Haemangioblastoma, light micrograph. Hemangioblastoma is a燱HO Grade I tumour爐hat may occur爏poradically爋r in the setting of爒on Hippel Lindau disease (about 25% of patients). The peak incidence is seen in the 3rd and 4th decades. The most common location is cerebellum. On MRI with contrast, the tumour usually appears a爏harply demarcated enhancing mass with cystic areas爄n the cerebellum. This appearance is seen in about 60% of cases; remaining 40% of cases are entirely solid. About 10-25% of patients with hemangioblastoma carry a germline mutation in the VHL gene. Grossly, hemangioblastomas are generally well circumscribed with solid and cystic components. They are usually dark red-brown given extensive vascularity. This high magnification image of a hemangioblastoma shows stromal cells with abundant vacuolated or lightly eosinophilic cytoplasm. Mitotic activity is generally not increased; but occasional mitotic figures may be present (as shown here). Necrosis is not a prominent feature.