This week's case is a brain biopsy from a middle-aged man with untreated HIV. The specimen appeared necrotic and bloody. Touch preps were made from the material and stained with Giemsa. From the images below taken with the 100x oil objective, what is your diagnosis?
Monday, May 12, 2025
Tuesday, May 6, 2025
Case of the Week 775
This week's case was inspired by Dr. Eric Rosenbaum. Several objects were submitted for parasite identification, including tan-white hair-like structures measuring 30 mm long by <0.2 mm wide. Here is their appearance by light microscopy. How would you sign this case out?
Sunday, May 4, 2025
Answer to Case 775
Answer to the Parasite Case of the Week 775: Not a parasite. This is actually a hair from my house cat, Walter. Here he is keeping me company while I am trying to update a parasitology chapter:
As noted by Florida Fan, "The objects have neither external nor internal organs. We have a common saying: "No head, no tail, no guts, no parasites”Monday, April 14, 2025
Case of the Week 774
This week's case features another great video from Dr. Rasool Jafari - an object identified from skin scrapings. What is this little arthropod?
Sunday, April 13, 2025
Answer to Case 774
Monday, April 7, 2025
Case of the Week 773
This week's case is generously donated by Dr. Rasool Jafari from the Department of Parasitology and Mycology, School of Medicine, Urmia University of Medical Sciences, Urmia, Iran. These objects were isolated from a patient and cultured in Modified TYI-S-33 medium. What parasite is this, and what are we seeing here?
Sunday, April 6, 2025
Answer to Case 773
Answer to the Parasite Case of the Week 773: Giardia duodenalis trophozoites with 'falling leaf' motility. As nicely described by Idzi,this is a "Beautiful video material of Giardia trophozoites! Note that it’s official name now is “Giardia duodenalis”. We used to cultivate these critters on Keisters medium for educational purposes. Not easy though, so the more impressing this video by Dr. Rasool Jafari is! Kudos!"
Indeed, you can make out multiple characteristic features of Giardia trophozoites, including the 'tear drop' shape with 2 nuclei and a central axoneme when viewed anteriorly, a concave spoon-shaped appearance when viewed from laterally, anterior sucking disk, and even some trophozoites dividing by binary fission. I believe I've captured one here but defer to Dr. Jafari for confirmation. Many thanks again to Dr. Jafari for sharing this interesting case with us.
Monday, March 31, 2025
Case of the Week 772
This week's case is generously donated by Dr. Evis Nushi who identified the following structure in direct microscopy of skin scrapings. What is seen here?
Sunday, March 30, 2025
Answer to Case 772
Answer to the Parasite Case of the Week 772: Demodex folliculorum
This little mite, also known as the follicle mite, is a common skin commensal and incidental finding in this case. I initially thought it was a larva emerging from an egg, but on closer examination realized that it is a more mature form (with 8 legs rather than the 6 found in the larval stage) and that it's posterior end is twisted around. I've done my best to demonstrate this here:
Thanks again to Dr. Evis Nushi who donated this fun case!Tuesday, February 25, 2025
Case of the Week 771
This week's case was generously donated by Dr. Emily Snaverly. The following images show an incidental finding from screening colonoscopy, measuring approximately 1cm long. The patient is an asymptomatic, middle-aged male with no known travel history whose previous colonoscopy did not show any parasites. What is your identification?