Congenital malformations and developmental changes of the breast: a neonatological view.

Congenital malformations of the breast and nipple-areolar complex are described from the aspect of neonatal dysmorphology. Their classification is based on the accepted nomenclature in the medical literature and on a special method of clinical examination. The embryology and the possible genes involved in breast development are also discussed to clarify the mechanisms underlying the occurrence of breast malformations. Except for amastia, polymastia and polythelia, which have received much attention, the data for many other breast malformations are sparse. Case control studies or even case series are rare, and good evidence is often lacking. In addition, more studies are needed to complete the map of genes involved in breast development. This information will contribute substantially to our understanding and clinical approach to breast malformations in the future.