I'm going from the top of my head on this one so anyone feel free to correct me.
It would be almost impossible that you would have graves if you do not show either TSI and/or TRAb and/or TPO antibodies and there's a few t's that are rarer that I don't remember.
It would be very unlikely that you would have hashis if you do not have TPO and/or TG antibodies but it has also been known to be found on biopsy without antibodies showing in the blood.
Cancer is found by fna biopsy or during surgery. I think there's an antibody they follow after surgery to make sure there's no remaining thyroid tissue but I think its a thyroid antibody and not a cancer antibody.
Helen, thanks for the info, i just wasn't sure that if you had an antibody blood test that is antibodies weren't present if you could still have cancer if though the blood work was negative for antibodies! And basically you would have to have more than just a TSH blood workup to find out about the others?