Malignant adenomyoepithelioma of the breast: cases report and literature review

Background: Malignant adenomyoepithelioma (MAME) of the breast is an extremely rare breast malignancy, in which they arise from either luminal epithelial or myoepithelial components, or both. At present, there is very little clinical data of MAME. Case Report: We present two cases, one of them is a 34-year-old woman who underwent needle biopsy for a 3.2 cm-size mass in the right breast, and the pathology was MAME of breast. Another case is a 45-year-old woman who had a 3.0 cm-size mass in the right breast. We performed a breast-conserving surgery and sentinel lymph node biopsy, both of which were negative. The histopathology of these two cases was invasive carcinoma; however, these cases were eligible for MAME of the breast through combining with immunohistochemistry. Conclusions: MAME of the breast is very rare, and has a diverse cell morphology, which must be combined with immunohistochemistry to make a clear diagnosis. Besides, it should be differentiated from adenoid cystic cancer, malignant leafy tumor, spindle cell carcinoma, etc. The clinical characteristics and treatment strategies were further discussed in combination with the literature.