A case of cerebellar hemangioblastoma with rhabdoid features.

We present an unusual case of cerebellar hemangioblastoma characterized by rhabdoid features. The patient was a 35-year-old Japanese man with occipital neuralgia and exacerbating blurred vision. Magnetic resonance imaging revealed a left posterior cranial fossa tumor, which was isointense on T1-weighted images and hyperintense on T2-weighted images with marked homogeneous enhancement. Histology of the surgically resected tumor showed cellular-type hemangioblastoma with extensive proliferation of rhabdoid cells Immunohistochemistry analysis showed tumor cells positive for inhibin A, CD56, vimentin, INI-1, and vascular endothelial growth factor; negative for PAX8, CD10, epithelial membrane antigen, cytokeratin, (AE1/3), alpha-smooth muscle actin and D2-40; and had focal positivity for glial fibrillary acidic protein and S100. The Ki-67 labeling index was <1 %. Ultrastructural analysis revealed large lipid droplets and abundant intracellular accumulation of intermediate filaments. Based on these findings, the diagnosis was hemangioblastoma with focal rhabdoid features. After a 14-month follow-up, there was no evidence of recurrence. This is the first report of hemangioblastoma with rhabdoid features in the central nervous system. In addition, we discuss the possible pathogenesis.