A case of young male with recurrent acute pancreatitis caused by an intrapancreatic gastric duplication cyst.

Gastric duplication cyst (GDC) is a rare gastrointestinal malformation that frequently occurs in the greater curvature of the gastric antrum or corpus. Herein, we reported a case of intrapancreatic GDC found as a result of recurring pancreatitis. A 15-year-old man experienced repeated episodes of acute pancreatitis and was found to have a cystic lesion in the pancreatic tail. Contrast-enhanced computed tomography revealed a 20-mm cystic lesion with an enhanced thick wall. Endoscopic ultrasonography revealed an anechoic cyst with a three-layered wall. Magnetic resonance cholangiopancreatography and endoscopic retrograde pancreatography (ERP) revealed a connection between the cyst and the main pancreatic duct (MPD), and the duplication of the MPD. ERP showed the pancreatic duct stenosis downstream of the cyst. Although preoperative diagnosis was difficult, distal pancreatectomy was performed to prevent recurrence of pancreatitis. Pathological examination revealed that the cystic lesion was circumferentially surrounded by the pancreatic parenchyma. The epithelial lining of the cyst was crypt epithelium containing the fundic or pyloric glands and surrounded by a smooth muscle layer. The final diagnosis was intrapancreatic GDC.