Three cases of renal oncocytoma, with reference to intracytoplasmic vacuoles

Abstract

Background: Renal oncocytoma, a benign and relatively rare tumor, has an excellent prognosis if completely removed.
Cases: We report three cases of renal oncocytoma. Histologically, tumor cells showed mild cytological atypia and eosinophilic granules of abundant cytoplasm on H-E sections. Oval nuclei are centrally located and showed few mitotic figures. Cytological examination of touch smear specimens showed intracytoplasmic vacuoles in 4.9% of tumor cells in renal oncocytoma. but fewer than 1.0% in renal cell carcinoma (RCC).
Conclusion: Renal oncocytoma consists of tumor cells with slight atypia and eoshinophilic granular cytoplasm. Intracytoplasmic vacuoles are more frequently seen in renal oncocytoma than in RCC.