What Are Tumors of the Brain?
Brain tumors are a mass of abnormal cells in your brain. The tumor may be primary (starting in the brain) or cancer may have spread to the brain (metastatic). All brain tumors are either benign (slow-growing, not cancerous) or malignant (growing quickly, cancerous). Brain tumors can cause serious damage, even if they are benign. The degree of damage depends upon the type, size and location of the tumor.