POEMS syndrome is defined by the presence of a peripheral neuropathy (P), a monoclonal plasma cell disorder (M), and other paraneoplastic features, the most common of which include organomegaly (O), endocrinopathy (E), skin changes (S), papilledema, edema, effusions, ascites, and thrombocytosis. Virtually all patients will have either sclerotic bone lesion(s) or co-existent Castleman's disease. Not all features of the disease are required to make the diagnosis, and early recognition is important to reduce morbidity. Other names for the syndrome include osteosclerotic myeloma, Crow-Fukase syndrome, or Takatsuki syndrome. Because the peripheral neuropathy is frequently the overriding symptom and because the characteristics of the neuropathy are similar to that chronic inflammatory demyelinating polyneuropathy (CIDP), patients are frequently misdiagnosed with CIDP or monoclonal gammopathy of underdetermined significance (MGUS)-associated peripheral neuropathy. Not until additional features of the POEMS syndrome are recognized is the correct diagnosis made and effective therapies initiated. Clues to an early diagnosis include thrombocytosis and sclerotic bone lesions on plain skeletal radiographs. Therapies that may be effective in patients with CIDP and MGUS-associated peripheral neuropathy (intravenous gammaglobulin and plasmapheresis) are not effective in patients with POEMS. Instead, the mainstays of therapy for patients with POEMS include irradiation, corticosteroids, and alkylator-based therapy, including high-dose chemotherapy with peripheral blood stem cell transplantation.
