Case 40: Pathology

Case 40 Index

Excellent work, your patient tolerated the kidney biopsy well. With rejection on the differential you ask the lab to rush the results, and that afternoon your pathologist shows you the H&E below.  Click here if you want some quick pathology tips.

Interstitial Inflammation and Lymphocytic Tubulitis in T-Cell Mediated Rejection

Which of the following do you see above (more than one may be correct)?
Inflammatory infiltrate in interstitium
Yes! We see collections of inflammatory cells (look for the dark blue clusters) in the interstitial space.
Podocyte effacement
The podocyte structure is best visualized under electron microscopy, not light microscopy, and there are no glomeruli to assess here.
Crescentic glomerulonephritis
We don’t have any glomeruli to assess here.
We don’t see any glomeruli here – try again!
Thrombotic microangiopathy (TMA)
Hm, we don’t see evidence of TMA here. Evidence of TMA would include intravascular fibrin thrombi, double contours of the glomerular basement membrane, and intimal proliferation of the arterioles. Pick again!
Double contours of the glomerular basement membrane (GBM)
We don’t see any glomeruli here – pick again!

Your pathologist tell you that the glomeruli and arteries appear normal, and shows you another sample. What stain is this?
Jones Methamine Silver Stain
Correct! The silver stain stains collagen and tubular/basement membrane a black color.
Immunohistochemistry (IHC) stain
An IHC stain looks for a particular antigen, and a “positive” stain reveals the antigen as a brown color. Try again!
Periodic-Acid Schiff (PAS) Stain
With a PAS stain, collagen appears a deep purple/magenta color. Pick again!

Click here once you are confident in your final diagnosis!

Case 40 Index
Case 40 Introduction
Case 40 Physical Exam
Case 40 Diagnostic Testing