My dad has a small growth in his lungs as well as has a growth on the brain (has being having fits). He has had a full body scan and there is no other tumours. Now they are saying that it might be something to do with the lymph system so have taken more blood tests - tomorrow they might do a bone marrow test or a needle biopsy into the growth on the lung

Anyone knows what this means? The doctor says that if it is cancer to do the lungs it is the more treatable cancer. I must say I am confused and cannot find any helpful info on this.