Renal Leiomyoma as a Bosniak IV Lesion: A Case Report

Leiomyoma is a benign neoplasm originating from mesenchymal cells, affecting the smooth muscle of the genitourinary tract. These tumors can occur in various places throughout the urinary tract, mainly in the bladder, but renal involvement is less frequent and is usually in the renal capsule. They are generally asymptomatic, and diagnosis is frequently incidental through imaging studies. When symptomatic, flank pain, palpable abdominal mass or hematuria can be present. This report describes a patient with lower back pain whose computed tomography(CT) revealed a complex Bosniak IV renal lesion. Later, the patient was submitted to a partial robotic nephrectomy and diagnosed with leiomyoma through immunohistochemistry.