Question:medium
Periodic acid-Schiff (PAS) positive macrophages are seen in which condition?
Periodic acid-Schiff (PAS) positive macrophages are seen in which condition?
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Foamy, diastase-resistant PAS-positive, non-acid-fast macrophages in lamina propria point to one infection.
Updated On: Jun 23, 2026
- Whipple's disease
- Crohn's disease
- AIDS
- None of the above
Show Solution
The Correct Option is A
Solution and Explanation
Step 1: Anchor on the classic association: PAS-positive macrophages stuffing the intestinal lamina propria is the textbook biopsy picture of Whipple's disease.
Step 2: The causative organism Tropheryma whipplei is engulfed by macrophages; its glycoprotein-rich cell wall takes up the PAS stain and resists diastase digestion, giving the diastase-resistant PAS-positive appearance.
Step 3: Distinguish from a mimic - in AIDS, $M. avium$ infection also yields PAS-positive macrophages, but those are acid-fast positive, whereas Whipple macrophages are acid-fast negative. The unqualified classic answer for PAS positivity remains Whipple's disease.
Step 4: Crohn's disease is defined by skip lesions, transmural inflammation and non-caseating granulomas, not foamy PAS-positive cells, so it is excluded. The single best answer is option a.\[\boxed{\text{Whipple's disease}}\]
Step 2: The causative organism Tropheryma whipplei is engulfed by macrophages; its glycoprotein-rich cell wall takes up the PAS stain and resists diastase digestion, giving the diastase-resistant PAS-positive appearance.
Step 3: Distinguish from a mimic - in AIDS, $M. avium$ infection also yields PAS-positive macrophages, but those are acid-fast positive, whereas Whipple macrophages are acid-fast negative. The unqualified classic answer for PAS positivity remains Whipple's disease.
Step 4: Crohn's disease is defined by skip lesions, transmural inflammation and non-caseating granulomas, not foamy PAS-positive cells, so it is excluded. The single best answer is option a.\[\boxed{\text{Whipple's disease}}\]
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