Monday, February 12, 2018

Case of the Week 481

Happy Valentine's Day! Here is a special photo taken by Emily Fernholz, my awesome education specialist. These 2 little worms were found in a concentrated stool specimen and measure approximately 250 micrometers long.  Identification?

Sunday, February 11, 2018

Answer to Case 481

Answer: Strongyloides stercoralis rhabditiform larvae
As noted by Florida Fan and Sugar Magnolia, these 2 larvae are "intertwined in romantic interlude" - "performing a romantic ballet". Perfect for Valentine's day!

The identification can easily be made by the size of these nematodes, their short buccal cavities (arrows in image below), and the genital primordium (less easily appreciated here).

Monday, February 5, 2018

Case of the Week 480

Starting us off with the first Monday of February 2018 is another exciting case from Idzi Potters and the Institute of Tropical Medicine, Antwerp.

The patient is a 65 year old Spanish woman who brought 3 worm-like structures to her physician. She had expelled the structures 30 minutes prior to presentation, and one was noted to still be moving. She reports no travel outside of Europe.

...and here is the moving one!!

Sunday, February 4, 2018

Answer to Case 480

Answer: Taenia saginata proglottid

As mentioned by Luis, Florida Fan, Atiya, and Sugar Magnolia, these proglottids can be differentiated by other large tapeworms by the size and shape of the proglottids, and the presence of more than 12 uterine branches arising from the central uterine canal/stem:
 Remember when counting uterine branches to only count them as they come off the central stem (primary branches), and only on ONE side (not both)!
As some readers mentioned, the proglottids of Taenia saginata are morphologically indistinguishable from those of T. asiatica; however, the patient's lack of travel outside of Europe makes infection with this latter parasite unlikely. Thanks again to Idzi Potters and the Institute of Tropical Medicine, Antwerp, for this interesting case!

Monday, January 29, 2018

Case of the Week 479

This week's case is from Dr. Kamran Kadkhoda. The following object was found in the diaper of 3 year old child. It measures approximately 30 cm in length. Identification?

Sunday, January 28, 2018

Answer to Case 479

Answer: Ascaris lumbricoides, adult female

The identification of this roundworm is based on its large size, tapered head and characteristic trilobate (3) "lips":
This worm can be further identified as a female based on its straight rather than coiled tail. Ali also astutely noted the presence of a "vulvar waist" - a narrowing at the junction on the anterior and middle thirds of the body, which also indicates that it is a female. Kamran was unable to express any eggs out of the worm; if found, the presence of eggs would also have confirmed the female gender. The size (30 cm) falls within the range of both male and female worms and therefore unfortunately cannot be used to identify the gender in this case.

Thanks to all of my readers for the excellent comments!

Monday, January 22, 2018

Case of the Week 478

This week's case was generously donated by our long time contributor, Florida Fan. The following were noted in the stool of a apparently healthy man with no known travel history. The eosin wet mounts were photographed using the 40x objective, while the trichrome-stained slides were photographed using 100x. We don't make eosin saline mounts in my laboratory anymore; I had forgotten how pretty they can be.


Sunday, January 21, 2018

Answer to Case 478

Answer: Entamoeba coli trophozoites and cysts. Also present is a trophozoite of Dientamoeba fragilis. 

This case from Florida Fan nicely shows the diagnostic features of E. coli, including the large size and >4 nuclei in the mature cyst stage:

Again, the colors of the trichrome and eosin saline mounts are beautiful.

As I mentioned above, there was also a D. fragilis trophozoite present. Because of its small size and indistinct chromatin features, this organism is significantly more difficult to identify. Here is the current case (bottom, left), as well as an idealized photo from my own collection (bottom, right). Note that the trophozoites have 1 to 2 nuclei with a 'fragmented' or 'fractured' chromatin pattern. The chromatin may also have a smudgy appearance.
Thanks again to Florida Fan for donating this case!

Monday, January 15, 2018

Case of the Week 477

This week's case was generously donated by Dr. Piryanka Uprety and the excellent Clinical Microbiology and Hematology Laboratories at the University of Pennsylvania. The following structures were initially observed by a hematology fellow in a wet mount (40X) from a BAL specimen. Photographs and videos are courtesy of Joyce Richardson, Vivian Whitener, and Darrin Jengehino from the Hematology Laboratory.

Wet preparation of the BAL fluid with iodine showed the following:


Sunday, January 14, 2018

Answer to Case 477

Answer: ciliated respiratory epithelial cells. These are a common parasite mimic, especially when seen in unfixed wet preparations, since the cilia remain motility for quite some time after being exfoliated from the respiratory mucosa. It is important to note that these are NOT parasites. Unfortunately there are several reports where these are misidentified as Lophomonas blattarum; however, L blattarum is a parasite found in various arthropods and is NOT thought to be a human parasite. 

You can easily identify ciliated epithelial cells by their small size and characteristic shape. Note that the cilia are present in a dense band at the apical surface:

You can really appreciate the columnar shape of the cells in this case.

It can be even more challenging when the ciliary tufts become detached (called detached ciliary tufts/DCTs or ciliocytophthoria). I've featured this multiple times on my blog in the past and have described how to differentiate ciliated host cells from other microorganisms. Check out these past posts for more information:

Case 396
Case 369
Case 283
Case 262

Thank you all for writing in!