RESUMO
BACKGROUND: Malignant adenomyoepithelioma (AME) of the breast is a rare tumor in which malignancy can arise from either epithelial or myoepithelial components, or from both cell types. The incidence and prognosis of malignant AME of the breast are difficult to assess due to its rarity. Therefore, the optimal treatment for this disease is still controversial. CASE SUMMARY: We present two middle-aged women (48 and 56 years old) with malignant AME of the breast. Core needle biopsy was performed before surgery. However, breast adenoma and malignant tumors were observed. The preoperative diagnosis of malignant AME of the breast is still challenging for pathologists and clinicians. Both patients underwent mastectomy and sentinel lymph node biopsy, both of which were negative, followed by adjuvant chemotherapy. CONCLUSION: The follow-up duration of the two patients was two years and four months, respectively. No signs of relapse or metastasis have been observed thus far.