Reason: Characterize new cystic mass anterior left shoulder History: Sudden appearance of left shoulder mass a month ago. ROTATOR CUFF: There is thickening and intermediate signal intensity within the supraspinatus indicating moderate tendinosis. There is a full-thickness tear of the posterior fibers of the supraspinatus at the level of its insertion on the greater tuberosity measuring approximately 1.5 cm in AP dimension. There is extension of the tear to involve the anterior fibers of the infraspinatus. There is increased signal abnormality within the muscle belly of the supraspinatus suggesting that this tear may be acute in etiology. The supraspinatus muscle appears intact. The infraspinatus muscle appears intact. The subscapularis and teres minor muscles and tendons appear intact.SUPRASPINATUS OUTLET: Moderate osteoarthritis affects the acromioclavicular joint. There is a small glenohumeral joint effusion which extends into the subacromial subdeltoid bursa confirming a full-thickness tear. There is an additional focus of signal abnormality within the anterior fibers of the deltoid musculature measuring approximately 1.2 x 0.8 x 3.7 cm with apparent increased signal abnormality on T1 and T2-weighted images and peripheral enhancement on postcontrast sequences. This collection is immediately adjacent to a skin marker which presumably corresponds to the patient's palpable area of concern. Additionally, there is another focus of signal abnormality more posteriorly within the deltoid musculature measuring 2.0 x 1.9 x 5.1 cm which also demonstrates increased signal abnormality on T1 and T2-weighted images and peripheral enhancement on postcontrast sequences. There are foci of low signal intensity debris within these collections as well as within the glenohumeral joint and subacromial subdeltoid bursa. GLENOHUMERAL JOINT AND GLENOID LABRUM: There is a small glenohumeral joint effusion which demonstrates enhancement on postcontrast sequences indicating a synovitis. The glenohumeral joint alignment is anatomic. There is heterogeneity and increased signal intensity within the anterior and superior glenoid labrum likely representing a combination of degeneration and degenerative tearing. There is focal near full-thickness articular cartilage degeneration along the superior aspect of the articular cartilage of the humeral head.BICEPS TENDON: There is thickening and intermediate signal intensity within the tendon of the long head of the biceps indicating moderate tendinosis. The biceps anchor is not well visualized which may represent a complete rupture of the tendon with retraction.ADDITIONAL
1. Multiple lobulated foci of signal abnormality within the deltoid musculature which demonstrate peripheral enhancement on postcontrast sequences. There is associated increased signal abnormality on T1-weighted images within these collections. This may represent subacute blood products/hematoma, however, melanoma and alveolar soft part sarcoma remain as differential considerations.2. Glenohumeral joint effusion with findings indicating a synovitis and subacromial subdeltoid bursitis.3. Full-thickness rotator cuff tear and tendinosis as described above.4. Probable complete rupture of the tendon of the long head biceps.5. Osteoarthritis of the shoulder and other findings as described above.