I just need to tell someone. Fuzzy had an MRI last week and the vet called with the bad news this evening. It's not really treatable (possibly with radiotherapy, but it would be palliative and is difficult for the cat and expensive). Prognosis is a few weeks but he's being fed through a syringe because he won't eat. But he doesn't seem ill otherwise, just a bit tired and very clingy with DH, who has scratch marks on his shoulder where Fuzzy likes to hold on! I've read that these tumours can be very painful though, and it could end with the eyeball popping out of its socket due to the pressure. Obviously we don't want him to get to that stage...
Before the scan the vet thought it might be an abscess, so I was expecting something treatable. It's such a shock. My husband and I were both crying. We just can't imagine him not being around any more.
His only symptom was not eating, and seeming to have pain when eating. Our first vet visit for this was end of October. He's had loads of tests, had his teeth cleaned just before Christmas because they thought it was gingivitis, had an ultrasound of his stomach in case it was that (it's now extra fuzzy whee the fur is growing back). At some point he had an X-ray, if it was of his head I'm surprised they didn't spot it. All blood tests seemed fine 
He is just under 10. Still middle ages for a cat surely? I was there when he was born and his mother died last summer of renal cancer (also only 10 or 11). My little cat family has terrible genes, it seems. One left, sister of the boy who is dying. I just feel so terrible and don't know what to do for the best.
Here he is (study of cat with speaker!)