Small bowel (small intestine)
Infectious disorders
Entamoeba histolytica


Topic Completed: 1 August 2012

Revised: 12 March 2019

Copyright: 2003-2019, PathologyOutlines.com, Inc.

PubMed Search: Entamoeba histolytica small bowel
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Cite this page: Gulwani H. Entamoeba histolytica. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/smallbowelentamoeba.html. Accessed March 21st, 2019.
Definition / general
  • Dysentery causing protozoa that can also cause fulminant colitis; causes up to 100,000 deaths per year (Trop Biomed 2011;28:194)
  • Increased incidence in homosexual men and AIDS patients
Pathophysiology
  • Fecal oral spread
  • Amoeba invade colonic crypts, burrow into lamina propria, create flask shaped ulcer with broad base
  • 40% invade portal vessels, embolize to liver and cause abscesses up to 10 cm
  • May activate apoptosis in target cells (Trends Parasitol 2011;27:254)
  • Rare abscesses in lung, heart, kidneys, brain
Diagrams / tables

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Life cycle

Microscopic (histologic) images

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Various images



Contributed by Hanni Gulwani, M.D.

Amoebic colitis, numerous trophozoites of amoeba are noted

Amoebic colitis, PAS stain

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