MUC-1 expression in pleomorphic adenomas using two human milk fat globule protein membrane antibodies (HMFG-1 and HMFG-2)

Pleomorphic adenoma (pa) is the most common salivary gland tumor and its microscopic features and histogenesis are a matter of debate. human milk fat globule protein membrane (hmfg) monoclonal antibodies (moabs) comprise a set of antibodies against the mucin 1 (muc-1) protein detected in several salivary gland tumors. objective: the aim of this study was to assess the immunoexpression of the pa neoplastic cells to muc-1 protein using hmfg-1 and hmfg-2 moabs,contrasting these results with those from normal salivary gland tissue. material and methods: immunohistochemical detection of muc-1 protein using hmfg-1 and hmfg-2 moabs was made in 5 mm thick,paraffin embedded slides,and the avidin-biotin method was used. results: positivity to hmfg-1 and hmfg-2 moabs was found in ductal,squamous metaplastic and neoplastic myoepithelial cells,keratin pearls and intraductal mucous material. two kinds of myoepithelial cells were identified: classic myoepithelial cells around ducts were negative to both moabs,and modified myoepithelial cells were positive to both moabs. this last cellular group of the analyzed tumors showed similar muc-1 immunoexpression to ductal epithelial cells using both hmfg antibodies. intraductal mucous secretion was also hmfg-1 and hmfg-2 positive. conclusions: our results showed there are two kinds of myoepithelial cells in pa. the first cellular group is represented by the different kinds of neoplastic myoepithelial cells and is hmfg-positive. the second one is hmfg-negative and represented by the neoplastic myoepithelial cells located around the ducts. © 2015,faculdade de odontologia de bauru. all rights reserved.