Malignant adenomyoepithelioma of the breast: a case report and review of the literature

Abstract

Malignant adenomyoepithelioma of the breast (MAMEB) is a rare subtype of breast cancer, being less than 100 cases reported in the literature. Due to its exceptionality, currently there is little evidence regarding the management of this tumor. The aggressive nature of breast MAMEB together with the lack of knowledge, make this entity a threat for patients and a challenge for physicians. We present a case of a 61-year-old woman diagnosed with MAMEB after detecting a single left 10 mm nodule in a screening mammography. After multidisciplinary Tumor Board discussion, wire-guided lumpectomy was performed, confirming the diagnosis of MAMEB with safe negative margins and not needing to receive any adjuvant treatments. Twenty-two months after surgery, the patient was diagnosed with a local multifocal recurrence of MAMEB in the left breast. A second two wire-bracketing-guided lumpectomy was performed. The patient is currently disease-free. The diagnosis of MAMEB is challenging, playing immunohistochemistry a key role for its pathologic diagnosis. Complete surgical excision of the lesion is the main treatment according to literature, with still no agreement regarding axillary sentinel lymph node assessment, nor the role of adjuvant treatments as radiotherapy and chemotherapy.