Entamoeba histolytica trophozoites are able to lyse host tissues. This allows the trophozoites to leave the lumen of the intestine, where it is relatively harmless, and penetrate into the tissues of the intestine. The cavities it forms can provide a site for secondary bacterial infection.
In this photo of a section of intestine, normal intestinal tissue is at the top (although it is cut somewhat obliquely). The * is located in an amoebic lesion. Note that the surrounding layers of host tissue are enlarged. If the lesion was examined under high magnification, trophozoites would be found.