CRP-19
CRP-019
Clinical History
The patient is a 38 year old female. Recent onset of possible TTP with renal failure. Plasmapheresis performed, but renal function has not improved. Grand mal seizure four days ago. BP 170/100, urinary protein 4.5 g/day. C-ANCA and P-ANCA negative. BUN 68.
Gross Description
Received in saline is one core measuring 15 x 2 mm. Three 1-mm pieces are taken for EM, and the remaining tissue is equally divided for immunofluorescence and light microscopy.
Pathology
Case CRP-019 H&E
Case CRP-019 PASH
Case CRP-019 Silver
Microscopic Description
Light Microscopy
Section contain one fragment of renal cortex with capsule on one end. There are forty-nine glomeruli in· the three levels. Two of these are obsolete, and the remainder show a range of morphology. Some of the glomeruli have a "solid” appearance with increased matrix and occluded capillary lumina. Others show segmental mesangiolysis and kaxyorrhexis. A few of the glomeruli contain capillary thrombi, and many of the capillary loops are markedly congested. The silver stain shows diffuse wrinkling and thickening of the glomerular basement membrane, and numerous double contours are identified. PASH and trichrome stains show diffuse mild interstitial fibrosis and focal mild tubular atrophy. There is also extensive acute tubular necrosis. There is minimal patchy interstitial inflammation. There is moderate arteriolosclerosis, and many of the arterioles are completely occluded by fibrin thrombi.
Immunofluorescence
There are three glomeruli in the sections. One glomerulus shows segmental staining for IgM, IgG, Clq and CJ. However, the remaining glomeruli show no significant staining. Visceral epithelial cells are swollen and contain protein droplets. There is no glomerular staining for IgA, albumin or light chains. There is no staining of the tubular basement membranes or vessels. Tubular epithelium contains numerous protein droplets that stain for IgG, C3, albumin and light chains.
Electron Microscopy
Six thick sections containing a total of four glomeruli are available, but two are globally sclerotic. Ultrastructural examination of the other two glomeruli reveals increased mesangial matrix and focal mesangiolysis. The glomerular basement membranes are markedly thickened, and the subendothelial space is markedly expanded in most of the capillary loops. The expanded space is filled with loose granular and fibrillar material. There is focal mesangial interposition. Most of the capillary are denuded, although occasional visceral epithelial cells are identified. No immune complex deposits are identified.