this is regarding my dog.. but had 2 needle aspirations over the course of 2 months. xrays head to toe, 2 sonograms..one on organs other on thyroid. Infection in one lymph node on neck, goes completely away with antibiotics. Comes back a week after off antibiotics. ALL TESTS WERE clear. both aspirations show INCONCLUSIVE. So with that said..they are basing all of this over ONE TEST..the needle aspiration yet she has no symptoms of anything. she's doing great with exception of lump that returns. Can you explain that? IMO a bad bacterial infection which the needle aspiration has definitively found. SEE under Comments:

I'm not a vet, but what I'm understanding is that the lump returned after antibiotic treatment, and the aspirate report is saying it is most likely a bacterial infection but squamous cell CA cannot be ruled out. If I'm misunderstanding let me know.

So the aspirate should have been sent for culture and sensitivity, because if a particular bacteria is not sensitive to the antibiotic that was prescribed it can persist or return. I can't tell from this report if culture and sensitivity was done?

The report is saying that a bacterial infection is the most likely diagnosis. The problem is that, at least in people and I would think dogs too, the aspirate should ideally be sent for culture and sensitivity before antibiotics are started, and once they are started it's more difficult to grow anything out in culture, although they can aspirate again and try.

I would think they would just try a different antibiotic, perhaps a stronger one, and see what happens. You could always biopsy la