A. Soft Tissue

1. Tendinitis
2. Biceps
3. Rotator Cuff
   1. Supraspinatus, infraspinatus
   2. Teres minor, subscapularis
4. Bursitis
   1. Subacromioclavicular, usually with tendinitis
   2. adiography should be obtained to rule out ectopic calcificiation

B. Tumor

1. Lung Carcinoma
2. Lymphoma
3. Metastatic Disease
4. Sarcoma
5. Very rare Tumors of the Joint

C. Referred Pain

1. Neuropathy
2. Pneumonia

D. Arthritis

1. Acromioclavicular joint
2. Glenoclavicular joint
3. Osteoarthritis
4. Inflammatory - RA, PMR, reactive
5. Infectious - septic arthritis
6. Crystal Disease - pseudogout more common than gout in the shoulder