Williamson SR Gadde R Trpkov K Hirsch MS Srigley JR Reuter VE Cheng L Kunju LP Barod R Rogers CG Delahunt B Hes O Eble JN Zhou M McKenney JK Martignoni G Fleming S Grignon DJ Moch H Gupta NS 2017 Renal oncocytoma and chromophobe renal cell carcinoma have been long recognized as distinct tumors; however, it remains unknown if uniform diagnostic criteria are used to distinguish these tumor types in practice. A survey was distributed to urologic pathologists regarding oncocytic tumors. Responses were received from 17 of 26 invitees. Histologically, more than 1 mitotic figure was regarded as most worrisome (n=10) or incompatible (n=6) with oncocytoma diagnosis. Interpretation of focal nuclear wrinkling, focal perinuclear clearing, and multinucleation depended on extent and did not necessarily exclude oncocytoma if minor. Staining techniques most commonly used included the following: cytokeratin 7 (94%), KIT (71%), vimentin (65%), colloidal iron (59%), CD10 (53%), and AMACR (41%). Rare cytokeratin 7-positive cells (≤5%) were regarded as most supportive of oncocytoma, although an extent excluding oncocytoma was not universal. Multiple chromosomal losses were most strongly supportive for chromophobe renal cell carcinoma diagnosis (65%). Less certainty was reported for chromosomal gain or a single loss. For tumors with mixed or inconclusive features, many participants use an intermediate diagnostic category (82%) that does not label the tumor as unequivocally benign or malignant, typically "oncocytic neoplasm" or "tumor" with comment. The term "hybrid tumor" was used variably in several scenarios. A slight majority (65%) report outright diagnosis of oncocytoma in needle biopsies. The morphologic, immunohistochemical, and genetic characteristics that define oncocytic renal tumors remain incompletely understood. Further studies correlating genetics, behavior, and histology are needed to define which tumors truly warrant classification as carcinomas for patient counseling and follow-up strategies. application/pdf https://sonar.ch/global/documents/258542 eng info:eu-repo/semantics/altIdentifier/doi/10.1016/j.humpath.2017.03.004 info:eu-repo/semantics/altIdentifier/pmid/28315424 info:eu-repo/semantics/openAccess Human pathology. - 2017 Chromophobe renal cell carcinoma Diagnostic criteria Hybrid tumor Immunohistochemistry Oncocytoma Tumor classification Adenoma, Oxyphilic Biomarkers, Tumor Biopsy Carcinoma, Renal Cell Cell Proliferation Diagnosis, Differential Health Care Surveys Humans Immunohistochemistry Keratin-7 Kidney Neoplasms Mitotic Index Molecular Diagnostic Techniques Pathologists Predictive Value of Tests Prognosis Urologists Diagnostic criteria for oncocytic renal neoplasms: a survey of urologic pathologists. http://purl.org/coar/resource_type/c_6501