Incidental Adrenal Nodules

Podcast Transcript

Dr. Dr. Scott Steele: Butts & Guts, a Cleveland Clinic podcast exploring your digestive and surgical health from end to end. Hi again, everyone, and welcome to another episode of Butts & Guts. I'm your host, Scott Steele, president of Main Campus, colorectal surgeon here at the Cleveland Clinic in beautiful Cleveland, Ohio. Today, we're going to talk about something that I haven't talked about in a long time, and that's incidental adrenal nodules. I'm so pleased to welcome Dr. Matthew Peebles, who's a general surgeon for the Digestive Disease Institute at Cleveland Clinic Florida. Matthew, thanks so much for joining us on Butts & Guts.

Dr. Matthew Peebles: Thank you for having me.

Dr. Scott Steele: So we always like to start out with a little bit about yourself. Where are you from, where'd you train, and how did it come to the point that you're here at the Cleveland Clinic?

Dr. Matthew Peebles: So I'm originally from east Tennessee. Grew up in Knoxville, Tennessee. I left that area, went to college up in Chicago, back to Memphis, Tennessee for medical school, and ended up doing my surgical training in Florida in Orlando, and, after then, moved to the Treasure Coast of Florida, where I've been for the last 22 years. Our health system was integrated into Cleveland Clinic starting about six years ago, so we have been part of Cleveland Clinic Florida since that time.

Dr. Scott Steele: Well, we're super excited to have you, and we're super excited to have you here today. As I said earlier, we're going to be talking about incidental adrenal nodules. So to start, what are the adrenal glands, and where are they located in the body, and what do they do?

Dr. Matthew Peebles: So I like to tell patients the adrenal glands are basically like a little tiny hormone factory. Another name for the adrenal glands is the suprarenal glands, which kind of describes where they are in our body. We have one on both our right and left side. They're relatively small, triangular-shaped glands that sit above the kidneys. The hormones that they release have multiple functions in our body. They help with body metabolism, our immune system, maintaining and regulating blood pressure, our body's response to stress, and even has minor effects on development of sexual characteristics.

Dr. Scott Steele: So what's an adrenal nodule, then, and what does that mean when we say incidental adrenal nodule?

Dr. Matthew Peebles: It's really been a phenomenon, I would probably say, of the last three decades. As CT scans have become more and more integrated into the diagnostic processes of healthcare, we have started to notice increasing amounts of these masses or nodules within the adrenal glands, and that's really what we're talking about. We were talking about a mass in the adrenal gland incidentally found on imaging done for other reasons. We're usually talking about a mass that's greater than one centimeter in size and most commonly found on computed tomography, or CT, or magnetic resonance imaging.

Dr. Scott Steele: So what you're trying to say here is that you are getting a CAT scan or something for something else, and all of a sudden, boom, they have this finding that's there. And what do we do with it now?

Dr. Matthew Peebles: That's usually how this all happens. Usually, this is not a urgent emergent problem. You could be in the emergency room for appendicitis, for a kidney stone, for a gallbladder attack, and as part of the workup, a CAT scan's done. After your appendix is taken care of, they're like, "Oh. By the way, we noticed this two-centimeter mass on your left adrenal gland." It's actually something that is probably more common than what we thought in the past.

If you look at CT scans that have been done, probably about 5% of them will incidentally be found to have some type of adrenal lesion. They are, fortunately, mostly a benign process, and the overwhelming kind of question when people find these lesions is, first of all, are we dealing with a malignant process? The secondary question becomes, is this thing actually hormonally active or functioning? Because there's a certain percentage of these tumors that, even though they are benign, will produce excess hormone from the level of the adrenal that the tumor is actually growing from.

Dr. Scott Steele: So we'll circle back to that just in a little bit here. So you mentioned CT scan. Are there any other imaging or ways that these incidental nodules can be found?

Dr. Matthew Peebles: The other common thing would be MRI. Even less common, they will show up on PET scans, and that's something we can probably touch upon later when we talk about, could a mass within the adrenal gland be malignant? There's kind of two different roads that you're looking at, and the first question would be, is this a malignancy that's arising from the adrenal gland proper? Or the other alternative is it could be a tumor from another location, such as a lung cancer that has metastasized to the adrenal gland.

Dr. Scott Steele: So let's talk about adrenal nodules in general, not just the incidental ones. Do adrenal nodules typically cause symptoms that people can feel?

