Immunohistochemical characterization of epithelial cells in human lacrimal glands

The distribution of cytokeratins (CK), actin, lactoferrin (Lf), lysozyme (Ly), vimentin and S-100 protein was immunohistochemically investigated in paraffin-embedded specimens of five inflammatory and five neoplastic lesions of lacrimal glands (LGs). Atrophic acini in dacryoadenitis reacted with antibodies (ABs) KL1 and Pkk1 (CK 7, 8, 17, 18) in a manner similar to ducts. Apart from myoepithelial cells and some luminal-duct cells, the remaining epithelia in dacryoadenitis were negative with AB 34 beta E12 (CK 5). The number of AB HHF35 (actin)-positive myoepithelial cells was not altered in dacryoadenitis. Epithelia in dacryoadenitis reacted weakly but consistently with Lf while revealing weak and inconsistent staining for Ly. Vimentin was negative in epithelial cells in dacryoadenitis except in one case. S-100 protein was detected only in epithelia of inflammatory major LGs. Epimyoepithelial islands in lymphoepithelial proliferation reacted variably for CKs, Lf, Ly and vimentin and remained negative for actin and S-100. In pleomorphic adenomas, neoplastic cells showing duct-like differentiation (luminal) reacted consistently with CK 7, 8, 17, 18 and S-100 protein and inconsistently with CK 5, Lf and Ly but remained negative for actin and vimentin. Other neoplastic cells (ovoid/peripheral cells) stained consistently for CK 5, vimentin and S-100 protein and focally for CK 7, 8, 17, 18, actin, Lf and Ly. Spindle-form neoplastic cells found in the stroma exhibited vimentin and S-100 protein and, less frequently, actin. Determination of these antigens in pleomorphic LG adenomas may help to evaluate their prognosis.