Monday, October 27, 2025

Case of the Week 790

This week's case was generously donated by Dr. Tudo Rares Olariu, the head of the clinical laboratory at the Municipal Clinical Emergency Hospital in Timisoara, Romania. The following object was seen in a stool specimen from a child with multiple mucosanguineous stools. It measures approximately 45 micrometers in greatest dimension. What is your diagnosis?

3 comments:

Anonymous said...

Though the egg yolk is lob sided, the given size indicates that this is an egg of the dwarf tapeworm Hymenolepis nana. Its cousin H. diminuta size would be much larger and has no polar filaments.
Florida Fan

Anatoly said...

Hooked oncosphere, splayed hooklets, inner membrane polar knobs are present for filaments attachment (cannot see the filaments clearly though), size in the range 30-47 µm - Rodentolepis nana egg (crushed egg?)

Antoine A said...

Based on the general morphology, hooklets, and size, I would suspect Rodentolepis nana, which commonly infects children. I recently learned that the eggs can be directly infectious, which means there’s a potential risk for lab technicians!