Monarch Disease Ontology entry MONDO_0003825 (kidney oncocytoma) is a benign tumor of the kidney, characterized by the presence of large cells with abundant eosinophilic granular cytoplasm. The majority of these tumors are discovered incidentally, during work-up of other conditions. Also known as: kidney oncocytic neoplasm, oncocytoma of kidney, oncocytoma of the kidney, renal epithelial oncocytic neoplasm, renal epithelial oncocytic tumor, renal epithelial oncocytic tumour, renal oncocytoma.