Abnormal growth in cells leads to the formation of a lump or mass of cells called a tumor. The brain is enclosed within a rigid structure called a skull and any extra or abnormal mass can cause problems.
There are two types of growth – malignant (cancerous) or benign (non-cancerous). The growth of these tumors put extra pressure inside the skull, and cause its enlargement. This can lead to brain damage and can even cause death.
Brain tumors are divided into two categories – primary and secondary.
Primary Brain Tumors
A primary brain tumor has its origin in the brain itself. These tumors can be benign or malignant. In adults, meningiomas and gliomas are seen as the most common types of tumors.
These tumors can develop from your brain:
- The membranes that envelop your brain, known as meninges
- Brain cells
- Nerve cells
These are tumors that having their origin from glial cells. The function of these cells is to
- Supply nutrients to the central nervous system.
- Clear the dead and non-functional neurons
- Clear the cellular waste
- Support the composition of the central nervous system
The types of tumors that originate in glial cells are:
- Oligodendroglial tumors (frontal-temporal lobes)
- Astrocytic tumors (in cerebrum)
Some other primary brain tumors are:
- Ependymomas – These are generally benign
- Pituitary tumors – Mostly benign
- Primary germ cells tumors – Both benign and malignant
- Schwannomas – originate from the schwannomas cells present in the myelin sheath
- Lymphomas of the primary central nervous system (malignant)
- Craniopharyngiomas – These are found in children and are mostly benign in nature. Premature puberty and changes in the vision occur as symptoms.
Schwannomas and Meningiomas appear between the ages of 40-70. Women are more prone to meningiomas than men. Schwannomas can appear in both men and women and are usually benign in nature.
However, despite being benign, these have the capability of causing some major complications due to its location and size. Malignant meningiomas and schwannomas are found rarely, but if present can be very destructive.
Secondary brain tumors
Most of the brain tumors are secondary forms of tumors. They originate in one part of the body and move, or metastasize, reaching the brain. Lung cancer, skin cancer, breast cancer, and kidney cancer can metastasize to the brain.
Secondary brain tumors are malignant because benign tumors don’t spread to other organs.
Factors that can cause brain tumor
- Age – The risk of getting brain cancer increases with age
- Family history – Brain cancer is usually not genetically inherited. Only 5-10% of cancers are due to genetics.
- Racial type – Caucasians are more prone to brain tumors. Meningiomas are found to be common in African-American people.
- Exposure to chemicals – Some chemicals are responsible for causing tumors. Exposure to these cancer-causing chemicals increases the risk of brain cancer.
- Radiation – A person having exposure to radiation is more likely to have a brain tumor. Even the high-radiation cancer therapies can put the professional performing it on the risk of getting a tumor. If you are living in the vicinity of a nuclear power plant, even a small leakage can put you at great risk. Chernobyl and Fukushima nuclear accidents are the best example of people getting exposed to radiation and developing cancers.
- Chickenpox – American Brain Tumor Association claims that a person having a history of chickenpox in their childhood tend to have a lesser risk of getting brain tumors.
Symptoms of brain tumor
The appearance of symptoms depends on the size and the location of the tumor. Some tumors directly destroy the brain tissue, and some indirectly put pressure on the surrounding area of the brain. In both cases, symptoms can be quite prominent, which includes:
- Headaches while sleeping, in the morning after waking, and during exercise, or sneezing and coughing.
- Change in vision
- Seizures (usually in adults)
- Weakness in part of a face or limb
- Disrupted mental functioning
Some other symptoms can include memory loss, clumsiness, difficulty in writing and reading, unequal pupils, drooping eyelids, changes in perception of senses, clumsiness, reduced alertness that may include loss of consciousness, uncontrolled movement, dizziness or vertigo, difficulty in walking, weakness in arms, legs, and face, tremors, difficulty in swallowing, loss of bladder, loss of bowel control, etc.
Symptoms of pituitary tumors
- Enlargement of feet and hands
- Gynecomastia (development of breast tissue) in men
- Galactorrhea (Discharge from nipples)
- Sensitivity to cold or heat
- Hirsutism (increased body hair)
- Low blood pressure
- Changes in vision
Diagnosis of brain tumors
Physical examination and medical history of the patient is the first step towards diagnosis. The doctor can prescribe a detailed neurological check-up during physical examination.
He may also conduct some tests to see the positioning of cranial nerves that originate from your brain.
An eye check-up is also conducted with the help of an ophthalmoscope (an instrument that puts light on your retinas), allowing the doctor to check the reaction of pupils to a light source.
It also allows the physician to check if optic nerves have any kind of swelling. Swelling can occur when a tumor puts pressure on the skull.
Doctors may also assess:
- Mental ability to do calculations
- Strength of muscles.
Other tests for diagnosis
CT scan – CT scans help the doctor to get a detailed examination of your body. These are more detailed than X-ray scans and can be developed with or without contrast. A special dye is used to create contrast, which helps doctors to identify internal structures clearly.
MRI – This also uses a special dye that helps doctors in detecting tumors. Unlike a CT scan, there is no radiation involved, and it generally gives even better and detailed images of the structures in your brain.
Angiography – A dye is injected into the artery, generally in the groin region, which reaches the arteries of the brain. It enables the doctors to see the blood supply in the brain. This information is then used at the time of surgery.
Biopsy – A small part of the tumor is extracted during a biopsy. A specialist also called neuropathologist, who takes it in a lab for further study. The biopsy helps in identifying whether the tumor cells are malignant or benign. It also helps in determining the origin of cancer, which could be the brain or other parts of the body.
X-ray – The pressure put by tumors on the skull can cause breaks or fractures in the bones, which can be identified with the help of a specific type of X-rays. X-rays can also show if some calcium deposits are present in a tumor. These deposits can be present in your blood vessels if the tumor has spread to the bones.
The treatment of the brain tumor can vary depending on the type, size, location, and your general well being.
Surgery – It is the most common treatment, especially in the case of malignant brain tumors. During surgery, the tumor is removed without causing damage to the rest of the healthy area of the brain.
While some tumors are easily located and can be removed easily, some are situated in difficult areas where it is extremely difficult for doctors to reach through surgical procedures. Even the partial extraction of the brain tumor can be extremely helpful for the patient.
Risks of surgery:
Some benign tumors are also removed through surgery. Malignant tumors or metastatic tumors are treated, keeping in mind the type of original tumor.
Radiation therapy and chemotherapy are some other ways that can be combined with surgery.
Apart from these methods, physical therapy, speech therapy, and occupational therapy are also provided to patients to help them recover in a better way after surgery.