Renal leiomyoma: an uncommon differential diagnosis of renal masses with a clinical relevance.

Renal leiomyomas are an extremely rare neoplasm which account for 1.5% of the benign lesions and 0.29% of all treated renal tumours, with autopsy evidence of 4.2% to 5.2%. Given their exceptional incidence, they are rarely included in the differential diagnosis of renal masses, despite their capacity to grow to a considerable size. The definitive diagnosis of a leiomyoma is only possible after histopathological examination, most of the times of a nephrectomy specimen. However, due to the rising number of diagnosis resulting from improved medical imaging and interventions, renal leiomyomas should gain importance in the differential diagnosis of renal masses, specialy with respect to kidney sparing surgery. Hereby, we report a case of 60-year-old male patient with a large well circumscribed left renal mass, diagnosed as Renal cell carcinoma on imaging.