Primary non-Hodgkin's lymphoma of the radial nerve: case report.

Objective: Primary lymphomas of peripheral nerves are extremely rare, with the bulk of the literature being case reports. The nerve most commonly affected is the sciatic nerve, with 9 cases reported. To date, there are no reports in the English literature of isolated involvement of the radial nerve by a primary lymphoma.
Clinical Presentation: A 69-year-old woman with a history of osteoporosis, irritable bowel disease, asthma, and Graves' disease presented with a 6-month history of paresthesia in her left superficial sensory radial nerve territory, weakness of thumb extension, and localized pain and swelling in the cubital fossa. Examination showed a painful tender mass in the line of the radial nerve in the cubital fossa, grade 4/5 supination, grade 4-/5 extensor carpi radialis longus and extensor carpi ulnaris, and grade 3/5 finger and thumb extension, all consistent with a radial nerve lesion at the level of the cubital fossa. Ultrasonography and computed tomography confirmed an intraneural tumor. Surgery revealed radial intraneural tumor just after the branch to the extensor carpi radialis longus. It was clearly an infiltrating lesion with no plane between tumor and nerve fascicles. Frozen section confirmed malignancy, and an incomplete excision was performed. Histopathology revealed diffuse large B-cell lymphoma. Surgery was followed with negative staging and a chemotherapy program.
Conclusion: Primary B-cell lymphoma of the peripheral nerve is exceedingly rare and to date has not been reported as an isolated occurrence in the radial nerve. We present a patient who is alive and disease free 65 months after incomplete excision and limited chemotherapy.