S3324 Ectopic Enigma: Acute Pancreatitis Triggered by Duodenal Pancreatic Heterotopia

Introduction: Pancreatic heterotopia, also known as ectopic pancreas, refers to the presence of pancreatic tissue outside its usual anatomical location, lacking vascular or anatomical continuity with the main pancreas. While often asymptomatic and incidentally discovered, heterotopic pancreatic tissue can occasionally lead to clinical complications, including inflammation, bleeding, obstruction, and, in rare instances, pancreatitis. Case Description/Methods: Twenty-four-year-old man with no significant past medical history presented to the clinic with 2 week history of nausea and vomiting, preceded by 1 week of diarrhea. He denied any abdominal pain, illicit drug use, alcohol consumption, or marijuana use. Initial laboratory evaluations, including comprehensive metabolic panel, liver function tests, celiac disease panel, and stool studies, were unremarkable. Abdominal and pelvic computed tomography imaging revealed mild hepatic steatosis but was normal. Despite antiemetic therapy with ondansetron and metoclopramide, he experienced 4–5 episodes of vomiting daily without relief. An esophagogastroduodenoscopy was performed, revealing a 7 mm gastric polyp and a 10 mm duodenal polyp, both of which were resected. Four hours post-procedure, the patient developed severe epigastric pain. Laboratory tests showed a markedly elevated lipase level of 15,000 U/L. Repeat computed tomography imaging demonstrated an edematous pancreas with surrounding fat stranding, indicative of acute pancreatitis. Magnetic resonance cholangiopancreatography (MRCP) confirmed these findings without evidence of biliary obstruction. Common causes of pancreatitis, including gallstones, alcohol use, hypertriglyceridemia, and hereditary factors, were ruled out. Histopathological examination of the resected duodenal polyp revealed significant pancreatic heterotopia. The patient's hospital course was complicated by ileus, but he eventually recovered with supportive care. Discussion: Pancreatic heterotopia is a rare congenital anomaly, with an incidence ranging from 0.5% to 13.7% in autopsy studies. In this case, the resection of a duodenal polyp containing heterotopic pancreatic tissue precipitated acute pancreatitis, a rare but recognized complication. Pathophysiology may involve disruption of the ectopic pancreatic tissue's ductal system during polypectomy, leading to enzyme leakage and subsequent inflammation. This case underscores the importance of considering pancreatic heterotopia in the differential diagnosis of unexplained pancreatitis, especially when common etiologies have been excluded.