Screening for thyroid cancer

Screening for thyroid cancer in patients with a history of head and neck irradiation. These patients are getting into their 50s and 60s. These are patients who had radiation for the thymus or acne or whatever benign diseases that we were zapping them for.
Implications of test results in the nodules and masses. Basically, we’re looking for whether the nodule or the mass is hyperfunctioning or hypofunctioning. If it’s hyperfunctioning, it only has a 3% incidence of being malignant. You don’t even have to touch these people. You can watch them. Followup palpation, that sort of thing. But basically if it’s a hot nodule or hyperfunctioning nodule, you’ve pretty much ruled out malignancy. On the other hand, if you have a hypofunctioning nodule, 15-25% of cases will be malignant. It’s even higher if they have a history of radiation to the neck. These people need a fine needle aspiration and you might as well just do it early instead of later. We had a case recently where a young man was delayed for two months before he got his fine needle aspiration which was entirely too long. He had a mass that was about this big and it would have taken two seconds to get a needle into that thing.

Toxic nodules can cause hyperthyroidism. Usually you see complete suppression of the rest of the thyroid gland. Usually you have already performed thyroid function tests and you already have an idea if they are hyperthyroid. Function nodules are autonomous if they continue to produce hormone despite TSH suppression. They are very easily treated with radioactive iodine because all of the radiation goes right to that overfunctioning nodule and wipes it out. The rest of the gland is protected because there is such a low TSH, it’s not taking up any radiation. Very easy to treat with radioactive iodine.
Multinodular goiters are very common in middle aged females. They are usually benign. They are usually not toxic. They’re usually euthyroid but if they are toxic and they do need treatment, you could go with radioactive iodine or PTU, again for the hyperthyroidism of multinodular goiters. A scan is a good idea in a multinodular goiter, mostly because you want to rule out a dominant cold nodule, again, which might indicate malignancy.

Graves’ disease, everybody knows about. Subacute thyroiditis, remember, is an inflammatory process. It’s transient. They’re just releasing all this preformed hormone. There’s a suppressed TSH and a high T4 or a high T3 and it looks just like the hyperthyroidism of Graves’ disease.
One thing that’s kind of come up in the past few years is that the TSH tests have gotten much more sensitive so I’m seeing more and more patients with normal free T4 and suppressed TSH. The first thing that you want to do in that case is check the T3. 10% of the cases of hyperthyroidism are where only the T3 is elevated.

The second thing that you want to do is get a thyroid uptake and scan. If their uptake is high, then they are truly hyperthyroid and we can go ahead and start treating them. Generally, we want to either watch these patients very closely or go ahead and start treating them because eventually they are going to develop hyperthyroidism. So you can either get on the bandwagon early or you can wait until they are really symptomatic. Generally, though, they are somewhat symptomatic because you’ve already tested them for their TSH.
Patients that are asymptomatic get a routine screening TSH. Your call is as good as mine. I’d call up my local endocrinologist and see what they would recommend in terms of treatment but that is an issue that’s come up in the last few years.

Leave a Reply

Your email address will not be published. Required fields are marked *