Entamoeba hartmanni cysts are smaller than Entamoeba histolytica cysts. Which statement is true?

• A. They are larger than E histolytica cysts
• B. They are smaller than E histolytica cysts
• C. They are identical in size to E histolytica cysts
• D. They are not found in humans

Answer: (B)

Entamoeba cyst size helps separate species in stool exams. Entamoeba histolytica cysts are relatively large, about 10–20 μm in diameter, while Entamoeba hartmanni cysts are noticeably smaller, roughly 5–12 μm (often in the 6–8 μm range). Because of this size difference, the true statement is that Entamoeba hartmanni cysts are smaller than Entamoeba histolytica cysts. This distinction is clinically useful for differentiation in practice, though size alone isn’t definitive and should be considered with other morphological features. Entamoeba hartmanni does occur in humans, so the option claiming they are not found in humans isn’t correct.