Immunohistological study of the epithelial components of Warthin's tumor.

In order to gain insight into the origin of Warthin's tumor, 10 cases of Warthin's tumor were compared immunohistologically with macroscopically and microscopically normal areas of the same glands, using 6 types of functional markers; carcinoembryonic antigen, secretory component, lactoferrin, keratin, S-100 protein and glial fibrillary acidic protein. It was shown that in normal parotid glands, the cells of acini, the intercalated ducts, the striated ducts, and the excretory ducts, as well as myoepithelial cells differed from each other in intensity and distribution of reaction products with antisera against those markers. Although the differences were rather subtle, the results suggested that those markers could differentiate the cell types of the salivary glands. In Warthin's tumors with double-layered tumor epithelia, the staining characteristics of the luminal and basal epithelia differed from each other. Epithelial cells on the luminal side showed immunological characteristics similar to striated duct cells of the parotid gland, while those of the basal side had characteristics similar to those of basal cells of the excretory duct. It is therefore suggested that the epithelia of Warthin's tumor may show differentiation into 2 different cell types.