Hemangioblastoma

Hemangioblastoma, also called angioblastoma, is a benign, highly vascular tumor that can occur in the brain and spine. Hemangioblastomas are low-grade central nervous system tumors. It accounts for approximately 2% of intracranial tumors, arising most frequently in the cerebellar hemispheres and vermis.

Histologically, the tumors are composed of multiple capillary and sinusoidal channels lined with endothelial cells and clusters of lipid-laden pseudoxanthoma cells. About 95% of hemangioblastomas are found in the posterior fossa with over three quarters of these tumors occurring as hemispheric tumors. One quarter of hemangioblastomas occurring in the posterior involve the cerebellar vermis and the brain stem with the vermis more commonly involved. Only about 1-2% of hemangioblastomas occur in the spinal cord and they are almost exclusively intramedullary. Cerebellar hemangioblastomas usually present in the third decade with intracranial hypertension, and ataxia. hemangioblastoma's possibly occurrence in other locations, such as the supratentorial compartment, the optic nerve, the peripheral nerves.

Hemangioblastomas are usually cherry red in color. It occur in two basic forms: Solid tumors consist entirely of tumor cells ; Cystic hemangioblastomas are composed of a generally small solid component, adjacent to an oftentimes much larger cystic portion of tumor.

Most hemangioblastomas arise sporadically. However, in 25%, they are associated with a genetic syndrome called von Hippel Lindau disease (VHL), an autosomal dominant disorder in which affected individuals develop cerebellar and retinal hemangioblastomas, pancreatic cysts and carcinomas, renal masses, and pheochromocytomas. When these tumors are associated with von Hippel Lindau syndrome, they occur in younger patients and sometimes in children. 80% of hemangioblastomas arising in the spinal cord occur in the setting of von Hippel-Lindau syndrome.

Hemangioblastomas are more common in men than in women. In most clinical series, the male-to-female ratio is approximately 2:1. Although hemangioblastomas may develop at any age, they rarely affect children. The usual age at diagnosis is between the third and fifth decades.