Myoepithelial cells are the main component in pleomorphic adenomas?

objective: the aim of this study was to quantify by immunohistochemistry the number of myoepithelial cells (myecs) in pleomorphic adenomas (pas). material and methods: we retrieved the paraffin cubes of 27 pas, new slides were done and they were stained with anti-s100 protein antibody. the amount of s-100 protein positive cells was quantified, their morphology was recorded and comparison among myec number with age, gender and involved gland were also done. results: with s-100 protein, myecs in normal salivary gland tissue were seen surrounding the ductual structures only. in the analysed pas a mean of 27.4% of the neoplastic cells were positive to the antibody. with the exception of one pa, in all the analysed cases the plasmacytoid cells were the most commonly identified cells (48,6%). conclusions: results of this study suggest that myecs do not constitute the main cellular component of the neoplastic compartment in pas and corroborate the previously reported evidence by different au-thors, who studying the pas suggested that myecs does not comprise the main cellular neoplastic component of these entities.