Oncocytoma is a benign, well-differentiated epithelial tumour of the kidney. Oncoytomas are usually found incidentally in middle-aged patients.
They represent 5% of all solid renal masses, are well-encapsulated, and may reach a size of up to 12 cm in diameter. They may exhibit a central stellate scar that manifests on CT scanning. Histologically, the tumour is composed of large eosinophilic cells with small nuclei.
Oncocytomas are treated as malignant tumours until histologically disproven - radical or partial nephrectomy. Prognosis is excellent.
Last reviewed 01/2018