Female, 58 years old. Reason: lateral shoulder mass History: lateral shoulder mass Markers were placed along the lateral aspect of the shoulder, presumably denoting a palpable mass.There is a mass of predominantly fat signal intensity arising from the lateral fibers of the deltoid muscle and extending into the subcutaneous fat. Interdigitation of the deltoid muscle fibers within the fatty tissue suggests an intramuscular lipoma. The mass is approximately 3.7 x 3 cm in transverse dimension and approximately 8 cm in craniocaudal dimension. The mass is not included in its entirety on postcontrast images, but we see no enhancement in the visualized component of mass or other findings to suggest malignancy. We see no additional soft tissue masses.Please note that this study was not optimized to evaluate the rotator cuff or intrinsic structures of the shoulder. Within these limitations, the following observations can be made:Intermediate signal intensity within the supraspinatus tendon indicates tendinosis with defects along the bursal surface of the tendon distally indicating partial thickness tearing. The supraspinatus muscle is within normal limits.There is mild increased signal suggesting tendinosis of the infraspinatus tendon, but we see no discrete tear. The infraspinatus muscle appears normal.The teres minor tendon and muscle appear normal.There is thickening and increased signal in the subscapularis, indicating moderate tendinosis.Small cysts in the anterior aspect of the humeral head are likely secondary to the aforementioned rotator cuff abnormalities.Moderate osteoarthritis affects the acromioclavicular joint, and there is spurring of the anterior aspect of the acromion process.There is fluid within the subacromial/subdeltoid bursa, particularly anteriorly with peripheral enhancement indicating synovitis.Glenohumeral joint alignment is within normal limits. We see no joint effusion.Although we see no fluid signal intensity within the glenoid labrum, intermediate signal intensity within the superior labrum likely reflects degenerative tearing.Mildly increased signal intensity within the tendon of the long head of the biceps particularly at its transition between the rotator cuff interval and intertubercular groove suggests mild tendinosis.
1.Intramuscular lipoma affecting the lateral fibers of the deltoid as described above.2.Degenerative arthritic changes of the shoulder as described above including rotator cuff tendinosis and bursal surface partial thickness tearing of the supraspinatus tendon.