Hemangioblastoma 2010-06-25T09:18:32Z SNOMEDCT_US:81201000 A hemangioblastoma is a benign vascular neoplasm that arises almost exclusively in the central nervous system. Hemangioblastomas consist of a tightly packed cluster of small blood vessels forming a mass of up to 1 or 2 cm in diameter. Haemangioblastoma UMLS:C0206734 NCIT:C3801 HP:0010797 Benign neoplasm of the central nervous system