of this would be an infection with bacteria, fungus or virus. A neurosurgeon may be asked to biopsy such a lesion to help in its diagnosis and treatment.

For more information, you can contact the Leukemia and Lymphoma Society of Canada at 1-877-668-8326 or www.leukemia.ca

MEDULLOBLASTOMA

Summary:

Medulloblastomas make up twenty percent (20%) of all pediatric tumours, however this tumour occurs infrequently in adults, and represents 1% of primary adult brain tumours.

These tumours are fast growing and symptoms include a short, progressive history of headaches, vomiting, loss of appetite and coordination difficulties. Spread outside of the brain and spinal cord is rare although it may occur. Very often, these tumours have spread within the central nervous system before diagnosis. Spread through the CSF is possible (See Carcinomatous Meningitis under Metastatic / Secondary Brain Tumour in this chapter).

Treatment almost always involves surgery with the goal of removing all (gross total) or as much as possible (subtotal) of the tumour. Radiation is very effective against this tumour and is generally done to the entire head and spinal cord because of the high possibility of seeding malignant cells by way of the cerebrospinal fluid. An effective chemotherapy protocol has been developed and the outlook for this type of tumour has improved dramatically over the past ten years. Shunting may be necessary to treat hydrocephalus caused by the tumour interrupting the pathways of the cerebrospinal fluid.

Depending on the age of the patient, the amount of resection and the spread of the disease, a high and a low risk group of medulloblastoma patients have been identified. Treatment is now based on these parameters.

MENINGIOMA

Summary:

These tumours arise from the arachnoid cells in the meninges (the outer protective layer of tissue surrounding the brain) and are almost always slow growing and benign. They are usually firm, enclosed tumours, which can become large before symptoms appear. These tumours cause pressure on the brain and can invade neighbouring bone. Unless they are malignant (very rare) they do not invade the brain. The symptoms produced by meningiomas depend on size, location and growth rate of the tumour.

Symptoms are usually related to malfunction in the part of the brain that is being depressed. These tumours tend to have many blood vessels but can often be completely removed. Incomplete removal may be related to the closeness of important blood vessels. In certain situations, blood vessels feeding the tumour may be embolized (blocked). This may improve the ability of the neurosurgeon to remove the tumour.

METASTATIC / SECONDARY BRAIN TUMOUR

Summary:

The brain is frequently the site of metastasis (spread) from a tumour elsewhere in the body. In major referral centers, metastatic disease is the most frequent type of brain or spinal cord tumour seen. The most common sites of cancer that spreads to the brain are lung, breast, kidney and skin (melanoma). The spread of a tumour to the brain may produce symptoms before the primary tumour is diagnosed.

Most tumours that spread to the brain do so via the blood stream and lodge between the gray and white matter. This often causes edema or swelling and hence the most frequent symptom of brain involvement is headache related to the increased pressure.

Tumours that spread to the brain may be single (solitary metastasis) or multiple. A single metastasis may be removed with surgery. Radiation therapy is also used for single or multiple metastases. If a solitary metastasis recurs, or a new solitary metastasis develops, re-operation may be a consideration as well as an alternate form of radiation therapy. Standard radiation cannot be given twice. An alternative form of radiation therapy would be stereotactic radiosurgery.

Carcinomatous Meningitis (Also known as "spinal fluid metastasis")
Tumour cells can grow in the fluid around the brain (cerebrospinal fluid). This can give the picture of meningitis at first. Treatment involves radiation or direct placement of drugs in the cerebrospinal fluid. This may be accomplished through an Ommaya Reservoir. Although this condition is more common in metastatic tumours, it may occur in other tumours as well.
 

NEUROBLASTOMA

Summary:

This tumour originates from cells known as neural crest cells. These primitive nerve cells are present in the adrenal gland (which sits on top of the kidney) and the sympathetic nervous system, which is a chain of nerves that run along the front of the spinal column. A tumour can occur anywhere from the head and neck to the pelvis. The cause of neuroblastoma is unknown and the tumour is usually found in infancy and early childhood. Signs and symptoms vary depending on where the tumour causes pressure. Surgery and chemotherapy are the usual treatment. Radiation may be used. The prognosis for this tumour is improving

NEUROMA

Summary:

Neuromas can occur on any nerve along the spinal cord or cranial nerves. The most common neuroma is the acoustic neuroma. Neuromas are made up of increased numbers of covering cells of the nerves (Schwann Cells). Neurofibromas can also occur along nerves. In these tumours, the structural cells of the nerve rather than the Schwann cells predominate. Treatment is usually surgery.

