The sternoclavicular ganglion cyst, a rare pediatric diagnosis.

We briefly describe the case of a 4-year-old girl, referred for imaging of a small, firm, round, skin-colored, subcutaneous nodule that suddenly appeared at her right sternoclavicular junction. A plain radiograph was non-contributory, but ultrasonography revealed a small cystic structure, leading to the diagnosis of a sternoclavicular ganglion cyst. Sternoclavicular ganglion cysts are a rare diagnosis, with only seven reported pediatric cases. A watchful waiting approach can be adopted so long as they remain asymptomatic.