Differential Diagnosis for Upper Extremity Back Pain

Given the presentation of back pain in the upper extremity, the following differential diagnoses are considered:

• Single Most Likely Diagnosis
  • Cervical Radiculopathy: This condition, often resulting from a herniated disk or bone spur in the cervical spine, can cause pain, numbness, or weakness in the neck and upper extremities. The symptoms typically follow a dermatomal pattern, making it a common cause of upper extremity back pain.
• Other Likely Diagnoses
  • Thoracic Outlet Syndrome (TOS): TOS involves compression, injury, or irritation of the nerves and/or blood vessels (arteries and veins) in the thoracic outlet area, which lies between your collarbone (clavicle) and first rib. This can lead to pain in the shoulders and upper back, as well as numbness or tingling in the arms.
  • Musculoskeletal Strain: Overuse or acute injury to the muscles and ligaments of the upper back can cause significant pain, especially if the pain is exacerbated by movement or certain positions.
  • Referred Pain from the Cervical Spine: Issues within the cervical spine, such as facet joint syndrome or cervical spondylosis, can refer pain to the upper back and extremities.
• Do Not Miss Diagnoses
  • Acute Coronary Syndrome: Although less common, chest pain or discomfort that radiates to the upper back can be a sign of a heart attack, especially if accompanied by other symptoms like shortness of breath, nausea, or sweating.
  • Pulmonary Embolism: Sudden onset of chest pain that worsens with deep breathing, accompanied by shortness of breath, could indicate a pulmonary embolism, which is a life-threatening condition.
  • Aortic Dissection: Severe, tearing chest pain that radiates to the back can be indicative of an aortic dissection, a serious condition where there is a tear in the aorta's inner layer.
• Rare Diagnoses
  • Pancoast Tumor: A type of lung cancer located at the top of the lung that can cause shoulder and upper back pain due to local invasion of the tumor into the brachial plexus or ribs.
  • Multiple Myeloma: A type of blood cancer that can cause bone pain, including in the upper back, due to bone lesions.
  • Osteomyelitis or Discitis: Infections of the bone or intervertebral disc, respectively, which can cause localized back pain and are more common in immunocompromised individuals or those with a history of recent infection.

Each of these diagnoses has distinct characteristics and requires a thorough medical history, physical examination, and possibly diagnostic imaging or laboratory tests to confirm. The key to diagnosis lies in a detailed clinical assessment and appropriate use of diagnostic tools.