Polypoid gastric heterotopy of the small intestine in a patient with primary hyperparathyroidism and alpha-1-antitrypsin deficiency belonging to a MEA-family. With particular reference to the ultrastructure of the epithelial cells.

A patient with a solitary polypoid gastric heterotopy in the jejunum and severe bleeding as a complication is described. Previous reports on this rare disorder and the conditions of its development are discussed. The patient belongs to a family with multiple endocrine adenomatosis (MEA), some members of which had an alpha-1-antitrypsin deficiency. The association between the familial disease and the gastric heterotopy in this case might be another argument for the assumed congenital nature of the latter. The polyp was studied by means of light and electron microscopy. It was mostly lined by fundic mucosa and only partially by antral mucosa. Focal foveolar hyperplasia, cysts and lymphoplasmacellular infiltration of the mucosa are regarded as secondary tissue alteration. Parietal cells, chief and endocrine cells were identified. The parietal cells were in the nonsecreting state and appeared in two distinct forms which are described in detail.