CRP-16
CRP-016
Clinical History
The patient is a 43 year old female. Malignant hypertension with progressive acute renal failure. BUN 64, creatinine 6.5, urinary protein less than 2 g/24 hr. BP 210/120.
Gross Description
Received in transport media are two cores measuring 6 and 7 mm in length and l mm in diameter. Three 1-mm pieces are taken for EM. The remainder of one core is submitted for immunofluorescence, and the other core is submitted for light microscopy.
Pathology
Case CRP-016 H&E
Case CRP-016 PASH
Case CRP-016 Silver
Case CRP-016 Trichrome
Microscopic Description
Light Microscopy
The specimen consists of a small fragment of renal cortex that contains 70 glomeruli in the three levels. Twenty-two of these are obsolete. The others are similar and show striking ischemic atrophy with shrinkage of the glomerular tuft, increase in mesangial matrix and markedly thickened and wrinkled capillary basement membranes. The silver stain confirms the marked GBM thickening, but no spike formation or splitting is identified. There is diffuse mild interstitial fibrosis, but there is moderate diffuse tubular atrophy. There is also patchy chronic inflammation, and occasional examples of tubulitis are noted. The mononuclear cell infiltrate is primarily lymphocytic with only a few plasma cells and no eosinophils. The most striking change in the biopsy is the appearance of the vessels. The arterioles and small arteries are markedly thickened with almost complete obliteration of the lumina. The interlobular arteries show concentric fibrosis and elastic reduplication (onion skinning). Several of the interlobular arteries contain fibrin thrombi, and occasional red cells and red cell fragments are identified in the thickened intima. No vascular necrosis is identified.
Immunofluorescence
There are twelve glomeruli in the sections. Three of these are obsolete. There is 1+ mesangial staining for C3. There is no glomerular staining for IgG, IgM, IgA, Clq or light chains. Some of the tubules contain casts that stain for IgA and kappa and lambda. There is 2+ staining for C3 in the vessels.
Electron Microscopy
Three thick sections containing a total of nineteen glomeruli are available. Three are obsolete, but the others are similar and show marked ischemic atrophy. Ultrastructural examination confirms the generalized thickening and wrinkling of the capillary basement membranes. Some of the peripheral loops demonstrate widening of the subendothelial space. No electron dense deposits are identified in the capillary basement membranes or mesangial regions. Foot processes show only focal fusion.