Fibroepithelial polyp of the renal pelvis: nephron-sparing surgery after false-positive biopsy for transitional cell carcinoma.

Benign fibroepithelial polyps of the renal pelvis are extremely rare, with only 23 cases previously reported. The diagnosis is usually made following nephrectomy or nephroureterectomy for an assumed malignancy. This case involves a 66-year-old woman referred with presumed biopsy-proven transitional cell carcinoma of the renal pelvis. Radiographic findings were suggestive of a benign lesion. Pyelotomy and frozen section confirmed these suspicions. The polyp was excised and the kidney spared. The diagnosis and management of fibroepithelial polyps are discussed and the literature reviewed.