Tell-tale immune-related neurological syndromes: Should we look for and underlying low-grade B-cell lymphoma? A retrospective study on 12 cases.

INTRODUCTION Immune-related neurological syndromes (affecting both the central and peripheral nervous system, as well as the neuromuscular junction) can associate with low-grade B-cell lymphomas. METHODS We conducted a retrospective study on the records of patients with miscellaneous immune-related neuropathies followed by the "Referral Centre for Neuromuscular Diseases and ALS" in collaboration with the Services of Internal Medicine and Hematology (La Timone Hospital, and the Paoli Calmettes-Insitute, Marseille, France; Geneva University Hospitals, Geneva, Switzerland). Clinical, biological, immunological and histological work-up was carried out and data collected. RESULTS We identified 12 patients with neurological syndromes and atypical presentation/course. In all these patients multiple autoantibodies were found. This prompted us to perform thorough hematologic investigations, that led to the diagnosis of different type of Low-Grade B-Cell lymphomas [i.e. marginal zone lymphomas with lymphoplasmacytic differentiation (n=3), splenic marginal area lymphoma with secondary lymph node invasion (n=1), unclassified marginal area lymphomas (n=8)]. Treatment of the underling lymphoma resulted in an improvement (n=8) or stabilization (n=4) of neurological disease. CONCLUSION Atypical presentation of immune-related neurological syndromes, as well as the presence of antibodies with different antigenic targets should be regarded as "warning signs" and raise the suspicion of a paraneoplastic origin sustained by an underlying low-grade B-cell lymphoma that should be actively sought and treated. Close collaboration between internists, neurologists and hematologists allows for the appropriate management of each case.