DDSEP® 8 Quick Quiz

November 2018 Question 1

Publish date: November 1, 2018

A 52-year-old man is referred because of diarrhea, with up to 6 loose bowel movements per day for the past 7 months. His stool has been nonbloody. He denies rashes or eye problems, but he has had significant arthralgias. He has lost 15 pounds and also reports having newly developed headaches over this time. A colonoscopy performed 1 year ago for routine screening was unremarkable. Celiac serologies checked last month were negative. Stool cultures, ova and parasite evaluation, and Clostridium difficile toxin assay were all negative.

An upper endoscopy reveals grossly unremarkable mucosa throughout and duodenal biopsies are performed.

Besides routine evaluation, what additional testing should be requested for the pathologist to perform on the duodenal specimens?

Congo red staining

Sudan staining

Birefringence

Periodic acid-Schiff staining

Immunohistochemistry

Rationale

This patient’s symptoms are most concerning for Whipple’s disease in light of the diarrhea, weight loss, arthralgias, and CNS symptoms. This diagnosis requires identification of periodic acid-Schiff staining macrophages in the duodenal lamina propria. Further PCR analysis can also be used to identify RNA of the causative pathogen, Tropheryma whipplei. Congo Red staining is indicated if amyloidosis is suspected. Sudan staining is used to test stool for fat. Birefringence is used to detect crystals, most typically in synovial fluid. Immunohistochemistry has many applications and is commonly employed to evaluate for Helicobacter pylori.

Reference

1. Moos V., Schneider T. Changing paradigms in Whipple’s disease and infection with Tropheryma whipplei. Eur J Clin Microbiol Infect Dis. 2011;30(10):1151-8.

ginews@gastro.org

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