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Unlocking the Mysteries of Thyroid Health with Dr. Melissa Bochner: What issues could possibly occur?

• Dr Gavin Nimon • Season 4 • Episode 59

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Discover the secrets of the thyroid gland with Dr. Melissa Bochner, ( Breast & Endocrine Surgeon ) as she unravels the mysteries of one of the body's most essential regulators. Prepare to be enlightened about the delicate balance of hormones that orchestrate our metabolism, heart function, and much more. As Dr Gavin Nimon ( Orthopaedic Surgeon and host os Aussie Med Ed) has an enlightening conversation with Dr. Bochner, head of the Breast and Endocrine Unit at Royal Adelaide Hospital, you'll gain insights into the subtle signs that may point to thyroid dysfunction, how these conditions can masquerade as other illnesses, and the particular challenges faced by older patients.

Thyroid health is more than just a blood test; it's a puzzle that requires a keen diagnostic eye. Dr. Bochner walks us through the intricate process of identifying the origins of hyperthyroidism and the crucial role of advanced imaging in crafting a precise treatment plan. Whether it's the unexpected side effects of immunotherapy or the tailored approach to surgery, our discussion with Dr. Bochner provides a deep understanding of the nuance needed in managing thyroid conditions while highlighting the significance of a thorough physical examination.

Step into the surgical suite as we navigate the complexities of thyroid nodule assessment and the considerations that lead to the decision to operate. Dr. Bochner shares the cutting-edge techniques that are transforming thyroid surgeries and minimizing their impact on patients' lives. We also dissect the Bethesda system for thyroid nodule categorization, offering a window into the future of thyroid cancer diagnosis and treatment, and ponder the emerging role of AI in advancing medical precision. Join us for a comprehensive journey into the world of thyroid health, guided by one of its most knowledgeable practitioners.

Aussie Med Ed is sponsored by OPC Health, an Australian supplier of prosthetics, orthotics, clinic equipment, compression garments, and more. Rehabilitation devices for doctors, physiotherapists, orthotists, podiatrists, and hand therapists. If you'd like to know what OPC Health offers.

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Dr Gavin Nimon:

The thyroid gland, while diminutive in size, is formidable in its impact. I like to think of it as almost like a fuel injection of the car. The actual fuel mix determines how fast the car idles at, and that's what the thyroid seems to do. It synthesises thyroxine and T3 hormones. That's intramedible in regulating metabolic rate, heart function, digestive health, muscle control, brain development and bone maintenance. It also produces calcitonin. Well, today we're going to learn more about it, but with Dr Melissa Bochner, head of Breast and Endocrine Unit at the Royal Adelaide Hospital.

Dr Gavin Nimon:

G'day and welcome to Aussie Med Ed, the podcast with a pragmatic approach to medical conditions. I'm Gavin Nimon, orthopaedic surgeon based in Adelaide, and I'm broadcasting from Kaurna land. I'd like to start the podcast by acknowledging the traditional custodians of the land on which this podcast is produced, the Kaurna people, and I'd like to pay my respects to the elders, both past, present and emerging. It's my pleasure now to introduce Dr Melissa Bochner, a breast endocrine surgeon, who's going to talk to me about thyroid disorders. I'm really pleased to be joined by Melissa.

Dr Gavin Nimon:

She's the head of the breast and endocrine surgery unit at the Royal Adelaide Hospital. She trained in general surgery at the Royal North Shore Hospital in Sydney, then specialised in breast and endocrine surgery, with fellowships at the Royal Adelaide Hospital and Edinburgh Breast Unit. Melissa has a research master's of surgery from the University of Sydney as well as working at the Royal Adelaide Hospital and provides a surgical service for breast and thyroid diseases at the Children's Hospital. She's going to talk to us about thyroid diseases in general. She's going to talk to us about thyroid diseases in general. Welcome, melissa. Thank you very much for joining us on Aussie Med Ed.

Dr Melissa Bochner:

Thank you so much, Gavin. Thank you for inviting me.

Dr Gavin Nimon:

Well, it's brilliant to have you on board. It's quite an crucial organ, the thyroid, and I'd like to hear more about it today, so I'm really looking forward to it. Perhaps we can start off by first of all just explaining what the thyroid does and its free function. I know there's a lot more we can go into we could spend hours on it, but just as a brief overview, what does the thyroid actually do?

Dr Melissa Bochner:

The thyroid is very complex, of course, in its mechanisms because essentially it does release the hormones that you've mentioned T4 and T3, and they have multiple metabolic effects throughout the whole body. So when I'm talking to a patient I might say to them that really the thyroid controls your energy hormones and your metabolism hormones. So in fact, if your thyroid disappeared tomorrow, you wouldn't die, but you would get pretty sick and you wouldn't be able to function properly. So sometimes it's easier to describe thyroid function in terms of the effects that it might have if you had too much of it or too little of it.

Dr Melissa Bochner:

And, for example, people that have an overactive thyroid, where they're making too much thyroid hormone. They may be anxious, they won't be able to sleep, they may lose weight, they may have diarrhea, they may have a rapid heart rate weight, they may have diarrhea, they may have a rapid heart rate. People who have too little thyroid hormone will have the opposite, so they might feel tired, they might feel depressed, they may gain weight. So sometimes the symptoms of thyroid disease can mimic other diseases and sometimes they can be nonspecific and sometimes they can be difficult to pick up without doing the thyroid blood test. It's particularly interesting, I think, when you're looking at, for example, the elderly. I saw an older man recently who'd been admitted under cardiology with rapid AF very hard to control. They knew he had a goit. Of course this man was significantly hyperthyroid and hyperthyroidism can tip the elderly particularly into tachycardias, svt and atrial fibrillation.

Dr Gavin Nimon:

Right. So is it purely disorders of thyroid, is it purely actually metabolic disorders as well, or is it can present in other ways as well?

