Regarding Sharon's question:
Just to present yet another scenario:
Last summer I had a CT scan that showed suspicious areas on my thyroid and also showed the lesion in my mouth (CT scan was done because my ear was stopped up and ENT couldn't figure out why-- the ear problem cleared on its own and apparently had nothing to do with the cancer). A fine needle biopsy confirmed thyroid cancer (but the radiologist could not get a good specimen of the mouth lesion). I had a total thyroidectomy and an excisional biopsy of the mouth lesion all at the same time. Both came back as different types of cancer-- totally unrelated to each other. Weird-huh?