Immunohistochemical study of malignant myoepithelioma of salivary glangs.

Objective TO study clinicopathologic characteristic and beharviour in malignant myoepithelioma of salivary glands.Methods 22 cases malignant myoepithelioma were examined by histopathological and immunohistochemical methods.Results The tumour arise most frequently within the parotid glands and palatine glands,sex distribution was men more than women,the median age was 49 years.The clear cell type and epithelial cell type of this tumour was mostly seen in the light microscope,with extensive invasion of the surrounding tissues.All cases showed the overexpression of Actin、Ck 18、EGFR、TGFβ.The average proliferation index(PI)of proliferating cell nuclear antigen(PCNA)in positive cells were 22.8% ±6.93,PI of clear cell type was the highest.The positive rates of c erbB 2 and p53 gene in 22 cases of the malignant myoepithelioma were 63.6%,31.8%,respectively.The cxpressions of clear cell type was also the highest.Conclusions The malignant myoepithelioma was epithelial tumour.The malignant grade of clear cell type was higher.The altered expression of oncogene c erbB 2 and antioncogenes p53 might play a promotive role in the tumorigenesis and development of malignant myoepithelioma.