Gastric Heterotopic Pancreas Presenting as Abdominal Pain with Acute and Chronic Pancreatitis in the Resected Specimen

Heterotopic pancreas, also known as ectopic pancreas, is pancreatic tissue located outside the pancreatic parenchyma without vascular or ductal communication with the gland. Ectopic pancreas is rarely symptomatic, typically detected incidentally at surgery or autopsy. Eighty-five to 90% are in the upper GI tract, especially the gastric antrum. We report a 54-year-old man with symptomatic gastric heterotopic pancreas presenting as recurrent, initially undiagnosed, abdominal pain. Surgery revealed heterotopic pancreas including excretory ducts, acini, and islet cells. Evidence of acute pancreatitis was present, marked by inflammation and abscess formation. Chronic pancreatitis was diagnosed by fibrosis and dilated ducts containing proteinaceous material. Submucosal location with normal overlying mucosa on endoscopy increases risks of delayed or missed diagnosis. Complications include GI bleeding, acute or chronic pancreatitis, pancreatic necrosis, pseudocyst, gastric outlet obstruction, perforation, and, rarely, pancreatic carcinoma. This rare disorder mimics more common diseases. Low suspicion, nondiagnostic imaging or endoscopy contribute to frequent diagnostic delay.

Magnifying endoscopy with narrow-band imaging for gastric heterotopic pancreas

Background and study aims Heterotopic pancreas is a common subepithelial lesion in the stomach. However, its histological diagnosis is difficult when tissue samples are obtained with a conventional biopsy forceps. This study aimed to describe the magnifying endoscopy with narrow-band imaging (ME-NBI) features of gastric heterotopic pancreas. Patients and methods We retrospectively analyzed a database of all patients who underwent endoscopic ultrasonography (EUS) at Pusan National University Hospital from January 2010 to December 2010. Thirty-six patients with endosonographically diagnosed heterotopic pancreas who underwent ME-NBI and endoscopic ultrasonography (EUS) simultaneously were studied. The ME-NBI features of their lesions were analyzed. Results Thirty lesions were located in the antrum and six in the body. Six lesions (17 %) showed umbilication or central dimpling on the surface, and nine (25 %) had a macroscopic opening on the surface. On ME-NBI, a microscopic opening was identified in 22 (81 %) of 27 lesions wherein a macroscopic opening was not observed during conventional endoscopy. Macroscopic or microscopic opening was observed in 31 lesions (86 %). The frequency of macroscopic or microscopic opening was higher in lesions with anechoic duct-like structures than in lesions without such structures on EUS (91 % [29/32] vs 50 % [2/4], P = 0.027). Focal loss of microsurface structure and presence of a thickened submucosal vessel were observed in 6 (17 %) and 5 lesions (14 %), respectively. Conclusions The characteristic ME-NBI feature of heterotopic pancreas is presence of a microscopic opening on its surface. This ME-NBI feature is potentially useful for differentiating heterotopic pancreas from other gastric subepithelial tumors.