Peripheral Nerve Lymphomatosis.

Lymphoma involvement of peripheral nerves is rare and it may mimic benign neurogenic tumors or neuropraxic injury. This study presents three patterns of presentations in four patients with neurolymphomatous involvement of their peripheral nerves. We reviewed the clinical records of four patients who underwent exploratory brachial plexus surgery (n = 1), pronator tunnel decompression (n = 1) and peripheral nerve exploration (n = 2) and subsequently found to have neurolymphomatosis (NL). Histological diagnoses were diffuse large B-cell lymphoma (n = 3) and NK/T-cell lymphoma (n = 1). NL lacks pathognomonic clinical and imaging features that aid clinicians in diagnosis. Apart from a history of lymphoma, and high clinical index of suspicion, PET-CT scans appear to be a helpful adjunct in detecting high metabolic lesions occuring in situ or systemically. Intra-operative frozen section is helpful to detect round blue cells, before final cytological diagnosis.