Monday, November 28, 2011

Case of the Week 186

The following was an incidental finding on pap smear. Identification? (CLICK ON IMAGES TO ENLARGE)

Pap stain, 400x original magnification

Pap stain, 1000x original magnification

Sunday, November 27, 2011

Answer to Case 186

Answer: Not a human parasite

I apologize to my readers that I don't know exactly WHAT this is. A consensus of knowledgeable parasitologists thought that this was not a human parasite, and possibly an artifact or fungal element. Meanwhile, my mycology colleagues did NOT think that this was a fungal element. Responses from the viewers also included Turbatrix aceti (vinegar eel) and hair.

The good news for this patient is that this is not a human pathogen and simply an incidental finding.

Thank you all for writing in with your interesting ideas!

Friday, November 18, 2011

Case of the Week 185

The following was worm was seen emerging from a cricket:

Here are photos of the worm itself:

Many thanks to Jason Pelletier who took the first photograph and Heidi Pierce who shared this cool case with me!

Thursday, November 17, 2011

Answer to Case 185

Answer: Horsehair worm, also known as the Gordian worm, in the group Nematomorpha.

Over 300 species in this group have been described. They are parasitic in their larval stage for various insects and crustaceans, and emerge from the host (as seen in this case) as free-living adults. The adults are typically found near or in water and are known to twist themselves into complex knots (resembling Gordian knots).

These worms superficially resemble nematodes and they are not uncommonly submitted to our lab for identification; however, they are not parasites of humans or other mammals.

Monday, November 14, 2011

Case of the Week 184

The following images are from a Papanicolaou-stained bronchoalveolar lavage obtained from a 70 year old man with increasing respiratory distress. His medical history is significant for hemodialysis-dependent end-stage renal disease and vasculitis (treated with cytoxan).

Any thoughts on what the last image represents?

x400 original magnification

x600 original magnification

Many thanks to Dr. Steven Goodman for donating this case!

Sunday, November 13, 2011

Answer to Case 184

Answer: Probable Strongyloides stercoralis larvae

Higher magnification would be needed to confirm the characteristic features of S. stercoralis filariform larvae (the stage that migrates to the lung during autoinfection). However, the overall appearance and clinical presentation is most consistent with strongyloidiasis hyperinfection.

To answer my question about the last photo - this does not represent a parasite, but might represent a fiber with proteinaceous debris. I was curious to see what others had to say, but no one commented.

Thanks to everyone for writing in!

Monday, November 7, 2011

Case of the Week 183

The following were seen on Giemsa-stained peripheral blood films. The objects shown measure approximately 220 microns in length. Identification? (CLICK ON IMAGES TO ENLARGE)

x1000 original magnification

Sunday, November 6, 2011

Answer to Case 183

Answer: microfilaria of Brugia malayi

The diagnostic features of this case include the brightly staining pink sheath with routine Giemsa staining, relatively small size, and both terminal and subterminal nuclei (see below; click on image to enlarge).