What you're seeing here on light microscopy is in fact that nodule,
but it took a long time for you to develop
and hence, what we did earlier, we walked up and down the body.
Meaning to say, diabetic microangiopathy, retinopathy, talked about cataracts.
I gave you two different types of pathways for damage,
including non-enzymatic glycosylation, hyaline arteriolosclerosis,
and blood vessels are affected.
Now, the picture or the arrow on the right represents hyaline arteriolosclerosis.
So that is a blood vessel. Do you understand that?
And that black head, by looking at that you can't tell if it’s afferent or efferent.
But what’s the first arteriole to be affected?
The efferent. What's that called?
When you have massive efferent arteriolosclerosis, what does it do to the glomerulus?
The spanking. What's that called? Hyperfiltration disease.
Increase in proteinaceous material in the wall of the vessel.
Next, that nodule that you're seeing is deposition of your type IV collagen,
here, this would be in the mesangium.
Where else could it be?
Well, you could also have deposition in different parts of your kidney.
At this point, we have completed the discussion on diabetic nephropathy in great detail.
We’re gonna continue through systemic disease.
And at this point, ladies and gentlemen,
we’ll take a look at what's known as renal amyloid.
What does that mean?
Well, I want you to take a look at the pictures on your right.
Top and bottom, congo red stain.
What does that mean? Amyloid.
Amyloid means what to you on congo red stain?
Apple-green birefringence, is that clear?
So what kind of issue you might be thinking about? High on your differential.
How about Bence Jones proteins? What does that mean to you?
Bence Jones protein represents your light chains, kappa/lambda, kappa moreso.
In other words, you're looking at immunoglobulins depositing.
Chronic inflammation, rheumatoid arthritis, plasma cell disease such as multi-myeloma.
In the amyloid here, is the fact that it’s depositing congo red stain.
As soon as you start amyloid depositing on organs, oftentimes,
the only-your next step in management is organ transplant.
Renal amyloid associated with secondary amyloidosis. That is important.
If there is amyloidosis, congo red stain,
we talked about how this stain appears of being apple-green birefringence.
If that is on H&E, that would be a bit more difficult.
This kinda looks like maybe a global proliferation and looks rather eosinophilic
and it pretty much affects the entire glomerulus.
Now, this is a little bit more difficult for you to follow but if your patient has lytic bone lesions,
you end up finding increase in IgG in a bone marrow aspirate,
you’ll find these plasma cells.
Then this has to be amyloid and your next step in management?
Congo red stain to find that apple-green birefringence.
But there is a difference in terms of how it appears on H&E
versus how it does on congo red stain.