Differential Diagnosis for Right Shoulder Pain

The patient's presentation of right shoulder pain, which is dull, located from the shoulder to slightly in the back, exacerbated by certain movements, and without radiating pain, suggests several potential diagnoses. These can be categorized as follows:

• Single Most Likely Diagnosis

  • Subacromial Bursitis or Rotator Cuff Tendinitis: This is the most likely diagnosis given the nature of the pain, its location, and the exacerbation by specific movements. These conditions are common and can cause pain that is worse with certain activities, such as pushing or lifting, and can disrupt sleep.

• Other Likely Diagnoses

  • Adhesive Capsulitis (Frozen Shoulder): Although the pain is not severe, and there's no mention of significant stiffness or limited range of motion, early stages of frozen shoulder could present with dull pain and be exacerbated by movement.
  • Scapulothoracic Bursitis: Inflammation of the bursae between the scapula and the thoracic wall can cause pain in the area between the shoulder blade and the spine, which might fit the patient's description of pain location.
  • Thoracic Outlet Syndrome: This condition involves compression of the nerves and/or blood vessels that pass into the thoracic outlet (the space between your collarbone and first rib). It could cause shoulder pain, especially if certain movements exacerbate the compression.

• Do Not Miss Diagnoses

  • Referred Pain from Cardiac or Pulmonary Issues: Although less likely given the description, it's crucial not to miss cardiac issues like myocardial infarction or pulmonary conditions such as pulmonary embolism, which can refer pain to the shoulder region. The absence of radiating pain and the specific exacerbating factors make these less likely but not impossible.
  • Pancoast Tumor: A type of lung cancer located at the top of the lung, which can cause shoulder pain due to local invasion of the brachial plexus or ribs. It's rare but critical to consider due to its severe implications.

• Rare Diagnoses

  • Osteonecrosis of the Humeral Head: A condition where the blood supply to the bone tissue at the head of the humerus is interrupted, leading to bone death. It's less common and might not be the first consideration without additional risk factors or symptoms.
  • Inflammatory Arthritis (e.g., Rheumatoid Arthritis, Polymyalgia Rheumatica): These conditions can cause shoulder pain but typically present with more systemic symptoms, morning stiffness, and involvement of other joints.