Systemic kappa light-chain deposition. An ultrastructural and immunohistochemical study.
This report describes the pathology of kappa light-chain deposition in a 55-year-old patient who presented with respiratory insufficiency and hepatomegaly. Biopsies of lung and liver showed PAS-positive deposits which did not stain with congo red, crystal violet, or thioflavin-T. By indirect immunoperoxidase techniques, the deposits were composed of kappa light-chain immunoglobin. Electron microscopy revealed granular and fibrillar electron-dense material which lacked the characteristics of amyloid. Subsequent clinical studies showed this patient had a plasma cell dyscrasia. These data show that kappa light-chain deposition is not limited to the kidney, and that the first manifestation of a plasma cell dyscrasia may be systemic deposits of light chain. These deposits can be distinguished from amyloid by their immunochemical, tinctorial, and ultrastructural appearance.
D000686:Amyloidosis / Q000473:pathology; D001706:Biopsy; D003937:Diagnosis, Differential; D006529:Hepatomegaly; D006801:Humans; D007124:Immunoenzyme Techniques; D007147:Immunoglobulin Light Chains / Q000032:analysis*; D007145:Immunoglobulin kappa-Chains / Q000032:analysis*; D008099:Liver / Q000473:pathology* / Q000648:ultrastructure; D008168:Lung / Q000473:pathology* / Q000648:ultrastructure; D008854:Microscopy, Electron; D008875:Middle Aged; D012131:Respiratory Insufficiency / Q000473:pathology*
D007147:Immunoglobulin Light Chains; D007145:Immunoglobulin kappa-Chains