Dr Melissa Bochner:

So I think one of the disclaimers here and obviously you've mentioned it is that I'm a surgeon and so I'm particularly interested in the diseases that are referred to me. There will be a slightly different cross-section of diseases that GPs might see or that endocrinologists might manage on their own. But for surgeons, of course, we will see what we've already spoken about patients with abnormalities of function. We will see patients with abnormalities of structure, and by that I mean an enlarged thyroid causing local symptoms, usually due to pressure in the neck there's obviously not a lot of room in the neck. And then, of course, we will see people who do not necessarily have a symptom from their thyroid but who have a nodule which may be suspicious for malignancy. They're the three main areas that we would see in our clinic.

Dr Gavin Nimon:

Yes, you mentioned hypo and hyperthyroid. Are they the two main disorders that occur in the function level, or can you actually get abnormalities of function with also normal levels of thyroid levels in the blood?

Dr Melissa Bochner:

Usually you will divide it up into hyper and hypo. We can see people with other diseases, the sick u thyroid, for example, that GPs are well aware of and that don't end up with a surgeon. But most people are either over or under and that will be easy really to determine on a thyroid function test, on a blood test. As I mentioned before, there may be some people who have a normal T4 and T3, but a suppressed TSH, so they will be subclinical hyperthyroidism. But those people, particularly the elderly, may still have some symptoms from that. So they would be the two really under or over.

Dr Gavin Nimon:

So start off with, say, hypothyroidism, which a lot of people always worry about, particularly if they're carrying a little bit of extra weight and they think there might be a hypothyroid disorder. What are the main causes of hypothyroidism and how common is that?

Dr Melissa Bochner:

Obviously, from my point of view, the patients that I see in my clinic who have been diagnosed with hypothyroidism most of them have an autoimmune condition Hashimoto's, thyroiditis, hypothyroidism Most of them have an autoimmune condition Hashimoto's, thyroiditis. Hashimoto's is extremely common, particularly in older women, and again it may be subclinical. So sometimes when we're removing the thyroid we will note that it is unduly inflamed, that the operation is somewhat difficult, but those people will have normal thyroid function. But in some people it will progress to thyroid gland destruction and that is the most common cause of hypothyroidism, particularly as you get older. Clearly that is a disease which may sneak up on a person and so somebody might say it becomes particularly severe because it's obviously easy to treat.

Dr Melissa Bochner:

Hashimoto's does not require surgery most of the time and for the vast majority of people the gland tends to atrophy and it isn't particularly big. The other thing worth talking about because I do treat children and clearly one of the screening tests for newborn babies is a thyroid function test, because there is a very small group of people who can be born with congenital hypothyroidism, either due to the gland not being there at all or not forming properly, or something wrong with the way that the thyroid hormone is made within the gland and, of course, congenital hypothyroidism is again treatable and a very important thing to do to prevent all of the terrible long-term effects in neurological development, in particular in undiagnosed babies.

Dr Gavin Nimon:

Right. So you've got hypothyroidism related to an autoimmune disorder called Hashimoto's disease. Slow, insidious onset with subclinical levels of thyroid causing low metabolic rates. You've got a congenital cause. Are there any other causes of hyperthyroidism that need to be considered too? I presume there must be some pituitary axis issues as well that can cause it. Is there or?

Dr Melissa Bochner:

I think that's right is that, understandably, the TSH released by the pituitary is the driver of thyroid hormone release and manufacture, and so, yes, there is a continuous feedback loop between the thyroid function and the pituitary function. Because I'm a thyroid surgeon, it's extremely unusual for me to see anybody with primary pituitary failure, and it is a much less common cause of hypothyroidism and, clearly, again, pretty easy to diagnose. If you see a patient and they have a low TSH and then you do T3 and T4 and they're low as well, then you do need to consider a pituitary cause, but it's much, much less common.

Dr Gavin Nimon:

All right. Any other causes of insidious onset apart from the autoimmune Hashimoto's, then, or is any that's really the main cause?

Dr Melissa Bochner:

I think that would be the main cause. The other one that you know, obviously, that we do to people is iatrogenic. So of course you can see someone who's had a hemithyroidectomy for a structural or diagnostic reason and then you may expect that the other half of their thyroid will continue to function normally and should compensate and step up to function normally, but it doesn't always do that. So certainly for patients who have had hemithyroidectomy, we would routinely check thyroid function at about three months, because a significant number of them do become hypothyroid after surgery.

Dr Gavin Nimon:

And in that scenario, either both the atrogenic in that scenario or Hashimoto's, with replacement of thyroid hormone. Are there any other hormones that need to be replaced as well, that we need to consider, because obviously the thyroid is more than just purely produced thyroxine? Is there issues with calcitonin, too, that need to be replaced?

Dr Melissa Bochner:

No, it's really interesting that calcitonin is produced by the thyroid and only by the thyroid, but there appear to be no clinical consequences of removing the thyroid in terms of calcitonin.

Dr Gavin Nimon:

Right.

Dr Melissa Bochner:

And the only people that you ever see with an elevated calcitonin, of course, are those with medullary thyroid cancer. The medullary thyroid cancers almost always secrete calcitonin, and people with metastatic medullary thyroid cancer, which can cause symptoms, but the absence of the thyroid does not cause any kind of problems with calcitonin.

Dr Gavin Nimon:

Right, excellent, okay, melissa. Can you get paraneoplastic syndromes causing hyperthyroidism or producing other hormones as well, such as calcitonin?

Dr Melissa Bochner:

You don't normally see ectopic thyroid hormone replacement, although you can see it occasionally with metastatic follicular thyroid cancer which can be extremely well differentiated and can produce its own thyroid hormone. It's not common. I've had patients with it who've had total thyroidectomy for metastatic thyroid cancer. They've done very well. They've got known metastatic disease. They've been quite asymptomatic from it and have required very little thyroxine replacement because their metastasis appears to be making it. So yes, it happens, but it isn't common.

Dr Gavin Nimon:

Okay, no worries. So if we move on to the hyperfunction of thyroid disease, hyperthyroidism, I believe Graves, is probably the most common cause and that's another autoimmune disorder. Is that correct?

