Adenomy oepitheliomas are uncommon breast tumours. By definition they have a prominent component of my oepithelial cells, in addition to glandular elements lined by epithelial cells. Malignant adenomy oepithelioma of the breast is even more rare, characterised by malignant proliferation of epithelial and my oepithelial cells that show characteristic histological and immunohistochemical f eatures. Only 11 cases have been reported to date. A case of malignant adenomy oepithelioma of the breast is reported.