Digital myxoid cyst - ganglion-like pseudocyst of the joint space

A myxoid cyst on the dorsum of the left index finger is presented. A connec tion of this pseudocyst to the underlying joint was shown by means of magne tic resonance imaging. Surgically the connecting tract to the distal interp halangeal joint was easily demonstrated and histologically a ductal : struc ture was focally seen by means of serial sections. These structures also su ggest such a connection. These findings confirm the : view that this pseudo cyst can be interpreted as a ganglion. Therapeutically complete excision wi th careful tying off of the channel to the joint appears to be the best met hod to avoid recurrence. The injection of sclerosing agents, a conservative treatment modality proposed by some authors, may be problematic in the lig ht of the pathogenesis discussed here; however dammage to the finger joint has not been so far observed.