3113 Anti-Ma1/Ma2 paraneoplastic neurological syndrome associated with malignant mesothelioma and demyelinating neuropathy

Anti-Ma1/Ma2 paraneoplastic neurological syndrome (PNS) is a rare disorder often associated with malignancies.We present the case of a 74-year-old left-handed man who initially presented with mild gait ataxia.Neuroimaging revealed T2 signal hyperintensity in the right amygdala and hippocampus, as well as in the left caudate head.Serum and cerebrospinal fluid (CSF) analysis confirmed the presence of anti-Ma-1/Ma-2 antibodies.Despite extensive radiological and serum biomarker investigations, no malignancy was initially detected.However, over two months, the patient exhibited progressive neurological decline, including severe gait ataxia, opsoclonus, and leftsided distal weakness indicative of ulnar nerve dysfunction.Electrophysiology studies demonstrated demyelinating large fiber polyneuropathy.Treatment involved high-dose corticosteroids, intravenous immune globulins (IVIG), mycophenolate, and Rituximab.While neurological symptoms stabilized, the patient developed insidious respiratory distress four months later, secondary to right-sided parapneumonic effusion.Subsequent biopsy confirmed malignant mesothelioma.This case underscores the rare association between anti-Ma1/Ma2 PNS and mesothelioma, emphasizing the necessity for vigilant surveillance even if initial extensive screening for malignancy yielded no results.Only three similar cases have been reported to our knowledge, with mesothelioma diagnosis emerging usually after few years of clinicoradiological surveillance.Although an association with axonal peripheral neuropathy has been reported previously, our case exhibited demyelinating neuropathy.Despite the rarity of the association between anti-Ma1/Ma2 PNS and mesothelioma, awareness of this association is vital for prompt diagnosis and treatment.This report contributes to the limited literature on this subject and underscores the importance of clinical awareness of anti-Ma1/Ma2 PNS and its associated malignancies.