Adenocarcinoma arising from gastric duplication: a case report with literature review.

Gastric duplication is a rare congenital malformation. We report the case of a 50-year-old man with adenocarcinoma derived from gastric duplication. He was referred to our institute because of persistent vomiting due to pyloric stenosis. Abdominal computed tomography revealed two cystic lesions: a 2-cm mass located along the greater curvature of the upper gastric corpus and a 3-cm mass adjacent to the bulbus. Under the diagnosis of gastric duplication cysts, the oral cyst was removed with the gastric wall and the other cyst lesion firmly adhered to the bulbus was treated with distal gastrectomy. Based on histological findings showing adenocarcinoma in the anal duplication cyst wall and regional lymph node metastases and cancer invasion into the duodenal stump, pancreatoduodenectomy was performed 9 days after the initial surgery. Invasion into the pancreas head and duodenal walls was seen in the resected specimen. Although the postoperative course was uneventful, he died of local recurrence and multiple liver metastases 14 months after surgical treatment. This case report with literature review indicates that alimentary tract duplication cysts should be recognized as risky lesions of cancer development in patients aged 50 years or over.