Dermoscopy of Melanomas on the Trunk and Extremities in Asians

Abstract

The incidence of melanoma among the Asian population is lower compared to that among the Western European population. These populations differed in their most common histopathologic subtypes, acral lentiginous melanoma being the most common in the Asian population. Although the dermoscopic features of the melanomas on the acral skin have been thoroughly investigated in the Asian population, studies concerning the dermoscopic patterns of melanomas on the non-acral skin have been scarce. The aim of this study was to investigate the dermoscopic patterns of melanomas on the trunk and extremities in the Asian population. To achieve this, we evaluated the dermoscopic patterns of 22 primary melanomas diagnosed at two university hospitals in Korea. In addition, 100 benign melanocytic lesions were included as the control group for comparative analysis. A P value less than 0.05 was regarded as statistically significant. Melanoma-associated dermoscopic features such as asymmetry (odds ratio [OR], 30.00), multicolor pattern (OR, 30.12), blotches (OR, 13.50), blue white veils (OR, 15.75), atypical pigment networks (OR, 9.71), irregular peripheral streaks (OR, 6.30), atypical vascular patterns (OR, 11.50), ulcers (OR, 15.83), atypical dots/globules (OR, 3.15), shiny white lines (OR, 5.88), and regression structures (OR, 7.06) were more commonly observed in patients with melanomas than in patients of the control group. The mean dermoscopic scores obtained on the 7-point checklist, revised 7-point checklist, 3-point checklist, ABCD rule, and CASH algorithm were 5.36, 3.41, 2.05, 6.89, and 9.68, respectively, in the primary melanomas, and 1.33, 0.93, 0.46, 2.45, and 3.60, respectively, in the control group (all, P < 0.001). The present study showed that melanoma-related dermoscopic patterns were common in Asian patients. Dermoscopy is a reliable diagnostic tool for the melanomas of the trunk and extremities in the Asian populations.

Fig 1. Clinical image and dermoscopic features of a malignant melanoma and benign nevus in a 60-year-old woman.

Compared to the clinical picture (a), dermoscopic evaluation provides detailed clues for the diagnosis of melanomas (b), dermoscopy of benign nevus showing a reticular pattern (c). Dermoscopy of malignant melanoma exhibits melanoma-associated patterns such as asymmetry, atypical pigment networks, blue-white veil, irregular blotches, irregular dots, peripheral streaks, shiny white lines, and multicolor patterns.

Fig 2. Dermoscopic features of a melanocytic nevus with a globular and reticular pattern (a), a blue nevus (b), a spitz nevus (c), and a malignant melanoma (d).

Compared to benign nevi, a melanoma exhibits more patterns such as asymmetry, irregular blotches, atypical pigment networks, irregular dots, peripheral streaks, multicolor patterns, and ulcer.