Pisotriquetral joint ganglion.

Physical examination of a woman with painful swelling about the ulnar side of her dominant right wrist but no history of trauma revealed a freely mobile soft-tissue mass on the ulnar aspect of the wrist. Radiographs of the wrist were normal. At surgery, a 1 cm x 1 cm ganglion immediately adjacent to the hypothenar muscles was dissected circumferentially and found to have a stalk originating from the ulnar aspect of the pisotriquetral joint. This report suggests that ganglions arising from the medial side of the pisotriquetral joint should be included in the differential diagnosis of ulnar wrist pain.