[A case of POEMS syndrome associated with Waldenström's macroglobulinemia and treated with lenalidomide].

This report deals with a 46-year-old male with Waldenström's macroglobulinemia (WM), who developed POEMS syndrome four years after diagnosis. The patient was diagnosed with WM, based on the presence of IgM-κ type monoclonal (M) protein and infiltration of lymphoplasmacytic cells identified in bone marrow aspirates. Four years later, the patient presented with progressive weakness and paresthesia of the limb extremities, and he was admitted to our hospital. Physical and neurological examination on admission revealed polyneuropathy, hepatosplenomegaly, hypothyroidism, IgM-κ M protein, leg edema, and cutaneous hyperpigmentation. He fulfilled the diagnostic criteria for POEMS syndrome. Laboratory tests showed normocytic normochromic anemia, elevated erythrocyte sedimentation rate, and increased levels of soluble IL-2 receptor, IL-6 and plasma vascular endothelial growth factor (VEGF). He was started on lenalidomide. After therapy, the leg edema and limb dysesthesia improved, and the VEGF level decreased from 608 pg/ml to 380 pg/ml. This is a very rare case of POEMS syndrome associated with WM, and is the first case treated with lenalidomide in Japan. VEGF presumably producted WM may be associated with development of POEMS syndrome.