Successful treatment with rituximab and thalidomide of POEMS syndrome associated with Waldenstrom macroglobulinemia

A POEMS syndrome is a rare disorder characterized by polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy and skin abnormalities including hyperpigmentation and hypertrichosis. Here we report a 55-year-old female case of a POEMS syndrome associated with Waldenstrom macroglobulinemia. The patient had bed-bound polyneuropathy, splenomegaly, IgM-λ type monoclonal (M) protein, elevated λ-type free light chain (FLC), infiltration of CD20-positive lymphoplasmacytic cells in bone marrow, edema and hypertrichosis, and was diagnosed to have an ‘atypical’ POEMS syndrome associated with macroglobulinemia. Nerve conduction studies and a sural nerve biopsy confirmed a demyelination and axonal degeneration without IgM deposition on myelin sheathes. None of neuron-related auto-antibodies characteristic of IgM paraproteinemic neuropathies was detected in her serum and cerebrospinal fluid. Weekly administration of rituximab (375 mg/m2) combined with thalidomide (50 mg/day) was initiated. By eight weeks of the treatment, the ambulation activity of the patient was restored and her polyneuropathy completely disappeared as determined by clinical symptoms and electrophysiological examinations. This is the first case report presenting a POEMS syndrome associated with WM treated with rituximab and thalidomide. The further examinations of the present case should shed light on the pathogenesis of the ‘atypical’ POEMS syndrome.