October 2019

Cystic mass at the AC joint

Clinical Info

Two elderly patients examined for SONOZORG a primary care ultrasound facility. Both patients have a lump at the AC joint.

Ultrasound Images & Clips

cystic mass at the AC joint

Cyst with some synovial proliferations without flow
Cyst with some synovial proliferations without flow
Another image of the cyst
Another image of the cyst
There is no flow in the cyst
There is no flow in the cyst
Another image of the AC joint
Another image of the AC joint
This is the AC joint of the second patient
This is the AC joint of the second patient
Another image of the AC joint
Another image of the AC joint
Another image of the AC joint
Another image of the AC joint
There is no flow in the cyst
There is no flow in the cyst
This is the AC joint on the other side of the same patient
This is the AC joint on the other side of the same patient
This is the AC joint on the other side of the same patient. In both patents we looked at the rest of the shoulder. There was no fluid in the bursa in both.
This is the AC joint on the other side of the same patient. In both patents we looked at the rest of the shoulder. There was no fluid in the bursa in both.
This is an example of a geyser sign in a patient with a complete absent of the rotator cuff
This is an example of a geyser sign in a patient with a complete absent of the rotator cuff
This is the X ray of the same patient
This is the X ray of the same patient

Conclusion

The lump is caused by a cyst in case of AC arthrosis. These cysts must be differentiated from the geyser sign a fluid collection at the AC joint in patients with a full-thickness rotator cuff tear that leads to instability of the humerus in the glenohumeral joint. Eventually, chronic impaction from the humeral head disrupts the inferior acromioclavicular (AC) joint capsule, and glenohumeral joint fluid "erupts" superiorly through the AC interval into the subdeltoid bursa and to the AC joint.


Created with

  • Hitachi Ultrasound System