hemangioblastoma /hēman′jē·ōblastō″mə/ pl. hemangioblastomas, hemangioblastomata [Gk, haima + angeion, vessel, blastos, germ, oma, tumor] , a brain tumor composed of a proliferation of capillaries and of disorganized clusters of capillary cells or angioblasts, usually occurring in the cerebellum.
