Pectus carinatum, also known as pigeon chest, is a rare chest wall malformation where the sternum and ribs protrude abnormally. It develops during childhood and worsens during puberty, causing symptoms like shortness of breath, chest pain, and asthma. It can be caused by genetic factors or abnormalities in cartilage development. Diagnosis involves x-rays, CT scans, or MRI. Treatment options include bracing or Ravitch surgery to remove abnormal cartilage and place the breastbone in a normal position.