 Hi there, my name is Jean Clapper and I am a surgeon. One of my passions is medical education. In this series of presentations, I'll talk about things surgical. Remember, these presentations are available for continuous professional development points, so I'll leave the description to that down below. In this presentation, I'm going to talk about thyroid malignancies. Now, I do have another presentation where I talk about the workup of a thyroid nodule. The name of that workup is to identify the patient with definite or possible thyroid malignancy. Fortunately, they are not very common, but it's important to know what to do with a patient with thyroid malignancy. These are a heterogeneous group of tumors. They are usually identified as thyroid nodules. And it must be remembered that thyroid nodules are very, very common. And thyroid cancers make up a small fraction of all thyroid nodules. The true proportion of nodules that are cancers, that depends on how the incidence of thyroid nodules are determined. Now, since the true incidence of the latter is probably in excess of two-thirds of all human beings, the minority of proper nodules are malignant. So thyroid follicular epithelium, that can give rise to four types of cancers. Most commonly, we have papillary thyroid cancer, then follicular thyroid cancer, herthal cell carcinomas, and anaplastic cancers. Now, the papillary thyroid carcinoma, as I said, that's in the majority of cases, 85% of all thyroid malignancies. And then follicular thyroid carcinomas, that's second most common, and that gets down to 10 to 12%, and then the anaplastic or undifferentiated thyroid cancers, that's very rare, it's about 3%. Now, there are subtypes of papillary thyroid cancer. So let's look at the most common papillary thyroid. We get the classical types, but we also get tall cell variant, the columnar cell variant, and the follicular variant of papillary thyroid cancer. Now, the tall cell and the columnar cell subtypes, they appear to be slightly more biologically aggressive than the classical type. And there's also a variety of follicular carcinoma subtypes, too. Now, these include the clear cell variant, the signet cell types, the follicular thyroid cancer with glomerular-loid pattern, spindle cell follicular thyroid cancer, and it's not really clear whether these variants have a different outcome from classical follicular thyroid carcinoma. The tall cell thyroid carcinomas, they used to be seen as a subtype of follicular thyroid cancers, but they are biologically distinct. Now, it does, however, follow a very similar clinical path to follicular thyroid cancers, and we really do manage them the same as a follicular thyroid cancer. There are two types of non-f follicular epithelium of the thyroid, and the first is medullary thyroid cancer that arises from the C cells in the thyroid that do help in the calcium metabolism. Medullary thyroid cancer, they can be sporadic or they can be part of familial syndromes. These are then the multiple endocrine neoplasias, type 2 to A and B, or isolated familial medullary thyroid cancers. Now, the second non-f follicular epithelium thyroid cancer, remember, is primary thyroid lymphoma. Yes, you can, a patient can also develop lymphoma, primarily in the thyroid itself. Then lastly, we get metastases from other tumors to the thyroid, and most notably, those will be the breast from the kidneys, from the colon, as well as malignant melanoma. Remember, malignant melanoma can really metastasize anyway, and they can present as thyroid nodules. So, let's look at the workup of a patient then with suspected thyroid malignancy. Now, the workup of thyroid carcinoma, that's the result of the workup of any thyroid nodule. Now, this involves a thyroid function test, an ultrasound of the head and neck, and final aspiration, the cytology of the nodule. Now, most patients with thyroid carcinoma are euthyroid. Now, it's only rarely do we find papillary thyroid cancer that is hypothyroid. So, that's very rare. Now, ultrasound, that should include imaging of the cervical lymph nodes. That's the central and the lateral neck regions, because we do look for metastasis specifically for papillary thyroid cancer that metastasizes to the lymph nodes. Now, they are present in up to a third of cases. If you look carefully with ultrasound, you're going to find those nodes. Now, the presence may require a change in management. So, yes, we have to look for them. Now, thyroid gland itself, it makes it a bit difficult to detect the central nodes, and they actually missed in up to a half of cases. So, invariably, we make this decision on the surgery at... or what to do with these nodes at surgery, because sometimes that is when you discover them for the first time. Now, final aspiration cytology, that can diagnose most thyroid cancers. It can unfortunately not differentiate between a follicular thyroid carcinoma and a follicular thyroid adenoma. So, papillary, most common, and yes, it can be diagnosed on final aspiration. The 10 to 12% of cases that are follicular thyroid carcinomas, no, we can't diagnose that on cytology. We really need the presence of infiltration of the nodule perimeter and associated blood vessels and nerves, and that is required to differentiate between an adenoma and a carcinoma. You need to see that tissue architecture and whether there is invasion. And we can only do that on histological evaluation of a surgical resection. So, you've got to take that low about and submit it for histology to differentiate between adenoma and carcinoma as far as follicular