Case 12

History
69 year old man with chronic right shoulder weakness and pain complaining of fluctuant painless superficial mass overlying the AC joint.

 
image A
A		 image B
B

image C
C

Diagnosis?

    

Findings
Coronal fat suppressed T2 weighted images (A & B) demonstrated massive rotator cuff tear with superior migration of the humeral head. There is acromioclavicular joint degenerative disease and fluid in the AC joint. There is communication of fluid between the glenohumeral joint, subacromial bursa, AC joint and a small cyst in the soft tissues above the joint.
               
Sagital fat suppressed T2 image (C) shows communication between fluid in the subacromial bursa and a cyst in the subcutaneous tissues above the clavicle.

Diagnosis
AC joint cyst. Geyser lesion.

Discussion
Fluid extending from the glenohumeral joint through a chronic rotator cuff tear, into the subacromial bursa, into the acromioclavicular joint, through the joint and into superior soft tissues is known as a geyser lesion.

AC joint cysts may be a manifestation of an underlying massive rotator cuff tear. Such a cyst represents fluid communication between the glenohumeral and AC joints. The term “geyser” reflects the associated arthrographic sign of contrast extending from the injected shoulder through a torn rotator cuff and into the AC joint. Aspiration or resection \of the cyst alone usually leads to recurrence.

References
Journal of Computer Assisted Tomography. 23(1):141-3, 1999 Jan-Feb.

 

Submitted by David Orange, M.D.
Reviewed by Paul Clifford, M.D.