Answer to Parasite Case of the Week 609: Not a parasite egg.
Idzi and I debated over what this is exactly but couldn't come up with a good answer. I like Old One's, Florida Fan's, and Sir Galahad's suggestion that it could be a mushroom spore. Regardless, it is too small and irregular to be a Schistosoma haematobium egg, and it lacks the features for other parasite eggs - all good news for the patient. Sam queried if this could be a uric acid crystal, which is a good thought. However, uric acids have a slightly different appearance in my experience (see previous posts HERE).
As Sheldon, Marc and Nandhu point out, we can exclude S. haematobium based on the following features:
- There is no miracidium inside of the egg
- The eggs is only ~75 micrometers long (expected size for S. haematobium is 110 - 170 micrometers)