lesions are concerned. With more advanced local disease, we ask for CT scan or an MRI of the neck, and usually to evaluate the extent of the disease. If it's advanced, it goes down into the thorax as it invades local tissue. We must remember, though, that if we use iodinated contrast medium for CT scan, that will delay the use of radioactive iodine therapy after surgery for months. So, we've got to think carefully way up the risk and benefit of using contrast-enhanced CT scans in these patients. And really the knowledge gained in planning the surgery can outweigh this delay in the use of radioactive iodine therapy. So, we just have to decide. And then also, laryngoscopy and endoscopy, we can use those as well to look for local infiltration into the esophagus or the tachyram. Now, symptoms and signs that may indicate the presence of advanced disease because we see all these patients in nodules. Most of them won't have a carcinoma, but things that make us concerned. And that is hard-matted lymph nodes. So, you examine the neck, central lateral compartments, hard-matted nodes. The nodule itself, if that's hard and fixed to local structures. Patients who complain of dysphagia. If there's any respiratory compromise, including dyspnea or this feeling of choking, proper voice changes, any kind of paralysis of the vocal cords and then also hemoptysis for advanced disease. All patients in whom the pre-optative workup is diagnostic of a thyroid cancer and in those with equivocal cases of advanced tyrades or Batista classification, they should be evaluated for thyroidectomy. So, we've worked up the patient. I do have a separate presentation on the workup of a nodule. We've come to the stage where this is highly suspicious and we need to go for surgery. Now, there's no randomized controlled trials that have investigated properly the extent of the surgery. And we do have a lot of literature to guide us though. Now, there are various terms used for the extent of the thyroidectomy and we just have to be clear about those. So, a total thyroidectomy that refers to the removal of both lobes, all the thyroid tissue. It's probably a bit of a misnomer as most patients still have some residual uptake on the scintigraphy post-operatively. So, it's very difficult to clear that whole bed. Now, by definition, the bilateral dissection is just the dissection of both lobes. And we take great care to preserve the laryngeal nerves and the parathyroid glands and we'll talk about those complications. Now, some centers advocate the use of autotransplantation of one of the parathyroid glands. So, we have a pathologist in theatre. They confirm the fact that there is a parathyroid gland. It gets sectioned into smaller pieces and autotransplanted in the sooner-cliter mastoid and that's really to prevent hypercalcemia in case all the other, or at least the other three, most people only have four parathyroid glands are injured. A near-total thyroidectomy that refers to a complete lobectomy on the one side, that's the affected side, and removing most of the contralateral lobe, most of the contralateral lobe. A unilateral lobectomy and isthmus resection, that's done most commonly. We have unilateral thyroid disease. We're not sure whether this nodule, not 100% convinced that this nodule is malignant, but there's a high potential. We're going to go for a unilateral lobectomy and isthmus resection. And we leave the contralateral side unopened, undisected, so in case we have to come back, the surgery on that side is a lot easier and with less complications. And then we get this horrible sub-total thyroidectomy. That's not a treatment option for any suspected malignancy or confirmed malignancy. And what that does is it just leaves the posterior parts of both lobes. Yes, it does protect the parathyroid. It does protect the recurrent laryngeal nerves, but it doesn't really play a part in the management of these patients. So our minimum surgery is a unilateral lobectomy and an isthmus resection. Now, we do reserve this procedure for lesions that are less than four centimeters in diameter. No suspicion of contralateral disease and no imaging or interoperative indication of any kind of extra-capsular invasion or nodal spread. Now, it should also not be reserved for patients with a history of head and neck irradiation or a strong family history of thyrocarcinomas. So if the preoperative evaluation identifies multifocal papillary thyroid cancer with more than five foci, or if a unilateral thyroidectomy is performed and the final histology is that of multifocal papillary thyroid cancer with more than five foci, we're going to do a thyroidectomy or come back and do that completion thyroidectomy. So a total thyroidectomy that is advocated for all advanced cases, so more than these that I've just mentioned. Now, this includes patients with distant metastases because this facilitates the concentration of radioactive iodine in the metastatic tissue that would otherwise have been concentrated in the remaining thyroid. So we still do a total thyroidectomy in patients with distant metastases. Now, in the cases of suspected but not confirmed malignancy, that's advanced thyroid or botesta. Remember, that's your ultrasound and your final aspiration cytology. A unilateral thyroidectomy and isthmus resection can be performed. Now, the final histology can then inform the need for follow-up surgery, the contralateral abectomy. So that happens quite often. So given an intrathyroid differentiated thyroid carcinoma of less than four centimeters in greatest diameter with no signs