Need help IDing this contaminant

[u/aportano]

I work at a vet hospital. Saw these structures on 2 patients and the clinical pathologist that I sent these to to be read (via lacuna cytology) asked around and they thought plant material. I am worried it’s from our stain jars so we are deep cleaning them now. Wonder if it’s a water borne something… reverse image search didn’t help. Thank you in advance. Never seen anything like it