Poland sequence with dextrocardia: which comes first?

We report on two cases of Poland sequence (defect of the pectoralis major and hand on the same side) with dextrocardia, and review the literature on such patients. In all 16 reported cases, the Poland defect was on the left side, and associated with a rib defect, whereas most cases of Poland sequence involve the right side, and few have a rib defect. The dextrocardia appeared to be a dextroposition, and was not associated with other cardiac defects, whereas isolated dextrocardias (without situs inversus) frequently are. These observations suggest that the dextrocardia associated with Poland sequence is usually secondary to it.