Case Reports
Paralabral "Air" Cyst of the Shoulder
Am J Orthop. 2009 June;38(6):E107-E109
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Santiago A. Lozano Calderón, MD, Catherine Maldjian, MD, and Richard M. Magill, MD
Dr. Lozano Calderón is Resident, Department of Orthopaedic Surgery, Dr. Maldjian is Clinical Instructor, Department of Radiology, and Dr. Magill is Instructor, Department of Orthopaedic Surgery, Westchester Medical Center, New York Medical College, Valhalla, New York.
Abstract not available. Introduction provided instead.
Cystic masses around the shoulder are an uncommon but clinically relevant finding1-3 for two reasons. First of all, they are associated with labral tears, more commonly located in the posterior and superior aspect of the glenoid.1,4 Secondly, they may cause suprascapular or axillary nerve impingement, the so-called quadrilateral syndrome.1,5,6
Diagnosis is mostly made through magnetic resonance imaging (MRI).1,3,7,8 Characteristically, this fluid collection is best demonstrated on a T2-weighted pulse sequence.1,3 When evaluated in the coronal, sagittal, and transverse planes, these cystic lesions have been reported to measure an average of 2.2 cm in diameter and 2.8 mL in volume.1 These lesions, loculated or not, are described as containing fluid.1,5,7-9 “Air” in paralabral cysts of the shoulder has not been reported to our knowledge.
We present the case of a female patient in her late 40s who had a posttraumatic air-containing paralabral cyst of the glenoid with prior history of shoulder trauma. Documentation of the lesion was performed with shoulder MRI, which was obtained because of persistence of symptoms after a self–standing height fall. Presence of the air was confirmed with simultaneous shoulder radiographs, which showed radiolucency in the same location. The patient had been in a motor vehicle accident in the past in which the same shoulder was injured. Radiographs from that time also showed the paralabral cyst as a smaller focus of air.