Renal Pelvis Leiomyoma- An Infrequent Clinical Case.

Renal pelvis leiomyomas are infrequent benign tumours. These tumours are more frequent in women, usually asymptomatic and difficult to distinguish from malign kidney masses. A 27-year-old female presented with an asymptomatic renal mass discovered after abdominal ultrasound during routine check-up. Percutaneous renal biopsy was performed and reported urothelial carcinoma. After open nephroureterectomy, histopathological evaluation and immunohistochemistry were positive for Smooth Muscle Actin (SMA), Ki67 <5%, and negative for cytokeratin and HMB-45. Thus, confirming the diagnosis of renal leiomyoma. The diagnosis of these infrequent tumours is often difficult and it is usually made by immunohistochemistry after surgical treatment.