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$Unique_ID{BRK03500}
$Pretitle{}
$Title{Astrocytoma, Benign}
$Subject{Astrocytoma Benign Astrocytoma Grade I Astrocytoma Grade II Brain
Tumor Intracranial Tumor Intracranial Neoplasm Astrocytoma Malignant Motor
Neuron Disease Multiple Sclerosis Brain Tumors}
$Volume{}
$Log{}

Copyright (C) 1990 National Organization for Rare Disorders, Inc.

775:
Astrocytoma, Benign

** IMPORTANT **
It is possible that the main title of the article (Benign Astrocytoma) is
not the name you expected.  Please check the SYNONYM listing to find the
alternate names and disorder subdivisions covered by this article.

Synonyms

     Astrocytoma Grade I
     Astrocytoma Grade II
     Brain Tumor
     Intracranial Tumor
     Intracranial Neoplasm

Information on the following diseases can be found in the Related
Disorders Section of this report:

     Astrocytoma, Malignant
     Motor Neuron Disease
     Multiple Sclerosis
     Brain Tumors

General Discussion

** REMINDER **
The information contained in the Rare Disease Database is provided for
educational purposes only.  It should not be used for diagnostic or treatment
purposes.  If you wish to obtain more information about this disorder, please
contact your personal physician and/or the agencies listed in the "Resources"
section of this report.

Benign astrocytomas are abnormal growths or tumors which occur in the
brain.  They are composed of star-shaped neurological cells called
astrocytes.  Astrocytomas may be benign (noncancerous) or malignant
(cancerous), and either type can be disabling.  The bones of the skull
prevent the brain from expanding outward as the tumor grows and takes up
space.  Consequently, healthy brain tissue is compressed, causing symptoms
controlled by the area of the brain that is compressed.  Because of the
pressure either type of astrocytoma (benign or malignant) exerts upon the
brain and the resulting symptoms, the distinction between benign
(noncancerous) and malignant (cancerous) tumors of the brain is less critical
than for tumors occurring anywhere else in the body.

Benign astrocytomas are usually more slow growing than the malignant
forms.  Astrocytomas can occur anywhere in the brain or spinal cord, with the
subcortical (beneath the brain covering) white matter (fibrous tissue) of the
brain hemispheres being the most common location in adults.  The optic nerve,
cerebellum and brainstem are the most common locations of benign astrocytomas
in children.

Symptoms

As a benign astrocytoma expands in size, it compresses brain tissue.  The
growth of the astrocytoma increases pressure in the skull, since both the
tumor and the fluid of the brain crowd the surrounding brain tissue.  The
growth of cysts within the astrocytoma can further increase the size of the
tumor.

Symptoms of a benign astrocytoma depend on the size, location and rate of
growth of the tumor.  Onset of symptoms may be sudden, appearing initially in
the form of a seizure or cerebral hemorrhage, or the onset may be very
gradual and subtle, characterized by slow but progressive mental
deterioration.  Tumors of the frontal and temporal lobes may grow very large
before producing any specific symptoms.

Headache is the initial symptom in 50 percent of individuals with benign
astrocytoma.  The headache usually results from pressure on blood vessels,
cranial nerves or pain sensitive tissue.  These recurrent headaches often
awaken the individual during the night and become much worse in the morning.
Seizures are the initial symptom in 20 percent of patients with brain tumors
and are more frequently the result of slow growing astrocytomas.

Symptoms of a benign astrocytoma may involve mental changes that may not
be obvious until the patient's behavior changes substantially.  These
symptoms may include impersistence in routine tasks, increased irritability,
emotional instability, faulty insight, forgetfulness, reduced mental
activity, indifference to social practices and loss of initiative or
spontaneity.  The patient may complain of fatigue, dizziness and lethargy.
If the tumor continues to grow, the symptoms may progress to confusion,
deteriorated intellectual functioning (dementia) and eventually stupor.
These personality changes are often initially confused with symptoms of
anxiety or depression.

Nausea and vomiting may result from increased pressure on the center in
the brain that controls the vomiting reflex (emetic center).  Vomiting may
occur suddenly and without preceding nausea.  Other symptoms may include
slowed heartbeat, an inability to control bodily discharge (incontinence), a
loss in the ability to recognize the shapes of objects by handling them
(astereognosis), paralysis, an inability to coordinate voluntary muscular
movements (ataxia), an inability to use or comprehend words (aphasia), rapid
involuntary movement of the eyeballs (nystagmus), facial pain or numbness and
hearing loss.

Causes

The exact cause of astrocytomas and other brain tumors is not known.
Scientists have suggested that genetic factors, infection, trauma, or
suppression of the immune system may contribute to the formation of brain
tumors.