of spread, who does not require postoperative radioactive iodine therapy and who can be followed up adequately, we do a unilateral abectomy and isthmus resection. That's advanced by the American Thyroid Association of which I'm a member. Now, 10-year disease-specific survival in these cases has been shown to be as high as 98.6%, so really excellent outcome. Now, since the presence of extra-captial invasion or contralateral disease and suspected lymph node spread can sometimes only be appreciated intraoperatively, remember we must, patients must be given, must give consent for a more radical dissection with all its increased risks prior to doing the surgery. So that must be part of the informed consent. We might change our mind from a unilateral resection and an isthmus resection to total thyroid abectomy. Now, nodal disease must also be managed during surgery. Now, the American Thyroid Association only recommends nodal dissection, that's central or lateral, in cases of evident nodal disease that's imaging or intraoperatively. So we decide on which nodes to remove. Now, prophylactic level 6, that's your central compartment node clearance, that's controversial though. So, you find these tiny little nodes, in this papillot thyroid cancer, do you do this prophylactic central clearance? So this level 6, the central compartment that is confined between the two jugular veins laterally, the high-weight bones superiorly and then the sternum inferiorly. Now, disease confined here, necessitates a resection of all the central lymph nodes. So if they are there, if they're bigger nodes there, yes, we clear that block. But if not, it's controversial whether you should do this prophylactic clearance. Now, levels 2, 3 and 4, that's the upper, middle and lower jugular compartments. Now, nodal involvement in these compartments, that really necessitates removal of that whole jugular chain. All patients require thyroid replacement therapy after surgery. So just remember that patients had thyroid cancer therapy, we put the majority of them, I should say, on thyroid replacement therapy. Now, the complications of surgery. We see these patients post-operatively, take care of these patients post-operatively. We've got to be aware of the possible complications, irrespective of the surgery that was done. And remember, nodal resection and complete thyroidectomies, they're obviously going to have a higher incidence of complications. Now, other than the risk of bleeding and surgical infection and aesthetic complications, the two main risks are hyperparathyroidism and nerve damage. And then the more radical injuries might have injuries to the erodigestive and the neurovascular structures. That's horrible, but it is possible. Now, post-operative hematomas, they are not common, but they can be fatal. And that's the first thing you've got to watch for, even if things went really smoothly during the surgery. The incidence is lowered by stopping all anticoagulants prior to surgery. Patients can't be in anticoagulants for these next sections. And we use meticulous technique with complete hemostasis prior to starting the closure. And we witnessed this by placing the operating table into a Dellenberg position that's head down to cause some venous congestion there and just make sure that there is no bleeding. That's prior to starting any closure. You can put a small suction drain to really avoid the formation of these hematomas. Now, the ward, the staff in the ward, they should really be made aware to be vigilant about checking for the development of a hematoma. And then the wound should be opened immediately, even if it has to be done in the ward prior to taking the patient back to theater. So just quickly snip open that wound. Remember, put subcuticular sutures and then some interrupted vicaral sutures in the fascia and fat layers underneath the skin. They just get opened right there in the ward. It's a life-saving procedure because that patient is going to die from asphyxia. Seromas, that's much more common. Fortunately, they're typically small and we just usually manage these conservatively. We don't have to drain seromas. Hyperparathyroidism is the result of damage to the parathyroid glands. This can either be due to direct damage or removal of those glands together with the thyroid or damage to the blood supply to these glands. Hyperparathyroidism follows more commonly in cases with large tumors causing anatomic derangements that you're not sure exactly where these parathyroids are. Remember, some parathyroids are intra-thyroidal, so they're inside the thyroid capsule, actually. Now, the resultant acute hypocalcemia that might be mild or even severe tetany. So in mild cases, patients present with this perioral numbness, peristegias of their hands and feet, and some muscle cramps. And then in severe cases, patients can experience carbopetal spasms, laryngeal spasm, or even seizures. Now, we're all familiar with the Shostec sign. That's the perioral twitch on tapping the facial nerve or the trussosa sign. That's the forearm muscle contraction when applying a 20K. And those are well-known signs of hypocalcemia. Now, patients with mild symptoms and then those with a calcium level below 2 millimoles per litre, we give them calcium triol, half a microgram twice a day and some calcium carbonate, 500 milligrams four times a day, and that should usually suffice. Now, in patients with more severe symptoms, we can give them calcium gluconate that's added intravenously for the first day or two, or until their calcium level rises above 2 millimoles per litre. And