Coexistence of sporadic cerebellar hemangioblastoma and pituitary null cell adenoma: simultaneous expression of von Hippel-Lindau gene product. Case report.

Coexistence of brain tumors of different pathologies is rare, and the majority of the cases were related to genetic disorders or secondary tumors occurring after radiotherapy. A 73-year-old man was introduced to the outpatient department suffering from severe nausea and vertigo. Magnetic resonance imaging showed a cystic tumor in the left cerebellar hemisphere and another lesion in the sella turcica. There was no evident family history of von Hippel-Lindau (VHL) disease, and the systemic investigation failed to detect any other tumors or signs of VHL disease. Treatment was performed in two stages, and he was discharged with remaining slight ataxic gait. The diagnoses were cerebellar hemangioblastoma and pituitary null cell adenoma. Additional immunohistochemical investigation using VHL disease gene-related protein in both tumors showed minute granular positive staining in the cytoplasm of stromal cells in the former, and diffuse and strong granular cytoplasmic positive staining in the latter. Further analysis is required to confirm the true implication of the VHL gene mutation, and the possible involvement of VHL gene-related protein in the pathogenesis of these coexisting tumors.