• BRCA2 mutation
• hamartoma
• male breast cancer

Breast cancer is a rare disease in men and represents only approximately 1% of all breast cancer cases.¹ Several factors have been reported to increase the risk for male breast cancer, including alteration in hormonal status, Klinefelter's syndrome, family history of breast cancer, and occupational exposures to high temperature, electromagnetic fields, and radiation.^2,3 Germline mutations in the androgen receptor gene and, particularly, in the BRCA2 gene are thought to increase breast cancer risk in male carriers.^4–9 Mutations in BRCA2 may account for 75% of families in which there is at least one case of male breast cancer and at least three more cases of female breast cancer.¹⁰ Most families have a single case of male breast cancer and familial clusters of male breast cancer cases are unusual. Recently, BRCA2 mutation analyses in male breast cancer were performed in the Polish population and five novel mutations were detected; however, aggregation of male breast cancer cases was observed in only one family from north eastern Poland.^11,12 Here, we report a novel BRCA2 mutation in a Polish family with two male breast cancer cases in a father and son and a first case of BRCA2 mutation with …