VHL and cystadenoma: The normal VHL gene is a tumor suppressor gene and it seems likely that the diminution of tumor suppression activity which results from the mutation of that gene leads to the various manifestations of the disease: renal cysts and renal carcinoma, pheochromocytoma, pancreatic cysts, neuroendocrine tumors, cystadenomas of the reproductive adnexal organs, and hemangioblastomas of the cerebellum, spinal cord, brain stem, and retina.