BREAST MYOEPITHELIOMA - ABOUT ONE CASE

Myoepithelial cell tumors of the breast are rare. They present diagnos tic difficulties not only on frozen sections but also after fixation a nd paraffin embedding. These tumors can give rise to a wide range of c linical evolution. Treatment vary from simple excision for myoepitheli osis to mastectomy with axillary node dissection for malignant myoepit heliomas. Large excision is necessary for adenomyoepitheliomas because of the risk of recurrence and, more uncommonly, their proclivity to m etastasise. We report the case of breast myoepithelioma in a 42 years old woman. The tumor was clinically, radiologically and macroscopicall y well demarcated. Histologically the tumor was composed of myoepithel ial cells with few cellular atypias and a low mitotic activity. Tumor cells expressed vimentin, actin, S100 protein and cytokeratin. This pa rticular immunohistochemical phenotype allows the differential diagnos is with other breast tumors.