NEUROFIBROMATOSIS

Summary:

Sometimes referred to as von Recklinghausen's Disease.

Type 1 - This is a genetically dominant disorder that is passed from one generation to the next. Neurofibromas are slow growing tumours located on or beneath the skin. They may also occur in deeper layers as well as in internal organs. Neurofibromas are composed of tissues from the nervous system (neuro) and fibrous tissue (fibroma), which form the support structure of the nerve. The skin, bones, endocrine glands and nervous system are sites of congenital abnormality.

Many types of brain tumours can be associated with neurofibromatosis. Most commonly, these are optic nerve tumours, gliomas in other areas, meningiomas and neurofibromas. These tumours are usually benign. Therapy may be indicated, when the tumour occurs within the central nervous system (brain and spinal cord).

Type 2 - This is different from Type 1 but is also a genetically dominant disorder. It is usually diagnosed by the presence of acoustic neuromas (Schwannomas) on the vestibulo-cochlear nerves on one or both sides of the brain. It usually presents as deafness. Other gliomas may be present. Surgery is often indicated. Occasionally, radiation and/or chemotherapy are used.
To learn more about Neurofibromatosis, you can contact one of the following organizations.

BC Neurofibratosis Foundation
1-800-385-2263
www.bcnf.bc.ca

L’Association de la Neurofibromatose du Quebec
(418) 598-3611
www.anfq.org

Neurofibromatosis Society of Ontario
1-866-843-6376
www.nfon.ca

Neurofibromatosis Foundation of Saskatchewan
(306) 384-3540
 

OLIGODENDROGLIOMA

See Giloma

PINEAL REGION TUMOUR

See Germ Cell Tumours

PITUITARY ADENOMA

Summary:

The pituitary gland is involved in the secretion of several essential hormones. The tumours of the pituitary gland can be divided into two groups. The first group shows signs of a space-occupying lesion where the other shows signs of abnormal activity of the gland.

Space-occupying Tumour (Non-Functioning Tumour)
Symptoms of these tumours result from pressure on neighboring structures. They may produce visual disturbances if they compress the visual pathways. Hormone secretion by the pituitary gland can be decreased by compression caused by the growing tumour. This can result in signs of hypopituitarism such as a lack of menstrual periods, reduction of body hair, increased sensitivity to the cold and decreased function of glands stimulated by the pituitary. Treatment is surgical removal and radiation is sometimes used, either alone or in conjunction with surgery.

Secreting Pituitary Tumour (Functioning Tumour)
These are pituitary tumours that contain hormone-secreting cells and often produce clinical symptoms before tests can actually show enlargement of the pituitary gland.

Prolactin Secreting Adenoma (Prolactinoma)
These tumours alter hormones resulting in lack of menstrual periods and infertility in women and impotence in men. Galactorrhea (milk coming from the breasts) in both males and females can occur.

Growth Hormone Secreting Adenoma
This tumour secretes excessive amounts of growth hormone. Giantism results in children and acromegaly results in adults. Common features of giantism include rapid growth, joint and muscle tenderness, exercise intolerance and fatigue. In an adult, changes can occur slowly over years. Other conditions that may occur include diabetes mellitus, kidney problems, increased metabolic rate and hypertension (high blood pressure).

ACTH (Adrenocorticotropic) Secreting Adenoma
These tumours produce ACTH, which stimulates the production of cortisol from the adrenal gland. This overproduction of cortisol impairs the body's response to injury and infection. It can deplete the body's potassium while retaining sodium and water. This tumour may result in a change in the body's fat distribution (Cushingoid appearance), cause fatigue, muscle weakness and elevate blood pressure. There may be increased growth of body hair and in females, menstrual periods may be irregular or absent.
A distinction needs to be made between Cushing's Disease which is secondary to a pituitary tumour which secretes ACTH and Cushing's Syndrome. Cushing's Syndrome is a generic term, which is given to a constellation (grouping) of clinical and chemical abnormalities resulting from a chronic excess of glucocorticoids (such as cortisol). Treatment for hormone secreting tumours may consist of surgery, radiation or drug therapy. Drug therapy consists of using a medication that decreases the compound released by a specific tumour (e.g. growth hormone, prolactin, ACTH). Hormone replacement may be required after surgery. For further information, see Neuroendocrine Function, Chapter 9.

PRIMITIVE NEUROECTODERMAL TUMOUR (PNET)

Summary:

The pathology of these tumours is identical to medulloblastomas but they occur primarily in the cerebrum (versus the cerebellum in the case of the medulloblastoma).