Dr. Matthew Peebles: Usually, they do not. Usually, these things are small enough and are in a location in our body that most patients are not going to have any idea that the nodule's even there. Generally, they have to get quite large in size before they may actually feel some discomfort. However, if the patient is one of these subset that has a hormonally-active adrenal mass, they may not have pain or discomfort from the mass, but there may be symptoms of the overproduction of the hormones from that tumor. You can see symptoms of high blood pressure that is hard to control, electrolyte abnormalities, weakness, muscle spasms, problems regulating blood sugar or diabetes. Some people can have even very episodic attacks of very high blood pressure or almost panic attacks can lead to headaches and irregular heartbeats.

Dr. Scott Steele: So you mentioned malignancy, functioning, non-functioning, but if you just look at the nodule itself, are there certain types of nodules, cystic, solid, big, little, bilateral, multiple, that are more, quote-unquote, "dangerous," or have a propensity to be more dangerous than others?

Dr. Matthew Peebles: In general, cystic lesions are far less of a concern than a solid lesion. So our predominant concern when we're working these lesions up is for something that is solid and not fluid-filled. There are certainly imaging characteristics that can help you or guide you toward, are we worried about a malignant lesion versus a benign lesion? The most common modality that we're talking about these days is CT scans, and generally, there are CT scan characteristics even on non-contrasted CAT scans that can give you a good idea that we're dealing with a benign adenoma or a benign tumor of the adrenal gland versus concern for malignancy.

MRI can also have a role in helping to differentiate between benign and malignant lesions if you don't have clear cut imaging characteristics from a CAT scan. The third imaging mobility that sometimes does get rolled in is PET scans, but again, as we mentioned, that's mostly when you're concerned about a metastatic process going to the adrenal gland.

As far as size, that's kind of interesting. I started training probably about 30 years ago when these things first became more recognized, and we had kind of a general rule back then that if a nodule wasn't functioning, and there weren't imaging characteristics overtly concerning for a malignancy, we would start to take out nodules, then, bigger than six centimeters. That number, over time, has migrated down, and I think most people recommend at this point that nodules over four centimeters, even with benign-appearing imaging characteristics, do harbor a risk for malignancy and should be considered for removal. The other thing that you mentioned is bilateral nodules. Those almost always are a benign process that may not require surgical intervention.

Dr. Scott Steele: So are there any known risk factors or maybe some underlying causes that are associated with adrenal nodules? Is this genetic? Is there hormonal changes? Are there underlying medical conditions? What is it?

Dr. Matthew Peebles: So there is a small subset of genetics that can be involved. One of the benign hormone-producing tumors called pheochromocytoma is related to a known genetic disorder known as multiple endocrine neoplasia, typically type 2A and type 2B. This is a relatively rare disorder, but it is certainly something where there, if there's a family history, should be investigated from a genetic standpoint. If the known mutation is identified, it is something that generally requires screening for development of these tumors. Even more rare genetic disorders such as Von Hippel-Lindau or neurofibromatosis type 1 can be associated with these tumors. So again, we're talking about a pretty small subset of all the adrenal masses that you're going to see.

Dr. Scott Steele: So you talked a little bit about imaging to tell the difference between harmless nodules versus ones that might be a little bit more dangerous. Do you have to biopsy these nodules? Is there a role for that? Are there other tests that you can do to tell the difference between a harmless one and one that might be more dangerous?

Dr. Matthew Peebles: So specifically, biopsies, and most of the time, when you're talking about doing a biopsy of the adrenal gland or talking about image-guided fine needle aspiration, most of the time, this does not pay a role in the evaluation of an adrenal nodule. If your predominant suspicion is a adrenal malignancy, fine needle aspiration generally cannot differentiate between a benign adrenal mass and a adrenal cortical carcinoma. However, fine needle aspiration does have a role in a patient where you may suspect a metastatic process, such as lung cancer going to the adrenal gland, and you may consider doing this to confirm the diagnosis before doing surgery.

Dr. Scott Steele: So do all adrenal nodules need to be removed or kind of treated right away? You mentioned that in some cases, they may have been there for a real long time.

Dr. Matthew Peebles: I suspect in most of the cases, they've been there for a real long time, and again, they've just been incidentally found. Most of these nodules probably do not require surgical intervention, and the general process I walk through, patients through in the office is just what we kind of hit up at the beginning. Our concerns when we find a nodule like this is to look at the size of the nodule. If the nodule is less than four centimeters, we start to ask the question, is this a malignant nodule? We're usually going to make that determination based off imaging.

