Lymphoma involving the ulnar nerve: sonographic findings.

e report a case of a 70-year-old man with lymphoma of the ulnar nerve that presented as a palpable mass on his left forearm and wrist. He had a history of oral lymphoma with complete remission after chemotherapy and radiotherapy. The lesion appeared sonographically as a hypoechoic mass mimicking a cyst encasing the ulnar nerve. However, the mass showed vascularity on color Doppler sonography. Lymphoma involving the peripheral nervous system is very rare.1 To the best of our knowledge, there has been no report of sonographic findings that describe lymphoma involving the peripheral nerves. In this report, we describe the sonographic features of a case involving lymphoma of the ulnar nerve and correlate sonography with magnetic resonance image, positron emission tomography/computed tomography, and histopathologic examination.