Sterile Seroma after Surgical Drainage of Purulent Psoas Muscle Abscess in Crohnʼs Disease

Abstract

Purpose: Introduction: Psoas muscle abscess can occur as a purulent complication of Crohn's Ileitis. We present a case of a sterile seroma of the psoas muscle occurring after surgical drainage of a chronic purulent psoas muscle abscess in Crohn's disease. Case: A 32 years old female underwent Ileal resection for Crohn's Ileitis and drainage of a chronic right psoas muscle abscess. Her psoas muscle abscess had been present for 3 years. She had previously refused surgical resection and drainage of her abscess and was therefore treated with prolonged course of antibiotics. She did not require immunosuppressant, immunomodulators, steroids or biologics postoperatively. 3 years after the resection she presented with right lower quadrant pain and a positive psoas sign. She was afebrile and had a normal white cell count. CT scan showed a 15 cm x 6 cm fluid collection in right psoas muscle at the site of her previous psoas muscle abscess. Colonoscopy with Ileoscopy showed no recurrence of Crohn's disease. Small bowel barium x-ray was negative for ileo-psoas fistula. CT guided aspiration showed a sterile fluid collection, with no organisms and sparse white cells. Multiple cultures were negative. She was treated with a prolonged course of percutaneous drainage and ultimately tetracycline injection to sclerose the remaining sinus tract. There has been no recurrence of her sterile seroma in 3 years. Discussion: Psoas muscle abscess is a known purulent complication of Crohn's ileitis. We describe a sterile seroma of the psoas muscle occurring 3 years after surgical drainage of a chronic purulent psoas muscle abscess. We speculate that the seroma developed in the dead space remaining in the psoas muscle after drainage of the chronic walled off abscess. Her sterile seroma was initially concerning for a recurrent purulent psoas muscle abscess. Gastroenterologists should be aware of the possible development of sterile seromas in such cases.