Parasitology Training Manual

Entamoeba Differentiation Charts


Diagnostic features E.h.c. E.c.c.
Size 10 - 30 microns 10 - 30+ microns
Shape Round Round
Cyst Wall thin/delicate thick
Nuclei shape Usually Round Round to irregular
Nuclei size 1N 1/3 - 1/2 cell diameter
2N 1/4 - 1/3 cell diameter
4N Approx. 2 microns
1N 1/2 cell diameter
2N 1/3 cell diameter
4N Approx. 2 microns
8N 1/6 - 1/8 of cell diameter
Nuclei Max. Number 4 (hypernucleation possible) 8 (hypernucleation possible)
Chromatoidal Bars Large-Cigar Shaped Fragmented Ends
Vacuoles Possible Possible
Other Diagnosic Features nuclei maybe irregular
in shape

If hypernucleation occurs
nuclei maybe smaller

nuclei maybe irregular
in shape

If hypernucleation occurs
nuclei maybe smaller

Diagnostic Features E.h.t. E.c.t.
Size 12 - 30 microns 12 - 40 microns
Cytoplasm clean with little ingested material dirty with much ingested material
Nuclear Position anywhere anywhere
Peripheral Chromatin fine/even along nuclear membrane coarse/uneven distribution along
nuclear membrane
Karyosome small, punctate often central large, diffuse
Peri-karyosomal space usually the same or lighter
than cytoplasm
usually the same or darker
than the cytoplasm
Size 3 - 6 microns 4 - 7 microns
Shape round round
Other Diagnostic Features May ingest RBC May ingest yeast and other
amoeba or cysts

Diagnostic Features E.hart.c. E.p.c.
Size 5 - 10 microns 8 - 30 microns
Shape Round Round
Cyst wall fine fine
Nuclei shape Often round Often irregular
Nuclei size 1N 1/3 - 1/2 Cell diameter
2N 1/4 - 1/3 Cell diameter
4N Approx. 1 micron
1N 1/4 - 1/3 Cell diameter
Chromatoidal Bars small, squared off corners small, jagged ends, numerous
Vacuoles Immature cysts may contain a vacuole Usually none present
Other Diagnostic Features nuclei may be irregular in shape may contain inclusion mass

Diagnostic Features E.hart.t. E.p.t.
Size 5 - 12 microns 10 - 40 microns
Cytoplasm clean Trophozoites of E. polecki resemble
E.h. and E.c. diagnosis requires the finding
of cysts
Peripheral chromatin fine and even along
Karyosome small and compact
Peri-karyosomal space clear/similar to E.h.
Nucleous Size 2 - 3 microns
Nucleous shape round

The material on this site is owned by Scientific Image and Consulting
David M. Raymondo
MLT, CLS(m)
Professional Affiliation: Gamma-Dynacare Medical Laboratories, Ottawa, Ontario, Canada
Gamma-Dynacare is a Division of the Dynacare Health Group