Case of the Week 326

Here is another great case from Dr. Orihel's collection at Tulane University.  No history, but the appearance is quite classic. Identification?

Answer to Case 326

Answer:  Taenia sp. larvae, otherwise referred to as cysticercae (cysticercus = singular).  If these were found in a human, then they would be cysticercae of T. solium, which are commonly referred to as Cysticercus cellulosae. Thank you to everyone who wrote in with the answer.  As noted by Florida Fan, you can see a similar image in Ash and Orihel's Atlas of Human Parasitology, 5th edition, on page 371.

Cysticercae have a characteristic solid structure (the inverted scolex) surrounded by a fluid filled cavity called a bladder.  For this reason, Taenia solium is sometimes referred to as the bladder worm (although I would discourage using this terminology since it is confusing to most people).

Remember that a 'bladder' is simply a fluid-filled or air-filled sac and doesn't just refer to the urinary bladder.  Other well-known bladders are the gallbladder and the fish swim bladder .

Case of the Week 325

Dear Readers,
For this post, I wanted to highlight one of the fabulous cases from Tulane University, the former lab of the Parasite guru, Thomas Orihel.  I had the pleasure of putting on a Parasitology workshop last week at the ASTMH annual meeting along with Christina Coyle, Michael Libman, and Susan McLellan; Susan is an infectious disease physician at Tulane and was our host for the workshop.

The following is one of the coolest displays I've ever seen - back from the 1950s when tapeworms were submitted following treatment (often with quinacrine) to ensure that the head was expelled. On an interesting historical note, quinacrine is not thought to have vermicidal activity, but causes the head to detach so that the worm can be expelled.  Its use has now been replaced by praziquantel and other more effective medications for treatment of cestode infection.

Identification?

Answer to Case 325

Answer:  Taenia saginata: intact long segment of attached proglottids wrapped around a glass rod and carefully preserved inside of a cylindrical tube at Tulane University.

Given that the proglottids are longer than wide and quite large, it is easy place this into the Taenia genus.  However, if you look carefully, you can also tell that the proglottids have been cleared so that the uterine branching pattern is visible; there are 15 or more primary uterine branches along one side of each proglottid consistent with T. saginata. What a beautiful display!

If you haven't already, please read the very poignant story that Florida Fan tells about his own experience with tapeworm infection.  It is in the comments from this case (question section).  

Case of the Week 324

The following large structures were seen on a stool wet mount preparation, measuring from 50 to 80 micrometers in largest dimension. The patient has a history of chronic intermittent diarrhea that is occasionally bloody and abdominal pain.  Identification?

Answer to Case 324

Answer:  Balantidium coli

As noted by Florida Fan, the cilia, macronucleus and cytosome (mouthparts) are plainly visible in the photos of the trophozoite (below, first image) while the macronucleus is partly visible in the cyst (below, bottom image).

As noted by Anon, the classic motility of the ciliated parasite is described as "boring" - not "uninteresting" but "rotary"!

Thank you to everyone who wrote in with the answer.

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?

Below is a different take on the same costume as above.  Any thoughts on what the fellows are? 

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.

Answer to Case 323

Thank you readers for giving your best guess for what my lab staff and trainees were for Halloween!  Here are the answers:

Mommy Taenia solium and her 3 motile proglottids. Note Jaydee's hooked rostellum, 4 suckers and proglottids of increasing length (arrows).  

As an interesting coincidence, these 2 ladies also came as T. solium with accompanying eosinophils for their dates.  Each have 3 proglottids in their costume.  Near the end of my 'wild' parasite party, the eosinophils degranulated and the parasites had to fend for themselves.

My lead tech and parasite queen extraordinaire came as a D. caninum egg packet containing ova with appropriately hooked onchopheres.

We also had a little parasite who couldn't make it to the party but was too cute to leave out:  a little Dermatobia hominis

 

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.

Identification?

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!