The estimated annual worldwide incidence of male breast cancer (MBC) is in excess of 40.000 and this is rising year on year in parallel with the female disease. Males are risk takers with a tendency to ignore symptoms or signs which would hasten their wives and sisters to consult a doctor. There is frequent delay in presentation but with wide international variation: 3 months in France but 28 months in Morocco. Delay upstages the disease at diagnosis so that 92% of Tunisian cases had stage III/IV MBC compared with only 19% of Japanese. Embryonic breast development combines mammary bud formation together with rudimentary mammary gland evolution but does not display any gender-specific characteristics which appear at puberty. Collaboration is the key to both understanding the biology of MBC but also enabling meaningful randomised trials of treatment in order to improve survival.