The distribution of various tissue
antigens was studied in
mucoepidermoid carcinomas (n = 74) and
acinic cell carcinomas (n = 38) by means of immunocytochemistry.
Mucoepidermoid carcinomas were generally positive for
cytokeratin and showed double expression for
cytokeratin and
vimentin in 31.1% and triple expression for
cytokeratin,
vimentin and GFAP in 24.1%. CEA was studied using new
monoclonal antibodies which distinguish between
epitopes that are present on CEA alone and those which are present on nonspecific cross reacting
antigens as well. The monospecific CEA antibody was completely negative in
mucoepidermoid carcinomas, while nonspecific cross reacting
antigens (NCAs) were positive in
mucoepidermoid carcinomas to a varying degree.
Alpha 1-antichymotrypsin, a marker formerly thought to be specific for tissues for histiocytic origin, was positive in 85.1% of
mucoepidermoid carcinomas. Twenty three percent of
mucoepidermoid carcinomas showed focal infiltration by S-100 positive dendritic stromal cells, tumour cell being negative.
Leu-M1 antigen was positive in 58.1% of
mucoepidermoid carcinomas.
Acinic cell carcinomas were generally positive for
cytokeratin and in single cases showed double expression for
cytokeratin and
vimentin and triple expression for
cytokeratin,
vimentin and GFAP. Monospecific CEA antibody positivity could be demonstrated in 24.2% of
acinic cell carcinoma, while nonspecific cross reacting
antigens (NCAs) were positive in
acinic cell carcinomas to a varying degree.
Alpha 1-antichymotrypsin was positive in 97.4% of
acinic cell carcinomas. 2.5% of
acinic cell carcinomas showed focal infiltration by S-100 positive dendritic stromal cells, 2.5% of
acinic cell carcinomas were positive for
S-100 protein with no dendritic stromal cells present.
Leu-M1 antigen was positive in 86.8% of
acinic cell carcinomas. For
S-100 protein and Leu-M1, no correlation with the
clinical course, as reported previously for other tumours, could be observed.