The patient went on to have a craniotomy. 

Histology

MICROSCOPIC DESCRIPTION: Sections of the cerebellum show scattered stromal cells in a background of many congested capillary-sized blood vessels. The tumor cells show mildly enlarged nuclei with hyperchromasia and foamy vacuolated cytoplasm. Mitoses are inconspicuous. There is no necrosis. The features are those of hemangioblastoma. There is no evidence of malignancy.

DIAGNOSIS: Left cerebellar tumor: Hemangioblastoma (WHO Grade I).