A Case Report of Geyser Sign on Magnetic Resonance Imaging (MRI) in a 65-Year-Old Female Patient.

The geyser sign is the flow of arthrographic contrast or joint fluid from the glenohumeral joint across the acromioclavicular joint (AC) and occurs when fluid erupts from the superior aspect of the AC joint during arthrography. The cyst's pathogenesis is linked to a rotator cuff tear and an increase in the amount of fluid in the cyst. This fluid escapes through a one-way valve created by a defect in the AC joint capsule.