Unexplained Liver Lesions

Had a CT recently revealed a small lesion on my liver.....ultrasound has now confirmed multiple lesions tests were done 2 weeks apart...... had an ultrasound done last october 2010 and liver was clean......bilirubin is elevated but have  not gone jaundice, loss of appetite, have lost 75lbs since november 23 2010, blood in stool, colonoscopy came back negative for anything .  are these lesions something to be concerned about? can begnine lesions just begin to appear? now i have a begnine cystic tumor in my right side brain called a DNET (dysembryoplastic Neuro Epythelial tumor) could that have thrown other tumors into my liver?

my GP does not seem too concerned but what concerns me is the fact  my ulrasound done not even three months ago was clean.