Immunohistochemical localization of the α and β subunits of S-100 protein in pleomorphic adenoma of the salivary glands

Plasmacytoid cells in salivary-gland pleomorphic adenomas: evidence of luminal cell differentiation

“…The anti-basic calponin antibody reacted not only with MECs and smooth muscle cells but also with duct cells, nerve fibers and keratinocytes [38]. Pleomorphic adenoma cells frequently possess tonofilaments and nerve proteins such as S100 protein and glial fibrillary acidic protein (GFAP) [1,9,10,13,14,20,34,35,52]. Therefore, these cells may have reacted with the antibody.…”

“…Therefore, these cells may have reacted with the antibody. S100 protein is not expressed by MECs but by duct cells [15,34,35]. MEC expression of GFAP is still a matter of controversy [1,32,34,52].…”

Current Status of Histogenetic and Morphogenetic Concepts of Salivary Gland Tumorigenesis

“…Such results indicate that whether antibodies to S-100 protein stain luminal or myoepithelial-like cells in salivary gland tumors, it is simply a reflection of genetic expression in neoplasia without necessarily implying a definite histogenetic role for a particular cell of the normal gland. This is most apparent in pleomorphic adenoma, where the outer layers of two-tiered epithelial cells show no or variable degrees of staining for S-100 protein, both within and between individual cases (Ninomiya et al, 1989). The data, then, do not support the contention that myoepithelial cells are the direct precursors of certain salivary gland tumors (Batsakis etal., 1989).…”

“…In the normal salivary gland, myoepithelium was initially reported to be positive for S-100 protein, and because antibodies to S-100 protein generally stain the modified myoepithelial cell, that is, nonluminal tumor cell, of pleomorphic adenomas and other salivary gland tumors (Nakazato et al, 1982;Crocker et al, 1985;Kahn et al, 1985;Zarbo et al, 1986;Mori et al, 1986Mori et al, , 1987, it was assumed to imply a key histogenetic role for myoepithelial cells in salivary gland tumors . In fact, various subunits of S-100 protein localize to acini and/or ducts of salivary glands and not myoepithelial cells (Ninomiya et al, 1989;Hosaka et al, 1989;Mori et al, 1990;Dardick etal., 1991). The occasional crescentic-shaped structures associated with normal acini, which are positive for S-100 protein, are fine, terminal branches of unmyelinated nerves (Ninomiya et al, 1989;Dardick et al, 1991) with which the gland is richly endowed (Garrett, 1967).…”

“…In fact, various subunits of S-100 protein localize to acini and/or ducts of salivary glands and not myoepithelial cells (Ninomiya et al, 1989;Hosaka et al, 1989;Mori et al, 1990;Dardick etal., 1991). The occasional crescentic-shaped structures associated with normal acini, which are positive for S-100 protein, are fine, terminal branches of unmyelinated nerves (Ninomiya et al, 1989;Dardick et al, 1991) with which the gland is richly endowed (Garrett, 1967). Adenoid cystic carcinomas of all subtypes have S-100 proteinpositive luminal cells and negative basal or modified myoepithelial cells (Mori et al, 1990).…”