In this case study and review, we present a case of a primary small-cell neuroendocrine carcinoma (SCNC) of the male breast. Primary SCNC of the breast is a rare tumor with less than 30 cases reported in the literature. Most cases are found in women. Another exceptional point is that human epidermal growth factor receptor-2 (Her-2) immunoreactivity was positive in our recent case, which differed to previous reports detailing SCNC in women. We have no evidence to demonstrate the differences between treatment and prognoses for males and females, because we do not have sufficient cases to undertake an evidence-based investigation. We provide this rare case history; review the literature on SCNC of the breast; and discuss detailed information regarding epidemiology, histogenesis, clinical and histologic diagnosis criteria, surgical and adjuvant treatment, and prognosis.