Poland syndrome: a concept of pathogenesis based on limb bud embryology.

A study of 15 patients as well as a review of the literature was made to determine the etiology of Poland syndrome. Neither the associated pathologic features nor any pattern of prenatal factors were helpful in revealing an etiology. A theory of primary nerve root dysgenesis was disproven. However, a concept of a localized insult at a particular embryonic stage based on known limb bud development is presented as a possible explanation of pathogenesis.