MALIGNANT MYOEPITHELIOMA (MYOEPITHELIAL CARCINOMA) OF THE BREAST - A DETAILED CYTOKERATIN STUDY

Aims-To study the expression of a range of cytokeratins by malignant m yoepithelioma of the breast. Methods-Immunophenotyping was carried out using a panel of antibodies on wax embedded and frozen using immunohi stochemistry and double-labelled immunofluorescence. Electron microsco py was also performed. Results-The tumour cells were positive for CAM 5.2, actin, vimentin, and cytokeratin 14 and negative for cytokeratins 18 and 19. Electron microscopy showed well formed desmosomes and hemi desmosomes together with pinocytic vesicles, plentiful rough endoplasm ic reticulum and 6 nM microfilaments with focal densities. Conclusions -The pattern of cytokeratin expression provides further evidence that tumours with a specific myoepithelial phenotype occur rarely in the br east.