Histopathologic Study of the Myoepithelial Cells in the Pleomorphic Adenoma

ABSTRACT

A total of 51 cases of pleomorphic adenoma was obtained from the pathologic files of Chosun University hospital from january, 1980 December, 1989. The studies of clinical, microscopic, immunohistochemical, and electronmicroscopic examination showed the following results. The peak age incidence of the pleomorphic adenoma in this study was in the 5th decade and no significant difference in the incidence between male and female patients was observed. The most common histologic type of myoepithelial data showed positive reactions of the myoepithelial cells to cytokeratin and S-100 protein in the solid, myxoid, and chondroid area. The electronmicroscopic examination of the myoepithelial cells revealed myofilaments, dense bodies, desmosomes, and basement membrane suggesting epithelial origin of these cells. In conclusion, the pleomorphic adenoma seems to be derived from epithelial component and the variable stromal change may be derived from modified myoepithelial cells considering the results of immunohistochemical and electron microscopic study.