Episode 46: AACE Clinical Case Report on A Middle-aged Woman With Recurrent Intrathyroidal Parathyroid Cyst Treated With Ethanol Sclerotherapy

Parathyroid cysts (PC) are a rare cause of cervical masses, with an ectopic intrathyroidal location being even rarer, with only 9 cases reported in the literature. Join endocrine experts Victor J. Bernet, MD, FACE, FACP, Director, Endocrinology, Diabetes and Metabolism Fellowship Program at the Mayo Clinic in Florida, and Sina Jasim, MD, MPH, Associate Professor of Medicine, and Endocrine Neoplasia Specialist at Washington University School of Medicine, as they discuss the clinical case report, A Middle-aged Woman With Recurrent Intrathyroidal Parathyroid Cyst Treated With Ethanol Sclerotherapy, which presents a case of a recurrent intrathyroidal cyst successfully treated with ethanol sclerotherapy. Key topics discussed include the sclerosis efficacy in orthotopically positioned PCs, how ethanol sclerotherapy is an effective treatment option for recurrent intrathyroidal PCs, and important teaching points or clinical relevance about this case. Visit https://www.aaceclinicalcasereports.com/article/S2376-0605(23)00131-1/fulltext to read the full AACE Clinical Case Report.

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January 19, 2024

Speaker 1: Welcome to AACE Podcasts. Thanks for tuning in as we elevate clinical endocrinology by taking deep dives into trends and topics that can help us improve our patient care and global health. Find the latest episodes on aace.com/podcasts. And now let's meet the endocrine experts who will be talking with us today.

Sina Jasim, MD, MPH: Hi, welcome to another AACE Podcast. I'm Dr. Sina Jasim, the editor-in-chief of AACE Clinical Case Report Journal. And I'm associate professor at Washington University in St. Louis. Today we have the pleasure of hosting Dr. Bernet, Victor Bernet to discuss their published case on recurrent intrathyroidal parathyroid cyst treated with ethanol sclerotherapy. Dr. Bernet is a professor of medicine and endocrinology consultant and fellowship director at Mayo Clinic in Florida. Dr. Bernet, thank you for joining us today.

Victor J. Bernet, MD, FACE, FACP: Hi, Sina. Thank you for having me. I'm looking forward to having our discussion about this case.

Sina Jasim, MD, MPH: All right. Please tell us a little bit more about yourself and your work.

Victor J. Bernet, MD, FACE, FACP: I actually spent my initial training in the U.S. Army Medical Corps and trained primarily, and my fellowship at Walter Reed. Was very lucky to be mentored by Ken Bertman and Hank Burch who already had a thyroid ultrasound in the endocrine clinic that I think Glenn Wirtowski, another big name in thyroid had arranged for. So despite it was the early 90s, I was trained in thyroid ultrasound early on, and so I've been very comfortable with doing ultrasound guided FNAs and other kind of minimally invasive procedures related to the thyroid and lymph nodes because I've been doing them for several decades and such, and presently again at Mayo Clinic in Florida, at primarily a thyroid or endocrine tumor practice. And I go over almost every day to radiology and do ultrasound guided FNAs and ethanol sclerosis of cysts and lymph node biopsies and such. And so have a fairly extensive experience in that area. And again, see lots of thyroid cancer patients and patients with parathyroid disease as well.

Sina Jasim, MD, MPH: Interesting. Well, we're very, very lucky to have you with us this morning. I have a question about minimally invasive procedures. As you know, they are now more widely relatively, I would say widely used in benign and some cancerous thyroid tumor. But can you tell us a little bit more about the difference in the utility of those procedures in parathyroid lesions?

Victor J. Bernet, MD, FACE, FACP: Sure. And I again, like you said, I think over the last 10 to 15 years we've seen an increased use of minimally invasive procedures. A lot of this work started in Asia and maybe in Italy, Korea, those places. And so we see it used more and more. I think ethanol specifically is going to be more useful for cystic structures, not as useful for structures, lesions that have a more nodular component, although in the case of thyroid cancer and lymph nodes, we found at Mayo Clinic, ethanol ablation of lymph nodes can be done very successfully. But in this case for a parathyroid cyst, see primarily it would be ethanol for a cystic type structure and that works fine. Thermal ablation with RFA or laser becomes more appropriate when you have a solid structure or there's discussion too, if you have a cystic solid structure, you might do a combination of ethanol sclerosis of the cystic part and then also thermal ablation of the solid part, which theoretically or practically could be done in the same procedure thing if you want on the same day.

