Since the original accounts by Froriep in 1839 and Poland in 1841, congenital chest wall deformities have long challenged surgeons in both diagnosis and treatment (1,2,3,4,5,6,7,8,9,10,11,12,13,14). In the past, these deformities were classified into five categories: Poland syndrome, pectus excavatum, pectus carinatum, sternal clefts, and generic skeletal and cartilage dysplasias (e.g., absent ribs, vertebral anomalies, chondroglandiolar depressions) (11). Of these, Poland syndrome, pectus excavatum, and skeletal dysplasias cause a depression in the anterior thoracic skeletal or soft tissue that results in a variety of chest wall deformities. Such deformities can be very disfiguring, especially when concomitant breast anomalies increase asymmetry and exaggerate chest wall depressions (7,10,11,14). Recently, however, an additional syndrome has been identified that falls into the subset of chest wall depressions, a syndrome called anterior thoracic hypoplasia (14).

Anterior thoracic hypoplasia consists of posteriorly displaced ribs resulting in a unilateral sunken anterior chest wall, hypoplasia of the ipsilateral breast, and a superiorly placed nipple-areola complex (Fig. 120.1). In these patients, the chest wall depression corresponds with posterior displacement of ribs 3 to 7 unilaterally and an average chest wall depression volume of 160 mL. There is no involvement of the pectoralis muscle, and the sternum is in normal position (14). This separates it from Poland syndrome, which is defined by the partial or complete aplasia of the sternal head of the pectoralis muscle, variable ipsilateral limb deformities, and variable breast hypoplasia (2,4,5,6,11,12,13). In contrast, anterior thoracic hypoplasia is associated with normal upper extremities and hypoplasia of the breast (which is always present to some degree).