It does seem a bit of a jump in diagnosis T1 to T4.
What scans have they done and what evidence do they base this diagnosis on? I had secondary tumours in my neck lymphs 10 years ago - necessitating a full neck dissection. Those tumours were classed as 3b/3c. .
I have replied to your other post - let us know how things are going for you.
Over 10 years ago I thought things were pretty hopeless for me - unknown primary and secondary extracapsular neck lymphs. Still here fortunately - a few scarea along the way.
All the best Tony K