Which among the following is the commonest type of intracranial tumour?
Secondary metastatic deposits are more common than primary brain tumors in adults and the opposite is true in children. Brain metastases are three times more common than all primary brain tumors combined. Must know: Brain metastases arise from hematogenous spread and frequently arise from either a lung primary or are associated with pulmonary metastases. Most metastases develop at the gray matter-white matter junction in the watershed distribution of the brain where intravascular tumor cells lodge in terminal aerioles. The distribution of metastases in the brain approximates the propoion of blood flow such that about 85% of all metastases are supratentorial and 15% occur in the posterior fossa. The most common sources of brain metastases are lung and breast carcinomas; melanoma has the greatest propensity to metastasize to the brain, being found in 80% of patients at autopsy. Ovarian and esophageal carcinoma rarely metastasize to the brain. Prostate and breast cancer also have a propensity to metastasize to the dura and can mimic meningioma. Leptomeningeal metastases are common from hematologic malignancies and also breast and lung cancers. Spinal cord compression primarily arises in patients with prostate and breast cancer, tumors with a strong propensity to metastasize to the axial skeleton. Ref: DeAngelis L.M., Wen P.Y. (2012). Chapter 379. Primary and Metastatic Tumors of the Nervous System. In D.L. Longo, A.S. Fauci, D.L. Kasper, S.L. Hauser, J.L. Jameson, J. Loscalzo (Eds), Harrison's Principles of Internal Medicine, 18e.
Astrocytoma
Medulloblastoma
Meningioma
Secondaries