CASE STUDIES
| CASE | ||
| Amoeba Colitis | ||
| HISTORY | ||
| 70 year old woman with a clinical impression of colitis. There was no history of recent travel. Endoscopy revealed cecal colitis. | ||
| MICROSCOPIC DETAILS | ||
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| Fig. 1 | Fig. 2 | |
| Fig. 1 & 2- Histologically in the cecum there was mild active colitis with focal acute cryptitis and increase of chronic inflammatory cells and neutrophils in the lamina propria. There was a focal ulceration with fibrinopurulent exudate and associated round organisms with a nucleus and foamy cytoplasm. A few organisms contained red blood cells. The organisms stained positively with PAS and weakly positive with trichrome. | ||
| DIAGNOSIS | ||
| Amoeba Colitis | ||
| DISCUSSION | ||
| Approximately 10% of world population is infected with amoeba. Although some patients suffer a severe dysentery-like, fulminant colitis, the others are asymptomatic or have vague GI-symptoms. Complications include serious bleeding and dissemination to the other sites especially liver. Cecum is involved most commonly. Grossly small ulcers are seen initially which may coalesce into large, irregular, “flask-shaped” ulcers. Intervening mucosa is often normal.
Histologically, the earliest lesion is mild neutrophilic infiltrate. Later ulcer become deep and may involve submucosa. Organisms are usually found within fibrinopurulent exudate. The adjacent mucosa is usually normal and may show mild architectural distortion and inflammation. The organisms may be very few and resemble macrophages with foamy cytoplasm and a round eccentric nucleus. The presence of ingested red blood cells is pathognomonic for E. histiolytica. The differential diagnosis is with macrophages. Amoeba are trichrome and PAS positive. Active inflammatory bowel disease is in differential diagnosis. We feel that clinicians and pathologists should be aware of this diagnosis, because of variation in clinical and histological presentation and potential serious complications if left untreated as liver abscess and fulminant colitis. |
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| REFERENCES | ||
| Upon request | ||
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