Intratendinous ganglion and carpometacarpal boss. A report of two cases.

Two cases of intratendinous ganglion which developed over the underlying carpometacarpal boss, the dorsal osteoarthritic spur at the second or third carpometacarpal joint, are presented. The intratendinous ganglion, which may predispose the affected tendon to spontaneous rupture, must be differentiated from carpometacarpal ganglion and bursitis, which are usually asymptomatic. When the intratendinous ganglion associated with underlying carpometacarpal boss is removed, this bony prominence at the carpometacarpal joint which is the cause of irritation leading to mucoid degeneration and ganglion formation should also be excised.