The incidence of male breast cancer is very low, accounting for less than 1% of that of female breast cancer. Because of its low incidence, the experience of individual physicians with male breast cancer is limited. Futhermore, screening and clinical trials do not exist for men. Thus, there is a delay to seek medical consultation. We describe a case of breast cancer occurring in an 82-year-old man. He presented with a solitary, asymptomatic, and rigid subcutaneous mass under the areolar area of the left breast. Histopathologic examination showed an infiltrating ductal carcinoma of the breast. Immunohistochemically, estrogen and progesterone receptors were expressed in 90% and 70% of tumor cell nuclei, respectively.