Résumé : Background: Adenoid cystic carcinoma of the breast is a rare malignant neoplasm associated with an excellent prognosis and a very rare occurrence of metastases. Case presentation: We report the case of an aggressive presentation in a 65-year-old woman, of Belgian origin, who was diagnosed as having adenoid cystic carcinoma of the breast and developed metastases to her lung, kidney, and brain. Conclusions: We describe similar cases reported in the literature and discuss the molecular characteristics and treatment paradigm of this controversially aggressive disease entity.