Purpose of review: A growing number of tumor entities with badly defined limits are enlarging in the last years the family of oncocytic tumors in the kidney.
Recent findings: Chromophobe renal cell carcinoma (ChRCC) and renal oncocytoma (RO) are classically well-known tumors, but the borderland between them, and their precise connection, remains a matter of debate. Aside from that, other emerging and provisional entities, like eosinophilic solid and cystic renal cell carcinoma (ESC RCC), eosinophilic vacuolated tumor (EVT), low-grade oncocytic tumor (LOT), and papillary renal neoplasm with reverse polarity (PRRP), have been recently described. This spectrum of tumors remains a diagnostic challenge in renal pathology, especially if the specimen obtained is scarce. This review focuses on practical diagnostic problems when managing core biopsies and proposes a diagnostic algorithm maximizing the information provided by both morphology and immunohistochemistry. So, a combination of morphologic features on hematoxylin-eosin and six antibodies (CK7, CD117, CK20, CD10, GATA-3, and cathepsin K) is advised to be used in a stepwise fashion.
Keywords: Chromophobe renal cell carcinoma; Core biopsy; Differential diagnosis; Immunohistochemistry; Oncocytic tumor; Oncocytoma.
© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.