The combination of thrombotic microangiopathy and nodular sclerosis in light chain deposition disease.

The authors reported the first case of nodular glomerulosclerosis, mesangiolysis, and thrombotic microangiopathy in a 69-year-old Thai man with chronic glomerulopathy from light chain deposition disease associated with multiple myeloma and kappa monoclonal gammopathy. He presented with subacute onset of generalized edema, hypertension, and renal insufficiency. Blood examinations revealed kappa monoclonal gammopathy. The diagnosis of multiple myeloma was confirmed by bone marrow aspiration and biopsy. The renal pathologies demonstrated specific findings for light chain deposition disease which were type II nodular glomerulosclerosis, strongly PAS-stained tubular basement membrane, monotypic-kappa light chain deposition along tubular and glomerular basement membranes, and granular electron dense deposits in electron microscopy. However the authors also found the concomitant findings of mesangial and endothelial injuries which were mesangiolysis and thrombotic microangiopathy. Of interest, type II nodular sclerosis and thrombotic microangiopathy were caused by the same cell injury. These might shed new light on the pathogenesis of glomerular injury in monoclonal immunoglobulin deposition disease (MIDD).