Malignant adenomyoepithelial tumor of the breast: multi-immunolabeling technique and detailed immunophenotypic study

Biphasic ductal and myoepithelial lesions of the breast are uncommon. A majority of these rare lesions behave in a benign fashion. Malignancy is rare, and preferentially involves the epithelial component. Malignancy in both epithelial and myoepithelial components is even rarer. We report such a case, employing the use of a range of cytokeratins and myoepithelial markers to delineate the extent of each component. In addition, we apply the relatively novel technique of multi-immunolabeling combined with Adobe Photoshop imaging to highlight the different components of the neoplasm on the same tissue section. These ancillary tests can provide much needed information about the contribution of epithelial or myoepithelial components to malignant tumors, hence providing the gateway to further study into their histogenesis and natural history.