Using light microscopy, the volume of the glomerulus was increased, and substantial amounts of PAS and fuchsinophilic
materials were present in the mesangial area.
Connor, "Focal myocytolysis and fuchsinophilic
degeneration of the myocardium of patients dying with various brain lesions," Annals of the New York Academy of Sciences, vol.
The pathological diagnosis of renal TMA wasdefinedbythe following: in acutephase, itwas marked with luminal narrowing or total occlusion by intraluminal, subendothelial, or medial accumulation of eosinophilic, fuchsinophilic
material with staining properties of fibrin, invariably associated with endothelial swelling, denudation, and sometimes fragmented and/or hemolyzed erythrocytes.
Subepithelial deposits, when present in substantial amounts, appear by trichrome stain as fuchsinophilic
granules on the outer aspect of glomerular basement membrane.
Biopsy specimens, taken both from patients and inoculated guinea pigs, demonstrated "small intracellular fuchsinophilic
granules and rods, similar in morphology to Rickettsiae."
Five microscopic features are seen: (a) compressed remnants of lymphoid tissue at the periphery; (b) spindle cells with nuclear palisading; (c) intraparenchymal hemorrhage and erythrocyte extravasation; (d) so-called amianthoid fibers; and (e) intracellular and extracellular fuchsinophilic bodies that stain positive for smooth muscle actin.
The fifth histological feature of IPM is extracellular and intracellular fuchsinophilic bodies.