Answer to Case 627

 Answer to the Parasite Case of the Week 627: Mite eggs; finding is not of medical concern

Mites and their eggs may occasionally be found in human stool specimens, given that mites are all around us - in dust, on our skin, and in our food! (check out my previous case of the week on Cheese Mites). Although mite eggs resemble those of some human parasites (e.g., the human hookworms), they are usually larger, and there is often evidence of an immature mite inside, as seen in this case:

Here are a couple of images from Dr. Jon Rosenblatt, my predecessor at Mayo Clinic. They show 2 larval mites, including one escaping from an egg. 

Live, moving, mites can occasionally be seen in direct wet preps of fresh stool - a somewhat disconcerting but insignificant finding. We don't report them when seen as it would just cause confusion for the ordering provider and patient!