Met with the surgeon this morning, and the mass is confirmed as cancerous. It is about 2cm across centred in the bile duct and is blocking the gall bladder also, as well as touching the portal vein.
I am scheduled for an operation to remove it (he says he is aiming to get the entire mass) on Friday.
My wife and I will meet with him again tomorrow and I presume we will discuss prognosis then. I keep hearing from others that the prognosis is good because the location of cancer leads to symptoms and therefore is caught early. Fingers crossed.