Dermoscopy: A useful tool for gauging atypical lesions

December 1, 2006

Dr. Schachner: Dr. Johr, tell me about your experience with dysplastic nevi and your management of patients with atypical pigmented skin lesions.

Q. DR. SCHACHNER: Dr. Johr, tell me about your experience with dysplastic nevi and your management of patients with atypical pigmented skin lesions.

DR. JOHR: It's important to get as much data as you can on the patient, which includes the history - the family history, the patient's personal history, the history of the lesion. That's step one.

If the patient does not have a particular concern, my standard question is if they have anything that is new, changing or bleeding. Step two is to do a total body skin examination in patients of all ages, not only in adults. Children and young adults have high-risk benign melanocytic lesions, and they get and die from melanoma. It's interesting for me that, (from) what I've seen in the literature (Fisher NM, Schafter JV, et al. "Breslow depth of cutaneous melanoma. Impact of factors related to surveillance of the skin including prior skin biopsies and family history of melanoma." J Am Acad Dermatol. 2005;53:393-406), a significant number of our colleagues are not doing total body skin examinations, and the statistics clearly show that a significant - up to 80 percent - of melanomas can be on areas of the body that are covered by clothes. It is considered by some dermatologists to be "an inefficient use of their time and valuable resources."

There are melanomas that cannot be diagnosed clinically or with dermoscopy (Kittler H, Guitera P, Riedl E, et al. "Identification of clinically featureless incipient melanoma using sequential dermoscopy imaging." Arch Dermatol. 2006;142:1113-1119), but only by finding dermoscopic changes over time. When I find melanoma with digital follow-up, they have always been in situ lesions.

I also examine lesions that do not look high-risk clinically with dermoscopy because there is the concept of melanoma incognito or false negative melanomas. Basically, any skin lesion could be a melanoma, and that is always in the back of my mind. With the technique you have a better chance to identify these lesions. You can also find the "ugly duckling" lesions with dermoscopy. There should always be a good clinico-dermoscopic correlation; if not, raise a red flag of concern and consider that you might be dealing with a high-risk lesion. A red flag of concern should also be raised for the lesion or lesions that stand out clinically or with dermoscopy from their neighbors - the "ugly duckling." I think the "ugly duckling" is a helpful concept both clinically and with dermoscopy. It is extra important information to help you decide on the disposition of a lesion or lesions.

Q. Dr. Schachner: One can only agree that the only "complete" skin exam is a complete skin exam, and you can't do that with clothing on. The readers (can) refer to the February (2006) issue of Dermatology Times for an editorial on that subject. Having said that, a total body exam and you're doing dermoscopy - Is it your experience, especially in children, that dermoscopy is a surgery-sparing technique for children?

DR. JOHR: One of the major benefits of dermoscopy for all patients is to avoid unnecessary surgery, and this is especially true in children.

We know that children - we'll define them as being 20 years and younger - are at risk to develop melanoma. There are some articles in the literature, and some people feel that the incidence of melanoma is increasing in this age group.