Entamoeba histolytica

• Immature, binucleated cyst in stool specimen, Trichrome stained
• Spherical or ovoidal in shape, 12-20 micrometer in diameter
• Cytoplasm  contains reddish-purple colored, cigar-shaped chromatoid bars
• Each nucleus contains reddish, concentric karyosome, and peripheral chromatin evenly distributed