 Trophozoites of Entamoeba
histolytica/dispar.
 (Reminder: in the
absence of erythrophagocytosis, the
pathogenic E. histolytica is
morphologically indistinguishable from
the nonpathogenic E. dispar!)
- Line drawing (A) and trichrome
stain (B, C, D).
- Each trophozoite has a single
nucleus, which has a centrally placed karyosome
and uniformly distributed peripheral
chromatin.
- (This typical appearance
of the nucleus is not always observed:
some trophozoites can have nuclei with an
eccentric karyosome and unevenly
distributed peripheral chromatin.)
- The cytoplasm has a
granular or "ground-glass"
appearance. Entamoeba
histolytica/dispar trophozoites
measure usually 15 to 20 µm (range 10 to
60 µm), tending to be more elongated in
diarrheal stool.
- (B: specimen contributed by
Dr. Ray Kaplan, SmithKline Beecham, Atlanta, GA.)
- Courtesy of the Division of
Parasitic Diseases at the National Center for
Infectious Diseases, Centers for Disease Control
and Prevension (public domain)
- http://www.dpd.cdc.gov/DPDx/HTML/Amebiasis.htm
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