Affected Population

Benign astrocytomas may occur in anyone at any age, but white males between
the ages of 40 and 70 are most commonly affected.

Related Disorders

Symptoms of the following disorders can be similar to those of benign
astrocytomas.  Comparisons may be useful for a differential diagnosis:

Malignant Astrocytomas (or Grade III Astrocytomas) are the most common
primary tumors, representing approximately three-fourths of nerve tissue
tumors diagnosed yearly in adults in the United States.  These rapidly
growing tumors most commonly occur in the thick layer of nerve fibers (corpus
collasum) that connects the two hemispheres of the brain.  Grade III
Astrocytomas also occur in the frontal, parietal (top) and temporal (side)
lobes of the brain and in the thalamus.  (For more information on this
disorder, choose "Malignant Astrocytoma" as your search term in the Rare
Disease Database.)

Motor Neuron Disease is a group of neuromuscular disorders characterized
by the progressive degeneration of motor neurons, the nerve cells which
control movement and reflex.  Symptoms of Motor Neuron Diseases may include
muscle weakness, spasms and exaggerated reflexes.  (For more information on
this disorder, choose "Motor Neuron Disease" as your search term in the Rare
Disease Database.)

Multiple Sclerosis (MS) is a chronic disease of the brain and spinal
cord.  MS is characterized by small lesions called plaques that may form
randomly throughout the brain and spinal cord.  These lesions consist of
areas of dissolved myelin, the fatty material that forms a sheath around
nerve cells (neurons) and conducts nerve impulses.  Large, star-shaped nerve
cells (astrocytes) overgrow and harden in the lesions, forming scars in the
brain and spinal cord called scleroses.  Destruction of the myelin sheath
creates a variety of neurological symptoms which may include visual
difficulties, impairment of speech, abnormal skin sensations or numbness,
walking disturbances and difficulties with bladder and bowel function.  (For
more information on this disorder, choose "Multiple Sclerosis" as your search
term in the Rare Disease Database.)

There are many different types of brain tumors, both benign and
malignant.  Symptoms of each type of brain tumor are related to the place the
tumor occurs in the brain and the pressure it exerts on the surrounding
tissue.  (For more information, type "Brain Tumor" as your search term in the
Rare Disease Database.)

Therapies:  Standard

Benign astrocytomas, which may evolve over several years, are detected by CT
(computed tomography) scan or by MRI (magnetic resonance imaging).  Brain
tumors are biopsied even if total removal is not possible.  Results of the
biopsy will dictate preferred treatment.

The major types of therapies used to treat benign astrocytomas after
surgery are radiation and chemotherapy.  The therapy chosen depends on the
type of tumor that is present, its location, and its sensitivity to radiation
therapy.

Pre-operative treatment is usually aimed at controlling the accumulation
of fluid in the brain and the occurrence of seizures.  Corticosteroid drugs
such as dexamethasone are usually initially prescribed.  In cases where
steroids do not relieve the accumulation of fluid, a surgically implanted
drain (shunt) may be required.  Anticonvulsant drugs may be prescribed for
individuals who have seizures.

Total surgical removal of accessible benign astrocytomas of the
cerebellum, lobes and optic nerve is often possible and successful.
Accessible tumors are those which can be operated on without causing
unacceptably severe damage to other parts of the brain.  If surgery is
performed, the surgeon will attempt to remove all identifiable parts of the
astrocytoma when possible, often using an operating microscope to distinguish
tumor margins.  In some cases, a laser and/or ultrasonic aspirator is used as
well.  Laser microsurgery has the advantage of being able to remove, by
vaporization, some tissue beyond the tumor's border with the objective of
removing microscopic tumor infiltrates with a minimal amount of damage to
normal tissue.  When the astrocytoma involves a crucial part of the brain,
partial removal of the growth usually reduces pressure, relieves symptoms and
helps control seizures.

Full or partial removal of the astrocytoma is sometimes followed by
radiation therapy to destroy any remaining tumor cells.  With the use of CT
(computed tomography) and MRI (magnetic resonance imaging), radiation
sometimes may be deferred for several months or years while the patient is
scanned at regular intervals.  Radiation as primary therapy is occasionally
used on low grade (benign) astrocytomas.  When radiation is used, it is
administered to the tumor and the entire brain, since the astrocytoma can
infiltrate surrounding tissue easily.

After radiation has reduced the number of tumor cells, chemotherapy is
often administered in an attempt to destroy any cells that remain.
Chemotherapy may also be given during the course of radiation treatment.  The
drugs used in chemotherapy are cytotoxins which are capable of destroying
cells.  Cytotoxins are not completely tumor-cell specific, so they may also
cause damage to normal tissue.  The type of chemotherapeutic drug selected is
determined by a neuro-oncologist who examines the grade of tumor, previous
treatment and current health status of the individual with the astrocytoma.

