Neurolymphomatosis of the Ulnar Nerve Presenting as Cubital Tunnel Syndrome: A Case Report.

Lymphoma is a malignant tumour of the lymphatic system. Neurolymphomatosis occurs when lymphoma cells invade the peripheral nervous system (PNS). Neurolymphomatosis has been reported involving the sciatic nerve, nerve roots and within the axilla and the upper arm. It can cause nerve dysfunction depending on the involved nerve. Neurolymphomatosis involving the ulnar nerve is rare. We report a patient with neurolymphomatosis of the ulnar nerve around the elbow that presented with features of cubital tunnel syndrome. A high index of suspicion is necessary in patients with cubital tunnel syndrome that present with uncommon symptoms such as sudden onset, rapid progression and/or severe pain. Level of Evidence: Level V (Therapeutic).