October, 2002

Case 93:
A stool specimen from a 61-year-old man was preserved in 10% formalin and PVA for an ova and parasites (O & P) examination.  Suspected protozoan cyst-like structures were observed in a hospital laboratory.  A portion of the specimen was forwarded to CDC for diagnostic assistance; no clinical or travel information was provided.  The following images show what was seen in a wet mount examination of an aliquot from the formalin-ethyl acetate (FEA) concentration (Figure A) and on PVA trichrome stained smears (Figure B).  The objects ranged in size from 8 to 14 micrometers in diameter.  What is your diagnosis?  Based on what criteria?

A	B

Click here for the answer to Case 93.

Case 94:
A 50-year-old scholar was seen in a hospital in Connecticut for severe diarrhea.  The patient’s travel history in the last 6 months included India and Mexico.  The video clip shows an object from trichrome stained smears of the patient’s stool specimen.  The size of the object was 13 micrometers.  The clip simulates focusing, showing the structures present in the object in different focal planes.  What is your diagnosis?  Based on what criteria?  Would you recommend a confirmatory test(s) for this case?  What test(s) and for what reason(s)?

After the video clip (Adobe Flash format) plays through one time, you can right click on the image and choose play to watch the video again.

Click here for the answer to Case 94.

Images presented in the monthly case studies are from specimens submitted for diagnosis or archiving.  On rare occasions, clinical histories given may be partly fictitious.