Poland's syndrome is a genetic disorder associated with abnormal breast development. The prevalence rate of this syndrome is approximately 1 in 20000 to 30000. Both chest wall and upper limb lost normal function, and this syndrome usually occurs unilaterally. Mild and partial forms of Poland's syndrome are common, which often been undiagnosed because the clinical feature is only breast asymmetry and a horizontal anterior axillary fold, without severe symptoms. Other abnormalities include deformation of ribs, absence of pectoralis muscle, hypoplasia or abnormalities of breast and subcutaneous tissue. Patients may also have webbed fingers on one hand, short bones in the forearm or sparse underarm hair.
