A 12-year-old girl was brought to the clinic for examination. She has a left chest wall abnormality. Her examination revealed an upper left thorax depression, the partial absence of the pectoralis major muscle of the left shoulder girdle, and hypoplasia of the left breast (as shown in the image). No absence of the costal rib cartilage was noticed. Other than her index finger being shorter than the other finger in her left hand and her left hand being slightly smaller than her right hand, the rest of the examination was remarkable. As she was adopted, there is no access to her official medical record. The appropriate imaging study has been ordered. Based on the physical examination findings,