S6186 A Rare Case of Duodenal Perforation Due To Large Retroperitoneal Mass

Introduction: Duodenal perforation resulting in the leakage of intestinal contents necessitates timely recognition and surgical intervention due to reported mortality ranging from 8%-25%. The most common etiology of duodenal perforation is peptic duodenal ulcers due to Helicobacter pylori infection or nonsteroidal anti-inflammatory drugs. A duodenal perforation due to a large central retroperitoneal mass is rare. We report an unusual case of a duodenal perforation due to a leiomyoma. Case Description/Methods: A 58-year-old woman with hypertension, gastric bypass, and cholecystectomy presented with 36 hours of acute abdominal pain and melena. Two weeks prior, she was admitted for abdominal pain and found to have active extravasation from the pancreaticoduodenal artery. Successful embolization of the third branch of the gastroduodenal/inferior pancreaticoduodenal artery was performed. On re-presentation, significant labs revealed WBC 15.7, Hgb 10.7, and total bilirubin 1.7. Exam was pertinent for diffuse abdominal tenderness. A computed tomography scan revealed a perforation in the third portion of the duodenum with a large, complex retroperitoneal collection. On upper endoscopy 2 perforation sites were identified, with visible retroperitoneal content inflow, which were not amenable to endoscopic repair. General surgery performed laparoscopic omental patch duodenorrhaphy, drainage of a retroperitoneal hematoma, and intraoperative identification of a large (13-18 cm), centrally located retroperitoneal mass. Pathology at the periphery found rare spindle cells positive for SMA and desmin with stains potentially consistent with leiomyoma and pending confirmation with repeat esophagogastroduodenoscopy and endoscopic ultrasound. Discussion: Retroperitoneal masses can be asymptomatic or have non-specific symptoms until large in size. As a result, these masses can be challenging to diagnose and may present with local extension. Literature review found 1 prior report of 2 patients with retroperitoneal sarcoma presenting with colonic perforations necessitating colectomies. This case uniquely demonstrates the consequences of a large, extrinsic retroperitoneal leiomyoma resulting in duodenal perforation. Duodenal perforation is an urgent, life-threatening consequence of the insidious growth of retroperitoneal masses which requires prompt diagnosis to reduce morbidity and mortality.