Sina Jasim, MD, MPH: I see. And in ACCR, in our journal, you shared a very interesting case of sclerotherapy in parathyroid cyst. Can you summarize the highlight of the case and the important teaching point or clinical relevance about this case?

Victor J. Bernet, MD, FACE, FACP: Sure. So this was a patient who came to us, about late 50s, female who had had recurrent intrathyroidal cyst in the left lobe since the early 1990s. And she had just started to come see us in around 2017 or so, but she had 25 years of having multiple cyst aspirations and then it would recur over a couple of years and she would get pressure symptoms. And so at that point in time when she came to see us, she had about a five centimeter intrathyroidal cyst. We ended up finding out it was actually a intrathyroidal parathyroid cyst because we measured a PTH level and it was like 370 something. She was eucalcemic and had normal calcium and PTH levels. So while it was producing PTH, it wasn't secreting it. So she finally came back and had a five centimeter cyst in her left lobe, but symptomatic. We talked to her, said, "You don't have to keep coming back and have this aspirated." We've shown its just going to recur. And so we said, "We can do this procedure where we do something called ethanol sclerosis." So we made the arrangements and we brought her over to our procedure room. And what we did was I usually use an 18 gauge needle, which is much bigger than I typically use for any thyroid FNAs where I'm using a 25 and actually primarily a 27 gauge needle. But the 18 gauge gives you good access if the fluid's a little bit thicker and such. And since using an 18 gauge needle, unlike when I use 27, we do use some lidocaine to try to numb the area. They still are going to feel some pressure. And then what we do is we guide that needle into the cyst and then we have it attached to some IV tubing extension and then to a three-way stopcock. And then with the three-way stopcock, one of the ports can be used to draw back and draw out how much fluid we want to. And so let's say if there's a 20 cc cyst, we'll take out maybe 10 cc's of that cyst. We always leave some cyst fluid in and then we can switch over to one of the other stopcock ports and then we have our ethanol in there and then we can slowly inject that. And typically we put in about as much as we take out. In her particular case, we took out about nine cc's and we put back in 10 and then we watch for about 10 minutes. During that period, we ask, how are you feeling? Do you have any pain in your neck? We don't want them talking a whole lot, but we do let them speak and see if their voice is okay. If there's any question about pain or leakage, we get concerned. But again, we like to use the one needle one time in because it doesn't tend to leak if you do it that way. And then we watch her 10 minutes and then if there's still remaining pressure, so I put in 10 cc's. I think in this case we took out like four cc's. Interestingly, it went from clear fluid to this orange thick kind of fluid when we pulled it out. And again, the 18 gauge made that easier to draw out and her pressure went away. We pulled out the needle, she felt fine. We did a post procedure ultrasound, watched her, sat her up slowly, she's feeling fine. And then we said, "Okay, let us know if you develop any bruising or signs of infection," which is very unlikely anyway, and then I said, "We could have re-imaged at three months, but I said, let's just give it five months or so." She lived locally. Actually, she's an allied health staff at our facility, so she easily had access to me. And so she did great. And then we did the ultrasound like six months out. And remember, this is a five centimeter cyst. You could barely see normal thyroid tissue because it was just smushed by the cyst. And five months, six months later, you just saw a wisp, like a three millimeter cyst in the middle of the lobe, and had looked like a regular looking lobe on that left side. And so she did great. And actually just recently in the last several weeks, we had her now about six years out, repeat the ultrasound. Looks just like it looks six months after, just a small little area where there might be some tiny residual amount of cyst fluid, but it's not worth talking about. It's like two or three, four millimeters in size and totally asymptomatic, so no recurrence and did great with the procedure.

Sina Jasim, MD, MPH: Excellent. And I refer the listeners to the case. The images are really impressive and you see the pre and post images. They're really fascinating. And Dr. Bernet, you already kind of covered most of the logistics aspect for the case for the people who are interested in doing that, but I'm curious about some of the additional logistics like obtaining the alcohol. Some people use expensive alcohol or different kind of alcohol. How long you keep them after the procedure to monitor them, and what do you expect are the short-term or long-term complications? And you already alluded to the surveillance and how do you monitor afterward imaging wise?

