Male Adenoid Cystic Carcinoma of the Breast.

Adenoid cystic carcinoma (ACC) of the breast, a rare malignancy that makes up less than 0.1% of all breast malignancies, is much rarer in males than in females. Due to the rarity of this disease, an optimal treatment strategy for male breast ACC has not been established, and therapy for male patients is currently based on guidelines for female patients. According to previous reported cases, some authors believe that male breast ACC may have higher invasive potential than female breast ACC and the prognoses in male patients may be worse than those in female patients. Therefore, a more proactive diagnosis and treatment regimen may be required. However, the clinical feature of our case is inconsistent with this view. Herein we report the case of a 24-year-old male without any antecedent medical or family history who presented with a slow-growing lump on his left chest wall for 5 years. The patient initially underwent lumpectomy, and the mass was pathologically diagnosed as breast ACC. Systemic examination was performed, and no evidence of distant metastasis was found. Then, he received modified radical mastectomy and ipsilateral axillary lymph node dissection. The mastectomy pathological examination revealed that no cancerous tissue was detected around the primary tumor bed, and all 22 axillary lymph nodes were negative. The patient did not receive postoperative chemotherapy, radiotherapy or endocrine therapy and remained well after 28 months of follow-up. In this study, we review the literature and summarize the clinical manifestations, imaging and histopathological characteristics, treatments and outcomes of male breast ACC. We share our experience in the hopes that this evidence will aid in the development of better therapeutics.