Balantidium coli – Cyst (45 µm to 65 µm) in stools (MIF concentrate)

France, CHU Poitiers Parasitologie-Mycologie

Due to their large size, cysts of Balantidium coli may be misdiagnosed as helminth eggs.They contain a single cell, often motile in wet mount. On this pic, the macronucleus has the appearance of a bean-shaped red spot.