Male breast cancer (MBC) is rare, accounting for less than 1% of all breast cancer but the incidence has increased worldwide. Risk factors include increased longevity, obesity, testicular diseases and tumours, and germline mutations of BRCA2. BRCA2 carriers have 80 times the risk of the general population. Men generally present with breast cancer at an older age compared with women. Histologically, MBC is often of grade 2, hormone receptor positive, HER2 negative, and no special type carcinoma although in situ and invasive papillary carcinomas are common. Reporting and staging are similar to female breast cancer. Metastatic lesions to the male breast do occur and should be differentiated from primary carcinomas. Until recently, MBC was thought to be similar to the usual ER positive post-menopausal female counterpart. However, advances in MBC research and trials have highlighted significant differences between the two. This review provides an up to date overview of the biology, genetics, and histology of MBC with comparison to female breast cancers and differential diagnosis from histological mimics.

男性乳腺癌 (MBC) 很少见，占所有乳腺癌的不到 1%，但在全球范围内发病率有所增加。风险因素包括寿命延长、肥胖、睾丸疾病和肿瘤，以及 BRCA2 的种系突变。BRCA2携带者的风险是普通人群的80倍。与女性相比，男性患乳腺癌的年龄通常更大。组织学上，MBC 通常为 2 级，激素受体阳性，HER2 阴性，没有特殊类型的癌，尽管原位癌和浸润性乳头状癌很常见。报告和分期与女性乳腺癌相似。男性乳房的转移性病变确实发生，应与原发性癌相鉴别。直到最近，人们还认为 MBC 与通常的 ER 阳性绝经后女性相似。然而，MBC 研究和试验的进展突出了两者之间的显着差异。这篇综述提供了 MBC 生物学、遗传学和组织学的最新概述，并与女性乳腺癌进行了比较，并与组织学模拟物进行了鉴别诊断。