Acute abdominal pain localized in right iliac fossa: Not always acute appendicitis. A case of giant hydronephrosis in an 8-year-old boy and literature overview.

Abdominal pain is a frequent complaint in children, leading them to seek medical attention. It can have several causes, though acute appendicitis is the most feared diagnosis when pain is localized in the right iliac fossa. We report a case of an 8-year-old boy with the complaint of acute abdominal pain, initially referred by his family doctor to a radiologist for an abdominal ultrasound (US) for suspected acute appendicitis. A fortuitous diagnosis of giant hydronephrosis (GH) was made upon admission, which showed the palpation of a huge poorly delineated abdominal mass that was probably missed at the previous examination by the general physician (GP). Uroscan confirmed the diagnosis of GH secondary to obstruction at the ureteropelvic junction. A renal MAG3 (mercaptuacetyltriglycine) scan showed revealed differential renal function (15%) on the right side, normal on the left side. Robot-assisted right pyeloplasty with the transposition of right lower polar vessels via trans-peritoneal laparoscopy was performed, and JJ probe left in-situ for a month. The boy is doing well and is under active follow-up. GH is rare; its diagnosis requires both meticulous examination and a high index of suspicion. Its management is uncodified but in children, pyeloplasty is preferred to nephrectomy.