Paralabral cyst of the shoulder
Paralabral cysts of the shoulder are a location-specific type of paralabral cysts. They are an infrequent finding on MRI, however, are an important diagnostic entity as they may cause a compression neuropathy of the suprascapular or axillary nerves depending on where they occur, along with a variety of other symptoms.
Epidemiology
They may occur in around 2-4% of the population and presentation may be commoner in males (especially around the third to fourth decades).
Pathology
The exact pathogenesis is not well known and they may represent a synovial cyst, ganglion cyst or pseudocyst.
Associations
There is a high association with glenoid labral tears.
Location
They most frequently occur along the posterior, anterior, and superior aspects of the glenohumeral joint in decreasing order, with inferiorly located cysts being the least common. The posterosuperior location may be the most common .
Radiographic features
Ultrasound
May be seen as a variably sized cyst in close proximity to the glenohumeral joint.
MRI
A paralabral cyst is termed when a focal well-defined collection of fluid is seen within 1 cm of the glenoid labrum. They can be unilocular or multilocular. They may be difficult to identify on MR arthrography unless a T2 sequence is performed. Direct communication between a cyst and joint is not commonly seen.
See also
Siehe auch:
Assoziationen und Differentialdiagnosen zu labrale Zyste Schulter: