Incidental contrast opacification of the appendix secondary to urological intervention.

A 23-year-old otherwise well male, with right ureteric stent in situ placed electively for a 9-mm symptomatic pelviureteric junction stone underwent a right ureteropyeloscopy, retrograde pyelogram laser lithotripsy and stent exchange for stone clearance. The procedure was uncomplicated. Following stent removal on day 2, the patient developed acute right lower quadrant pain, which was investigated with non-contrast CT abdomen. The scan demonstrated a contrast-filled vermiform appendix, secondary to vicarious contrast excretion. This case report describes a rare manifestation of vicarious contrast excretion and explains this phenomenon.