Case #440 – March, 2017

Stool specimens were collected from an asymptomatic 10-year-old boy from Panama as part of a refugee screening program. The stool was collected in 10% formalin and zinc PVA (Zn-PVA) and sent to the county health department for routine ova-and-parasite (O&P) examination. Figures A I show what was observed at 1000x magnification with oil on a trichrome-stained slide made from stool preserved in Zn-PVA.  Objects in Figures A and G measured approximately 10 micrometers; all other objects of interest ranged from 17-25 micrometers. Figures C E show different focal planes of the same object of interest to highlight internal structures. What is your diagnosis?  Based on what criteria?

Figure A

Figure B

Figure C (Focal Plane 1)

Figure C (Focal Plane 2)

Figure D (Focal Plane 1)

Figure D (Focal Plane 2)

Figure E (Focal Plane 1)

Figure E (Focal Plane 2)

Figure F

Figure G

Figure H

Figure I

Figure J

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

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