Dr Melissa Bochner:

Yes, I think that's right, and I like to think of Graves and Hashimoto's as being a sort of a spectrum of autoimmune thyroid diseases. Graves, of course, is an association of symptoms which includes hyperthyroidism, but also the eye disease that we're familiar with and some other soft tissue depositions which appears to be related to a circulating protein. The mechanism of some of those things is still not completely understood, but traditionally Graves is a spectrum of symptoms involving more than just the thyroid. People with Graves disease will be hyperthyroid and the disease will affect the whole thyroid, which differentiates it from the other two causes. I know we like to talk about things in threes. So we've got Graves' disease, we've got toxic multinodular goiter is not uncommon and then the third major cause of overactive thyroid is a toxic nodule, which is often a solitary toxic nodule.

Dr Gavin Nimon:

Brilliant. So there's another group of threes we can think of hypothyroidism with If we go back to the graves. Actually, one of the comments you made just then which actually just threw me, because I always thought the actual ocular proptosis that occurs with the graves disease was associated with the thyroid hypothyroidism, but you've implied that it actually is a paraprotein that causes it and actually separate to the hypothyroidism the cause and actually separate to the hypothyroidism.

Dr Melissa Bochner:

It's part of the Graves. So if you've that's right if you've got eye disease, then you have Graves, you don't have toxic goiter and you don't have a toxic nodule and you're not over replaced with thyroxine usually yes, and that's why one of the interesting things about the treatment of Graves disease, because obviously there are medical treatments for Graves disease but if you remove the thyroid, then you are also removing the source of perhaps the abnormal antibody in the protein and that may improve the eye disease. So one of the indications for surgery in Graves' disease in fact is significant eye disease.

Dr Gavin Nimon:

Moving on to the treatments of those three conditions, then you've mentioned surgery. A question that comes to mind first of all actually is, when you talk about autoimmune disorders both for Hashimoto's and Graves use of biologic agents for treating autoimmune disorders. Is that one of the medical managements for these conditions as well?

Dr Melissa Bochner:

No, we would not use biological agent for treatment, but it does bring me to our old friend, yatrogenic, again as causes of hyperthyroidism. So a little bit of a fourth cause that we need to think about. Amiodarone, of course, has been long known to cause hyperthyroidism, which is difficult to treat, and one of the other diseases that I treat, as you would be aware through my practice at the Royal Adelaide, is breast cancer. There's been a big change in some of the treatments for breast cancer lately, including the use of immunotherapy for women with triple negative breast cancer, and the drug that our patients get is called pembrolizumab. Pembrolizumab has a lot of autoimmune side effects and our patients will frequently develop thyroid disease as part of their breast cancer treatment. So I think that one of the things that treating doctors need to be aware now is that certainly some of our immunotherapies can actually cause thyroid disease.

Dr Gavin Nimon:

Right. Is that a hypo or hyperthyroidism?

Dr Melissa Bochner:

Either. So certainly when we're coming around to operate on these people, you know, because they'll complete their neoadjuvant chemo and then we're getting them worked up for surgery and we need to be very careful to make sure that their thyroid function is normal, as well as adrenal function, with those drugs.

Dr Gavin Nimon:

Right. So we've got hyperthyroidism, which can be treated medically with replacement or with surgery to excise the thyroid. You've got hyperthyroidism that's similar, with some medical treatment and surgery in that scenario, and that includes the toxic multinodular goiter as well as the toxic nodule.

Dr Melissa Bochner:

I think that the thing that you know, because we will be sent patients with hyperthyroidism for treatment and I think, surgically, it is important for us to understand the cause of the hyperthyroidism because we need to know how much of the thyroid to remove to try and cure the person. So if we go back to the etiology, we actually want to know which of those diseases it is. We will be happy that the person is hyperthyroid, based on pretty standard blood tests, which is the suppressed TSH and the elevated T4 and or T3. Clearly again, when you're looking at blood tests, you sometimes see someone with a normal T4 who has an elevated T3. So they may have purely T3 thyrotoxicosis, which can be tricky when you're ordering thyroid function tests. If you don't put T3 in there, the lab won't do it and then you'll have to come back and order it again.

Dr Melissa Bochner:

So yes, we can say, okay, you've got hyperthyroidism. We're not sure why. You can order thyroid antibodies, which are often elevated in people with autoimmune thyroid disease. So people who are hypothyroid with Hashimoto's will have an elevated autoantibodies. People with hyperthyroidism may have elevated TSH receptor antibodies and that may be worth measuring.

Dr Melissa Bochner:

But the most important thing I think for people that are hyperthyroid is to have a nuclear medicine scan so that we know which part of the thyroid is abnormal, so that, for example, with Graves' disease, the whole thyroid will light up on nuclear medicine and you can't cure them unless you take out the whole thyroid, whereas with a toxic goiter they may have a more patchy uptake or a dominant hyperthyroid nodule or collection of nodules, and for people with a toxic solitary nodule, then clearly they have a single focus for their hyperthyroidism and you only need to do a hemothyroidectomy under those circumstances. So as surgeons we like to know exactly which bit of the thyroid is overactive, so that we can then make the correct recommendation to the patient.

Dr Gavin Nimon:

So the workup is the bloods, including thyroid antibodies T3 and T4s, progressing to nuclear medical scan. Do you include ultrasound as part of your workup as well, or was it a CT or MRI as well?

Dr Melissa Bochner:

The nuclear medicine scan is a functional scan, so that will tell us which bit of the thyroid is overactive. Clearly, when you're offering someone an operation, you want to be able to talk to them about the risks and how long the operation is going to take and what you're removing. So ultrasound is very important and for us really, we consider that to be an adjunct to clinical examination. So we have these days a portable ultrasound machine in all of our clinics and in our office, and so I would normally examine a patient, examine their neck with the standard thyroid examination, and then I would actually look at their thyroid with ultrasound myself, and the things I'm most interested in would be how big is it and where is it? Is it in the neck or does it go down into the chest? Because that's really important when you're talking to someone about surgery.

