Image Description
Some cases of microcystic adenoma are lined by atrophic-appearing flattened epithelium. The stroma in between cysts may show amyloid deposits or dystrophic calcification. These epithelial lesions are immunoreactive for epithelial membrane antigen and cytokeratins 7, 8, 18, and 19. They may focally express CA19-9 and B72.3, but are negative for carcinoembryonic antigen (CEA), CK20, trypsin, chromogranin A, synaptophysin, MUC2, S-100, desmin, vimentin, factor VIII-related antigen and actin.