What are benign brain tumors?
Brain tumors arise due to abnormal growth of the cells of the brain. Some are cancerous (malignant) while others are not (benign). In terms of benign tumors of the brain, these growths are usually slow growing, with a clear cut margin and do not spread to the surrounding tissue. Malignant brain tumors (cancer) are fast growing and rapidly spread to other parts of the brain or other organs. Brain cancer is often seen as more dangerous due to its life threatening potential. However, in the brain, even benign tumors are dangerous depending on the location of the brain where it occurs. Usually brain tumors do not recur after surgery and benign tumors rarely become cancerous (malignant).
Benign Brain Tumor Symptoms
Symptoms of benign and malignant brain tumors do not differ much. Symptoms occur due to increased pressure (pressure symptoms) on the surrounding structures (brain tissue, blood vessels, nerve) and irritation of the brain tissue. In addition, malignant tumors (cancer) destroy healthy brain tissue.
Symptoms due to compression of the surrounding structure :
- Headache with the following characteristics :
- occurring during sleep.
- immediately after waking up.
- associated with vomiting, change of position, cough.
- loss of memory, confusion, drowsiness
- change of personality.
- weakness of limbs and facial muscles.
- problems with speech.
- eye symptoms (like redness) and visual disturbances (like double vision).
- abnormal walking pattern.
- loss of coordination.
- hearing loss.
- abnormal smell.
Symptoms due to irritation of brain tissue :
- Convulsion (epileptic fits / seizures).
- Abnormal involuntary movement of the limbs.
- Muscle twitching.
Symptoms specific to the nature of the tumor :
- Acoustic neuroma (tumor arising from nerve traveling from ear to brain) causes sudden hearing loss along with tinnitus (ringing sound) in the affected ear and imbalance.
- Pituitary adenoma due to susceptibility to cold, fall in blood pressure, constipation, excess body hair, secretion of milk (galactorrhea), obesity or weight loss.
Types of Benign Brain Tumors
Most of the benign brain tumors arise from the brain tissue or surrounding structures like the glands within the intracranial cavity. Different benign tumors originate from different structures of the brain and can be classified accordingly.
Accounts for about 20% of all the brain tumors. It arises from the meninges, the coverings of the brain and the spinal cord.
Makes up about 9% of all the brain tumors. It arises from the 8th cranial nerve and spreads along the nerve from the inner ear to the brain.
These tumors constitute about 8% of all the brain tumors and arises from the pituitary gland (major gland controlling different hormone secretion).
Accounts for only about 1% to 3% of all the brain tumors.
Choroid plexus papilloma
Makes up less than 1% of all the brain tumors.
Dermoid and epidermoid cysts
These growths arise from the lining of the organs or body cavities and are also sometimes considered as benign brain tumors as they also cause similar symptoms like other benign brain tumors.
Causes and Risks
- Radiation exposure by handing radioactive material or being in close proximity to it. Although not as yet proven cell phone and microwave radiation is believed to be responsible for initiating tumor growth.
- Associated genetic disorder: neurofibromatosis 2 (associated with development of acoustic neuroma, meningioma), multiple endocrine neoplasia (MEN I, associated with pituitary adenoma).
- Female sex hormones may have some role in meningioma.
The approach to treatment depends upon the size, location, symptoms and malignant (cancer) potential. For most benign tumors, regular monitoring without any intervention is recommended provided that :
- the tumor is small.
- there are no symptoms.
Surgery, radiation (stereotactic radiation and external beam radiation), drug therapy (for prolactin secreting pituitary adenoma) are recommended as active intervention.