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Tips on Using Dermoscopy to Identify More Than Pigmented Lesions
Roman Bronfenbrener, MD, is a dermatologist and owner of Pennsylvania Dermatology Specialists. He is also a clinical assistant professor of dermatology at Penn Medicine in Philadelphia, PA. He is a board-certified medical, surgical, and cosmetic dermatologist practicing the full gamut of dermatology. He lectures extensively and also teaches residents on a plethora of subjects that generally cover topics such as dermoscopy, practice management, and skin cancer management. He met with The Dermatologist to discuss dermoscopy and atypical nevi, topics he lectured on at the Society of Dermatology Physician Assistants Annual Summer Dermatology Conference 2021.
Your session addressed how dermoscopy changes the management of common dermatologic conditions. How can common conditions benefit from dermoscopy?
Dermoscopy is not usually the be-all, end-all to make the diagnosis, but in every case, it adds additional information that can help increase your accuracy and confidence. Findings have been reported for essentially all of general dermatology, from hair loss to papulosquamous to vascular conditions. If you are seeing something, you can easily compare with other findings that have been reported.
You can also use those findings to manage certain dermatologic conditions, because you can track the progress dermoscopically to see how the condition is doing on a microlevel. I find this particularly useful in hair loss, where dermoscopic signs of improvement generally predate clinical improvement. Also, if you are doing a scabies preparation, you know exactly where to do the scraping as opposed to just blindly looking for burrows. You can actually confirm the presence of a mite and do the scraping in the right place. This additional information also improves patient buy-in, because they now are privy to information about their condition.
What are the main dermoscopic features within general dermatology that clinicians should utilize in general dermatological presentations?
For general dermatology, scale is important. Sometimes before I look at something with a contact medium, I might look at it with polarized non-contact dermatoscope first to get a better idea of the scale pattern. This is particularly useful for alopecia and papulosquamous disorders.
Once I look past the scale, I will usually use a contact medium like alcohol or ultrasound jelly to access some of the vascular patterns. It is important not to press down on the dermatoscope too hard, because it might blanche out some of the blood vessel patterns that you are looking at. Blood vessel patterns of common dermatoses such as psoriasis or eczema usually present with a dotted vessel pattern. Rare exceptions might make me pause, because then it might not be 100% clear-cut eczema dermoscopically. In that situation, you could biopsy and find out if you are dealing with mycosis fungoides.
For foreign bodies, there are various things that you might be looking for, whether it is a suture, a splinter, or a piece of embedded glass. If I am looking at something vascular, eg, a port wine stain, I might look at the predominant vessel pattern, because that might indicate the depth and therefore how well they would respond to laser treatment. It can inform your decision just based on what you're seeing with the clinical, pathologic, and dermoscopic correlations.
In what ways can dermoscopy be used with photographs to educate dermatologists?
Photographing dermoscopy images is not generally HIPAA-sensitive, so you can easily share those pictures. Unless you are taking a picture of the person's name inside a tattoo or another potentially identifying feature, it will be difficult to know whose lesion it is. You can share that image with colleagues and ask for their opinion without worrying about cropping or being unable to present the whole picture to them. It is incredibly useful for teaching and learning purposes.
Sometimes, you might biopsy something that could be a collision, such as a seborrheic keratosis with a basal cell carcinoma (BCC) nearby. If you see BCC features with the dermatoscope, but pathology does not see it under the microscope, that might be a case where you can ask the pathologist to take some deeper sections, because maybe the specimen was only bisected and a cut through the diagnostic area was not made.
I also use dermoscopy and pictures sometimes before Mohs surgery to delineate the borders. It helps with finding little pockets of residual malignancy and planning your first stage appropriately to avoid cutting through them.
From a monitoring standpoint, if someone has hair loss and you take a dermoscopic picture, you can monitor their progress. On trichoscopy, measurements can be made regarding follicular size, number of follicles, hairs per field, etc. It's incredibly useful for measuring things for you, and it can get a lot of patients buy-in, because you will see changes on the dermatoscope long before you see them clinically. This is especially true with hair loss. Also, as patients improve, you can take pictures and show them the percentile that is improving. The other nice thing is that there are actually some trichoscopy systems that can help you generate a report that will also be used for tracking these patients—very useful if you are in a practice that offers hair loss treatment or sees patients with hair loss.
Your next session discussed atypical nevi to melanoma. Can you share what new techniques and treatments are on the horizon?
There are three things I would like to address:
- The first is gene expression profiling, which is becoming more commonly utilized for the management of everything from determining whether a lesion needs a biopsy to trying to decode how a malignancy may behave based on genetic potential. It's not yet a standard of care, but it seems to be the direction that dermatology is headed, so that we can risk stratify people appropriately. Well-run prospective trials on large numbers of patients will help us understand what role these tests play and whether they will complement the existing diagnostic and staging criteria.
