The cysts of Entamoeba coli are relatively large, measuring 10 to 35 micrometers in diameter, and have 8 (or even 16) nuclei in their characteristic mature form. The nuclei have the standard "Entamoeba-type" chromatin pattern, with a small karyosome (usually eccentric in E. coli) and a peripheral rim of condensed chromatin (so-called "dot and rim" pattern). The peripheral chromatin is often coarse and granular. The cytoplasm may contain glycogen and chromatoid bodies (usually with splintered ends).