Data from: Reflectance confocal microscopy features of BRAF V600E mutated thin melanomas detected by immunohistochemistry

The classification of melanoma into four histological subtypes has been questioned regarding its clinical validity in providing relevant information for treatment for metastatic tumors. Specific genetic alterations are associated with particular clinical and histopathological features, suggesting that these could be helpful in refining existing melanoma classification schemes. We analyzed BRAF V600E mutated melanomas to explore the Reflectance confocal microscopy (RCM) utility as a screening aid in the evaluation of the most appropriate patients for genetic testing. Thus, 32 melanomas were assessed regarding their BRAF V600E mutational status. Experts blinded to dermoscopic images and V600E immunohistochemistry results evaluated RCM images regarding previously described melanoma features. BRAF positive melanomas were related to younger age (p=0.035), invasive melanomas (p=0.03) and to the presence of hiporreflective cells (p=0.02), epidermal nests (p=0.02), dermal-epidermal junction nests (p=0.05), edged papillae (p=0.05), and bright dots (p=0.05), and to absence of junctional thickening due to isolated cells (p=0.01) and meshwork (p=0.02). This study can not characterize other mutations in the BRAF, because the immunohistochemistry is specific to the type V600E. The findings should encourage the genetic evaluation of BRAF mutation. This study highlights the potential of RCM as a supplementary tool in the screening of BRAF-mutated melanomas.

将黑色素瘤（melanoma）划分为四种组织学亚型的分类方案，其在为转移性肿瘤治疗提供相关临床信息方面的有效性正受到学界质疑。特定的基因改变与特定的临床及组织病理学特征相关，提示此类基因改变或可用于优化现有的黑色素瘤分类方案。本研究针对携带BRAF V600E突变的黑色素瘤展开分析，旨在探讨反射共聚焦显微镜（Reflectance Confocal Microscopy, RCM）作为筛查辅助手段，在筛选最适合接受基因检测的患者方面的应用价值。为此，本研究对32例黑色素瘤的BRAF V600E突变状态进行了评估。在不了解皮肤镜图像及V600E免疫组化（immunohistochemistry）结果的前提下，专家们针对此前已报道的黑色素瘤相关特征，对RCM图像进行了评估。BRAF阳性黑色素瘤与以下特征显著相关：患者年龄更轻（p=0.035）、为浸润性黑色素瘤（p=0.03）、存在低反射性细胞（p=0.02）、表皮巢（p=0.02）、真皮表皮交界处巢（p=0.05）、边缘状乳头（p=0.05）以及亮点（p=0.05）；同时与因孤立细胞导致的交界处增厚缺失（p=0.01）以及网状结构缺失（p=0.02）相关。由于本研究采用的免疫组化仅针对V600E型突变，因此无法对BRAF基因的其他突变类型进行鉴定。本研究结果可为BRAF突变的基因检测提供临床参考依据，同时凸显了RCM作为辅助工具，在筛查BRAF突变型黑色素瘤中的应用潜力。