Renal disease in POEMS syndrome: report on a case and review of the literature.

POEMS syndrome is a multisystem disorder associated with plasma cell dyscrasias. This report describes a patient with POEMS-associated renal disease and reviews the literature on biopsy-proven renal involvement in POEMS syndrome. Our patient had glomerulonephritis with membranoproliferative features on light-microscopy without characteristic findings on immunofluorescence, and with ultrastructural evidence of glomerular microangiopathy. Ultrastructural evidence of microangiopathy was also found in vasa nervorum. In 20 other cases of POEMS-associated renal disease, 16 had glomerular disease. Light-microscopy showed membranoproliferative-like glomerulopathy in 14 patients and glomerular microangiopathy in two. Ultrastructural evidence of microangiopathy was present in all 15 patients in whom electron-microscopy was done. Thus, in most patients with POEMS-associated glomerular disease a characteristic lesion is present with evidence of endothelial injury. As endothelial damage is also found in endoneural vessels, generalized endothelial injury may play a role in non-renal manifestations of POEMS syndrome. In previous reviews manifestations of the POEMS syndrome were similar for patients with or without myeloma. Among patients with biopsy-proven glomerular disease, however, myeloma patients are underrepresented. Whether this represents a sampling error or has true pathophysiological significance remains to be established.