Ct shows bilat hilar, all mediastl & virchows node enlarged @ least 3 mos dr says not sarcoid. Past endo cancer 1a, can biopsy of virchows tell issue?

Yes. Biopsy of the enlarged virchow's node would in all probability either rule in or out a cancerous cause for the enlargement. Good luck!
Biopsy. You need to have a pet scan if your insurance will cover for it. If not, you should have those lymph nodes biopsied to tell you definitively what they are.