Tardy Ulnar Nerve Palsy by Neurofibroma

ABSTRACT

Tardy ulnar nerve palsy is ulnar neuropathy at or around elbow and commonly evaluated in the electromyography laboratory. However, ulnar neuropathy at the elbow due to neurofibroma is rare. Neurofibromas are tumors that arise within nerve fasciculi and anywhere along a nerve from dorsal root ganglion to the terminal nerve branch. We report one case of ulnar neuropathy at the elbow due to neurofibroma. Patient had paresthesia on the left 5th finger and there had been left hypothenar atrophy since 2 months ago. Tinel's sign was positive at left elbow. As a result of electromyography, there were suggestive of right ulnar neuropathy at or around elbow, referred to as tardy ulnar nerve palsy. Ultrasonography showed a diffuse tortuous thickening with multiple neurofibromas arising from individual fascicles of the ulnar nerve in cubital tunnel area. Surgery was then performed to release cubital tunnel of left elbow, then the patient's symptoms improved.