Nephron-Sparing Surgery in Pediatric Renal Tumors Arising From a Horseshoe Kidney: Proposal of a Lacking Definition

Renal tumors account for 7% of pediatric malignancies, with Wilms tumor (WT) or nephroblastoma being the most frequent. WT has been associated with a heterogenous group of congenital urogenital anomalies, including renal fusion anomalies. Horseshoe kidney (HSK) is the most common type of fusion renal anomaly, with an estimated incidence of 1/500 newborns [1]. The diagnosis of a tumor arising from HSK needs a Nephron-Sparing Surgery (NSS), defined as a complete resection of the tumor, sparing the viable renal tissue [1,2].