Sunday, October 26, 2014

Case of the Week 323

Happy Halloween to all my readers!  This week's case will be a be a bit unusual.  I had my annual Halloween party last night and had a great turn out from my lab and our pathology and microbiology trainees.  Here are some of the top parasitology costumes.  Can you guess their identity?

I also made some special 'myiasis' cupcakes for the party.  Here is the assembly process and the final product:

Rolled fondant with red sugar sprinkles

Fondant 'maggots'

 Assembled cupcakes containing a 'maggot' in a custard 'pus' center.  The fondant is held onto the cupcake by a layer of buttercream frosting:

Removing the maggot reveals almost too realistic custard 'pus'

The cupcake idea was not my own, alas.  I got the idea from this web site.

Monday, October 13, 2014

Case of the Week 322

The following case was donated by Dr. Tess Karre.  This was an incidental finding in sections of duodenum that had been removed during a gastric restrictive procedure from a 50 year old morbidly obese patient.  There was no travel history outside of the United States.


Sunday, October 12, 2014

Answer to Case 322

Answer:  Cross-sections of Enterobius vermicularis adults in the duodenum.  Although this is an unusual location for this worm, the characteristic lateral alae and features of an adult worm (internal organs including intestine and testes) allow us to make the diagnosis.  E. vermicularis is the only adult worm found in humans that has lateral alae (although various larvae may also have lateral alae).
From Blaine Mathison:

While the duodenum is an unusual place to find this worm,
the morphologic features shouldn't cause you to squirm
With lateral alae pointing to the sides
and platymyarian musculature low and wide
a diagnosis of pinworm should be relatively firm!

Sunday, October 5, 2014

Case of the Week 321

The following object was extracted from a foot wound of a 80 year old male.  It measures approximately 15 mm in length.  No travel history is available.  Identification?

Saturday, October 4, 2014

Answer to Case 321

Answer:  Lucilia sp. ("green bottle fly"), a genus of blow flies in the family Calliphoridae

This was a bit of a challenging case.  When it comes to bot flies, the overall body shape and, in particular, features of the spiracular plates, are used for identifying the genus of the infesting fly.  In this case, the peritreme of the spiracular plates is complete, the button is clear and the slits are straight (below), which is consistent the with Lucilia species.

Some readers suggested that this could be Cochliomyia hominivorax, the New World screw-worm. However, the peritreme of this fly is incomplete and the button is not clear as what is seen in this case.

From Blaine Mathison (inspired by Kenny Rogers!)

You picked a fine time to eat me, Lucilia
Diabetes mellitus and a lesion on my heel
I’ve had some bad times
Infested by blow flies
But this time the lesion won’t heal
You picked a fine time to eat me, Lucilia

Monday, September 29, 2014

Case of the Week 320

Multiple motile small white objects were found in the diaper of an infant.  The specimens were submitted to surgical pathology where they were fixed in formalin, sectioned, and the resultant slides were stained with H&E.  Below are representative sections taken at 20x to 1000x final magnification).  Identification?

Sunday, September 28, 2014

Answer to Case 320

Answer:  Dipylidium caninum proglottids containing numerous egg packets.  Each of the small structures shown in the low power images is a (very) gravid proglottid:

On higher magnification, the characteristic eggs packets are seen, each containing eggs with hooklets (you have to use your imagination a bit to see the hooklets).

Although the eggs look a little different than what we see in stool preparations, I think that, with a bit of practice, parasitologists can learn to correlate these 2-D section to our familiar 3-D objects , given that D. caninum is the only parasite in humans to produce these characteristic egg packets.  Thank you all for writing in!

And now a poem from Blaine Mathison:

A baby cuddling with a kitten is such a cute scene
Until the kid accidentally swallows an infected cat flea
For down in his intestines a new pet does come
For he’s host to the cestode Dipylidium caninum 
shedding motile proglottids in the kid’s soiled Onesie