Cerebellar Hemangioblastoma Associated With a Vascular Malformation: A Case Report Treated With Surgery and Radiosurgery.

Hemangioblastoma is well known as an essentially benign cystic and/or solid tumor classified WHO grade I, mainly originated in the posterior fossa. One of the characteristics of this tumor is very rich vasculature in and around the tumor. We have encountered a case of hemangioblastoma in association with a vascular anomaly near the tumor, though they were located separately by the tentorium. A vascular anomaly with arteriovenous (AV) shunting flow in the left occipital lobe was verified at angiography, which received a blood supply from left occipital artery and drained to occipital cortical veins. Successful removal of the cerebellar tumor and pathological diagnosis of hemangioblastoma was made. The second angiography in our hospital demonstrated the same vascular anomaly above the tentorium with feeding artery of posterior cerebral artery, a small nidus, and cortical draining veins, which were less obviously stained. Only the arteriovenous malformation (AVM) nidus in sigmoid vein was targeted for radiosurgery and 20 Gy at the margin was delivered. Since AV shunting was less remarkable on the second angiography than that on the first angiography may be because of a decreased vascular supply to the supratentorial AVM after surgical resection of the infratentorial hemangioblastoma and might indicate an indirect connection between the two lesions.