Therapies:  Investigational

One of the new experimental techniques for the treatment of astrocytomas is
brachytherapy, also called "interstitial radiation" or "seeding."  Via a
surgical procedure, radioactive pellets of iodine, iridium or gold isotope
are implanted directly into the brain.  Brachytherapy is used primarily when
a tumor recurs if it is confined to one side of the brain and measures less
than 2 1/2 inches (about the size of an egg).

Other investigational therapies include use of 1) cell radiosensitizers
to increase the effectiveness of radiation; 2) different types of radiation
such as neutron, heat (hyperthermia) and light (photoradiation); 3)
intraoperative radiation; and 4) hyperfractionation.  These are ongoing
research projects which are being clinically tested against astrocytoma
cells.

Immunotherapy aims to stimulate the body's defenses against the tumor.
Using drugs such as interferon, levamisole, interleukin-2 and thymosine, and
BCG, it is hoped that the body's own immune system can be stimulated to fight
the tumor.  More research is needed to determine whether these therapies will
be successful.

A multitude of new drugs and drug combinations are being tested for
effectiveness against astrocytomas.  Other research seeks to develop better,
methods of drug delivery, such as direct intra-arterial administration and
blood brain barrier disruption to increase the amount of anticancer drug
reaching brain tissue.

A new orphan drug and delivery system is being tested for the treatment
of astrocytoma.  During brain surgery, a biodegradable wafer containing a
cancer fighting drug (BCNU) is implanted at the site of the tumor.  As the
wafer dissolves over a period of many weeks, the drug is slowly released.
Those interested in this experimental trial should have their physicians
contact, Nova Pharmaceutical Corp., 6200 Freeport Centre, Baltimore, MD 21224
or phone [phone].

This disease entry is based upon medical information available through
April 1990.  Since NORD's resources are limited, it is not possible to keep
every entry in the Rare Disease Database completely current and accurate.
Please check with the agencies listed in the Resources section for the most
current information about this disorder.

Resources

For more information on Benign Astrocytoma, please contact:

     National Organization for Rare Disorders (NORD)
     P.O.  Box 8923
     New Fairfield, CT 06812-1783
     [phone]

     NIH/National Institute of Neurological Disorders & Stroke (NINDS)
     9000 Rockville Pike
     Bethesda, MD  20892
     [phone]
     [phone]

     Association for Brain Tumor Research
     3725 North Talman
     Chicago, IL 60618
     [phone]

References

CECIL TEXTBOOK OF MEDICINE, 18th ed.:  James B. Wyngaarden, M.D. et al., eds;
W.B. Saunders Company, 1988.  Pp. 2229-2235.

INTERNAL MEDICINE, 2nd Ed.:  Jay H. Stein, ed.-in-chief;  Little, Brown
and Co., 1987.  Pp. 2220-2222.

THE MERCK MANUAL, Volume 1, 14th Ed.:  Robert Berkow, M.D., ed.-in-chief;
Merck Sharp & Dohme Laboratories, 1982.  Pp. 1406-1410.

PROGNOSIS OF BENIGN CEREBELLAR ASTROCYTOMAS IN CHILDREN.  J. Szenasy et
al.; CHILDS NERV SYST (1983:  issue 10 (1)).  Pp. 39-47.

LOW-GRADE ASTROCYTOMAS:  TREATMENT WITH UNCONVENTIONALLY FRACTIONATED
EXTERNAL, BEAM STEREOTACTIC RADIATION THERAPY.  F. Pozza et al.; RADIOLOGY
(May, 1989:  issue 171 (2)).  Pp. 565-569.

BENIGN ASTROCYTIC AND OLIGODENDROCYTIC TUMORS OF THE CEREBRAL HEMISPHERES
IN CHILDREN.  J. F. Hirsch et al.; J NEUROSURG (April, 1989:  issue 70 (4)).
Pp. 568-572.

LOW-GRADE ASTROCYTOMAS:  TREATMENT RESULTS AND PROGNOSTIC VARIABLES.  C.
A. Medbery 3rd et al.; INT J RADIAT ONCOL BIOL PHYS (October, 1988:  issue 15
(4)).  Pp. 837-841.

LONG-TERM FOLLOW-UP AFTER SURGICAL TREATMENT OF CEREBELLAR ASTROCYTOMAS
IN 100 CHILDREN.  S. Undjian et al.; CHILDS NERV SYST (April, 1989:  issue 5
(2)).  Pp. 99-101.