Breast and Pectoralis Muscle Hypoplasia

Abstract

Purpose: Poland's syndrome is a congenital and unilateral aplasia of the pectoralis major muscle (PMM), with other anomalies of the ipsilateral upper extremity. We present 6 cases in which the only clinical expression was asymmetry of the breasts associated with partial absence of the PMM. Material and Methods: We reviewed 95000 mammograms (obtained 1985–1995) to find patients with asymmetrical breast size. Where the asymmetry could not be ascribed to any other cause, the patients were recalled for an examination of the PMM which was conducted at rest and with active contraction of the muscle. Results: Unilateral volume reduction of the PMM was found in 5 women of whom 2 were studied with MR. A 6th case was a fortuitous finding in a male patient. Conclusion: Mild forms of Poland's syndrome are more frequent than severe forms, and may go undiagnosed. Hypoplasia of one breast or a horizontal anterior axillary fold may be the sole clinical manifestation of this syndrome.