Two Schwannomas Derived from the Ulnar Nerve Confirmed by Ultrasonography

ABSTRACT

Schwannoma is a rare tumor from the peripheral nerve and is mainly found alone. Diagnosis is made by ultrasonography or magnetic resonance imaging, and magnetic resonance imaging is preferred to ultrasonography for differential diagnosis of mass. After diagnosis, treatment is performed through surgical excision. In this case, a very small-sized neuropathy-causing lesion was identified through ultrasonography with electrodiagnostic study, and the other mass in the same nerve was discovered by chance through ultrasonography. Both masses were identified as schwannoma originating from the ulnar nerve and were successfully excised. We confirmed the advantages of ultrasonography in the rare diagnosis and again showed that ultrasonography has a diagnostic value that is not inferior to magnetic resonance imaging. Also, cases of multiple schwannomas confined to the ulnar nerve are rare and have been rarely reported worldwide. Therefore, it is reported together with the previous reports.