A 10-week-old male infant was brought in by his mother for an examination after she noticed an abnormality in his upper thorax. Pregnancy and delivery were unremarkable. On physical examination, he was found to have partial absence of the pectoralis major muscle of the right shoulder girdle (Figures 1 and 2). In other respects, the examination was unremarkable.
The answer is A: Poland's anomaly. Poland's anomaly (also called Poland's syndrome) was first described by Alfred Poland in 1841.1 It is a congenital anomaly with variable penetration, consisting of a unilateral absence of components of the shoulder girdle and upper extremities, particularly the pectoralis major and minor muscles.2,3 Poland's anomaly is often associated with syndactyly of the ipsilateral hand.
In this child, decreased muscle bulk of the pectoralis major muscle on the right side can be seen. This is the area of dimpling superior and lateral to the right nipple (bottom figure). In a female child, this would create a significant cosmetic deformity after puberty. Augmenting the breast area in a female with Poland's anomaly often provides an interesting challenge to plastic and reconstructive surgeons. The abnormality in the child presented here is being followed by observation only, and it may not have a significant impact on him, although he may experience some loss of strength. The use of physical therapy may help to develop compensatory muscles to preserve as much shoulder girdle function as possible.