Osteosclerotic myeloma and 'POEMS' syndrome

Metabolic bone disease is a major cause of morbidity and mortality in patients suffering from multiple myeloma. This usually results from an imbalance between the osteoclast and osteoblast activity of bone resorption and formation due to the secretion of an osteoclast-activating factor by the myeloma cells. This generally takes the form of lytic lesions, hypercalcaemia and osteoporosis but, in a minority of patients, osteosclerosis is a striking feature. In a proportion of patients with gammopathy and the osteosclerotic form of the disease, there appears to be an association with other symptom complexes including Polyneuropathy, organomegaly, endocrine changes, and skin abnormalities. This article summarizes the clinical, radiological and laboratory features of this syndrome, which is known by the acronym 'POEMS'. It is important to recognize this condition, as it carries a better prognosis than the more common lytic form of the disease and because vincristine, and agents frequently used to treat this condition, may severely exacerbate the neuropathy and should be avoided. This syndrome is also important because it may give some insight into the pathophysiology of the plasma-cell dyscrasias.