Chagas' disease Trypanosoma cruzi
General: A chronic infection by Trypanosoma cruzi, which is endemic to South and Central America and is a significant cause of cardiac failure in those areas. Although cardiac transplant is occasionally used to treat advanced cases with irrecoverable fibrosis, post-transplant immunosuppression is occasionally associated with recurrent infection.
Gross: In the chronic, advanced state the ventricular chambers are dilated and there is diffuse myocardial fibrosis.
Microscopic: Myocyte destruction with intramyocyte amastigote pseudocyst formation, which eventually ruptures. The remaining myocytes become hypertrophic and there is intense reactive fibrosis which may lead to cardiac dilation & cardiac failure. On peripheral blood smear, trypomastigotes are "C" shaped and have an undulating membrane. Amastigotes are 2-4 microns and have a distinct kinetoplast, unlike Trypanosoma cruzi.
Differential Diagnosis:
- Cytomegalovirus infection
- Toxoplasma gondii
- Acute rejection, Acute cellular rejection, Acute cardiac rejection
Stains:
- Positive:
- Negative:
- Suggested, focused panel:
(Lefkowitch: AP Board Review)
Images:
Cases:
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