- Next is total-body photography, because that is far easier now than in the past. When you used to have to take standardized images, you used to have a photographer in place and you had to have a protocol for how you took the pictures (eg, positioning). You had to train somebody on how to do it, the equipment was expensive, and the staff cost was high. It would cost patients several hundred dollars to have this done, which led to poor adoption. The printed photos were also inconvenient, as they were large and needed to be securely stored either in the clinic or in the patient’s home, or both.
Nowadays, there are several apps and other software that will allow you to take total body photographs using readily available equipment and without having a specially trained staff. They do it in an inexpensive manner, and in a way that also gives the patient access to those photos so that they can view them whenever they want.
Some of these systems use artificial intelligence (AI) to attempt increase our sensitivity for noticing something that might be different. It is easier sometimes for a computer to notice a couple of pixels of change compared with us, especially when a patient has countless lesions to examine. AI is not going to tell us what to biopsy, but it might tell us what deserves a closer look or what might have changed from the prior imaging. This aims not to replace the provider but to improve our ability to detect cancer in its earliest stages by hinting at the lesions we should be examining closer. - The last thing I want to address is Mohs surgery for melanoma. Especially for melanomas of a certain depth, specific cosmetic areas, or in areas where that might have subclinical extension not immediately visible, Mohs has been shown to have outcomes and recurrence rates superior to standard surgery and with margin sparing techniques.
What key points should dermatologists keep in mind when managing atypical nevi?
Patients with a lot of atypical nevi often have many atypical lesions that begin to blend and overlap with melanoma. As a dermatologist, that is an issue, because you're struggling to see what is different enough to biopsy or if the lesions are all atypical in the same way. There is a component of experience and gestalt that goes into this. It's also difficult for the pathologist, as they only look at a small selection of lesions from a particular patient, whereas with the dermatoscope, you can screen all of them. I think a dermatoscope will definitely improve your ability to find the outliers.
The approach I usually have is comparative. I will go around and try to look at a scattering of nevi that otherwise do not raise my attention, just to see what kind of pattern a patient makes. Then I look around for things that break the pattern, understanding that biology does not always follow completely perfect rules.
Things are going to be slightly asymmetric but, generally, people will make the same pattern repeatedly. A pattern that looks different for some reason usually raises my suspicion a bit. I might consider either a biopsy or closely monitoring that kind of patient. These are also patients in whom it is useful to do total body photographs repetitively. It will indicate what is new and if something has changed.
I find that for patients with many atypical nevi, it is important to get them involved too. I tell them to check themselves, and I take their concerns seriously. I have caught melanomas that clinically and dermoscopically would not have been all that outrageous, but the patient thought it was new or doing something different. This should definitely be taken seriously.
Any other pearls of wisdom you would like to share with your colleagues regarding either dermoscopy or atypical nevi?
Our goal is never to diagnose someone with an atypical nevus. We are always looking for a melanoma, and then we sometimes stumble upon atypical nevi. That's usually how it happens in my clinic.
It's all about comparison. I could show you the lesion, then I could show it to you on the back of an 80-year-old White patient who is otherwise fair-skinned without any other lesions, and that would be a melanoma. In comparison, I could show you that same lesion in a person with multiple dysplastic nevi that all look like this one lesion, and in that case, it would be considered fine. Under the microscope it would be biopsied, and it would be like a dysplastic nevus.
Everything is about context. Patients with multiple dysplastic nevi probably harbor some mutations that predispose them to making nevi and, because constitutively their whole body has those mutations on their whole skin surface, it explains why they might have a signature nevus pattern. If those nevi undergo more mutation, they can go on to develop into melanoma. That is where the comparison comes in to make sure that there are no melanoma-specific features. In general, atypical nevi should not have melanoma-specific features. They will usually have fuzzy-type features and a slightly atypical network, but it's not going to be horrible. They might have some globules, but they are not terribly asymmetric and all similar in size. If there is a little bit of regression, it tends to be focal and central. Those are all important characteristics to look for in a lesion that you're concerned might be a melanoma.
Importantly, I find negative pigment network to be a sensitive predictor of malignancy in patients with numerous dysplastic nevi, as this is a common feature of nevus-associated melanoma. Keep a close eye on them, do total body photography, and screen them more often if they have got a lot of nevi. Finally, counsel them extensively about looking at themselves, looking for outliers. I think sharing the wealth and sharing the liability is not a bad thing. Getting the patient involved is so helpful, because they will definitely bring things to your attention.