Renal Medullary Fibroma- A Histopathological Surprise in a Patient With an Asymptomatic Abdominal Mass

Renal medullary fibroma is a fairly common, but unusual benign mass lesion of the kidney. These are often small in size, and rarely produce symptoms; hence they frequently go unnoticed, diagnosed only during autopsy in most cases. Very rarely, they achieve large enough sizes to produce compressive symptoms or a clinically palpable mass. This tumour, however, poses a radiological dilemma, as it cannot be differentiated from malignant lesions of the renal parenchyma. Here we present a unique case of an asymptomatic, incidentally detected left renal mass, which was reported as renal medullary fibroma, a benign disease.