A comparative immunohistochemical study of adenoid cystic carcinoma of the skin and salivary glands.

We performed an immunohistochemical study that compared a primary adenoid cystic carcinoma (ACC) of the skin with two salivary gland ACC. All three tumors stained positively and in identical fashion for epithelial membrane antigen (EMA), carcinoembryonic antigen (CEA), broad-spectrum keratins, and low-molecular-weight keratins. Both EMA and CEA were localized to the luminal surfaces and the secreted contents of the tubular structures and the ductlike structures of the cribriform formations. The staining reactions for both types of keratin were more intense in the cells lining the tubular structures and the ductlike structures of the cribriform formations. One of the two salivary ACCs stained positively for S-100 protein; the other was positive for vimentin. The cutaneous ACC was negative for both antigens. Leu-7 antigen was not detected in either type of ACC. These results show that primary cutaneous ACC and salivary ACC have similar immunohistochemical staining patterns for a number of antigens. We believe this similarity is due to the fact that these antigens are shared by the sweat glands and salivary glands, which are considered to be the respective sites of origin for these two types of tumors.