Solitary periosteal chondroma presenting as a snapping finger: an unusual location.

We report an unusual case of a solitary periosteal chondroma presenting as a snapping finger and pain in the ring finger in a 37-year-old man. The snapping symptom was caused by impingement of this solitary chondroma. In this case, the periosteal chondroma was detached due to a finger sprain. Thus, the solitary chondroma was impinged between basal phalanx and extensor tendon, causing the pain and snapping finger. When patients with snapping finger present, CT scans can be helpful to make a correct diagnosis. To the best of our knowledge, this condition has not been described in the PIP joint.