Husband recently diagnosed with Cholangiocarcinoma and had no symptoms

My husband was recently diagnosed with Cholangiocarcinoma. We were referred to Mayo and have our first appointment in a week. What I don't understand is why blood tests taken the end of Sept were all normal range. Lesion was found on the liver by accident otherwise no symptoms. They say it's about 8cm which is quite large. We don't know what to expect and it's scaring me. I'm assuming the size would mean it's more advanced. Can anyone share their experience if it's similar?