Dr Gavin Nimon:

And for the examination part, you've mentioned the standard examination. What are the key things for a medical student to watch out for? Obviously, we've talked about proptosis for Graves' disease. We've talked about, obviously, irregular shape to the thyroid and a bit more prominence. Is there anything else systemically that we need to look for as well?

Dr Melissa Bochner:

Yeah, I think the standard thyroid examination that you do as a medical student and particularly if you were in an exam or if you didn't have an endocrinologist in your clinic which we luckily do at the Royal Adelaide would include pulse rate, blood pressure, you would look for a tremor, you would look for the eye signs, which includes the proptosis, but also the external ophthalmoplegia, so perhaps diplopia on lateral gaze, and you may also then be, as I said, interested in the neck examination as to how big the thyroid is. A lot of people with Graves' disease can have a moderately enlarged gland which is not retrosternal but which can be quite firm because of the inflammation. So the thyroid examination is clearly important.

Dr Gavin Nimon:

Okay, with that examination out of the way, then, and obviously with the ultrasound you talked about and the investigations, including the blood tests and the nuclear medical scan you mentioned, the medical management Is that managed by purely an endocrinologist and you come in for the surgery part of it, or is that something that you get involved in as well?

Dr Melissa Bochner:

We have a multidisciplinary team in our clinic at the Royal Adelaide and we're really lucky because in fact management of thyroid disease includes endocrinology, nuclear medicine, specialty and surgery, because the one thing that we haven't spoken about for hyperthyroidism is in fact use of radioactive iodine to control thyroid function. So we have all of those specialties within our clinic and we can share patients so they can talk to the endocrinologist who might say you can try a drug such as carbamazole. Many patients with Graves' disease in particular will be well controlled on carbamazole. They won't need to come and see anybody else. They will go into remission and stay in remission. So not everybody with Graves' disease even sees a surgeon. The ones who end up coming back for surgery will be the patients who relapse, because multiple relapses or prolonged Graves' disease probably will not be cured and will need more definitive management. People with a very large thyroid who have pressure symptoms, as mentioned before, people with eye disease may be better having surgery. And then there are people who can't tolerate the drugs or people who shouldn't have the drugs, and I'm including here young women who may wish to have a pregnancy, where the thyroid function can be very difficult to control during pregnancy and we know that abnormalities of thyroid function during pregnancy are not good for the baby. It may increase risk of miscarriage, for example. So there is a group of people who will come through for definitive management. At that point they may wish to speak to the nuclear medicine physician about the use of radioactive iodine to destroy the thyroid and then they may want to speak to the surgeon about surgical management. Clearly those two things are different.

Dr Melissa Bochner:

Radioactive iodine is appealing for some patients. It's obviously non-surgical. They don't need an operation. They don't get a cut in their neck. They don't have to consider the complications of surgery, the worst of which is damage to the recurrent laryngeal nerves. The downsides to nuclear medicine, of course, is that some people don't like the idea of a radioactive treatment. There may be an increased risk of some malignancies down the track after use of radioactive iodine. It doesn't work immediately. So if you need to control the thyroid straight away, then that isn't the right treatment. It may not work as well in very large multinodular goiters because of the patchy nature of the uptake. It may shrink the gland a little bit, but it will not make a very large gland significantly small if someone also has compression symptoms. So there are pros and cons to each of the treatments, and we like our patients with hyperthyroidism to have the opportunity to talk to all the different specialists and make an informed decision.

Dr Gavin Nimon:

So there's obviously some medical management, the radioactive thyroid and the surgical options as well. How often do you see abnormalities of structure as well, Melissa?

Dr Melissa Bochner:

A lot, and I think one of the statistics that I've been quoted is that 50% of women over 50 have a thyroid nodule. So lots of people have a thyroid nodule and actually the trick for us as specialists is working out which ones to ignore and which ones to do something about. There is clearly a group of people who have a multinodular goiter and who have pressure symptoms in the neck relating to that. Now, that might be a more non-specific feeling of pressure across the front of the neck. Some people will complain that they wake up at night feeling that they can't breathe, that something's pressing on their neck. Sometimes I think that's just because when you're asleep and the head goes down, the pressure effects are worse. Some people will complain of difficulty swallowing and will say that they can feel something when they swallow, that the food passes past an obstruction and clearly in the the worst-case scenario, people will present with a stridor or difficulty breathing.

Dr Melissa Bochner:

Again, there is a lot of people out there who get a bit of a weird sensation in their neck.

Dr Melissa Bochner:

They see their GP, they have an ultrasound and thyroid nodules are seen.

Dr Melissa Bochner:

So there is a significant number of people whose thyroid nodules are coincidental to their symptom and it can be difficult sometimes working through that, because clearly removing the thyroid and having someone still telling you that their symptom is still there is very unsatisfactory.

Dr Melissa Bochner:

So sometimes we do need to work with colleagues in ENT, for example, or in gastroenterology. Sometimes we do need to work with colleagues in ENT, for example, or in gastroenterology, where abnormal sensations in the neck may be related, for example, to reflux, esophagitis, pharyngitis, sinusitis and a whole lot of other things. So you have to really look very carefully at the patient and what symptom they're describing and whether you think the nodules that they have are causing that symptom. I find that thyroid ultrasound is very good for looking at the characteristics of individual thyroid nodules. It is not very good at looking at local structures in the neck and determining whether the thyroid is compressing them or not. So for me, if I think someone's telling me that they've got an obstructing symptom, then I will order them a CT scan of their neck and always include the chest in that, because sometimes the thyroid in the neck is just the tip of a thyroid iceberg and the rest of it's inside the chest.

Dr Gavin Nimon:

And is that CT? Is that just purely a plain CT, or do they need to have like a barium swallow or anything like that at all?

Dr Melissa Bochner:

I think intravenous contrast is always good because you can sort of see where the vascular structures are.

