男性乳腺癌是一种少见恶性肿瘤，在男性恶性肿瘤中所占比例<1%。男性乳腺癌重要的危险因素有乳腺癌家族史和乳腺癌易感基因（BRCA）突变等因素、导致雌雄激素代谢紊乱的内分泌疾病、某些职业和环境因素以及饮酒等。男性乳腺癌的临床表现以乳晕区无痛性肿块最为常见，主要病理类型为浸润性导管癌，激素受体阳性表达率较高，预后较差。

The risk factors and the clinical characteristics of male breast cancer        WU Ke-jin, DING Long-long. Department of General Surgery, Xin Hua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200092, China
Corresponding author: WU Ke-jin, E-mail: kejinwu@163.com
Abstract    Male breast cancer is a rare malignant tumor, accounting for <1% of all male malignant tumors. Epidemiological risk factors for male breast cancer include family history of breast cancer, BRCA mutation, clinical disorders relating to hormonal imbalances, certain occupational, environmental exposures and alcohol. The most common clinical sign of male breast cancer is painless lump. The main pathological type of male breast tumor is invasive ductal carcinoma with high positive expression rates of hormone receptors. The prognosis of male breast cancer is much awful.