Answer: Toxoplasmosis; tachyzoites of Toxoplasma gondii seen.
This was a very challenging case since the multiple small objects (the tachyzoites) blended in with the surrounding tissue. However, if you click on the second image (also shown below), you get a larger view where it is easier to make out the organisms. I've added some arrows to highlight 2 of the tachyzoites that have a particularly nice arc shape. (CLICK ON THE IMAGE TO ENLARGE)
I posted this case because it is what you may expect to see in real life. When available, the clinical history, serology and radiology can help support the diagnosis. Thanks to everyone who was brave enough to write in on this case!