Adult Patient Resource Handbook - 5th Edition
BRAIN TUMOUR TYPES: N - Z
NEUROBLASTOMA
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
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
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 Glioma
PINEAL REGION TUMOUR - See Germ Cell Tumour
PITUITARY ADENOMA
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)
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)
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.
SPINAL CORD TUMOUR
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:
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dura (meningiomas) or nerves (neurofibromas and Schwannomas) surrounding the spinal cord. These tumours indent the spinal cord like a marble.
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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.
TUBEROUS SCLEROSIS
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
RHABDOMYOSARCOMA
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.
SARCOMA
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.
Other Brain Related Diagnoses:
HYDROCEPHALUS
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.
LEUKEMIA
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
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À 2003 Brain Tumour Foundation of Canada 1.800.265.5106
Charitable Registration #BN118816339RR0001 |