A brain tumor is a collection of unusual, abnormal cells that have grown out of control in your brain. Some brain tumor cells are benign, which means they aren’t cancerous. Others are malignant, which means they are cancerous. The term “Primary Tumor” refers to a brain tumor that starts in the brain. They’re categorized as secondary if they started elsewhere in your body and spread to your brain. Types of Brain Tumors Primary brain cancers arise from the brain and central nervous sys...