It seems to me, and I'm no expert, that all an US would do is tell them if a needle biopsy is needed. That's the only way I know of to really rule out cancer so seems you could just skip to the biopsy. Again, no expert, just mho. Anyway, welcome to the forum, Hope you don't need it but it's here if you do.

David R. 65 yr old male non-smoker, light drinker, stage 3 or 4, depending on which doc you ask, scc rt. tonsil, 2 nodes, 7 weeks radiation and chemo. No surgery. Teatment ended 3/20/08. PET scan 8/08 showed no cancer.
And now, as of oct, 2010, caregiver to wife, Linda, with breast cancer.
May, 2013, Linda diagnosed with stage 3 ovarian cancer. Enuf already.