Characterization of 1152 lesions excised over 10 years using total-body photography and digital dermatoscopy in the surveillance of patients at high risk for melanoma

Background: The combined use of total-body photography and digital dermatoscopy, named "two-step method of digital follow-up," allowed the detection of incipient melanoma as a result of dermatoscopic or macroscopic changes during follow-up.

Objective: We sought to assess dermatoscopic features and dynamic changes leading to excision of melanocytic lesions during our 10-year experience of monitoring patients at high risk for melanoma.

Methods: We analyzed 1152 lesions excised during the surveillance of 618 patients at high risk for melanoma from 1999 to 2008.

Results: A total of 779 excised lesions had been previously recorded: 728 were removed because of dermatoscopic changes during follow-up and 51 were removed even though no significant change was noted. The remaining 373 excised lesions were new or undetected on previous total-body photography. A total of 98 melanomas were detected, 60 in the monitored lesions, and 38 among the "new" lesions. The most frequent dermatoscopic changes detected were asymmetric enlargement in almost 60% (n = 418), focal changes in structure in 197 (27%) and in pigmentation in 122 (17%), the latter two being more frequently seen in melanomas than in nevi (both P < .001). No significant differences were detected between dermatoscopic or histopathological characteristics of the melanomas in each group, with a considerable proportion of melanomas misclassified as benign in both groups (26.3% and 38.3%, respectively).

Limitations: The dermatoscopy pattern of stable lesions and the histopathology of lesions not removed were not included in the study.

Conclusion: The most frequent dermatoscopic features associated with melanoma were focal change in pigmentation or structure. Melanomas detected by dermatoscopic changes were remarkably similar to those detected in total-body photography. Almost 40% of melanomas diagnosed in individuals at high risk corresponded to lesions that were not under dermatoscopic surveillance.