Sonographic appearance of a schwannoma mimicking an axillary lymphadenopathy.

Schwannomas are benign nerve sheath tumors derived from Schwann cells and are the most common type of peripheral nerve tumor. Schwannomas occur mainly in the extremities, trunk, and head and are rarely manifested in the axilla. Although various solid tumors can develop in the axilla, only a few cases of schwannoma in the axillary cavity have been reported. Herein, we describe the sonographic appearance of a schwannoma arising from the brachial plexus in the axilla.