Schwannoma of the ulnar nerve: a case report and review of the literature.

: We report a case of a large ulnar nerve schwannoma, a rare type of soft tissue neoplasm. Diagnostic pearls are described to facilitate a more accurate and timely diagnosis. These characteristics include mobility, Tinel's sign, MRI target sign, S100 histological staining, Antoni patterns, and others. With a correct diagnosis, the tumor can be extirpated with preservation of nerve function and a low risk of recurrence.