Orange is not a common color in cytology... 🍊
You don't see the color orange everyday in cytology.
That is, unless you look at a lot of bleeding lesions/masses!
Hematoidin is a g-o-r-g-e-o-u-s orange, typically rhomboid crystal that looks like this:
So what is it? Hematoidin is a red blood cell breakdown product.
Macrophages gobble up RBCs, break them down, and voila, you end up with hematoidin crystals.
Why would you see these?
I thought you'd never ask.
You see them when there has been previous/chronic hemorrhage.
Any process that's causing bleeding into a mass or body cavity can result in the formation of hematoidin crystals.
Can you think of some pathologies where you might see this?
This particular case was from a salivary mucocele, which commonly involves chronic hemorrhage...and thus, hematoidin crystals.