What is a Tumor?
A tumor is a mass of abnormal cells. There are many different types of brain and spine tumors, and they can be categorized as either benign (noncancerous) or malignant (cancerous). Tumors can be divided into two broad categories: primary and secondary (metastatic).
Primary tumors originate in the brain or spine itself or in tissues near it. They form when mutations occur in the DNA of normal cells, causing the cells to multiply abnormally and survive in conditions that normal cells would not.
Secondary tumors (metastatic) spread to the brain or spine from other cancerous sites in the body. They occur most often in people with a known history of cancer; however a metastatic tumor may be the first sign on cancer that began somewhere else in the body.