Let me pose a question to you. What if you injure the recurrent laryngeal nerve? What happens?
I’ll give you a second to think about this. Findings of recurrent laryngeal nerve injury:
Remember that the recurrent laryngeal nerve is actually a branch of the vagus nerve or cranial
nerve number X. It innervates the intrinsic muscles of the larynx. With injury, one may get
hoarseness or weakened voice. The vocal cord remains in a midline position. Remember, if you
were to injure both recurrent laryngeal nerves, now both vocal cords would be resting
in a midline position. This, of course, can cause respiratory distress. Medical management
of thyroid cancer includes radioactive iodine specifically the radiotracer iodine-131 in high doses.
Remember, radioactive iodine therapy does not work in medullary because medullary cancer
does not uptake radioactive iodine. Radioactive iodine concentrates in the remaining thyroid
tissue particularly, remember, even though you thought you may have removed the entire
thyroid, there may be some residual tissue. Thyroid tissue uptake is stimulated by high TSH levels.
This is why patients do not undergo a period of thyroid replacement to allow the thyroid
stimulating hormone levels to rise. High thyroid stimulating hormone levels are achieved
by thyroid suppression therapy. Let’s talk about anaplastic thyroid cancer briefly.
It’s got uniformly poor prognosis; it is locally invasive; and surgery, if possible. Unfortunately, the vast
majority of surgery offered to anaplastic thyroid patients are palliative in nature. Palliation, we mean
symptoms such as difficulty swallowing or difficulty breathing with local invasion. Otherwise, they
may need chemo and radiation for palliation only. There are some clinical trials that are running
for anaplastic thyroid cancers and your patient may be a candidate. Let’s talk about medullary
thyroid cancer. Medullary thyroid cancer requires central lymph node dissection.
That’s an important clinical pearl as opposed to selective lymph node dissection for papillary.
Let me pose a question to you. What blood test can help diagnose a recurrence?
I’ll give you a second to think about this. Answer is thyroglobulin. This is a useful marker
after total thyroidectomy. Remember though in medullary thyroid cancer, we follow
calcitonin levels, not thyroglobulin levels. Let’s talk about medullary thyroid cancer
in a hereditary pattern. These are considered associated with RET proto-oncogene.
This is associated with MEN, multiple endocrine neoplasia 2 syndrome. This is high-yield information.
Remember though that the vast majority of medullary thyroid cancers are still sporadic.
Thank you very much for joining me on this discussion of thyroid cancer.