Denouement and Discussion
Absence of the pectoralis major or, more frequently, of the sternal portion of this muscle with syndactyly on the same side.
Does not appear to be genetically determined (only one reported case which was hereditary).
Appears equally in both sexes.
The pectoralis major or its sternal head is missing, thereby causing the absence of the normal, well-developed anterior axillary fold. There may be a band of fibrous tissue present, forming a web over the anterior surface of the axilla which limits the abduction of the arm.There is syndactyly on the involved side. There may be associated congenital anomalies of the homolateral hemithorax such as rib and costal cartilage defects, absence of the ipsilateral nipple, and asymmetry of breasts. The extremity on the affected side is usually smaller than on the unaffected side, and there may be limitation of movement at elbow and
GELLIS SS, FEINGOLD M. Picture of the Month. Am J Dis Child. 1965;110(1):85-86. doi:10.1001/archpedi.1965.02090030091013