Lymphoma involving the ulnar nerve: Sonographic findings

We 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.