Background: Melanomas on chronically sun-damaged skin (CSDS) can be difficult to identify and often manifest morphologic features that overlap with benign lesions.
Objective: We describe and analyze the clinical and dermoscopic characteristics of melanomas on nonfacial CSDS.
Methods: Melanoma cases on nonfacial CSDS were retrospectively identified from the biopsy specimen logs of 6 melanoma clinics. Clinical and dermoscopic images were combined into 1 database. Demographics, clinical, dermoscopic, and histopathologic information were analyzed. Descriptive frequencies were calculated.
Results: One hundred eighty-six cases met the inclusion criteria: 142 melanomas in situ (76%) and 39 invasive (21%; mean thickness, 0.49 mm). Lentigo maligna was the most common histopathologic subtype (n = 76; 40.9%). The most frequent dermoscopic structures were granularity (n = 126; 67.7%) and angulated lines (n = 82; 44%). Vascular structures were more frequent in invasive melanomas (56% vs 12% of in situ melanomas). Most manifested 1 of 3 dermoscopic patterns: patchy peripheral pigmented islands, angulated lines, and tan structureless with granularity pattern.
Limitations: This was a retrospective study, and evaluators were not blinded to the diagnosis. In addition, interobserver concordance and sensitivity and specificity for dermoscopic structures were not evaluated.
Conclusion: Outlier lesions manifesting dermoscopic structures, such as granularity, angulated lines, or vessels and any of the 3 described dermoscopic patterns should raise suspicion for melanoma.
Keywords: actinic damage; dermoscopy; lentigo maligna; melanoma; sun-damaged skin; ultraviolet radiation.
Copyright © 2015 American Academy of Dermatology, Inc. Published by Elsevier Inc. All rights reserved.