[Histological study of heterotopic pancreas tissue of the stomach--histogenesis and immunohistochemical findings].

Forty resected cases of heterotopic pancreas (15 of Heinrich's type I and 25 of type II) in the stomach were investigated. Acinic cells were more remarkably positive by pancreatic polypeptide and amylase in the cases of type I consisting of acinic cells, ducts and islet cells compared with those in type II consisting of acinic cells and ducts. Staining behavior by insulin, gastrin, glucagon, somatostatin and serotonin was similar to that of normal pancreas. However, the intestinal epithelium containing goblet cells and pyloric gland-like glands consisting of the cells with clear cytoplasm were not infrequently produced from the ducts in the lesions of type II. Muscle fibers with transition to muscularis mucosae were more frequently intermingled in the lesions of type II compared with type I. Acinic cell-differentiation in the mucosa apart from the main lesion was found in several cases of type II. It was suspected that there are two types of histogenesis for the heterotopic pancreas in the stomach; one arises from the fetal immigration of pancreas tissue in the stomach and the other from the immature gastric mucosal penetration into the submucosa with secondary differentiation to the pancreas tissue.