Intrarenal supernumerary ovary excised with partial nephrectomy.

Differentiating between complex renal cysts and cystic renal tumors is a difficult task that requires balancing unnecessary surgery with failure to diagnose cancer. We report a case of a Bosniak Class III renal mass removed by partial nephrectomy that was subsequently identified as an intrarenal supernumerary ovary. This report documents the rare anomaly of ectopic ovarian tissue and highlights the extraordinary combination of intrarenal location, lesion complexity, and surgical management with partial nephrectomy that makes this case unique.