POEMS syndrome is a plasma cell proliferative disorder is characterized by the presence of peripheral neuropathy (P), organomegaly (O), monoclonal gammopathy (M), endocrinopathy or edema (E) and skin change (S). It can be rarely related to multiple myeloma. A 48-year-old man was admitted to our hospital due to paresthesia of both inguinal areas and weakness of both lower extremities. He had a history of Castleman's disease, and showed features of polyneuropathy, multiple osteoblastic lesions, hepatosplenomegaly, pretibial pitting edema, and papilledema. The serum and urine electrophoresis were negative, but urine immunofixagion could detect monoclonal protein. Plasmacytoma was confirmed through the biopsy for the osteoblastic lesions. We present a case of combined POEMS syndrome and multiple myeloma with positive M protein only on immunofixation in order to share our experience with physicians and specialists. (Korean J Hematol 2008;43:253-257.)

Keywords: POEMS syndrome, Multiple myeloma, Osteoblastic lesion