Image Interpretation: There is a well-defined hypoechoic cystic structure measuring approximately 18 × 16 × 9 mm overlying the capitate with internal irregular hyperechoic debris. The lesion is noncompressible with sonopalpation and demonstrates no internal Doppler flow. The capitate demonstrates no cortical irregularity. The extensor digitorum, extensor pollicis longus, and extensor carpi radialis brevis tendons are normal in appearance without focal heterogeneity, tendon sheath fluid, or increased Doppler signal.

Teaching Pearl: Historically, dorsal ganglion cysts have been cited as the most common location within the wrist and account for between 60-70% of all wrist ganglion cysts. Dorsal ganglion cysts most often occur superficial to the scapholunate ligament. Volar ganglion cysts will most often occur between the flexor carpi radialis tendon and radial artery. However, in more recent imaging studies, volar ganglion cysts are more common and underrepresented in surgical literature. Volar cysts are also more common in pediatric patients less than 10 years old. When evaluating a ganglion cyst, the entire structure should be scanned both in transverse and sagittal planes to fully evaluate the structure for well-defined borders as well as a possible stalk from a surrounding joint space or tendon sheath. Doppler evaluation of cystic area should be performed with ganglion cysts classically having no internal Doppler flow. References: 1. Zhang, A., Falkowski, A.L., Jacobson, J.A., Kim, S.M., Koh, S.H. and Gaetke-Udager, K. (2019), Sonography of Wrist Ganglion Cysts: Which Location Is Most Common? J Ultrasound Med, 38: 2155-2 2. Wang, G., Jacobson, J.A., Feng, F.Y., Girish, G., Caoili, E.M. and Brandon, C. (2007), Sonography of Wrist Ganglion Cysts. Journal of Ultrasound in Medicine, 26: 1323-1328. https://doi.org/10.7863/jum.2007.26.10.1323 60. https://doi.org/10.1002/jum.14912 3. Krishnan P, Wolf JM. Pediatric Ganglions of the Hand and Wrist: A Review of Current Literature. J Hand Surg Am. 2022 Jun;47(6):554-560. doi: 10.1016/j.jhsa.2021.12.015. Epub 2022 Feb 22. PMID: 35216864.