Monday, August 4, 2025

Case of the Week 783

This week's case was generously donated by Dr. Richard Bradbury. The following were seen in a stool specimen from a middle-aged man with diarrhea. Preparations are a concentrated wet prep and trichrome stained permanent mount. Object measure 10-15 micrometers long. What is your identification?






4 comments:

Anonymous said...

Looks like a trophozoite stage of an amoeba. My guess is Entamoeba histolytica

Florida Fan said...

The shape and size are compatible with cyst and trophozoites of Chilomastix mesnili. This organism is usually considered a commensal, as such I do not know its role in the diarrhea. Could it be something else?

Anonymous said...

E. histolytica/dispar? Would ask. /Patrik

Anonymous said...

Lemon-shaped cysts (pic 1,2,4) with "shepherd's crook" (pic 1,2); karyosome more diffuse and eccentric, nuclear chromatin is not evenly arranged (DDx from E.histolytica); feeding groove in trophozoites (pic 3). Possibly C.mesnili cysts and trophozoites.