Destructive processes of salivary gland parenchyma and development of epimyoepithelial islands assessed by immunohistochemistry.

Thirteen salivary gland lesions showing destructive features and development of epimyoepithelial islands were studied using a panel of monoclonal antibodies to B cell (Dako, CD20 L26), T cell (UCHL1), macrophage histiocyte MH cell (Dako, MAC387), cytokeratin PKK1, KL1, K8.12, actin, vimentin and Von Willebrand factor (v WF). B cells were distributed closely in some limited areas and T cells were scattered throughout the lesion. MH cells were located particularly in the periductal tissue as well as in ducts and acini. Actin staining was positive in myoepithelium around acini but was negative or weak around degenerative acini. Endothelial cells of blood vessels stained strongly with v WF. Cytokeratin KL1 and K8.12 were positive in duct cells of the unaffected area while in the degenerative region they were negative or weak. K8.12 was positive in epimyoepithelial islands, indicating that the epimyoepithelial cells in lymphoepithelial lesions may originate from duct basal cells.