Sporadic hemangioblastoma of the kidney in a 29-year-old man.

Hemangioblastoma of the kidney is a rare, newly recognized tumor with morphological features similar to its cerebellar counterpart. There have been only 4 cases reported in the literature in English, all of them occurring in middle-aged to elderly patients. Here, we report a case of renal hemangioblastoma in a young adult without clinical evidence of von Hippel-Lindau disease. The tumor was composed of polygonal cells with mildly eosinophilic to clear cytoplasm and a rich vascular network. Immunohistochemical staining revealed a typical profile (positivity for α-inhibin, neuron-specific enolase and S100; negative results for epithelial membrane antigen, HMB-45, and Melan-A), which confirmed the diagnosis. Despite the similarity to renal-cell carcinoma in morphology, hemangioblastoma of the kidney is clinically indolent. Correct recognition of this pathological entity is important to avoid overdiagnosis and unnecessary clinical treatment.