POEMS Syndrome with Biclonal Gammopathy and Renal Involvement.

Polyneuropathy, Organomegaly, Endocrinopathy, M-protein and Skin changes (POEMS) syndrome manifests as elevated levels of vascular endothelial growth factor (VEGF) and monoclonal gammopathy. We treated a case of POEMS syndrome showing monoclonality in both IgA-λ and IgG-κ. Serial renal biopsies before treatment and after normalization of the VEGF levels suggested that glomerular microangiopathy had developed due to VEGF, while biclonal gammopathy was not eliminated. The renal pathology, proteinuria, and renal function all clearly improved. Although severe polyneuropathy limited activities of daily living and enforced a bedridden state, the patient dramatically regained his motor function, achieving crutch walking after induction of remission. This case is highly notable due to the presence of biclonality and repeated biopsies.