Sonography of wrist ganglion cysts: variable and noncystic appearances

In our clinical practice, we have noted wrist ganglion cysts that do not fulfill the criteria for simple cysts. This study retrospectively evaluated the sonographic features of wrist ganglia.

After Institutional Review Board approval, medical records from 1993 through 2003 were searched using International Classification of Diseases, Ninth Revision codes and key words, and sonography log books from 2000 through 2004 were reviewed, which identified 20 wrist ganglion cysts in 16 patients that were proven at surgery or aspiration. A retrospective review of sonographic images was carried out by 2 musculoskeletal radiologists by consensus. Images were evaluated for cyst location, volume, largest dimension, joint or tendon extension, echogenicity, septations, internal echogenicity, posterior acoustic enhancement, margins, lobularity, and vascularity.

Of the 20 wrist ganglia, 15 were volar (10 between the flexor carpi radialis and the radial artery), and 5 were dorsal (2 over the scapholunate ligament). The mean volume was 2081 mm3 (range, 90-15,000 mm3), and the mean largest dimension was 17.3 mm (range, 7-30 mm). Seven volar ganglia showed joint communication. Ten ganglia were anechoic; 7 were hypoechoic; and 3 had anechoic and hypoechoic areas. Eight had septations; 8 had internal echogenic areas; 15 had posterior acoustic enhancement; 13 had well-defined margins; 12 were lobular; and none were vascular. Cysts that were anechoic (P < .0001) or with posterior acoustic enhancement (P = .04) were significantly larger than those that were hypoechoic or without posterior acoustic enhancement.

Small wrist ganglion cysts (< or = 10 mm in the mean largest dimension) often appear hypoechoic without posterior acoustic enhancement and do not fulfill the criteria for a simple cyst.