Affiliation:
1. Department of Plastic and Reconstructive Surgery, Shanghai Ninth People's Hospital Shanghai JiaoTong University School of Medicine Shanghai China
2. Department of Pathology, Shanghai Ninth People's Hospital Shanghai Jiao Tong University School of Medicine Shanghai China
Abstract
AbstractBackgroundLimited research exists on laser treatment of giant congenital melanocytic nevus (GCMN).ObjectiveWe sought to elucidate the efficacy of the Erbium: YAG laser on GCMN and the histologic factors associated with a positive clinical response.Methods and MaterialsBetween 2019 and 2022, we enrolled 30 medium‐to‐giant CMN patients who underwent Er: YAG laser treatment. All patients received biopsies before and after laser treatments. Clinical efficacy outcomes were evaluated by the investigator's global assessment (IGA), 5‐point scale of depigmentation, and Vancouver Scar Scale (VSS) scores at least 6 months after treatment.ResultsOf the 30 cases, 18 (60.0%) showed improvement (IGA score ≥3). Eight (26.7%) patients showed repigmentation. Eight (26.7%) patients developed hypertrophic scars. The average IGA, depigmentation, and VSS scores were 2.93, 3.57, and 3.20. The IGA score was higher (3.24 ± 1.18 vs. 2.22 ± 0.97, p = 0.031) and a lower repigmentation rate (14.3% vs. 55.6%, p = 0.032) was observed in the cases with Grenz zone. The IGA score was higher (3.33 ± 1.24 vs. 2.13 ± 0.89, p = 0.023) and the repigmentation rate was lower (11.1% vs. 50.0%, p = 0.034) also in the cases with the melanocytes nests with aggregation of melanin. Lesions with superficial ablation resulted in less hypertrophic scar formation than those with deep ablation (5.9% vs. 53.8%, p < 0.05).ConclusionThe Er: YAG laser demonstrated effective clinical results for GCMNs. The grenz zone and the melanocytes nests with aggregation of melanin are promising predictors of laser efficacy.