Torsion of an accessory spleen with situs inversus in a child

We present an unusual case of acute abdomen caused by torsion of an accessory spleen with situs inversus in a child. A three-year-old girl was admitted to our hospital with an 11-day history of right flank pain with fever. Her medical history revealed an operation of coarctation of the aorta with situs inversus at one month of age. Physical examination revealed a right flank mass and tenderness. A contrast-enhanced CT scan showed a normally enhanced small spleen in the right upper quadrant and a 7.0×6.0×3.5 cm, hypodense, marginal enhancing mass in　the right midabdomen adjacent to　the intestine. An emergency laparotomy was　decided upon with a preoperative diagnosis as an acute abdomen. During surgery, a mass was found under the greater omentum and two accessory spleens of 1.5 cm in diameter were found surrounding the main spleen. Several loops of bowel were adherent to the mass. The loops of bowel were dissected away. A pediculated congested mass was observed as an accessory spleen emerging from the greater omentum. The mass was twisted on its vascular pedicle and strangulated. The necrotic mass was removed and the postoperative recovery was uneventful. Though torsion of an accessory spleen is extremely rare, it should be considered in the differential diagnosis of acute abdomen in childhood.