Morphologic variants of light-chain deposition disease in the kidney.

A variety of histologic changes have been observed in the kidneys of patients with light-chain deposition disease. We report 3 cases with kappa light chain deposition who presented with diverse clinical, histological, and ultrastructural features. All the cases were diagnosed by the presence of monoclonal kappa light chain deposits by immunohistochemical methods. Based on the present study and review of literature, four basic patterns of glomerular lesions are identified: (1) minimal glomerular changes without glomerular deposits, but with extensive tubular involvement; (2) mild glomerular changes with glomerular deposits; (3) focal or diffuse proliferative glomerulonephritis with or without crescents, and (4) nodular glomerulosclerosis resembling diabetic glomerulosclerosis. This pathological and clinical variability can cause diagnostic problems at initial presentation. A high index of suspicion is necessary along with appropriate laboratory data and routine staining for light chains.