Fig. 1.

(Top left) Several immunoglobulin thrombi are seen within glomerular capillary lumens and within arteriolar lumens (arrows) (haematoxylin and eosin). By immunofluorescence, these areas stained for kappa light chain (inset) and fibrinogen but not for lambda light chain (immunofluorescence). (Top right) An arteriole contains an immunoglobulin thrombus with a crystalline structure (haematoxylin and eosin). (Bottom left) By electron microscopy, crystalline immunoglobulin thrombi fill a glomerular capillary lumen. (Bottom right) On higher magnification, crystalline immunoglobulin thrombi show a fine periodicity.