Case of the Week 669

Here's another fun parasite histopathology case for you: a full-thickness section of bladder wall from an Egyptian man with invasive bladder cancer (not shown here):

Click HERE for the whole digital slide. 

Diagnosis?

Case of the Week 668

This week's case is a lovely cross-section of an arthropod embedded within the epidermis. The patient is a middle-aged woman with a lesion on her foot after returning from the Caribbean on holiday. Here is a still image of the digital slide:

Click HERE to zoom in for higher power.

Identification?

Answer to Case 668

 Answer to the Parasite Case of the Week 668: Tunga penetrans (likely one adult female flea) embedded in skin. Hopefully you all had a chance to look at the digital slide HERE. It is fun to zoom around on the slide and see the various features.

The follow photos show some of the key diagnostic features:

Case of the Week 667

Happy New Year! Here's a great case to start off 2022. A large structure (~25 cm-long) submitted to the Clinical Parasitology lab (found in stool).  Identification? 

Photo is courtesy of Heather Morris.

  

Answer to Case 667

 Answer to the Parasite Case of the Week 667: Ascaris lumbricoides. 

This adult nematode is easy to identify when found in human stool, or expelled through the mouth, nose, or anus, due to its large size and characteristic 3 fleshy lips. Importantly, anisakid larvae also have 3 fleshy lips, and must therefore be differentiated from immature Ascaris when expelled from the human gastrointestinal tract. This can be accomplished by examining the characteristics of the intestinal tract, mouth and tail.

Thanks again to Heather for this beautiful photograph!

Case of the Week 666

I have a fascinating parasite for the dreaded Case of the Week 666 - not a bad way to end out 2021! I promise I will start us off in 2022 with something fun.

The following was seen on a Giemsa-based stain from a liver cyst. Identification?

Answer to Case 666

 Answer to the Parasite Case of the Week 666: Echinococcus sp. degenerating protoscolex (immature scolex) and free hooklets. We can't say which species of Echinococcus is present from the image alone, but it is most likely to be E. granulosus, as this is the most common species to infect humans, and it commonly forms a liver cyst that is amenable to aspiration. 

This is a beautiful example of rostellar hooklets in a protoscolex.

Here are some other great examples of Echinococcus sp. protoscoleces and hooklets in aspirate fluide from previous posts:

Case of the Week 537:

Case of the Week 280:

Case of the Week 514:

Case of the Week 665

This week's case was made possible by BEI Resources and the NIH-NIAID Filariasis Research Reagent Resource (FR3) Center. They provided the materials and excellent instructions for this special experiment:

These black elliptical objects measure ~550-600 micrometers long, and came dried on a piece of paper towel. I added a strip of the paper towel to a Petri dish containing distilled water and waited about 30 minutes for the action to start. Here is what happened:

Here are some still shots of the action:

What are these objects??

Special thanks to Dr. Shelly Michalski and Teagan at the FR3 for providing the materials for this special experiment!

Answer to Case 665

 Answer to the Parasite Case of the Week 655: Culicidae mosquito eggs and larvae. The appearance of the eggs (darkly-colored, individual eggs, not in a raft, and without bilateral floats) is consistent with Aedes spp. Since I ordered these specifically from the FR3, I can say with certainty that these are eggs those of Aedes aegpti. I hope you all enjoyed the video of the wriggling L1 larvae!

Case of the Week 664

 Here's another fun case from my lab, courtesy of our awesome parasitology technical specialist, Heather Morris. The following objects were found on screening colonoscopy.

The following helpful object was found in the accompanying fluid:

Identification?