Definition of Brain tumor

Brain tumor: A benign or malignant growth in the brain. Primary brain tumors initially form in brain tissue. Secondary brain tumors are cancers that have spread (metastasized) to the brain tissue from tissue elsewhere in the body. Brain tumors can occur in people of any age.

Source: MedTerms™ Medical Dictionary
http://www.medterms.com/script/main/art.asp?articlekey=2519
Last Editorial Review: 3/19/2012