A Case of Malignant Adenomyoepithelioma of the Right Breast with Metaplastic Carcinoma Component

Abstract

The patient was a 53-year-old woman. Four years previously she was aware of a right breast mass, of which fine needle aspiration cytology (FNAC) revealed bloody discharge, but it was diagnosed as benign. A year before, swelling and pain of the right breast appeared. It was diagnosed as breast abscess and her symptoms improved with puncture and drainage and oral administration of antibiotics at another hospital. Three months before, right bloody milk discharge appeared, for which two times of FNAC at the other hospital revealed the same class II bloody discharge as they gained in the cytology done 4 years previously. As they could not rule out a possibility of malignancy due to an increase of the tumor size and easily bleeding tendency, she was referred to our hospital. She had a 2.4 cm mixed patterned lesion in the right breast, which was Class V on cytology, and squamous cell carcinoma was suspected. Right partial mastectomy and sentinel lymph node biopsy were performed, leading to the histopathological diagnosis of malignant adenomyoepithelioma with metaplastic carcinoma component. As it was triple negative, 4 courses of dose-dense doxorubicin and cyclophosphamide (ddAC), 4 courses of dose-dense paclitaxel (ddPTX) and irradiation to the breast remnant were performed after surgery. As of 2 years after surgery, the patient is alive without recurrence. Due to rarity, we present this case of malignant adenomyoepithelioma of the breast.