@skm101 , You may want to wait to see what the PET scan shows before reaching out for a second opinion or transfer to one of the Mayo locations, but just in case you need it, here is a link to request an appointment: http://mayocl.in/1mtmR63
IF this is a cancer, there are also many well-respected cancer centers around the world. If you are in the US, the National Cancer Institute has a list of designated cancer centers here:
https://www.cancer.gov/research/infrastructure/cancer-centers/find