Chapters Transcript Nail Tales: Exploring Nail Dermoscopy Course: 44th Annual Advances in Dermatology So we're gonna talk now about some tips you can use for dermoscopy when you're looking at nails. I don't have any relevant relationships with industry. So I find pigmented lesions in the nail to be especially challenging because when you're looking at a line on the plate, that's not the lesion. Like when you look at something on the arm, you're looking at the lesion itself. But what you're seeing in the plate is really this indirect reflection of what's going on in the matrix. It's like looking at your living room floor. And figuring out who, which kid made the money footprints there, right? You just have indirect clues, and that makes it very difficult to distinguish your benign from your malignant lesions. And anywhere else on the body when you're on the fence, you think, OK, I guess I'm just gonna do a biopsy, but on the nail, it's a big deal. It hurts, it bleeds, it's not trivial. So what can we do to avoid some of those unnecessary biopsies but not miss the malignancies? Hopefully dermoscopy can help. I'm gonna tell you what you can take home from this today. This is the framework that I like to think about when I'm thinking about melaninicia for an algorithm. First, we divide it into what's making the color? Is the color coming from melanin or is it coming from something else entirely, not even melanin? And that could be something like a stain, a fungus, or blood. Then the the color is coming from melanin and it could be a growth, a proliferation, or it could just be melanocytic activation. Normal melanocytes, just too excited, making some extra pigment, and that could be in a single nail or multiple nails, for example, in a single nail could be from trauma, a tumor that's not melanocytic or lentigo, or multiple nails, and that's often something systemic or a drug or a syndrome. And then we have the true proliferations, and that's really where we come to Nevis versus melanoma. So first we'll start with the color is coming from not melanin, something else like a stain on the outside of the nail. So for example, off to the side there you see that's a stain, and one clue, even if it doesn't come off with a solvent, is if you look at the shape of it, it's the same shape as the free edge of the nail. And so if you just scrape it off with a 15 blade, that's one clue. It's obviously it's on the outside, it's not something to worry about. For fungus, fungal melaninicia, this was a paper that showed the dermoscopic features, the A lot of these are clinical features yellow scales, subungual hyperkeratosis, the shape of the band, that it's not necessarily a band but more of just a blotch. The fact that it's a triangle but a reverse triangle. We're going to talk later about how in melanoma you see a triangular shape because it's wider proximally and fungus, it tends to be the opposite. So that's reassuring. So if you're getting these kinds of features, instead of going right to the biopsy, maybe you just clip it and look for a fungus first. Blood, such a common reason we see patients who get worried coming in urgently and when you look with your scope, you can sometimes see these blood spots, these little globules that are red, sometimes they're kind of orangey, yellow, purple, black, and it has that filamentous edge that you see off to the side there. As it's growing out, and usually it's trauma, but sometimes the patient doesn't remember the trauma, so that can throw you, but sometimes it's repetitive micro trauma where the patient's a runner or they play basketball and the toe just keeps hitting against the shoe, or maybe they've been wearing nail polish for the last 3 weeks and they forgot that somebody stepped on their toe on the subway a couple of weeks ago. Now, it can be a tumor and that's why you do wanna make sure that this is growing out. And so if you trust the patient because they just watch this, make sure it grows out, or if you're not so sure you can have them come back, you need to give it longer than just the plate would take to grow out. The blood under it can lag a little bit more. So it grows out slower than the plate. OK, now we're moving into the color is coming from melanin, but it's just melannoytic activation. No melanocytes, excited, making more pigment, and the clue here is the color. So it's usually this light color, kind of a gray tan color, and should be nice parallel lines. So you see how it's the same proximally as it is distally. As hard as nails are, the one good thing they offer you is a time. Course, so you could see because the proximal parts of the new nail, the distal is the old, so you have this nice comparison. So if it's running up and down straight, you say, OK, well that's pretty stable, that's reassuring ethnic melaninicia very, very common, often happens in patients with darker skin. It's often the same patients who have a lot of lentiginies on the palms or the soles, and I think of this as just one of those lentiginies happens to be sitting in the matrix, and that's what's shooting the band out from the nail. Trauma induced pigmentation, I think of it like post-inflammatory hyperpigmentation, essentially, like you would anywhere else on the skin. So fingernails are frequently used fingers. People who have eczema around the proximal nail fold, sometimes you'll see some melaninniy in those patients. Or a lot of times on the toes, people who have curly toes that curl in and the sides of the nail keeps banging against the side of the toes of the shoe. And now we move into the real proliferation. This is really the meat of it where melanoma starts to become a question. And here in proliferation, now we look at the color as opposed to the gray, it's this rich kind of chocolatey brown or black. And now the question is, is this a nevus or is it a melanoma? So first, what can reassure us that it's just a Nevis, it should be nice and regular. It should be once again with the melannoytic activation should be the same with proximately as it is distally shows you it's stable, uh, the bands themselves, when you go on the scope, you can actually see the bands, they should look like each other. You can see a pseudo Hutchinson. So in the bottom right, you see a pseudo Hutchinson sign, and the pseudo Hutchinson sign is when there's