Abstract
This is a case report of 71-year-old female who complained about a gradually progressive symptom of her right hand. She had a claw hand deformity, numbness of the ring and the little finger, and precision grip disability. She had no episode of trauma. At first, she had visited another clinic, and had been treated with medication. Three weeks after onset, she visited our outpatient clinic in our hospital. Her physical examination findings were as follows: atrophy of the adducter pollicis brevis muscle and the abducter muscle of the little finger. Tinel's sign was positive on the proximal end of the Guyon's canal. Froment's sign was positive. Hand X-ray showed no abnormal findings. Wrist MRI showed a swollen ulnar nerve at the proximal end of the pisiform bone, but there was no space occupying lesion near the ulnar nerve. EMG tests for the ulnar nerve were immeasurable. Laboratory data did not show any abnormal values. We diagnosed this patient as Guyon's canal syndrome, Although the cause was unclear. We performed surgical treatment of Guyon canal release. We identified a mass between the bifurcated site of the ulnar nerve. We removed the mass, released the dorsal carpal ligament, and checked for other occupying lesions. Six months later, her chief complaints were resolved. From the pathological findings, the removed mass was a hematoma. In this case, we were not able to determine the etiology of this mass.
