Malignant Adenomyoepithelioma Combined with Invasive Ductal Carcinoma of the Breast: A Case Report

Malignant adenomyoepithelioma is an adenomyoepithelioma in which the epithelial or myoepithelial components may undergo malignant transformation. Malignant adenomyoepithelioma of the breast is a rare tumor and often affects elderly women. We report an 85-year-old female patient who presented with 5.5 cm mass in the outer quadrant of the left breast. Biopsy of the mass showed metaplastic spindle cell carcinoma. The patient then underwent a total mastectomy. The final pathology found malignant adenomyoepithelioma and in addition, coexisted with well-differentiated invasive ductal carcinoma. The findings raised an interesting discussion of potential pathogenesis, the implications in clinical management and emphasized the importance of extensive tissue sampling in large breast tumors.