Dr Melissa Bochner:

So you don't need a barium swallow, particularly although there are some people that you think actually this is a esophageal problem, not a thyroid problem.

Dr Melissa Bochner:

So we do order the occasional barium swallow for people, for example, with dysmotility, which is why it is good to have that multidisciplinary input, including from radiology, in our thyroid clinic. Multinodular goiter is obviously very common around the world. There are a lot of countries where endemic goiter occurs, and in our multicultural society that we have here, we have a lot of patients who come from areas of endemic goiter and we see a lot of patients with multinodular goiter, some of which is asymptomatic and some of which is very symptomatic. Endemic goiter is generally caused by iodine deficiency, and so you will see that in people who have grown up in regions often mountains and away from the sea where the iodine leaches out of the soil so some areas in Central Asia and Central Africa and so some of those populations seem to have more goiter than some of the people who have grown up eating an iodine-rich diet, which includes seafood and, of course, the iodine that's added to our food.

Dr Gavin Nimon:

There's a lot of iodine added to bread. I understand, but is that the same for all the local bakeries and stuff? Will they be adding iodine to the bread as well?

Dr Melissa Bochner:

I think most of them would, because it's in the salt Right and so most people would, and I advise people to cook with iodinated salt and that I think that some of the thyroid problems that we see may be related to trendy salt, because if you bake your own bread with trendy salt and you don't eat any seafood and you have a restricted diet for whatever reason, then you may actually be iodine replacement in the diet and having satisfactory dietary iodine is very important to avoid unnecessary goiter in communities, and we know that the very groundbreaking work done, for example, in Nepal, where iodine was added to the diet, changed the outcome for a generation of people there who were living with severe iodine deficiency up until then.

Dr Gavin Nimon:

And that leads to a hyperthyroidism type multinodular goiter.

Dr Melissa Bochner:

Often the thyroid function is actually normal, but the gland is enlarged.

Dr Gavin Nimon:

Okay.

Dr Melissa Bochner:

So we will see people with normal thyroid function and very large thyroids would be the usual situation.

Dr Gavin Nimon:

Is a goiter, the terminology used to define an abnormality in structure of the thyroid, because you can get hyperthyroid goiter.

Dr Melissa Bochner:

That's right. I think goiter is a general term that implies enlarged thyroid, for whatever cause.

Dr Gavin Nimon:

Right.

Dr Melissa Bochner:

Yeah.

Dr Gavin Nimon:

Okay. So once you've assessed someone for abnormality of structure, you've done a ct scan. Then I presume, assuming it's not a correctable cause such as like an iodine deficiency, I presume surgery is recommended in that scenario if it's causing symptoms. Is that correct?

Dr Melissa Bochner:

that's correct. If somebody's got obstructive or compressive symptoms, you're comfortable that the thyroid's causing it, then surgery would be recommended. For a lot of people that disease is symptomatic but not life-threatening. So it is not unreasonable to talk to a patient and say to them I believe your thyroid nodule is touching your trachea or it's touching your esophagus and your symptoms will probably be relieved by removing half or all of your thyroid, and talk to them about the risks and benefits and allow them to make the decision. And they may not wish to make that decision very quickly and we have people coming back to our clinic over and over again over many years.

Dr Melissa Bochner:

The goiter slowly enlarges and at some point they may decide to do it. The situation where we feel that surgery needs to be strongly recommended, of course, is when the trachea is narrowed. Most of the time that occurs in a retrosternal goiter because, understandably, if the thyroid enlarges in the neck it will tend to enlarge anteriorly and it'll be visually obvious but perhaps not symptomatic as compared to the thyroid that goes down into the chest. It's got nowhere to go and those are the ones that can cause very significant and quite frightening tracheal narrowing.

Dr Gavin Nimon:

Right, because, as I understand, the thyroid is not really well encapsulated.

Dr Melissa Bochner:

It has a very loose capsule over the front but when it enlarges it goes down the path of least resistance and it will push the other structures out of the way, you know, unless it's a malignant thyroid. So you'll find that a patient will have a lot of disease in their chest, their carotid artery, jugular veins will be pushed to the side. So they're close, but not particularly in a lot of danger. But going back to the clinical examination, of course the Pemberton sign is the one where you ask the patient to put up their arms above their head and their face goes blue. That's venous obstruction from the thyroid, often intrathoracic, and patients may come and complain of that symptom. When I go to hang out the washing, my face goes blue, I feel faint, I can't keep going. So those people need surgery and we, you know, particularly if someone's got significant airway narrowing where the tracheal calibre can be down to four millimetres or so, then they have to do something.

Dr Gavin Nimon:

And, of course, surgery, as you mentioned, has got risk with the recurrent laryngeal nerve. There's obviously a few other structures around the area that are at risk as well.

Dr Melissa Bochner:

The main risks of thyroid surgery in the immediate period time will be bleeding. The thyroid is very vascular. In graves it can be amazingly vascular and coupled with the venous obstruction that you get in very large thyroids, then every tiny blood vessel that you touch can just bleed, even small ones. So there is a risk of bleed, even small ones. So there is a risk of bleeding intraoperatively and postoperatively and patients need to be managed by experienced nursing staff immediately postoperatively. For that reason there is a risk to the recurrent laryngeal nerve, one on each side the risk of permanent damage to that we would normally quote at one percent. But at least five percent of people have a voice change after thyroid surgery, which improves.

Dr Melissa Bochner:

And then, of course, there are our friends that we haven't spoken about already the parathyroid glands. The parathyroids unlike the thyroid, which I said, if it disappeared, you probably wouldn't die if your parathyroids unlike the thyroid, which I said, if it disappeared you probably wouldn't die. If your parathyroid's disappeared now, you'd probably die in about 10 minutes, maybe a bit longer, because you need your parathyroids to control your serum calcium. So parathyroid preservation is really, really important and they're often very close to the thyroid. They're very easy to injure or to remove inadvertently because they're very small and they often share a blood supply, so we do worry about causing permanent hypoparathyroidism in somebody having thyroid surgery. It's a very annoying complication for the patient to have to have because they need to be on a lifelong calcium and calcitriol replacement and they will get symptomatic if they can't take it.