Other Primitive Neuroectodermal Tumours

• cerebral neuroblastoma (located in hemispheres)
• ependymoblastoma (arises from ventricles)
• pineoblastoma (occurs in area of pineal gland)

The cells of these tumours are generally not alike and they are fast growing. They are found throughout the brain and tend to seed (spread in the spinal fluid). They are treated with complete surgical removal if possible and are followed by radiation and chemotherapy. These tumours are rare.

PSEUDOTUMOUR CEREBRI (BENIGN INTRACRANIAL HYPERTENSION)

Summary:

This entity may initially be confused with a brain tumour and/or hydrocephalus. The reasons for this confusion are two-fold:

1. The patient may complain of headache, blurred or double vision, slight numbness of the face, or dizziness.
2. When the physician looks into the patient's eyes, he/she finds evidence of increased pressure or papilledema.

Together, these findings make one suspicious of a brain tumour or build up of CSF. However, when a CT scan is done, no tumour in the brain is found but the ventricles may be small.

The reasons for this problem are not entirely clear. It can occur in association with medications including tetracycline, corticosteroids and large doses of Vitamin A. A significant number of these cases develop thrombosis (blood clotting) in a major vein within the brain and require treatment with blood thinning drugs. This condition can occur spontaneously. It appears to be related to obesity in the female sex. The diagnosis is made when a lumbar puncture is performed and the pressure measured (it will be increased significantly). It is very important to treat promptly because the increased pressure can lead to permanent visual loss.

Treatment consists mainly of medication (Diamox®), which decreases CSF production and may be supplemented by lumbar punctures (explained in the glossary) to remove CSF until normal pressure is maintained. Lastly, it may be necessary to place a permanent shunt.

RHABDOMYOSARCOMA

Summary:

Rhabdomyosarcoma is a cancer of the connective tissues, specifically the skeletal muscle (the muscle attached to the bone). Cells that form these muscles can grow to become a malignant tumour. Since there is so much skeletal muscle in the body, this kind of tumour can arise almost anywhere including the head, neck and muscular areas around the eyes.

The extent and location of this disease will determine the required treatment. Radiation and chemotherapy are the usual treatment. Surgery may be an option.

SPINAL CORD TUMOUR

Summary:

Tumours that occur within the brain can also occur in the spinal cord, the most common ones being in the glioma family (astrocytomas, ependymomas).

Intrinsic
These occur in the substance of the spinal cord and may be invasive. Treatment is surgery and/or radiation.

Extrinsic
These occur outside the spinal cord and exert pressure on the cord as they grow. The symptoms of these tumours are related to pressure. These tumours can arise from:

• dura (meningiomas) or nerves (neurofibromas and Schwannomas) surrounding the spinal cord. These tumours indent the spinal cord like a marble.
• metastatic deposits from tumours elsewhere in the body. These tumours start in the bone surrounding the spinal cord and may compress the spinal cord from a number of sides.

Spinal cord tumours frequently present with pain. The pain is usually worse at night and may disturb sleep. At times, the pain may radiate around the chest wall and feel like a grip. Any patient who has had a tumour elsewhere in the body and develops frequent back pain should see his/her doctor.

Loss of sensation, muscle weakness and loss of bowel and bladder control should always be reported immediately.
Treatment is surgery and/or radiation. See Spinal Cord in Chapter 3.

SARCOMA

Summary:

Primary sarcomas in the brain are rare. They arise from the dura, the pia arachnoid and from the blood vessels of the subarachnoid space. Treatment is surgical removal. Radiation and chemotherapy are of limited benefit. These tumours are fast growing and treatment is difficult.

TUBEROUS SCLEROSIS

Summary:

This is a genetically dominant disorder, which usually starts with seizures. Tumours associated with it are usually giant cell astrocytomas in the region of the third ventricle, presenting with hydrocephalus. It can cause tumours in organs other than the brain. Treatment includes control of seizures and surgery for tumour removal and often seizure control as well.

To learn more about this disorder, contact the Tuberous Sclerosis Alliance at 1-800-225-6872 or www.tsalliance.org

YSEMBRYOPLASTIC NEUROEPITHELIAL TUMOUR (DNT)

Summary:

These tumours are usually located in the temporal lobe and are often associated with seizures that are difficult to control. It is a low-grade tumour and slow growing. This tumour resembles an oligodendroglioma but is different on a cellular level. This distinction is important, as aggressive therapy of DNT is usually not necessary. It is commonly located in the frontal or temporal lobes of the brain. Treatment consists of surgery if necessary and good seizure control.