Recurrent Psoas Abscess associated with Retrocecal Appendicitis in an Adolescent Female

Psoas abscess (PA) is encountered infrequently in children. Pyogenic psoas abscess is most commonly a primary process associated with Staphylococcus aureus in children. Herein we present a female adolescent of secondary psoas abscess associated with ruptured retrocecal appendicitis, and it was successfully treated by broadspectrum antibiotics and prompt surgical intervention. The patient was a case of ruptured appendicitis with successful conservative treatment. The patient missed the follow-up schedule for elective interval appendectomy. Two years later, she presented with fever, limping gait, and right flank pain. Ultrasound revealed fixed dilated bowel loops, a fecalith and a heterogeneous hypoechoic lesion (3.7×3.6×3.3 cm) at right psoas muscle, suspecting PA. The patient received intravenous antibiotics for 2 weeks and made an excellent recovery. A follow-up ultrasound showed complete resolution of the abscess. The patient missed the schedule for interval appendectomy again, and same symptoms recurred 4 months later. Laboratory data indicated leukocytosis and marked elevation of serum Creactive protein. Computed tomography scan of the abdomen showed a gas-containing fluid collection within the right psoas muscle, and connecting with a dilated appendix. Laparotomy with appendectomy and tube drainage of the abscess was done, and the patient had uneventful recovery. The bacterial culture of pus grew Enterobacter cloacae. The patient discharged eight days after surgery. Neither abdominal symptoms nor evidence of recurrent PA on follow-up ultrasound was observed in the later years.