What are primary and metastatic tumors?
Primary tumors of the CNS are growths that begin in the brain or spinal cord. They can be either malignant or benign and are identified by the types of cells they contain, their location, or both. Most primary CNS tumors occur in adults. Metastatic, or secondary, tumors in the CNS are caused by cancer cells that break away from the primary tumor that developed in a non-CNS part of the body. These tumors are named after the type of cancer that causes them. Metastastic tumors (also called metastases) to the brain occur in about one-fourth of all cancers that develop in other parts of the body, such as cancer of the lung, breast, or kidneys; or melanoma, a form of skin cancer. They are more common than primary tumors and occur more often in adults than in children. Metastatic spine tumors usually form within the bony covering of the spinal column but may also invade the spinal canal from the chest or abdomen.
