Low-Grade Oncocytic Tumor of Kidney: A Distinct Emerging Entity in Renal Oncocytic Neoplasms with Diagnostic Challenge in An Old Female: A Case Report

Abstract

Low grade Oncocytic Tumor (LOT) is an emerging category in renal tumors having oncocytic morphology. It has overlapping features with Renal Oncocytoma and Eosinophilic variant of Chromophobe Renal Cell Carcinoma. LOT typically shows solid nests of cells with oncocytic cytoplasm and uniform round to oval nuclei with a CK7 positive/ CD117 negative immunophenotype. Pathogenesis is not well-understood, however, variations in mTOR pathway related genes have been described. The clinical course is indolent. Here, we present the case a 64-year-old female patient who presented with a solid enhancing mass in right kidney with the clinical impression of Renal cell carcinoma. Right radical nephrectomy was performed, and histologic features were consistent with LOT.