Intraductal Papillary Mucinous Neoplasm Arising from Heterotopic Pancreas in Stomach: A Case Report and Review of Literature

Heterotopic pancreas is generally an asymptomatic condition which is found incidentally at surgery, endoscopy, or autopsy. Intraductal papillary mucinous neoplasm (IPMN) arising from heterotopic pancreas is extremely rare. In this study, we report a patient with IPMN arising from heterotopic pancreas. A 28-year-old man presented to our department with epigastric pain for 20 days. Physical examination revealed no abnormal findings. Computed tomography (CT) revealed an intramural cystic-solid mass on the gastric wall. Endoscopic ultrasonography (EUS) revealed a hypoechoic, heterogeneous, and multilobulated lesion with septa. Cyst fluid analysis based on EUS guided fine needle aspiration (EUS-FNA) indicated that the concentration of carcinoembryonic antigen (CEA) was 492 ng/ml. The patient received Billroth I subtotal gastrectomy, and then a 4.6 cm mass from the lesser curvature of the stomach was removed. Finally, the patient was diagnosed as IPMN with low grade dysplasia in an ectopic pancreas based on histopathological analysis. This report described the clinical, radiologic, endoscopic and histologic features of IPMN arising from heterotopic pancreas in a 28-year-old man involving the stomach. All pathologists involved in the diagnosis and clinicians involved in the treatment should be aware of this kind of tumor pattern to improve the correct identification, diagnosis and management of patients.