[Lesions of the male breast].

Lesions of the male breast are rather rare. The most frequent lesion is gynecomastia followed by breast cancer. Gynecomastia is well known but male breast cancer is a rather rare tumor. It occurs in less than 1% of all cancers in men and of breast cancers. The mean age is high with a median of 68 years. Predisposing factors appear to be associated with hyperestrogenism such as testicular factors including maldescensus, orchitis and infertility. Other factors are Klinefelter, adipositas, diabetes mellitus and liver disease. In recent years an increased risk of male breast cancer has been reported in families with positive family history and in which BRCA2 mutations have been identified. Diagnostic procedures for male breast lesions should be the same as for the female breast. Underdiagnosis of male breast lesions is a frequently reported problem. Histology of male breast cancer differs in some aspects from female breast cancer. Male breast cancers are more frequently invasive ductal, G3 and steroid hormone receptor positive. In case of intraductal cancer male lesions are more frequently papillary. Lobular carcinomas almost never occur. Prognostic factors for male breast cancer are similar to female breast cancer. For male breast cancer no randomised therapy studies are described. Therefore all therapy strategies are extrapolated from female breast cancer. The existing main therapeutic problem is undertreatment.