Thyroid cancer is most frequently going to present as a solitary thyroid nodule. These are by no means uncommon findings. In the Framingham study, just the health surveillance study, the prevalence of these nodules was close to 10% in women. The important figure that I tell my patients when I first see them is that the a priori odds of a solitary thyroid nodule being a cancer is actually not that high; only about 5-10% of thyroid nodules are ultimately going to prove to be malignant.
Clinical risk factors: the important risk factors, issues that would make one highly suspicious, a nodule that is growing rapidly. Say, over a period of weeks to months. A family history of a familial syndrome, multiple endocrine neoplasia or perhaps medullary thyroid cancer. Not by any means a common situation and in fact I would hope not to be seeing anybody with that history at this point, for reasons that we’ll discuss. Among the physical characteristics, a nodule that is very hard, that appears to be fixed to adjacent structures. Very rarely there will be vocal cord paralysis present. Obviously the presence of clinically suspicious lymph nodes or the occasional patient who would present with frank metastatic disease. But in fact, most of the time when patients come to see me with a thyroid nodule they are asymptomatic and there is very little a priori reason to feel that they either do or do not have a thyroid cancer.
This is kind of a busy algorithm. It’s reproduced in your notes. The important point here is that from my perspective the single most important test, in terms of evaluating solitary thyroid nodule, is a thyroid aspiration. Frequently I will do that at the time of the initial visit, even if I know nothing else about laboratory studies or anything like that. Oftentimes a biopsy will provide enough information to make a treatment decision right off the bat. If the biopsy is highly suspicious for being a papillary cancer, you don’t need at that point to do a lot of scanning or imaging studies. On the other hand, if the biopsy is very reassuring about this being a colloid nodule, for example, or perhaps chronic thyroiditis or something like that, you also don’t need to do a whole lot. The one area to keep in mind in which the biopsy can be difficult is where the cytologist reports back the biopsy findings as being suspicious for a follicular neoplasm. The problem here is that on an aspiration cytology level, a follicular neoplasm, that aspirate will not distinguish a follicular carcinoma from a follicular adenoma. So those are the areas that can be a difficulty. It’s in those patients that I’ll get a scan because occasionally the nodule will be hot and if we know the nodule to be hot on scan, we know it’s not a follicular carcinoma. So that’s the one situation in which a scan is particularly useful in distinguishing a cancer from an adenoma. Otherwise, if the scan shows it to be cold then most of those patients are going to be indeterminate and I would recommend surgery for most of those patients because there won’t be any other less invasive procedures that will be definitive.