Case #458 – December, 2017

A 69-year-old male, with recent travel to Peru, was undergoing a routine colonoscopy performed as a screen for colorectal cancer. The patient was asymptomatic and a stool ova and parasite examination (O & P) performed prior to the procedure was negative. However, the gastroenterologist recovered a worm from the ascending colon during the procedure and sent it to the pathology laboratory for identification. Figures AC show what was observed on hematoxylin and eosin (H & E) stained slides. Eggs seen inside the worm measured 50 x 25 micrometers on average. What is your diagnosis? Based on what morphologic features.

This case and images were kindly provided by Keck Medical Center or University of Southern California.

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Figure A

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Figure B

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Figure C

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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