Hemangioblastoma

Hemangioblastoma of the central nervous system is a benign tumor (WHO grade I) that is typically cystic and can occur throughout the central nervous system. It is a tumor composed of hemangioblasts, a type of stem cell that normally give rise to blood vessels or blood cells. Hemangioblastomas occur more often in middle-aged adults aged 30-50 years. Patients with VHL present at a younger age than patients with sporadic cases, with an age range of 25-40 years. Hemangioblastomas present most commonly in the posterior fossa, representing 7-12% of posterior fossa tumors in adults.

Almost 95% of infratentorial tumors are located in the cerebellum, primarily in the hemispheres, less frequently in the vermis, and even less commonly in the medulla oblongata and the spinal cord. Supratentorial hemangioblastomas are rare, with 85 reported cases, mostly in the cerebral hemispheres. Hemangioblastomas have been described as intraventricular (in the third ventricle), from where cerebrospinal fluid seeding has been suggested to occur. Most hemangioblastomas occur as a single lesion. However, some patients develop hemangioblastomas as part of a genetic syndrome called von Hippel Lindau disease (VHL), a genetic disorder inherited from either parent (dominant inheritance).

Over their lifetimes, such patients develop multiple tumors within the brain and spinal cord. Hemangioblastomas occur in two basic forms solid tumors consist entirely of tumor cells and cystic hemangioblastomas are composed of a generally small solid component, adjacent to an oftentimes much larger cystic portion of tumor. There are two basic treatment options for hemangioblastoma, surgery and radiosurgery. Surgical resection involves operating on the brain or spine to physically remove a tumor. If a hemangioblastoma can be completely removed and is not associated with von Hippel Lindau disease, then a patient is cured.

Surgical treatment of hemangioblastomas is total resection, with the main goal being the preservation of surrounding neural tissue. In regards to general surgical management, having blood products available for transfusion is very important because the vascular character of hemangioblastomas may result in serious intraoperative blood loss. Stereotactic radiosurgery can be used to target and destroy a hemangioblastoma. A single radiosurgery session will result in the gradual death and eventual shrinkage of a treated lesion. The main potential complication of radiosurgery is the chance that radiation may destroy the tumor but injure the adjacent normal brain.