Monday, November 29, 2021

Case of the Week 662

This week's case is a stool specimen from a 52-year-old Bolivian farmer.  He complains of intermittent right upper quadrant pain, and an abdominal CT showed edema and dilation of the bile ducts.



Tuesday, November 16, 2021

Case of the Week 661

The following microfilariae were seen on Giemsa-stained preparations of whole blood following the Knott's concentration procedure. They are between 180 to 200 microliters in length. No travel history was initially available. Identification?

Thanks to Heather Morris for these beautiful photos.

Monday, November 15, 2021

Answer to Case 661

Answer to the Parasite Case of the Week 661: Mansonella perstans microfilariae.

As many of you noted, this filarial worm has very small, unsheathed microfilariae. Note that the microfilariae are more slender than the eosinophils - and even the RBCs! That is one of the most helpful features. They also have a blunt tail, and the nuclei extend to the tip of the tail.

Monday, November 8, 2021

Case of the Week 660

This week's case is another histopathology finding from an eye. The entire orbit was removed because of the presence of a parasitic cyst. You can see the digital slide HERE. Identification?

Here is a screen shot of the digital slide:

Sunday, November 7, 2021

Answer to Case 660

 Answer to the Parasite Case of the Week 660: Cysticercus; larval form of Taenia solium

As noted by Blaine, this is "ocular cysticercosis caused by T. solium, as indicated by a single protoscolex. Coenurosis caused by a zoonotic Taenia is also a possibility, but coenuri have multiple protoscoleces, as do hydatid cysts of Echinococcus. Sparganosis is another cestode infection that can manifest in the eyes, but they do not produce protoscoleces at all."  Lots of great eye puns in the comments!

Here are some of the key diagnostic features:

Monday, November 1, 2021

Case of the Week 659

This week's case features a digitally-scanned section of a subcutaneous nodule from the thigh of a man living in rural Senegal. The man presented with a several month history of severe itching in his lower extremities and abdomen, accompanied with a papular skin rash and focal loss of skin pigmentation. 

Here is a low power view of the skin and underlying nodule: