plasmacytoma) usually in bone (occurs in ~33% of cases). Polyneuropathy: The nerve damage is usually symmetrical, located in distal extremities, and due to the nerve losing its fatty myelin coating and axonal damage. Neurons of the Sensory, motor and autonomic nervous systems are all affected. The typical symptoms are therefore numbness, tingling, and weakness in the feet, later affecting the legs and hands. Pain is unusual, but the weakness may eventually become severe and disabling. The autonomic neuropathy may cause excessive sweating and erectile dysfunction; hormonal changes may also contribute to the latter. It is usually the symptoms of neuropathy which prompt a person with POEMS syndrome to seek medical attention. Other major criteria
Castleman disease: The lymphoproliferative disorder Castleman disease associated with POEMS syndrome is multicentric and occurs in ~15 of cases. It is characterized by a morphology in lymph nodes termed angiofollicular lymph node hyperplasia; an overly activate immune system; excessive production of cytokines including particularly IL-6 and to lesser extents, proliferation of immune B cells and T cells, enlarged lymph nodes, enlarged liver and spleen, capillary leak syndrome, anasarca, evidence of extravascular fluid overload, and organ failure. Patients with Castleman disease without a plasma cell dyscrasia and peripheral neuropathy but having other signs and symptoms of POEMS syndrome can be classified as a Castleman disease variant of POEMS syndrome. Sclerotic bone lesions: These lesions consist of plasma cell tumors encased within or associated with abnormally dense bone structures; in different studies, they have been observed to occur in 27% to 97% of cases.
Papilledema: Papilledema (swelling of retinal optical discs) occurs in 29% to 64% of cases. Papilledema in POEMS syndrome patients may occur with or without visual disturbances, increased intracranial pressure, or changes in cerebral spinal fluid protein levels. Thrombocytosis/polycythemia: Thrombocytosis (increase in blood platelet count) and polycythemia (increase in red blood cells) occurs 54% to 88% and 12% to 19%, respectively, of POEMS syndrome patients and may be may underlying causes of these patients to experience thrombosis events. Laboratory findings
In addition to tests corresponding to the above findings, such as EMG for neuropathy, CT scan, bone marrow biopsy to detect clonal plasma cells, plasma or serum protein electrophoresis to myeloma proteins, other tests can give abnormal results supporting the diagnosis of POEMS syndrome. These included raised blood levels of VEGF, thrombocytes, and/or erythrocyte parameters. Differential diagnosis
Patients diagnosed as having Castleman disease but also exhibiting many of the symptoms and signs of POEMS syndrome but lacking evidence of a peripheral neuropathy and/or clonal plasma cells should not be diagnosed as having POEMS syndrome. They are better classified as having Castleman disease variant of POEMS syndrome. These patients may exhibit high blood levels of the interleukin-6 cytokine and have an inferior overall survival compared to POEMS syndrome patients. Treatment of patients with this POEMS syndrome variant who have evidence of bone lesions and/or myeloma proteins are the same as those for POEMS syndrome patients.