The features of this syndrome are polyneuropathy, organomegaly, endocrinopathy, multiple myeloma, and skin changes (POEMS). Patients usually have a severe, progressive sensorimotor polyneuropathy associated with sclerotic bone lesions from myeloma. Polyneuropathy occurs in ~1.4% of myelomas, but the POEMS syndrome is only a rare subset of that group. Unlike typical myeloma, hepatomegaly and lymphadenopathy occur in about two-thirds of patients, and splenomegaly is seen in one-third. The lymphadenopathy frequently resembles Castleman’s disease histologically, a condition that has been linked to IL-6 overproduction. The endocrine manifestations include amenorrhea in women and impotence and gynecomastia in men. Hyperprolactinemia due to loss of normal inhibitory control by the hypothalamus may be associated with other central nervous system manifestations such as papilledema and elevated cerebrospinal fluid pressure and protein. Type 2 diabetes mellitus occurs in about one-third of patients. Hypothyroidism and adrenal insufficiency are occasionally noted. Skin
changes are diverse: hyperpigmentation, hypertrichosis, skin thickening,and digital clubbing. Other manifestations include peripheral edema, ascites, pleural effusions, fever, and thrombocytosis.The pathogenesis of the disease is unclear, but high circulating levels of the proinflammatory cytokines IL-1, IL-6, VEGF, and TNF have been documented and levels of the inhibitory cytokine TGF-? are lower than expected. Treatment of the myeloma may result in an improvement in the other disease manifestations.Patients are often treated similarly to those with myeloma. Plasmapheresis does not appear to be of benefit in POEMS syndrome. Patients presenting with isolated sclerotic lesions may have resolution of neuropathic symptoms after local therapy for plasmacytoma with radiotherapy.Similar to multiple myeloma, novel agents as well as high-dose therapy with autologous stem cell transplant have been pursued in selected patients and have been associated with prolonged progression-free survival.