Case #258 – August, 2009
A biopsy was performed on a 23-year-old woman with no known travel history, presenting with a perianal ulcer. The specimen was preserved in formalin and sent to a pathology lab for work-up. Figures A and B show what was observed at 500x magnification from a section of the tissue, stained with hematoxylin and eosin (H&E). What is your diagnosis? Based on what criteria?
This was a case of invasive amebiasis caused by Entamoeba histolytica. Morphologic features seen in the images included:
- the presence of trophozoites in tissue with a single nucleus that contained peripheral chromatin and a central karyosome.
- trophozoites with ingested red blood cells.
More on: Amebiasis
Images presented in the DPDx case studies are from specimens submitted for diagnosis or archiving. On rare occasions, clinical histories given may be partly fictitious.
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