This syndrome is characterized by a partial or total absence of the pectoralis major muscle (chest muscle) on one side of the body. However, it syndrome can include a spectrum of chest-wall deformities affecting the rib cage (absence of ribs) and the chest wall muscles (underdeveloped). It can also affect the spinal curvature making it deviate to one side (scoliosis).
Patients with Poland Syndrome could present with upper extremities deformities and webbing fingers. Also, there are some abnormalities in the breast and nipples, including under-developed (hypoplastic) glands or absent nipples.