Abstract
Amylase (AM), lactoferrin (LF), lysozyme (LY) and secretory component (SC) were traced by the peroxidase-antiperoxidase (PAP) method in formalin-fixed specimens from 20 cases of benign salivary gland tumors (pleomorphic adenoma 16, adenolymphoma 2, tubular adenoma 1, myoepithelioma 1).
LF and SC were detected in most of the cases except for myoepithelioma and thus regarded as universal markers of glandular differentiation of neoplastic cells. In pleomorphic adenoma, LF and SC were exclusively localized in the cells forming duct-like structures, often in the corresponding cells in the serial sections, indicating their functional resemblance to intercalated duct cells. In adenolymphoma, LF and SC were localized not only in columnar apical cells but also in occasional cuboidal basal cells. The frequency and stainability of these markers resembled those in striated ducts.
In tubular adenoma, in addition to an extensive reaction of LF and SC, AM and LY were partly demonstrated within the inner cells lining tubules, indicating their high degree of differentiation toward the secretory epithelium.
In conclusion, combined immunohistochemical findings of these functional markers may provide helpful information to estimate the participation and degree of differentiation of secretory epithelial cells in various salivary gland tumors.
