Adenomyoepithelioma with carcinoma of the breast: A report of two cases and a review of the literature

We herein described two cases of adenomyoepithelioma (AME) with carcinoma of the breast. Both of them were Japanese women, and they presented with a mass in their breast. Post-operative specimens revealed encapsulated and well-circumscribed tumors with local invasion, necrosis, cytological atypia, and a high mitotic rate. In immunohistochemistry, coincidentally with the loose adhesion pattern of myoepithelial cells in both cases, the intensities of E-cadherin and beta-catenin were much weaker in myoepithelial than luminal epithelial cells, with almost negative finding of beta-catenin in one case. We first found deletion of CDH1 and polysomy of CEP16 in myoepithelial cells by double color-fluorescence in situ hybridization. The two cases have been followed up for 5-8 years, and both remained free from local recurrence and distant metastases. We also presented an overview of 47 cases of AME with carcinoma in English-language literatures.