A wide variety of primary brain tumours may affect adults. As per the latest World Health Organisation classification, common primary brain tumours include gliomas, meningiomas, lymphomas, embryonal tumours, sellar tumours and others. These are distinct from brain metastases, which represent the spread of primary cancers from other parts of the body to the brain via the bloodstream. At one end of the spectrum are benign, slow-growing tumours which may often go undetected during the lifetime, e.g. meningiomas, pituitary adenomas, while at the other end are the rapidly progressing, malignant brain tumours like glioblastoma, anaplastic astrocytoma, medulloblastoma, etc. which require prompt diagnosis and treatment. In India, the incidence of brain tumours ranges from 5 to 10 per 100,000 population and accounts for approximately 2% of all malignancies.
Brain Tumours: Causes and Risk factors
Like other cancers, brain tumours are also caused by uncontrolled growth and multiplication of cells. The possible factors which may bring about this DNA mutation include ionizing radiation (as from radiation therapy, CT scans or X-Rays), familial predisposition, a prior history of cancers like leukaemia, and also advanced age. A few reports have associated prolonged mobile phone usage with some low-grade brain tumours.
Brain Tumours: Symptoms
They may arise at different locations in the brain, and lead to symptoms corresponding to their site of origin. However, common symptoms of most brain tumours may include headache, projectile vomiting (sudden onset vomiting without preceding symptoms of retching or nausea), weakness in one or more limbs, seizures, tremors, behavioural changes, loss of bladder or bowel control, and visual or memory disturbances.
Brain Tumours: Investigations
- The tests required to evaluate a case of a suspected brain tumour include a contrast-enhanced MRI or a CT scan of the brain. Depending on the location and type of brain tumour, an MRI of the spine and examination of the cerebrospinal fluid (the fluid that is formed and circulates in and around the brain and spinal cord to provide nutrients and to cushion effect). Gliomas may additionally require particular types of MRIs.
- Spectroscopy or MR Perfusion, while lymphomas require PET-CT scan to rule out similar disease process outside the brain. The definitive diagnosis is obtained only after the Neurosurgeon has removed the tumour or taken out a piece of it (biopsy), which can be studied under the microscope by a pathologist to confirm the type and the grade of the tumour, which then helps determine the need for further treatment.
Brain Tumours: Preventive measures and general aspects
There are no guaranteed ways to prevent brain tumours, and the focus is on early detection. A person who is having a persistent headache over few days that is not otherwise related to stress, fluctuations in blood pressure, or refractory errors or other similar underlying conditions, and if also associated with other symptoms mentioned above should be evaluated for a brain tumour. The correct treatment, instituted at the right time, goes a long way in coming out healthy from a brain tumour.
(With inputs fro Dr Kushal Narang, Consultant, Radiation Oncology, Cancer Institute, Medanta - The Medicity).
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