Age / Sex : 58 / F

Age / Sex : 58/F

Chief complaint : Pain in upper arm for 7 days

calcific tendinitis of pectoralis major

Discussion

Findings:

MRI :Low signal nodules anterior to midhumeral shaft with high signal intensity of edema in surrounding muscle of pectoralis major

Plain: Multiple calcification in upper arm, anterior to proximal humeral shaft

Differential Diagnosis:

 Calcifying or bone forming mass

 Heterotopic ossification

Diagnosis:  

 Calcific tendonitis of pectoralis major

 Traumatic avulsion of pectoralis major muscle

Discussion:

 Calcific tendonitis is a crystal ( calcium hydroxyapatite ) deposition disease in perarticular region frequently in the shoulder (supraspinatus tendon), hip (gluteal insertion), elbow(triceps insertion) and wrist (flexor carp ulnaris, flexor carpi radialis) at the tendinous insertion site of numerous muscles. Pain and swelling are due to the inflammatory response by the calcification.

Tendon calcification is better delineated with routine radiography or CT than with MRI imaging. MRI may demonstrate extensive edema in the muscle and adjacent bone marrow as high signal intensity on T2.  

References:
        1.       Cahir J, Saifuddin A. Calcific tendonitis of pectoralis major: CT and MRI findings.

Skeletal Radiol (2005); 34: 234-238
 2. Resnick & Kang. Internal Drangements of Joints : Emphasis on MR imagingPhiladelphia , PA: Saunders, 1997:215-218.