Renal oncocytomas: clinical, radiological and histological features

Proximal renal tubular adenomas with oncocytic features, also known as renal oncocytomas, are rare, probably benign, tumors of the kidney. They are easily misdiagnosed as carcinomas. However, radiological, histological and ultrastructural characteristics allow their differentiation from adenomas and adenocarcinomas. We report 4 cases of renal oncocytomas and review the literature.