Victor J. Bernet, MD, FACE, FACP: Yeah, so it's interesting and things have kind of changed over the last several years. We use 99% ethyl alcohol, and it comes in five ml vials, although interesting, they're those vials, you remember the ones you have to crack open? And so a teaching point is you have to use a filter needle because you don't want to have any glass come into the particles into what you're injecting into the patient and stuff. So again, they come in five cc or ml vials. So I usually have two available. And then we go ahead and then can administer anywhere in between what we can do less than five if we want. That's pretty unlikely for a big cyst to five to 10. I've never really had to do over 10 yet. I don't think that's usually necessary. I will comment, and then we have an interventional radiologist, Dr. Paz-Fumagalli who does a lot of our lymph nodes in thyroid cancer patients with percutaneous ethanol ablation, which uses smaller amounts of ethanol, but we noticed that suddenly it was harder to get and it's quadrupled in price. So it is available in a kind of a medical-grade thing, but the expense has gone up dramatically and not exactly clearly why and not clear how. I mean a lot of things were disrupted during the Covid pandemic, so for whatever reason some production was cut back and it seems like they're less vendors that have it available, but we are able to get it. In our facility, I go over and it's kind of a hybrid situation. I actually have been invited to go over to radiology and actually have an appointment with our radiology section, and so go over and do these procedures. And so they have a dispensing thing where we can put in and how many of these vials of alcohol we would like and then again have the filter needle to draw them up and such. But more recently, that seems to be readily available. We haven't had as much of a shortage as we did maybe in 2020, 2021 or early 22. In regards to complications, just like with any FNA, we always ask patients to look for signs of infection or bleeding. Although I tease my patients. I'm unaware of any of my patients ever getting an infection. I mean, we prep with an alcohol-based prep and sterile gloves, some sterile towels, and it's pretty much really an aseptic technique and such. And patients can do really well. Bleeding's pretty rare. We do, if there's any question, we do a post procedure scan to see, and if there's a question, we'll hold them, give them an ice pack and hold that and just watch and make sure. But they tend to do very well. I had one case where a patient was extremely anxious and during the procedure she started to say she had voice issues. But the thing is we hadn't seen no leakage of alcohol whatsoever. And then her symptoms totally vanished like five minutes later. And if it had really leaked when you have that happen, which is pretty infrequent, but with our thyroid cancer patients, sometimes their nodes right by the recurrent laryngeal nerve, then it usually last for several days or a week or two. Usually does go away and it's typically not permanent and it's pretty rare with the experience we have but. So that's one other thing to be careful about. Another thing I mentioned is, is I'm very careful about labeling my syringes. And my ethanol syringe is very clearly were labeled as is my lidocaine syringe because you never want to mix up the two. So I think that's another thing that seems common sense. But if you're not used to doing these procedures, something that you need to think about.

Sina Jasim, MD, MPH: Do you use the approach or otherwise?

Victor J. Bernet, MD, FACE, FACP: I go straight into the nodule.

Sina Jasim, MD, MPH: Okay.

Victor J. Bernet, MD, FACE, FACP: Some people talk about going a little bit normal tissue and then in because maybe that prevents more leakage, but I think when you introduce the needle once, we've not had that issue. So I've not personally done it that way. And my partner who's the interventional radiologist, when we talked about this, I started doing these, he didn't recommend doing that way. So it's fine if you want to do that way, make sure you have some normal tissue. Usually there's a rim of normal tissue, and what happens is you push the needle in. When you pull it back out, that flaps back and I'm watching with ultrasound and during the injection, don't see it leaking and don't see it leaking afterwards, but.

Sina Jasim, MD, MPH: Excellent. So this lead me to the next question. As you know, sclerotherapy was used before in parathyroid, actually even before the thyroid here, at least in the United States and non-operative parathyroid lesions or for gland disease, and they were publications since the 90s. And so I'm curious, why do you think the practice did not progress much since, in other word, what do you think the challenges or barrier to implement this type of practice and how the clinicians or endocrinologists can be better educated or informed about offering these kind of procedures for non-operative cases?

