Clinicopathological characteristics of tumor-like lesions arising in gastric heterotopic pancreas

Heterotopic pancreas is defined as the presence of pancreatic tissue, outside its usual location, which lacks anatomical and vascular continuity with the pancreas proper. The heterotopic pancreas can accompany various lesions of the pancreas, such as acute pancreatitis, epithelial cyst, pancreatic pseudocyst, and exocrine and endocrine tumors. Tumor-like lesions arising from heterotopic pancreas appear to be rare, and there are only sporadic cases available in the literature. This study analyzed the clinical and pathological characteristics of our single patient and 31 previously reported cases in the literature. Assessment of all 32 cases showed no gender differences and a median age of 57 years. The most common site of tumors occurred in the gastric antrum (14/26). Most of the cases were classified according to the Heinrich classification of heterotopic pancreas. The most frequent Class of heterotopia associated with tumors was Class I (11 cases, 42%), followed by Class III (9 cases, 35%). Our patient presented with a Class III heterotopic pancreas. Most of the tumors associated with heterotopic pancreashave been adenocarcinomas (21/32). Other less common types of pancreatic neoplasia included intraductal papillary mucinous neoplasms (5/32), acinar cell carcinoma (4/32), and neuroendocrine tumors (2/32). With a median follow-up of 18 months, 12 patients (60%) survived and were disease-free, and 5 patients (25%) died of disease. Only 3 patients had recurrence or metastasis after partial tumor resection.