Myoepithelioma of minor salivary gland--an immunohistochemical analysis of four cases.

INTRODUCTION AND METHODS: We performed an immunohistochemical study in four cases of myopitheliomas with objective to realize a profile in respect of differentiation grade by the monoclonal antibodies CK14, vimentin and alph-SMA, besides to investigate the cell proliferation by anti-PCNA, besides, we compare the immunoreactive with glandular normal tissue.

RESULTS: In the glandular normal tissue the myoepithelials cells had shown expression for alpha-SMA and CK 14, while that in the ductals cells, only the presence of CK 14 was verified. All the cases was verified positivity for CK 14 and vimentin, however, CK 14 had been present only in epithelioid and fusiform cells, while that the vimentin revealed positive also in the cytoplasm of the plasmocytoid cells. alpha-SMA was not detected in the neoplasic cells. Immunopositivity for the PCNA was observed in more than 75% of the cellular component of the analyzed tumors, independent of the cellular type.

CONCLUSIONS: We concluded that it did not have difference in the proliferative activity among the cellular types presents in the myoepitheliomas and, still, the results of this study suggest that the constituent cells of this neoplasia one really represent cells of the mioepitelial ancestry, but in different stages of differentiation.