Case 36 Nephrology

Hematuria

Work it one clue at a time. The diagnosis stays hidden until you reveal it.

Clue 1

A young man presents with hematuria and is found to have these painful skin lesions on physical exam.

Clue 2

In a patient with hematuria, the first question I always ask is: what is the source of that blood? Is it glomerular or non-glomerular?

Clue 3

How can we tell if the bleeding is glomerular or not? We have to evaluate the urine sediment. But the eyes can’t see what the mind doesn’t know. So what are we looking for?

Clue 4

Are the RBCs normal in shape (isomorphic)? Or are they abnormal in shape (dysmorphic) because they have squeezed through an inflamed glomerulus?

If we look closely some of these RBCs are indeed dysmorphic (purple arrows). Blue arrows point to isomorphic RBCs.

Clue 5

When those RBCs squeeze through the glomerulus they end up in the tubules, where they can form casts.

Check out what we found on urine sediment. That’s an RBC cast. Another clue that our bleeding source is glomerular.

Clue 6

Clue 7

Our patient has hematuria of glomerular origin.

Clue 8

I like to approach GN serologically:

Clue 9

But instead of just ordering all of those labs simultaneously at a high cost, history and physical exam should guide that workup. Let’s revisit the exam.

What is this skin lesion?

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