The rarest phenomenon of flexible ureterolithotripsy: Kidney stone in supernumerary type combination with a horseshoe kidney

The horseshoe kidney (HSK) is common and supernumerary kidney is the rarest developmental anomaly of the urogenital system. The supernumerary kidney in a HSK conjunction is extremely rare, and prevalence of it is unknown. A review of literature, there have been a few case reports about the supernumerary and HSK combination, however, none of which also had a concomitant kidney stone and obstructive pathology. Our case indicated that patient referred to flank pain and visible hematuria to our clinic, and further investigations demonstrate supernumerary kidney in a horseshoe configuration and kidney stone. Kidney stone could not be found at the first attempt because of the anatomical malformation. Retrograde pyelography showed ureteral branching and helps to define the placement of stone. This stone was fragmented with flexible ureteroscopy in the lower pole of the middle kidney in the second session. There was no stone fragments absence at the 1(st)-month control. This exceedingly rare type case should be evaluated meticulously on preoperative duration otherwise can be a challenge for surgeons. Visualize pelvicalyceal system under the fluoroscope is a vital step in this regard to being guidance during the procedure.