[POEMS syndrome]

Abstract

POEMS syndrome has been defined as an association of plasma cell dyscrasia with polyneuropathy, organomegaly, endocrinopathy, M protein and skin changes. Although certain authors do not distinguish this syndrome from osteosclerosing myeloma, syndromes comparable to POEMS have been observed without bone lesions. Others have described the clinical features involved under the terms of Crow-Fukase's syndrome, PEP syndrome (pigmentation, oedema, plasma cell dyscrasia, or Takatsuki's syndrome. Seen in men twice as often as in women, usually between the ages of 40-50 years, all five clinical features are not always present or may be accompanied by other signs. The first sign of the peripheral polyneuropathy is usually sensorial impairment followed by distal then proximal motor deficit. The deficit is usually severe and 50% of the patients become unable to walk. Cranial nerves are rarely involved. Liver, spleen and lymph node enlargement are observed. The most frequent signs of an endocrinopathy are gynaecomastia, atrophy of the testicules, impotence and amenorrhoea. Testosterone levels are low and oestrogen levels are increased in men together with luteinizing hormone, follicle stimulating hormone and prolactin. Hypothyroidism is frequent and diabetes mellitus is observed in 50% of the patients. Protein M is a monoclonal immunoglobulin (IgG or IgA), almost always with a light lambda chain. Skin changes include hyperpigmentation, hypertrichosis, hyperhidrosis, thickening of the skin suggestive of sclerodermia and papillary angiomas. Other signs, especially peripheral oedema often occur early in the disease course and may precede the peripheral neuropathy. POEMS syndrome is often associated with a myeloma (up to 50% of the cases in certain series). Although immunoglobulin deposit on myelin sheaths, anti-endocrine antibodies and receptors of lambda chains have been proposed as playing a role, no mechanism of pathogenesis has been determined. The natural history of the disease leads to a severe polyneuropathy. The patients become totally bedridden and death results from complications of decubitus rather from the direct effect of the underlying dyscrasia. When bone lesions are minor, radiotherapy or surgery can improve the neuropathy and resection of a solitary plasmocytoma can lead to total remission. Chemotherapy or corticosteroids may improve the polyneuropathy in certain cases. Plasma exchange has not been successful.