If we do not think, based on the imaging, that this is a malignant nodule, the next question we then ask, is this nodule hormonally-active? You can do a battery of tests that could be a combination of blood test or urine samples to evaluate for hormonal activity. If there's no evidence of hormonal activity, the nodule is less than four centimeters in size, and the imaging is not concerning for a malignancy, this is something, generally, that we're going to watch with time for any potential progression and eventually get to a point where it may not need to be watched at all.

Dr. Scott Steele: So you talk a little bit about the term out there, watchful waiting. What does that mean for people with adrenal nodules? I know this may vary depending on either the individual or what the lesion looks like, but how often do doctors need to check on these adrenal nodules over time if you don't resect them?

Dr. Matthew Peebles: So if we've done our initial workup, and we're not concerned about a malignancy, and we're not worried about this being hormonally active, there's not a tremendous amount of data on what the, quote, "right answer," is. But the general recommendation is that this should be followed with unenhanced CT imaging every year for about four years.

If over one of those yearly time periods, there is interval growth greater than one centimeter, the general recommendation would be to go ahead and remove that adrenal gland. In a small subset of patients who might be genetically prone to hormonal activity, you can, at a year time, repeat the hormonal workup to make sure it has not become hormonally active with time.

Dr. Scott Steele: So for our listeners out there, is there anything that can be done to reduce your risk of forming adrenal nodules or maybe, even if you know have one of these small ones, to get it to regress?

Dr. Matthew Peebles: Not really. There isn't, beyond general basic healthcare, nothing that's been documented to help reduce the risk. Now, the one exception to that is some of those rare genetic disorders that we talked about. Certainly, if there's a family history of, "I had an uncle with an adrenal mass. I had another grandparent with adrenal mass," that is somebody that may need a more formal genetic counseling workup to see if they may be prone to one of these disorders. At that point, maybe start some surveillance to catch a problem before it becomes more significant.

Dr. Scott Steele: Fantastic. And so now, it's time for our quick hitters, a chance to get to know you a little bit better. First of all, salt or sweet?

Dr. Matthew Peebles: Both. You need both.

Dr. Scott Steele: Touche. What was your first car?

Dr. Matthew Peebles: '82 Oldsmobile Toronado.

Dr. Scott Steele: Fantastic. And so if you could take one of the superhero powers, which one would it be?

Dr. Matthew Peebles: Oh boy. That is a good question. My oldest son, who's 14, and I have been doing a lot of scuba diving over the last year, so I'll take Aquaman's ability to go underwater without having to take a tank on my back.

Dr. Scott Steele: Fantastic, and you get that sweet, sweet trident, as well. And so finally, if you could go back to your 17-year-old self and give you just one piece of advice, what would you say?

Dr. Matthew Peebles: That's a good question. I don't know. I mean, honestly, I think if I went back to that point, I don't know if I would change much. I think I would do what I've done, and very happy where I've ended up and how life has taken me.

Dr. Scott Steele: Fantastic. Tell him to stay the course. So give us a final take-home message for our listeners.

Dr. Matthew Peebles: So I think the big thing about this is with these lesions being found incidentally, this is often a conversation of, "I ended up in the emergency room. I was having this horrible thing happen. I finally recovered from it, and oh, by the way, my primary care doctor says, 'You have a tumor in your adrenal gland.'" It tends to get people's level of concern probably up higher than they need to be.

I think part of the take-home is, just like thyroid nodules, these adrenal nodules are probably far more common than we give them credit. Almost all of them are going to be benign. They can be taken care of, most of the time, in a minimally-invasive fashion, even when they need surgery. So it's not something to get overly worried about and something that we can take care of.

Dr. Scott Steele: Great advice. And so for more information on the Digestive Disease Institute at Cleveland Clinic Florida, please call 877.463.2010. That's 877.463.2010. You can also visit clevelandclinicflorida.org/digestive for more information. That's clevelandclinicflorida.org/digestive. Matthew, thanks for joining us on Butts & Guts.

Dr. Matthew Peebles: Thank you for taking the time.

Dr. Scott Steele: That wraps things up here at Cleveland Clinic. Until next time, thanks for listening to Butts & Guts.