then an emergency treatment for patients with cardiac electrical derangements on the ECG, or those with seizures, we add to that the administration of 10 millilitres of a 10% solution of calcium gluconate over 10 minutes. So oral vitamin D and calcium carbonate, that's given orally, and then it's tapered and discontinued over about two months, a two-month period. Now, if that's not possible, a low parathyroid hormone level will confirm the diagnosis of permanent disease. So remember, I'm talking about these 20%, 25% of cases with this transient disease. We give them the vitamin D and calcium carbonate, taper that over two months and they're fine. But if the calcium levels do not improve, we do that PTH and we can see it's low and that will be a permanent disease for them. In some centres, vitamin D and calcium carbonate are started the day before total thyroidectomy and continued and tapered over the next two months or so, and that really tries to avoid this transient hypocalcemia. And then the opposite that is obviously just to treat the cases that actually develop. There are two schools of permanent hoarseness that can follow from dislocation of the retinoid or nerve damage. And if it's dislocation, those have to be promptly relocated. Now, recurrent and superior laryngeal nerve damage, that's well described. In many cases, the damage is transient and that can actually happen in up to 7% of thyroidectomies. If you look for it carefully, you're going to find it. The recurrent laryngeal nerve, that might be intentionally sacrificed in advanced cases. So we can discuss that with a patient beforehand and we might have to sacrifice that nerve. Now, vocal cord paralysis, that can follow traction injuries to the recurrent laryngeal nerve and these usually resolve by about 6 months. So it's just that traction on the nerve during the resection. There's a bit of vocal cord peresis and just from that traction of the nerve and that will resolve. Now speech therapists may be of help and they help the patient to reduce the strain on their vocal cords and that's usually of great help. Now unilateral vocal cord paralysis, that follows ipsilateral permanent recurrent laryngeal nerve damage. So we're talking the peresis, that's just from the traction that resolves but permanent paralysis that's from that same side complete injury of the nerve. Now the affected vocal cord that's paralyzed, either in the paramedic or in the lateral position and what we try and do is to get the vocal cord fixed immediately we call it medialization and that allows for the contralateral vocal cord to actually close the larynx and that really improves swallowing in speech. So if they stuck medially that's fine, if they stuck in the lateral position we've got to medialize that you know as in throat, colleagues help with that. Now it's usually it's useful to commence with speech therapy and in those who develop aspiration pneumonia and ineffective cough or disabling dyspnea or hyperfonia those are really the ones that we go for the medialization and that's instituted quite early. So bilateral recurrent laryngeal nerve injury that's a devastating injury and that usually follows it's a high incidence after re-operation and it's diagnosed on extubation with acute stridor and dyspnea, horrible situation patients re-intubated if the cords are adducted though together you even have to do an emergency tracheostomy just to get airflow then a partial posterior laser cordectomy it can be done just to get these vocal cords open again. Now when the nerve is transsector doing surgery at attention-free repair must be made right then and then and we can even do a little interposition nerve grafts and we take nerve tissue from the Anso-Cervicalis or the hypoglossal nerve those can be sacrificed as an interposition graft. Now the superior laryngeal nerve that damage that produces vocal fatigue and subtle voice changes with the inability to to project the voice. So the patient has had their surgery for extended carcinoma, it turns out to be carcinoma what do we do now? We stratify the risk after the surgery and the patients must be continuously monitored because the risk evaluation can need to change in the risk and we really look at low risk, intermediate risk and high risk patients. So the low risk patient that's papillary thyroid cancer and with all of the following must be present. They've got to have no metastases all macroscopic tumor has been resected there's no invasion of local tissue there's no aggressive histology the variants that I spoke of before there's no vascular invasion there's no radioactive iodine uptake in the thyroid bed and it's an N0 that means no nodes or N1 nodes less than 6 of these micrometastases these small little nodes that are less than 2mm so if you have all of those that's low risk. Also low risk group is the intrathoroidal the variant of papillary thyroid cancer also the intrathoroidal follicular thyroid cancers with no or minimal vascular invasion less than 4 foci and then lastly intrathoroidal papillary microcarcinoma even if they are multifocal so that gives you a low risk that patients in a low risk group. Intermediate risk group microscopic invasion into the perithyroidal soft tissue cervical lymph node metastases or radioactive iodine uptake or metastatic foci in the neck on the post treatment scan done after thyroid remnant ablation is done with radioactive iodine therapy tumour with aggressive histology tall cell variants, insular cell variants columnar cell carcinomas hurdle cell carcinomas follicular carcinomas or the