Monday, March 21, 2011

Case of the Week 154

A biopsy of the large intestine was performed on a 43 year old HIV positive male with chronic watery diarrhea. Hematoxylin and eosin stained sections are shown below, which reveal multiple small (5-7 micron diameter) objects that appear to sit on the mucosal surface.

Large intestine mucosal surface, 400x original magnification. Objects of interest shown by arrow heads.


1000x original magnification


Deep mucosal crypt in the large intestine, 400x original magnification


1000x original magnification


What additional tests could be performed for confirmation?

7 comments:

Alasdair Hill said...

Difficult one! I think it might be Cryptosporidium pavum owing to the site and morphology of the parasite, the symptoms and the fact the patient is HIV positive; crypto can be fatal in HIV+ and is one of the most common infections assoc. with HIV.

Other tests include Z-N staining...is there an antigen test for this????

Anonymous said...

Cryptosporidium -- used a modified acid-fast stain to confirm.

Anonymous said...

Cryptosporidium oocysts. Should be about 5 microns in diameter. If an AIDS patient, look also for Isospora belli.

Anonymous said...

Cryptosporidia. We've seen lot's in SF and oddly almost never recognized isospora on biopsy which is intraepithelial usually (only see maybe 1/yr in stool so I don't think just stupid pathologist).

Anonymous said...

Agree: Cryptosporidium

Anonymous said...

Cryptosporidium, and I believe there is an antigen test, and also PCR for this, though not widely done.

VSpyder said...

Agree - Cryptosproidium pavum

stool sample examination?