Adenoid Cystic Carcinoma of Breast: A Rare Case Report

Background: Adenoid cystic carcinoma (AdCC) of the breast is a rare type of invasive breast cancer, accounting for less than 1% of all breast cancer cases. It is usually a low-grade tumor that rarely metastasizes to the axillary lymph nodes and distant organs. AdCC of the breast is mostly negative for estrogen receptor, progesterone receptor, and HER2-neu. However, despite being triple-negative, it has favorable outcome, and patients with AdCC of the breast generally have a good to excellent long-term survival. Case presentation: Here we report a case of a 51-year-old female presenting with left breast mastalgia who was finally diagnosed with AdCC of the left breast. The patient underwent breast-conserving surgery and axillary staging followed by adjuvant chemoradiation. Conclusion: Because of the rarity of AdCC of the breast, it has been difficult to conduct prospective trials to determine the best treatment option. Different types of therapy, including BCS and mastectomy with or without axillary staging with or without adjuvant chemoradiation have been reported, all with overall good to excellent long-term results. Prospective controlled trials will help in determining the best treatment.