A brain tumour or intracranial neoplasm, is an abnormal mass of tissue with cells growing and multiplying uncontrollably, seemingly unchecked by the mechanisms that control normal cells. There are more than 125 types of brain tumors officially recognized by the world health organization. Brain tumors can be either primary or metastatic.
Primary brain tumors are those arising from the tissues of the brain or it’s immediate sorroundings like meninges etc. They can be benign or malignant i.e., cancerous.
Primary brain tumors occur in around 250000 people a year globally, making up <2% of all cancer. Median age at diagnosis is around 55yrs and has a bimodal distribution with the incidence peaking in the 1st and 6th decade of life. In children, brain tumors are second only to Leukemias as a cause of cancer. Most common types of tumors in children are medulloblastomas, low astrocytomas, craniopharyngiomas and brainstem gliomas. In adults, the most common types include meningiomas and astrocytomas such as glioblastom
Metastatic brain tumors are those which originate elsewhere in the body (most commonly lung cancer, breast cancer etc) and migrate to brain, usually through the bloodstream. These are malignant tumours.