Monday, September 30, 2019
Case of the Week 562
This week's case was generously donated by Dr. David Hernandez Gonzalo. The patient is a middle-aged male who presented with abdominal discomfort and nausea. An endoscopy was performed which revealed the following object in the gastric antrum:
The worm was sent to pathology and was sectioned, revealing the following (H&E):
Identification?
I believe it is an Acanthocephalan based on the body wall muscle and lack of an intestinal tract. I would need to see the glass slides to be sure.
ReplyDeleteNo idea ma'am
DeleteNo idea ma'am
ReplyDeleteAccording to the endoscopy of photo 1, it seems to me a larva 3 of Anisakis. A whitish structure that could be the ventricle can be observed.
ReplyDeleteOf the other two photos I do not have enough experience to distinguish characteristic structures, except what appears to be a striated cuticle.
Nice photos by the way
Luis.
Terranova spp (Anisakidae)
ReplyDeleteIt looks like Anisakis larva (or another Anisakidae), but laboratory confirmation of the genus is usually made by specimen clarification. I do not know by histopathological section.
ReplyDeleteThis is a tough one because the histopath is so mangled, but given the coelomyarian musculature and the (apparent) lack of reproductive structures, I'd have to say an L3 larva of an anisakid; location in the host...er...patient is also supportive.
ReplyDeleteI would venture an ID of Anisakidae.
ReplyDeleteAnisakid sure sounds tempting as an identification, However the histology blows my mind.
ReplyDeleteWhat is that netting-like structure? Is that striated muscle or pseudosegmentation? Am I seeing a digestive tract? I've seen nothing like this in a nematode.
I'm agreeing with David that I think it's an Acathocephalan (larval stage).
Definitely this case is tough. Most of us who work in a Parasitology lab do not have the training and education on the reading of parasites histology smears.
ReplyDeleteThe tail end is reminiscent of an Anisakid missing its mucron. The front is not typical of Macracanthorhynchus nor Moniliformis.
The best way for me to put 2 and 2 equals 3 is that it is an Anisakid worm. We all are anxiously awaiting the shedding of a light from Dr. Pritt
Florida Fan
Paraphrasing myself from a few years ago:
ReplyDeleteWhy are pathologists so quick to slice-and-dice
When a diagnosis would be much more precise
If they just left it in tact
and the microbiologists have a whack
Alas now a diagnosis is a roll of the dice
Trichuris trichiura
ReplyDeleteBlaine,
ReplyDeleteYour poem is very well written and full of humor. Indeed I got a whack from this case. "Cut worm" has never been my cup of coffee.
Florida Fan
Trichuris is a good differential based on the cuticle and musculature, but the gross morphology doesn't support Trichuris (besides if this was Trichuris one would expect sexual structures present, even in a mangled cut like this).
ReplyDeleteFlorida Fan - don't think you can determine 'heads vs. tails' from this pic.
Everything I see morphologically suggests anisakid.
After looking at Images in The Lancet, Infectious Dis.,Vol 15, Issue 2, P248.
ReplyDeleteI will eat my words like so many pickled herring and change my identification to Anisakis simplex (or perhaps just anisakid).
I do this with a much greater degree of certainty. It certainly fits with the image of the worm in the stomach.
Considering the clinical presentation, location in the gastric antrum and gross morphology, an Anisakid worm is high in the differential. The histopathology shows some interesting angles and makes it hard to speciate... (probably not the best idea to submit the worm for pathology if it wasn't embedded in the tissue... just send it to the micro lab!). However, looking at photomicrographs in the literature, the histopathology in this case seems to be consistent with an Anisakid worm, although I couldn't distinguish prominent lateral cords. Regarding Trichuris trichiura, the gross morphology is not consistent with it and the location would be unusual.
ReplyDelete