Clinical characteristics and outcomes of benign, atypical, and malignant breast adenomyoepithelioma: a single institution's experience

Background: Breast adenomyoepithelioma (AME) is rare. We sought to evaluate clinical characteristics, treatment, and outcomes of a contemporary patient cohort stratified by histology. Methods: We queried health records containing “adenomyoepithelioma” between 2000 and 2018. Histology was confirmed with centralized review and classified into benign, atypical, and malignant. Clinical characteristics, demographics, treatment, and oncologic outcomes were compared. Results: Our query yielded 24 patients with adenomyoethelioma. Histologic diagnosis was confirmed in 12 (benign n = 6, atypical n = 3, malignant n = 3). Excision (n = 11) was the usual initial treatment, with margin status available in 10 patients. Mean follow up was 44 months (range 1–138 months) with no local recurrence observed. Two patients with benign AME presented with concurrent contralateral breast cancer, and one with malignant AME died of metastatic AME. Conclusion: Wide excision of atypical and malignant AME is recommended as local recurrence when excised completely was not observed. Given metastatic potential of malignant AME, multimodal therapy may be warranted.