please help im confused about my dad case

hi all,my dad was diagnosed last year with a 12 cm tumor in the liver the doctor said its cholangiocarcinoma he’s ca-19-9 was slightly elevated about 57
we went and saw the surgeaon and he said that the surgery is the only hope for cure , he had a lobectomy since 1 year with clear margins then he has been on gemzar the onc said it would be better to reduce the risk of a reccurence then had a hepatic MRI not showing any reecurence and was appointed to do a new MRi after six months ,now, last month he had the MRI that is showing multiple secondary lesions on the liver, im shocked!!! and the ca-19-9 is normal not elevated, i asked his onc how could it be that the ca-19-9 is not elevated and he have a reccurence of the diseaswe now??? is that possible??? please someone tell me, i asked another onc about my dad situattion he told me that he doubt that my dad have cholangiocarcinoma!!!!! he asked me to make the alfa pheto protein and the cea test, because he doubt its a cholangiocarcinoma cause the ca-19-9 is not elevated and is normal he think it is not the primary of the cancer but a metastaze that is coming from a unknown primary location, my dad is now on xeloda waiting for next MRI the 10/6 and is doing well he deosnt have any symptoms and just feeling ok , im so afraid that its not a cholangiocarcinoma but a unknown primary location that is coming to the liver ,can anybody help me please im so confused.is it possible to have a reccurence with multiple lesions on the liver from 6mm to 25mm without having the ca19-9 elevated??? please tell me or its not cholangiocarcinoma???
please any advice of you will be very helpful to make some desicion about my dad situation