Monday, May 29, 2017

Case of the Week 447

This week's case is in honor of Memorial Day and was generously donated by Florida Fan. I've actually revived this from a previous case, since the colors (red, white and blue) are so beautiful with Florida Fan's rendition of the modified safranin stain. The red objects seen below were found in stool and measure approximately 10 micrometers in diameter.


Sunday, May 28, 2017

Answer to Case 447

Answer: Cyclospora cayetanensis oocysts

The beautiful red staining of these round oocysts is characteristic, whether using the standard modified acid fast stain or the modified safranin stain.

Monday, May 15, 2017

Case of the Week 446

This week's very timely case was donated by George at Memorial Sloan Kettering Cancer Center. The following objects were seen in a wet mount of a concentrated stool specimen. They measure less than 20 micrometers in dimension and do not have an apparent operculum.

Here is their appearance using iodine:


Sunday, May 14, 2017

Answer to Case 446

Answer: not a parasite; most consistent with mushroom spores.

In this case, the spores were noted in the stool of an individual who had consumed morel mushroom spores, and therefore we can be more specific about the identification.

Mushroom spores are a convincing mimic of parasite eggs. They can be differentiated by a few features, however:
1. Their size is smaller than Enterobius vermicularis eggs - one of their closest mimics.
2. Although in the size range for some of the smaller trematode eggs (e.g. Clonorchis, Metagonimus), they lack an operculum.

Again, special thanks to George who donated these images and reminded me that it is now morel mushroom season!

Monday, May 8, 2017

Case of the Week 445

This week's amazing case was donated by Mr. Boren Huot. This object was seen in a stool specimens from a patient in Cambodia.  Identification? (CLICK ON THE IMAGES TO ENLARGE)

Sunday, May 7, 2017

Answer to Case 445

Answer: Capillaria philippinensis

This case shows an adult worm containing characteristic eggs of C. philippinensis. Note that each egg has a striated wall and bipolar plugs.
Thanks to the CDC DPDx for the photo of the egg shown in the upper right hand corner of the above image.

One reader asked how you could tell C. philippinensis apart from C. hepatica, since both can infect humans. The biggest clue in this case is that the worm was found in stool, whereas the adult worms of C. hepatica are only found in the liver. There are also subtle features of the adult worm and eggs that allow the 2 species to be differentiated.

Thanks again to Mr. Huot for donating a case that we don't get to see very often in the United States.