Ugly spindle cells - what do they mean?

Here's a nasty one. 

This middle aged pup presented to his vet for 2 "blood-filled" masses on his pinna. 🩸

When I read the description of them being blood filled, I wasn't super optimistic they would be that cellular, since a lot of times those end up being mostly blood (unsurprisingly...).

But this one had these little pockets that were really cellular, so it was a nice diagnostic sample. ✔️

What you're seeing here are lots of nastyyyy mesenchymal cells which have a lot of criteria of malignancy (can you spot them?).

Of course, we have to be cautious in cytology-land to not mistake reactive fibroblasts for sarcoma, since those can look scary and mimic neoplasia.

But in this case, there is no inflammation at all (which we expect to be present with reactive fibroplasia in most cases), and there are lots of these cells.

The combo of the cellularity, lack of concurrent inflammation, and atypical features these guys show make me comfortable saying this is consistent with a sarcoma.

We would need histopath to confirm and tell which kind, but I'm suspicious of hemangiosarcoma given the multifocal nature of this, location, and description of being blood-filled.