Remission of Chronic Acquired Demyelinating Polyneuropathy Associated With Paraproteinemia After Removal of Skull Plasmacytoma

Abstract

Chronic acquired demyelinating polyneuropathy can be caused by various etiologies. Although chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is the most common chronic acquired demyelinating polyneuropathy, currently there is no suitable biomarker to diagnose CIDP; hence misdiagnosis of CIDP has not been unusual. Herein, we present a patient with initially presumed CIDP, who maintains disease remission after early surgical removal of solitary plasmacytoma during 1-year follow-up. A 55-year-old woman was referred to our hospital due to progressive upper and lower extremity weakness from 6 months ago. Nerve conduction study findings were compatible with acquired demyelinating polyneuropathy, fulfilling electrodiagnostic criteria of CIDP. Serum electrophoresis suggested monoclonal gammopathy of lambda type, but the bone marrow biopsy showed no evidence of neoplastic plasma cell infiltration. Brain magnetic resonance imaging revealed an osteolytic mass involving the right parietal skull and adjacent dura mater. Total excision of the skull mass was performed. The biopsy result was compatible with plasmacytoma. Even without long term administration of high dose corticosteroid, the patient not only has continued to improve clinically, but also showed markedly improved electrophysiological findings during 1-year follow-up.