Peripheral nerve neurolymphomatosis: Clinical features, treatment, and outcomes

INTRODUCTION: This series characterises 9 patients with neurohistopathologically proven peripheral nerve neurolymphomatosis. METHODS: A search of the hospital neuropathology database from 2002-2019 identified biopsy proven cases. Clinical data, investigation modalities, treatments and outcomes were collated. RESULTS: Median age at neuropathy onset was 47 years, commonly as the initial disease manifestation. Most (8/9) presented with painful asymmetrical sensory disturbance, with additional cranial nerve involvement in three. Neurophysiology typically demonstrated multiple axonal mononeuropathies. Cerebrospinal fluid protein was often raised (6/8). Magnetic resonance imaging suggested peripheral nerve infiltration in 6/9 and positron emission tomography CT in 4/9. Bone marrow biopsy was abnormal in 6/8. Treatment involved systemic or intrathecal chemotherapy and radiotherapy. Median survival was 23 months. DISCUSSION: Neurolymphomatosis is a rare but important cause of neuropathy, particularly in those lacking systemic evidence of lymphoma as correct aggressive treatment can prolong survival. Nerve biopsy is essential to classify lymphoma type and rule out alternatives