[Complete and dissociated forms of Poland's syndrome (5 cases)].

The authors report 5 cases of aplasia of pectoralis major including 2 associated with a malformation of the hand falling within the context of Poland syndrome, which is a relatively common congenital malformation consisting of an association in varying degrees of hypoplasia of pectoralis major and a complex malformation of the homolateral hand. The pathogenesis of this malformation is gradually emerging and while familial cases have been reported, the majority of Poland syndromes are sporadic. The hypothesis involving interruption of the embryonic blood supply of the subclavian arteries during a critical period of embryonic development at about the 46th day is the most attractive. This hypothesis also enables extension of the manifestations seen to other congenital malformation syndromes. However, it could be disproved in one of our cases and the notion of early embryonic damage was more plausible.