Brain tumor is a mass or growth of abnormal cells in the brain. More than 150 types of brain tumors have been described. There is no specific cause for these tumors but some cases may be hereditary. Two major types of tumors are primary and secondary (metastatic) brain tumors. Primary tumors may be benign or malignant. Benign brain tumors include tumors that originate from the tissues of the brain or the brain’s immediate surroundings and do not spread to other organs or tissues. Metastatic brain tumors include tumors that arise elsewhere in the body (such as the breast or lungs) and migrate to the brain, usually through the bloodstream. Metastatic tumors are considered cancer and these are highly malignant. Examples of benign tumors are meningioma, pituitary adenoma, ganglioglioma, and schwannoma, etc. Examples of malignant tumors are glioblastoma multiforme (GBM), anaplastic astrocytoma, metastasis, and medulloblastomas, etc.
WHO Grading of Tumors
WHO has defined four grades of brain tumors from Grade I to IV. Grade I is the most benign tumors and Grade IV are the most malignant tumors. Grade I and II are categorized as low-grade tumors. Grade III and IV are categorized as high-grade tumors.
Symptoms of Brain Tumors
Most of the patients, later diagnosed with brain tumors, present with symptoms like headache, seizures, vision loss, weakness of one side of the body, speech difficulties and hearing loss, etc.
Diagnosis
Diagnosis is usually made by CT or MRI scan. These scans may help in reaching up to the diagnosis, but some lesions may mimic brain tumors in MRI. Therefore, sometimes the only way to make a definitive diagnosis of a brain tumor is through a biopsy. The neurosurgeon performs the biopsy and the pathologist makes the final diagnosis, determining whether the tumor appears benign or malignant.
Treatment
Brain tumors (whether primary or metastatic, benign, or malignant) usually are treated with surgery, radiation, and/or chemotherapy; alone or in various combinations.
Surgery
It is generally accepted that complete or nearly complete surgical removal of a brain tumor is beneficial for a patient. The neurosurgeon’s challenge is to remove as much tumor as possible, without injuring brain tissue, which is important for the patient’s neurological functioning (such as the ability to speak, walk, etc.). Traditionally, neurosurgeons open the skull through a craniotomy to ensure they can access the tumor and remove as much of it as possible.
Another procedure that is commonly performed sometimes before a craniotomy, is called a stereotactic biopsy. This smaller operation allows doctors to obtain tissue in order to make an accurate diagnosis
Radiation
Radiation therapy uses high-energy X-rays to kill cancer cells and abnormal brain cells and to shrink tumors. Radiation therapy is often combined with surgery for malignant tumors or as stand-alone therapy when surgery cannot be done.
Chemotherapy
Chemotherapy generally is considered to be effective for specific pediatric tumors, lymphomas, and other malignant tumors such as GBM.
It is a common myth about brain tumors that tumor means cancer only but the majority of the brain tumors are benign and if managed timely then one can live a normal life.