Victor J. Bernet, MD, FACE, FACP: Yeah, it's an interesting question. Actually, I knew this question was coming, and so I did some homework and I looked at the hyperparathyroidism workshop guidelines that came out last year and they talk about different medical options for hyperparathyroidism, but they don't, and they talk about surgery. I couldn't find unless I missed something, anything written about doing these minimally invasive procedures, which I thought was interesting because I think there are times when patients are poor surgical candidates and yes, in a [inaudible 00:14:46] and some of these other things can work. I think it's a combination of things at play though. I think one, well, if you have a very accomplished head and neck surgeon, we get such great results typically with these patients. I think that's one issue. Another thing when you take, and this was an intrathyroidal parathyroid. So the other issue was we did surgery, we were going to lose the left lobe, and so then is that going to impact patient's thyroid function? And so this way we were able to spare that, whereas with the parathyroid, you're just taking out the parathyroid. It shouldn't be impacting thyroid function unless you have an intrathyroidal parathyroid adenoma, which does happen. And so with some of these parathyroid cysts, they're just in their usual location outside the thyroid. So I think that's it. But then I think there's also the combination of knowledge about this, how many people are really feel comfortable doing these procedures. A lot of endocrinologists are comfortable doing ultrasound guided FNA's, but again, we've been doing ethanol ablation of thyroid cancer, lymph nodes for several decades at Mayo Clinic, and that has not been popularized either for various reasons. And I think there's a little bit of a concern. I think you could potentially not successfully treat an adenoma and then you are left with having to go back in or doing something. I think it can be successful, but not always. I think billing related issues always sometimes play a role with this, and it seems like the powers that be don't always reimburse well for some of this. And I don't know actually with the ethyl alcohol, how that impacts reimbursement. And I have to mention I'm working in the outpatient part of the hospital, which has different billing than you're in private practice. So I think that plays a role. And then I think we will see more minimally invasive procedures increase because patients are becoming more and more savvy. They're hearing about this, they don't want surgery. And then from an insurance standpoint, if you can successfully do this non surgically, I mean, wow, we're talking about something that is going to cost much, much less than a thyroid surgery for, like I've heard for thermal ablation of nodules, thyroid nodules, thermal ablation costs five or $6,000 versus I've heard surgeries cost 25 or $30,000. So from a system standpoint, I would think there would be some interest on this, but I think you need to have people who really do this a lot. I have noticed, and this is an editorial comment, when I go to my national meetings, they seems to be more and more vendors who are marketing, especially for the thermal ablation and such, and talking about doing these minimally invasive procedures. And at some point, I suspect this is going to be like we talk about, well send your patients to a high volume thyroid or parathyroid surgeon. Well, if you're going to be doing this, you probably are going to want a high volume minimally invasive person who does a lot with ethanol sclerosis or the thermal ablations. And then the final comment with the thermal type stuff, you have to be careful because you have to leave a rim of unaffected tissue or you have to do hydrodissection. And with a parathyroid that's outside the thyroid, there are a lot of sensitive structures and you need to ablate the whole thing. And if you don't, you're going to have persistence. So I think that's another issue right there, is that you got to successfully ablate whatever you're trying to target and the parathyroid's not going to give you that rim of safety where you have a benign nodule inside a thyroid, you can hydrodissect, and you usually have a little bit of normal thyroid tissue around it.

Sina Jasim, MD, MPH: Right. I think you are absolutely right. Experience is really important here. And even choosing the patients, which patient is a good candidate, even if those procedure become covered by insurance or more available is still, not every patient is a perfect candidate. And oftentimes even at Mayo Clinic, the sclerotherapy for lymph nodes are the cases that very, very selective and intermediate cases who underwent throat surgery are not a surgical candidate and what have you. Dr. Bernet, are there any additional thoughts you'd like to share regarding this case or the field?

Victor J. Bernet, MD, FACE, FACP: Yeah. Well, one thing I'd like to say is, so looking back, this is a patient who for basically a quarter-century was having a recurrent cyst that it wasn't horribly symptomatic, but it was giving her symptoms and it finally gets so much pressure, be swallowing and stuff like that. And we have this non-surgical outpatient procedure that we can do. And so I would just say people should be aware of this is available, whether it's a thyroid cyst or an intrathyroidal parathyroid cyst. And then for patients who maybe, like you said, aren't the best surgical candidates and they have a parathyroid cyst, this can be done. Now, having said that, I've had patients who I find asymptomatic cysts in. They're not bothering them at all. I don't advocate doing this because I mean, it's more because they have symptoms and these cysts can be bothersome and if it gets a little bit under the sternum and stuff like that. So we're not doing it for the sake of doing it or just trying to expunge all cysts. Now, every once in a while, I'll come across something with a patient like I'm doing a thyroid nodule FNA, and I notice they have a fairly good-sized cyst. I sometimes offered to drain it at that procedure, and then they note, "Oh, you know what? I was having symptoms and I didn't even realize." And then we said, "Well, if it comes back, then we can think about doing that minimally invasive procedure." But as I tease my patients, I have plenty of work to do. I get paid what I get paid. I don't get paid more for doing this procedure. So I make the decisions based on what's best for the patient and what makes the most sense clinically and such.

Sina Jasim, MD, MPH: Absolutely, and I 100% agree with you on that. Dr. Bernet, I want to thank you very much for joining us today and to share your expertise with us this morning. To learn more about this case or other cases or even to submit your interesting cases or visual vignette, please visit www.aaceclinicalcasereport.com. This is Sina Jasim, AACE Clinical Case Report Editor-in-Chief. Thank you very much and have a great day.

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