Dr Gavin Nimon:

Right and through an anterior approach. You mentioned before a cut in the neck.

Dr Melissa Bochner:

Usually all large thyroids will be done through a cut in the neck. Usually all large thyroids will be done through a cut in the neck. Sometimes for the massive thyroids we've had to ask our cardiothoracic friends to come and do a sternotomy as well. Not common and there is a little bit of a trend which hasn't taken off particularly well, particularly in Australia, for a minimally invasive approach to the thyroidectomy through the mouth, and some people overseas are doing them robotically through the axilla or other remote approaches in order to try and avoid the incision on the neck which some people will find cosmetically unacceptable. Countries like Korea have really pioneered the transoral and robotic thyroidectomy to avoid the neck incision.

Dr Gavin Nimon:

So obviously these are for the structural but benign conditions, but obviously malignancy is also an issue too. What are the main types of malignancies you do see, and how common are they in thyroid? Are they something I need to be aware of, being an orthopedic surgeon and doing a lot of image intensifier in theatre?

Dr Melissa Bochner:

Certainly If you haven't been wearing your thyroid shield.

Dr Melissa Bochner:

Thyroid cancer is interesting and it's certainly increasing worldwide and there's some kind of thyroid cancer epidemic which we're not sure why. It is possibly or almost certainly due to increased detection because of many people having more neck imaging for these non-specific neck symptoms that they get. So there is more thyroid malignancy around and the issue again for us with thyroid malignancy around and the issue again for us with thyroid malignancy is trying to diagnose it accurately, differentiating it from non-malignant nodules and making the correct treatment recommendation. Because I suppose that it's counterintuitive for a lot of patients that if you say to somebody, well, you've got a 10 millimeter thyroid cancer and it doesn't matter, that doesn't sound right to them because most other cancers it matters, whereas thyroid cancer may not be life-threatening except for over a very long period of time, and so it is a disease where we worry a lot about over-diagnosis and over-treatment and it's difficult to choose which procedure to do on which person.

Dr Melissa Bochner:

So if we see a patient with a solitary thyroid nodule, there is a lot of effort made into trying to work out. Am I worried about that nodule? Is that something that I need to biopsy? Is it something I need to remove, or is it something that I need to follow up, or is it something that I can reassure the patient and let them go? Having said that, lots of people have got solitary nodules and there are lots of causes for having a solitary nodule, which would include a dominant nodule within a multinodular goiter, what's called a colloid nodule, so just an overactive or hyperplastic nodule or a benign tumour like an adenoma.

Dr Melissa Bochner:

And then some people will have a thyroid cyst, a benign cyst. So there are quite a lot of nodules that people have and they will come into the thyroid clinic and we have to try and work out what to do about them. There are, I suppose, two different ways of classifying thyroid nodules and trying to get a bit closer to a diagnosis. One of them is using ultrasound characterization. There's a system called TYRADS, which is a radiology classification which tries to stratify nodules into a risk of them being malignant and therefore the need for those nodules to have a needle biopsy. So TyRADS has five different components that can be assessed on ultrasound and they all get given a score and then you add up the score and you end up with a TyRADS classification of a nodule, and there are five of those.

Dr Melissa Bochner:

So, someone will come into the clinic and will say this lady had a funny feeling in her neck and we've done a thyroid ultrasound and she's got a tirads 3 nodule. Thanks for looking after her. And one of the problems with the tirad system which I think is a bit of a flaw is that the way that they're categorized can be frightening for the GP and for the patient. So a TIRADS 1 nodule is benign and a TIRADS 5 nodule is highly suspicious, but the one that I just mentioned, tirads 3, which is almost certainly fine, for some reason they decided to call that mildly suspicious on the classification Right.

Dr Gavin Nimon:

okay.

Dr Melissa Bochner:

So GPs will say got a woman with a suspicious thyroid nodule, which is correct because it's called mildly suspicious, because what tirads hasn't helped them to do is understand how many of those are actually cancers and most of them are not.

Dr Melissa Bochner:

So tirads can sometimes be a problem for us and our patients just because of the way they've decided to name it, and we need to be a little bit careful about the way that we speak to people and what we call someone's nodule that we're suggesting that they don't have anything done to, including not even biopsied. The thing about tirads is it does try to stratify management of thyroid nodules. So it looks at the characteristics of the nodule under ultrasound, which might include something like the composition Is it solid, is it cystic, does it have calcifications in it, does it have a regular border, for example. But it also looks at the size of the nodule. And that's when we come back to being a little bit counterintuitive, because you may have a nodule which ticks all the boxes for looking like a cancer, but because it's very small, they might say this does not need a biopsy, even though it has some suspicious features. On the flip side, some larger nodules that look benign will be called more suspicious or need more investigation because of their size. So tirades can be a tricky system to work and there is an app. You know everything's got an app. You can download the app on your phone.

Dr Melissa Bochner:

I quite like redoing the tirades when I see a patient. I look at the nodule myself and reclassify it, and sometimes I agree with the radiologist and sometimes I don't, because there is quite a lot of variability in the way you might choose to interpret some of the ultrasound features. Most particularly, papillary thyroid cancer may have micro calcifications in the nodule. So calcifications, especially tiny little punctate ones in a thyroid nodule, can be quite suspicious. However, there is an ultrasound appearance called comet tails which is associated with sometimes with the appearance of colloid within a nodule, which is benign, but sometimes those comet tails look like calcifications, and so probably the major cause of disagreement about the thyroid classification of a nodule is what you think. The little echogenic foci are within the thyroid nodule and different people have different opinions on that particular scoring point.

Dr Gavin Nimon:

So, for the intern or the GP or the thyroid classifications, what do they need to know? They need to know, basically, the ultrasound will help guide them and then refer them to a breast endocrine surgeon, or they need to know more detail about that.

