Monday, April 6, 2026

Case of the Week 805

This week's case was generously donated by Dr. Karra Jones, and features H&E histopathologic sections of intestine from patient with intussusception. Upon close examination, the culprit behind the intussusception can be seen:

What is your diagnosis?

6 comments:

Anonymous said...

Anisakis/Pseudoterranova?
I'm not good with histology...

-HLCM

Anonymous said...

You’re not alone, histology is termed by my former lab director “that’s where I suck” and so am I. Given the most usual nematode of man, I suspect Ascaris suishominis. I see a cuticle, a thin hypodermis, a thick layer of tall muscle cells a central intestine with very tall absorbing cells and an excretory duct. On the outer lower part, there seems to be a pointed alae. That’s what I believe seeing.
Florida Fan

Anonymous said...

The location seems to be the intestinal wall or mesentery. The worm penetrated the wall and caused granulomatous inflammation with eosinophils, leading to intussusception. - SM

Anonymous said...

I stand corrected! Not satisfied with my previous comment as I believe having seen this morphology before, I checked back and HLCM was right. The Y shape lateral chords are unmistakable.
Florida Fan.

Anonymous said...

E. vermicularis? /Patrik

Idzi P. said...

For sure the patient has consumed raw/undercooked fish, as this is one of the anisakids! Indeed the Y-shaped lateral chords are typical! I seem to remember that you may distinguish between pseudoterranova and anisakis as one of both had more “plumpy” lateral chords (I think it was pseudoterranova). My guess would be Anisakis then…
But more cautiously I’d write this one out as “anisakid L3 larva”.