In this issue of The Melanoma Letter, Drs. Terushkin, Marghoob, and Argenziano present an excellent review of “slow-growing melanoma,” a clinical entity that their own recent research has greatly illuminated. This phenomenon takes on greater importance given the increased recognition of the lifesaving potential of melanoma screening and the growing emphasis on change as the most sensitive indication of melanoma.
Public and physician education on melanoma detection have moved beyond the ABCDs to emphasize outlier lesions. The “Ugly Duckling” sign has been popularized to connote the morphologic outlier that looks different than other spots, while the ABCDs have been modified to include “E” for “evolving” to connote the dynamic outlier, a lesion that is changing relative to other spots. Dermoscopy has increased the sensitivity for finding both morphologic and dynamic outliers, with digital dermoscopy an especially effective tool for following the dynamic outliers over time. Lesions that look clinically similar can differ under dermoscopy, and lesions that appear unchanged clinically can manifest change under dermoscopy. The challenge of slowgrowing melanomas is that they can defy even dermoscopic recognition.
The data reviewed here represent an important starting point for better understanding these gradually evolving lesions. As with all cancer screenings, an inherent trade-off exists between sensitivity (finding all cancers) and specificity (avoiding unnecessary biopsies of benign lesions). There is also the problem of “overdiagnosis” — labeling as cancerous some lesions that would not eventuate in harm if left untreated. Keeping these limitations in mind, it will be very important to learn more about the biology of slow-growing melanomasand to incorporate that knowledge into our melanoma screening strategies.
Allan C. Halpern, MD
Ashfaq A. Marghoob, MD