a lot of pigment on the nail plate, but the cuticle is kind of translucent. So you're looking through the translucent cuticle. Onto the plate and seeing the color that's a pseudo Hutchinson sign that's OK. That's a neus. This is not a neus. that's a true Hutchinson sign in a melanoma. Hutchinson sign is on the anywhere in the skin proximal lateral, distal, and the hyponicum. That's all bad. OK, other bad things other than your um Hutchinson sign, again that reverse this is the real triangle sign wider proximately we see up on the top left, look how it's growing. A few months ago it was only this thick, and now it's this thick, it tells you this is actively changing. The middle lesion actually doesn't look that scary, right? It's not that dark, but it's wide, so width turns out to be very important, and that's a citation from an international dermoscopy Society that said, if it's more than 2/3 the width of the nail, you want to be a lot more worried. Then if it's less than 1/3 in between is a bit of a gray area, but we see in the middle case, different bands are different colors, and then sometimes we see destruction of the plate because there's so much melon in, it changes the texture of the plate and it can get crumbly. Now I'm gonna talk to you about two important exceptions to those melanoma features. The first big one is kids. They can do everything I just said is an exception in kids. They could be very dark, very irregular, very wide. They can have a Hutchinson sign. They can have a triangle sign. Why? Because nails, because in nails just like anywhere else, Nevi and kids. Grow some of these are congenital nevi, and we know congenital nevi anywhere else on the body could be a little bigger, a little more irregular. Same for the same when you're in the nail also. They can have the dystrophy with the crumbling nail because they're so dark. You know how a lot of times in kids moles are dark and then when they get older they kind of poop out and they get lighter. Same thing in nails so they can have all these things remember. Nail melanoma in kids is exceedingly rare. Last I saw there's like 20 something total ever cases of known melanoma in the nail in kids, very, very rare, and this was a paper we see on the left all their cases of pediatric nevi, very bizarre looking. You see all the melanoma signs and those compared to their adult cases where everything was nice and narrow. This is a feature in kids called a longitudinal brush pigmentation. This is just an acral nevus that happens to be sitting in the hyponicum, and I think of it as like a fibrar pattern, which, you know, if you're familiar with acral dermoscopy, it's just a benign pattern you see on places, usually it's the side of the foot, but it could be in the hyponicky. Places that bend will have a fibular pattern, so don't worry about this. So now people always say to me when I talk about nails in kids, like, OK, you said. All these bad things, when do we actually worry? When will you actually biopsy a kid? So I really like this algorithm, um, and this comes from Adam Rubin who I'm super excited to say is actually gonna be joining us at NYU as our new director of dramatopathology. So he's a wonderful dramatopathologist, but he's also a world renowned expert in nails, especially in kids and does nail procedures as well. So his algorithm is he first separates it into a single nail versus multiple nails. If it's multiple nails, it's not melanoma, it's something systemic or medication or ethnic or familial, etc. If it's a single nail, he takes a picture and measures it and has the parent, the parent or the kid do the same thing, then the parent's got to measure it every month. And if it's stable, he usually sees them back once a year. Maybe he shares with another person, another germ, he'll see them a little bit more often. If there's a marked change, which he defines as greater than 50% increase in the width, change in color, symptoms, bleeding, that's what he, but still, even with all those, it could still be benign, but that would be the red flag, a real market change. That's when he would refer for. Biopsy, it needs to be somebody who's really good at doing those procedures and is comfortable doing that in kids. As hard it is to do a nail biopsy in an adult, now you throw in a kid who's kicking and screaming and sometimes has to be done under sedation, so you would need access to something like that. And if you've gone through all of that, you wanna make sure the path is being read by somebody who's comfortable with nails and also kids nails because they're even harder. The other important exception is in darker skin, where we also can see some breaking of those traditional rules of nail dermoscopy. Remember I talked about the width. Look at this. This is from ethnic melaninicia. We see bands that are wider than 2/3 of the nail. Not all those bands look exactly the same. It's an area of active investigation, the International Dermoscopy Society He's working on this right now. I would say meanwhile my one pearl is look for one nail that looks different from the rest. So this is a patient who had ethic melaninicia, but he's got one nail like this. That is an outlier. It's that chocolatey brown color compared to other nails which are just that gray tan, that's activation. So in summary. That light gray tan think about melaniccitic activation and when you have that rich brown black color, that's the proliferation. What you want to watch out for is when it's getting wider proximally irregularly space spans, that triangle sign, Hutchinson sign, think about melanoma with your two exceptions being first in kids where you could see all of that. So you're looking for a very high bar. Before you think about doing your biopsy, skin of color, look for one that's different from the rest, but it's an area we're currently working on International Dermoscopy Society, and we're running a study. If you have cases of melanoma and skin types 4 through 6 or even benign things, we're collecting them from all over the world. My colleague Marisa Crescido and I are working on this, so hopefully next time we'll have more information to give you and thank you for your attention. Published June 6, 2024 Created by Related Presenters Jennifer Stein, PhD View full profile
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