Cysts of Entamoeba coli

Cysts of E. coli are 15 - 30 microns in diameter and contain 1 - 8 nuclei.  Chromatoid bodies are not frequently seen but when present they are usually splinter-like with pointed ends.  Glycogen is usually diffuse but in young cysts is occasionally found as a well defined mass which stains reddish brown with iodine.

Cyst of Entamoeba coli without iodine

Cyst of Entamoeba coli with the presence of iodine

Cysts of Entamoeba hartmanni

Cysts of E. hartmanni are similar to E. histolytica but are smaller in size, usually 7 - 9 microns in diameter.

ACyst of Entamoeba hartmani exhibiting 1 nucleus

Cysts of Iodamoeba butschlii

Cysts of I. butschlii are 9 - 15 in diameter and have one nucleus in mature cysts usually eccentrically placed.  Chromatoid bodies are not present.  Glycogen is present as a compact, well defined mass staining dark brown with iodine.

Cysts of Iodamoeba butschlii stained with iodine

Cysts of Endolimax nana

Cysts of E. nana are 6 - 9 in diameter.  They can be spherical or ovoid in shape and contain 4 pin-point nuclei which are highlighted by the addition of iodine.  Chromatoid bodies are not found and glycogen is diffuse.

Cysts of Endolimax nana showing pinpoint nuclei