I've seen this one before. Many sizes, similar structure. I've found it INSIDE many patients, in their mouth and in their stool. I've examined the blood but so far I haven't found it, but I don't know why I get this wild idea from time to time that it may be there.
I've been trying to figure out what it is for almost a year now, and what most expert parasitologists tell me is that it "may be" "root-hairs" from plants, if you can believe that. I'd have no trouble believing it expect that I may have seen it move, and that it does NOT look like the root-hairs I've examined.
I heard a couple of experts suggest that it may be just "debris" or a "randomly-formed structure" (!??), and at least one said that they're "ascaris worms in a sac" (where's the sac? The dot in the middle?). They could be ascaris, or could they be? A first glance had me suspect 8 different organisms joined together.