Dr Melissa Bochner:

I think that they need to just read the report really carefully and if it says a Tyrad's 3 nodule, as per the guidelines, this nodule is 30 millimetres in size and FNA is recommended. I'm happy with all of that. Or a Tyrad's 3 nodule this is 5 millimetres in size, suggests an ultrasound in 12 months. I'm happy with that too. I don't mind it. What I mind is the fact that it's called mildly suspicious, because that frightens everybody. So my point really is that most thyroid nodules aren't cancer and don't get upset when you see that word suspicious, particularly if it's a Tyrad's 3 or 4. We're happy to see them, but people arrive quite upset. My doctor told me I've got thyroid cancer. Oh, hang on a minute.

Dr Melissa Bochner:

You know, let's just clear that up for a minute because usually they don't. So it's really it's a communication practice point rather than anything else. Absolutely most of our needle biopsies are done under ultrasound. Back in the olden days we used to do them freehand, but of course now we've all got ultrasound, so they're done under ultrasound. And again, I think that over the last what 10 to years we've had an improvement in our stratification of cytology on thyroid nodules and so again, if you send a patient for a needle biopsy of their thyroid nodule, then you will come back with what's called a Bethesda category on that nodule and that Bethesda category will correlate with a risk of malignancy. So in fact there are six Bethesda categories and we about a long time ago now, maybe 10 years ago, when Bethesda had been around for a while, we looked at our own cohort of patients at the Royal Adelaide who'd had a Bethesda category on their needle biopsy and then went on to have thyroid surgery. So we could correlate the Bethesda category with the final pathology and the categories matched up pretty well with international standards.

Dr Melissa Bochner:

So we know that if someone tells you that your nodule is a Bethesda 2, which is benign, then there is a 4% chance that that's a cancer. If someone tells you that your Bethesda category is 3, then that's atypia, so there's a 15% chance it's a cancer. A four is 25 to 30% chance of cancer. Fives and sixes are pretty high risk of being cancer, but neither of them is 100%. And when we're talking about that, clearly we're talking more about papillary thyroid cancer than the other subtypes, because papillary thyroid cancer is easier to diagnose on a needle biopsy than the other types. And I know you're going to ask me what are the types of thyroid cancer, because we didn't see that before.

Dr Gavin Nimon:

yeah, well, perhaps we can go through those, yeah that's right.

Dr Melissa Bochner:

Papillary thyroid cancer is the most common by far, and we see that in all age groups and certainly we do see that in our children. Then there is follicular thyroid cancer, which is the next most common, and that would be the two that we see most of. Medullary thyroid cancer that I mentioned briefly earlier is a cancer of the c-cells of the thyroid. It's not a true thyroid cancer per se, although obviously only occurs in the thyroid. It's very, very rare, but we do see it in people with a genetic condition, men2. And so people who are born with that genetic condition may need prophylactic thyroidectomy when they're children. And then other rare subtypes, including anaplastic, which tends to be a fatal disease of older people. So papillary and follicular are the two most common, and they would be the ones that we'd be thinking about when doing a needle biopsy of the thyroid. Again, if you have a patient who's got a Bethesda category of four, five or six, the risk of malignancy is felt to be high enough to warrant diagnostic hemothyroidectomy. At least If the Bethesda category is three, where we're sitting at about 15% malignancy, then it's worth redoing the needle biopsy after a period of time, just in case the cellular atypia is, for a reason, not due to an intrinsic problem with the thyroid. Obviously, if you do a needle biopsy, sometimes you can make the cells abnormal by crushing them when you do the smear, or abnormalities with the fixation.

Dr Melissa Bochner:

So we will tend to repeat a Bethesda 3. A Bethesda 2, we will normally accept as being benign but might wish to follow it up. And obviously in our series where we had 116 patients having removal of Bethesda 2 nodules, most of those were because they were symptomatic, not because we were worried about them being cancer. So a small Bethesda 2, you can probably reassure that patient. So we like the Bethesda system. It's clear If you think about it from a patient's point of view, of course. Having said that, if you've got a Bethesda 4, maybe it's 30% risk of malignancy. So we're now talking about a group of people who may be asymptomatic. They've had a thyroid nodule picked up for many of the reasons we pick up thyroid nodules these days Ultrasound done for another reason, ct done for another reason, pet scan done for another reason. They've now another reason pet scan done for another reason. They've now got a bethesda 4 nodule. We're telling them they need a diagnostic hemothyroidectomy.

Dr Melissa Bochner:

So we know, that maybe 60 percent of those people 60 to 70 percent of those people don't have thyroid cancer. Maybe they've got a follicular adenoma and it's worth taking that out because that will probably grow and it may have malignant potential. But there's still a significant number of diagnostic hemothyroidic tomies being done that you'd like to think you wouldn't have to do if you had a better diagnostic tool for thyroid cancer. So that's one of the holy grails of thyroid diagnosis really is having a more accurate preoperative thyroid histopathology diagnosis, and we're not there yet.

Dr Gavin Nimon:

Well, listening to this, you've got a classification system based on ultrasound to decide whether you observe it or do an aspiration or final aspirate. Then you've got a classification system based upon that final aspirate and then you've got a classification system based upon the actual hemithyroideectomy and the actual cytology of their cells. They're three different types of classification systems. Would the artificial intelligence and AI help combine those three to actually help with that Holy Grail?

Dr Melissa Bochner:

I've never seen an AI that was able to combine tirads and Bethesda, but I think that would be great, and what we need is somebody with a massive series to be able to do that, because I think you need a lot of numbers. So if you said it was a Tyrad something and a Bethesda something else, then maybe that would be good. There are some diagnostic tests that are available in the United States looking at tumor molecules and cancer markers and a few more nuanced things within the cells in the needle biopsy. At the moment they're not super accurate either and they are super expensive and they're only available in the States and you've got to send them away and people don't really want to spend $3,000 on their thyroid FNA either. So I think there is movement in that space, but we're just waiting for a good test to become available One of the things about thyroid cancer is that thyroid cancer cells are often very well differentiated, which is good, you know.

