Immunohistochemical investigation on 5 cases of adenoid cystic carcinomas.

Normal salivary glands and 5 cases of adenoid cystic carcinomas were examined by immunohistochemical staining with the antibodies to S-100 protein, neuron-specific enolasc (NSE), glial fibrillary acidic protein (GFAP), carcinoembryonic antigen (CEA), and immunoglobulin A (IgA) to speculate the differentiation of the tumor cells of adenoid cystic carcinoma. The myoepithelial cells of normal salivary glands were stained positively by the antibodies to S-100 protein and NSE. In adenoid cystic carcinomas, tumor cells of tubular areas were intensely stained and those of cribriform areas showed positive reaction to the anti-S-100 protein antibody. A little reaction was identified at the solid areas. These findings suggested that most of S-100 protein positive tumor cells might show a functional differentiation from the myoepithelial cells. NSE showed similar localization as S-100 protein, and the latter showed more intensive and extensive reactions than the former. No distribution of GFAP was shown in the normal salivary glands and adenoid cystic carcinomas. CEA was observed in the luminal surface of normal salivary glands, while IgA in the duct epithelial cells. Intraluminal contents of tubular areas were stained positively by the antibodies to CEA and IgA, which suggested intensive secretory activities at tubular areas in adenoid cystic carcinomas.