Differential Diagnosis for a 12-year-old Female with Uneven Chest

Single Most Likely Diagnosis

• Scoliosis: This is a common condition in adolescents, particularly during the pubertal growth spurt, where the spine curves abnormally to one side. It can cause uneven shoulders or chest, with one side appearing higher than the other. The absence of pain does not rule out scoliosis, as many cases are asymptomatic.

Other Likely Diagnoses

• Pectus Carinatum: Also known as pigeon chest, this condition involves an abnormal protrusion of the sternum and ribs, which can cause the chest to appear uneven. It is more common in males but can occur in females.
• Musculoskeletal Asymmetry: Differences in muscle development or posture can lead to an uneven appearance of the chest. This could be due to various factors, including habitual posture, sports activities, or minor anatomical variations.
• Breast Asymmetry: Although more commonly associated with differences in breast size, uneven breast development during puberty can also contribute to an uneven chest appearance.

Do Not Miss Diagnoses

• Pectus Excavatum: A congenital deformity of the chest wall characterized by a sunken breastbone (sternum). While it's less likely to be completely asymptomatic, mild cases might not cause significant discomfort.
• Spinal Tumors or Infections: Although rare, conditions like osteoid osteoma, spinal infections, or tumors can cause scoliosis or uneven chest appearance. These conditions are critical to identify early due to their potential for serious complications.

Rare Diagnoses

• Poland Syndrome: A rare congenital condition characterized by underdevelopment or absence of the chest muscle (pectoralis major) on one side of the body, which can also affect the development of the breast and chest wall.
• Marfan Syndrome: A genetic disorder that affects the body's connective tissue, which can lead to an uneven chest appearance among many other symptoms, including tall stature, long limbs, and eye and heart problems.
• Neurofibromatosis: A genetic disorder that can cause tumors to form on nerve tissue, potentially leading to scoliosis or an uneven chest if spinal nerves are affected.

Each of these diagnoses has a different set of implications for treatment and management, ranging from observation and physical therapy for scoliosis and musculoskeletal asymmetry to surgical intervention for conditions like pectus excavatum or carinatum. A thorough medical evaluation, including imaging studies and possibly genetic testing, is necessary to determine the underlying cause of the uneven chest appearance.