Dr Melissa Bochner:

they're less aggressive cancers with a very good prognosis. But it makes the job of a cytopathologist very, very difficult to tell the difference between a benign and a malignant thyroid cell on a needle biopsy. Very big thyroids you can imagine that you can do a core biopsy on and that can happen. But it's a bit of tiger country in the neck Throwing a core into the neck with all the structures and the thyroid is quite vascular so you can occasionally do it but it's very uncommon to be able to get an actual piece of tissue out of the thyroid.

Dr Gavin Nimon:

Thinking about cancers in general. I know in breast cancer you often do a lymph node clearance to assess actually a risk of metastases. Is that done in thyroid surgery as well? And also, what adjuvant treatment do you use after thyroid surgery as well in that scenario?

Dr Melissa Bochner:

So I think if you know that you're operating on someone with thyroid cancer because you're almost sure they've got a bethesda five or six, they've got characteristic ultrasound findings etc then yes, you might do a prophylactic central neck dissection, which is really those lymph nodes that sit in front of the trachea, just below the thyroid. That's called level six or level seven. You can get, you know, half a dozen lymph nodes from that area. The risk of doing that additional little bit of lymph node surgery is that it's often the area where the lower parathyroid sits. So you do risk removing a parathyroid inadvertently. And to do a proper level six node dissection you actually have to dissect down the recurrent laryngeal nerve and then remove all of the tissue in between the nerve and the trachea, including in front of the trachea. So there is a slightly increased risk of damaging the nerve while you're trying to protect it. Interestingly, the mortality for thyroid cancer is not particularly altered by the presence of nodal disease. So it's not like the cancers that we worry about colon cancer, breast cancer where you need to know how many nodes are involved and you need to get rid of them. Your nodes are involved and you need to get rid of them.

Dr Melissa Bochner:

People with positive nodes, particularly for papillary thyroid cancer, will end up with more local regional disease and may end up having more procedures, but they're probably not more likely to die. So we are more cautious in removing normal lymph nodes in people with thyroid disease. You would not do a routine neck dissection for node negative disease, except for the unusual circumstance of medullary, which is different, but the papillary and the follicular you wouldn't do it. Having said that, there will be some people who will present with a lot of lateral node disease and therapeutic node dissection for known positive disease is the correct thing to do.

Dr Melissa Bochner:

So some of the children that I treat actually present with a lot of nodal disease in the neck and so I would generally do a total thoracotomy and neck dissection for them, and I work quite closely with head and neck colleagues at the Children's Hospital on those procedures. So adjuvant treatment. Going back to that, one of the things, of course, is what we're saying is that thyroid cancer generally has a pretty good prognosis. So again, you don't want to overdo it. So back when I was training, which was a long time ago, everyone with thyroid cancer had a total thyroidectomy and then they had radioactive iodine and suppressive thyroxine dose to suppress the TSH down low, it's become clear that not everybody needs all of those treatments.

Dr Melissa Bochner:

So, there will be a group of people with a well-differentiated papillary or follicular cancer which is not super big. It's sitting in the middle of the thyroid, there's nothing else that looks abnormal. You can treat them with a hemothyroidectomy and observation. The people with the increased risk of disease may need a total thyroidectomy and radioactive iodine and clearly sometimes you'll do a hemithyroidectomy for a nodule that you're not sure what it is. You'll find out that it's a cancer.

Dr Melissa Bochner:

You'll decide to give radioiodine and then you need to go back and do a completion thyroidectomy for the other side. Because if we think about how radioactive iodine works, it's a radioactively labeled iodine molecule which is taken up into functioning thyroid cells, of which we know that cancer is part of. But if you've got normal thyroid tissue in your neck, then that will take it up preferentially and you'll be treating the normal thyroid, not any potential residual disease. So radioactive iodine in principle is only given to people that have had a total thyroidectomy. So I think the modern times we're doing a lot more hemothyroidectomy, observation rather than the total thyroidectomy for thyroid cancer well, we've covered a fair bit.

Dr Gavin Nimon:

Where do you think thyroid treatment's going in the future?

Dr Melissa Bochner:

I mean what are the sort of forefronts of?

Dr Gavin Nimon:

research where things heading in the next 20 years.

Dr Melissa Bochner:

They say yeah, I think that, um, there's a few different areas. One of them is, as I've said, in the diagnosis. I think it would be really nice to be able to rule out. You know a bunch of people having purely diagnostic thyroid surgery when they've got no symptoms and you really think that it's too much for them. So improvements in thyroid nodule diagnosis would be great.

Dr Melissa Bochner:

And then I know we spoke earlier about biologicals for treatment of thyroid disease and clearly there are some biologicals that are used for treatment of metastatic thyroid cancer or inoperable thyroid cancer, because, unlike a lot of oncology, really thyroid disease has maintained the realm of the surgeon and there are not many medical treatments for thyroid disease and some of the treatments that we do give to people with metastatic disease are quite toxic and poorly tolerated and may not work very well. So finding a good medical oncology agent for people the rare group of people with advanced disease locally advanced or metastatic disease is going to be really important as well, and thyroid disease is a long way behind some of our other diseases at the moment for medical oncology treatments.

Dr Gavin Nimon:

Right. Well, it's been fantastic hearing about these conditions. There's so many different areas of it. Appreciate you coming on board and thank you very much, Melissa. I really appreciate your effort and thanks a lot for coming on Aussie Med Ed.

Dr Melissa Bochner:

Thank you, gavin, it's been really great talking to you. I've enjoyed it.

Dr Gavin Nimon:

I'd like to remind you that the information provided today is just one medical opinion, and this may vary depending on the region in which you're studying, practising or being treated. If you've enjoyed the podcast, please subscribe to the podcast for the next episode. Until then, please stay safe and we'll see you again for our next episode.

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