A hemangioma is an abnormal buildup of blood vessels in the skin or internal organs. Two types of hemangiomas are discussed here:
- Hemangioblastoma: These tumors are benign, slow-growing, and well defined. They arise from cells in the linings of blood vessels. Hemangioblastomas tend to have well defined borders. They do not typically invade surrounding healthy tissue. Single or multiple tumors may be present.
- Hemangiopericytoma: These are rare, grade II or III tumors. They appear to originate in the cells surrounding the blood vessels in the meninges. They do not invade the brain, but can recur locally or even spread elsewhere in the body (bone, lung, and liver). This spread generally does not take place until late in the disease.