hopnail variant all of these fancy variants or if there's vascular invasion that's an intermediate risk patient clinically if the N1 N1 nodal disease with a TNM classification or more than 5 pathological N1 nodes with all involved lymph nodes less than 3cm in the largest diameter intermediate risk and then also multifocal papillary thyroid microadenomas with extra thyroidal extension high risk the ones that we worried about that's macroscopic tumour invasion that is incomplete tumour restriction with gross residual margins patients with distant metastases postoperative seromethyroglobulin suggestive of distant metastases and pathological N1 nodes with any metastatic lymph nodes more than 3cm in the largest diameter and then a follicular thyroid cancer with extensive vascular invasion more than 4 foci so that's your high risk patient now we use this risk certification to determine the use of adjuvant therapy now there are actually numerous classification systems and they're not all routinely used by everyone and that makes comparison in the literature and what exactly to do very very difficult but let's look at radio iodine treatment so radioactive iodine that is taken up by functional thyroid tissue similar to the non-radiactive iodine so iodine is essential in the production of thyroid hormone and thyroid tissue is unique in its ability to concentrate and store iodine there's also breast tissue that can absorb iodine but really it's concentrated and stored in the thyroid gland now thyroid tumor cells they have a reduced expression of the sodium iodine transporter in the cell membrane that actually absorbs that iodine so they're not like normal thyroid follicular cells so radioactive iodine therapy is of no use in patients with little or no uptake and we're really thinking here of anaplastic carcinomas and then also carcinomas in the thyroid that do not come from follicular epithelium that's the medullary thyroid cancer and lymphoma that's not going to help to give these patients radioactive iodine therapy so iodine 131 so 131 nuclei, protons and neutrons in the nucleus of the iodine atom that is radioactive and it produces high energy beta particles and also gamma rays in those gamma rays that are used obviously in the scintigraphy and the imaging so these beta particles, high energy electrons they have a short path length 1 to 2 millimeters and they cause a acute cell death so radioactive iodine that's used to ablate remnant thyroid tissue after surgery so if there's any remnant tissue left or left in the bed even after total thyroidectomy we ablate that tissue and so why do we ablate it? why do we get rid of everything? well the aim is then to be able to use thyroglobulin so blood test, test thyroglobulin it's made by follicular cells and that can monitor the patient following surgery so we're really looking for metastasis here a patient has no thyroidal tissue left there's no thyroglobulin post-operatively there's no thyroglobulin and with follow-up suddenly that rises up it gives us an idea that there's a recurrence or a distal metastasis so if normal thyroid tissue is ablated and metastasis that produce thyroglobulin we can detect them on serial follow-up and it also facilitates the use of radioactive iodine in detecting these metastasis used on imaging because those metastasis or econs might then take up the radioactive iodine so radioactive iodine therapy it is also used as adjuvant therapy eliminating subclinical tumor deposits and treating known metastasis so not only for ablation but also for actual therapy so the role in the former that's adjuvant therapy that requires a balance between the potential risk and benefit risk of the use of radioactive iodine therapies generally not recommended in the following cases intra-thyroidal cancer less than 4cm in greater diameter and with no other risk features and multifocal disease or less than 1cm in greater diameter with no other high risk features so this includes then all cases with less than 5 nodes measuring less than 2mm so radioactive iodine therapy is indicated in the intermediate risk cases with microscopic invasion into the peri-thyroidal tissue with significant lymph node metastasis vascular invasion, histological subtypes such as tall cell cost numbers, columnar cell cost numbers and insular cost numbers and in cases that are deemed high risk so for all of those patients now the uptake of radioactive iodine that requires thyroid stimulating hormone TSH and all iodine containing food and medication that should be stopped in advance of the therapy we want those TSH levels to be high now the use of iodine containing contrast during CT imaging that will delay the use of the possible use of radioactive iodine by several months so we can use recombinant human TSH that is used in some centres to improve the uptake of the radioactive iodine and then all thyroid hormone therapy that's really withdrawn 4 weeks prior to radioactive iodine therapy it must be remembered that pregnancy and breastfeeding there those are hard contraindications for the use of radioactive iodine therapy and then lastly just to remember the side effects cell adenitis, secondary tumours dysfunction of the gonads and then a reduction in fertility that goes with that and then naso-electrimal duct obstruction with the dry eyes and then swelling of the tumour tissue itself so there you have it the management of thyroid cancers please remember that this video series is part of a programme of continued medical education and the information for that will also be in the description down below