Dermoscopic criteria associated with BRAF

Summary Background The identification of BRAF mutations in melanoma led to the development and implementation of new and effective therapies. Few clinical and histological features have been associated with this mutational status. Objectives The main objective of this study was to investigate clinical, histopathological and dermoscopic characteristics of primary melanomas according to BRAF or NRAS mutational status. Methods An observational retrospective study including melanoma dermoscopy images assessed for somatic mutations in BRAF and NRAS. Results Seventy‐two patients were included, 30 women (42%) and 42 men (58%), mean age was 59 ± 15·51 years. BRAF‐mutated melanomas were more frequently located on the trunk (n = 18, 64% for BRAF‐mutated vs. n = 11, 29% for wild‐type melanomas, P = 0·013). Histological ulceration was associated with the presence of BRAF mutations [odds ratio (OR) 3·141; 95% confidence interval (CI) 1·289–7·655; P = 0·002]. The Breslow index tended to be thicker in BRAF‐mutated compared with wild‐type (P = 0·086). BRAF mutations were present in 28 (39%) patients and only four cases were positive for NRAS mutations (6%), BRAF and NRAS mutations being mutually exclusive. The presence of dermoscopic peppering was associated with MAPK mutations (BRAF and NRAS) (OR 1·68; 95% CI 1·089–2·581; P = 0·015). Dermoscopic ulceration was also associated with BRAF mutations excluding acral and facial melanomas (OR 2·64; 95% CI 1·032–6·754). Conclusions This study showed a correlation between BRAF and NRAS status and dermoscopic findings of ‘peppering’ as an expression of regression and melanophages in the dermis, suggesting a morphological consequence of immune behaviour in BRAF‐mutated melanomas. What's already known about this topic? Knowledge of BRAF or NRAS mutations has allowed the development and implementation of new therapeutic options. Mutation status has been related to clinical and histological features. What does this study add? The results show an association between dermoscopic regression such as blue‐grey peppering in BRAF‐ and NRAS‐mutated melanomas, which could be a result of their immune morphological behaviour. The presence of dermoscopic and histopathological ulceration was also related to BRAF‐mutated melanomas

Dermoscopy of acral melanoma: a multicenter study on behalf of the international dermoscopy society

Background: Most studies on dermoscopy of acral lesions were conducted in Asian populations. In this study, we analyzed these features in a predominantly Caucasian population. Objective: Estimate the prevalence of dermoscopic features in acral lesions, and assess their level of agreement between observers. Methods: In this retrospective multicenter study, 167 acral lesions (66 melanomas) were evaluated for 13 dermoscopic patterns by 26 physicians, via a secured Internet platform. Results: Parallel furrow pattern, bizarre pattern, and diffuse pigmentation with variable shades of brown had the highest prevalence. The agreement for lesion patterns between physicians was variable. Agreement was dependent on the level of diagnostic difficulty. Conclusion: Lesions with a diameter >1 cm were more likely to be melanoma. We found as well that a benign pattern can be seen in parts of melanomas. For this reason one should evaluate an acral lesion for the presence of malignant patterns first. © 2013 S. Karger AG, Basel