I'm no doctor, but this really does sound a swollen vein. I have something similar on the side of my tongue. Please try not to worry - difficult I know... 

Hi Clizzy

I thought I would reply as your picture will be shortly removed by the moderators as not allowed as part of policy.
As for ENT appointment, none of us are medically qualified, but the fact that you have had for years and not displaying any other symptoms is  good sign. Many are referred to ENT and the majority of tests come back with nothing sinsiter or to worry about at all.
It does sound like a routine check to get the view of the ENT consultant as they are the specialists and not the GP's
My biggest bit of advice is to please stay off google. There is so much mis information out there as well as being so out of date and its really easy to self diagnose yourself with pretty much anything if you type in any symtom.
Forget Dr Google and try and stay positive as you can and I'm pretty sure your ENT appointment will put your mind at rest. Google most certainly will not

Please let us know how you get on at ENT and feel free to chat away on here if it helps

kind regards

Ian