Dermoscopic Interface Features in Melanoma-Seborrheic Keratosis Collision Tumors: A Scoping Review with an...

Background/Objectives: Collision tumors between seborrheic keratosis and melanoma represent a well-known diagnostic pitfall, particularly when the benign keratinocytic component constitutes the predominant portion of the lesion. In such cases, melanoma-specific dermoscopic clues may be obscured by typical seborrheic keratosis patterns, leading to potential underestimation. The aim of this scoping review was to map and summarize the dermoscopic interface features reported in melanoma-seborrheic keratosis collision tumors. Secondary aims were to discuss diagnostic pitfalls, explore potential tumor microenvironment considerations, and assess the adjunctive role of Wood's lamp-assisted dermoscopy. Methods: This review was conducted as a scoping review and reported according to the PRISMA-ScR guidelines using PubMed, Scopus, and Web of Science. Studies reporting histologically confirmed melanoma-seborrheic keratosis collision tumors with available dermoscopic documentation were included. Eligible articles consisted of case reports and case series. Dermoscopic features at the interface between seborrheic keratosis and melanoma were qualitatively synthesized. Results: Five studies describing five melanoma-seborrheic keratosis collision tumors met the inclusion criteria. In all cases, the seborrheic keratosis component was dermoscopically recognizable. Asymmetric interface-related hyperpigmentation was consistently observed in collisions involving pigmented melanomas, whereas it was absent in the single reported case of hypopigmented melanoma. Conclusions: Asymmetric interface-related hyperpigmentation within seborrheic keratosis is a recurrent dermoscopic finding in melanoma-seborrheic keratosis collision tumors and could be considered a monitoring clue rather than a melanoma-specific diagnostic criterion. Given the dynamic nature of melanoma growth, longitudinal assessment of the dermoscopic interface may be particularly informative. Adjunctive techniques, including Wood's lamp-assisted dermoscopy, may support interface-focused evaluation in selected equivocal cases.