Massi Daniela, Pinzani Pamela, Simi Lisa, Salvianti Francesca, De Giorgi Vincenzo, Pizzichetta Maria A, Mirri Francesco, Steffan Agostino, Orlando Claudio, Santucci Marco, Canzonieri Vincenzo
Department of Surgery and Translational Medicine, Division of Pathological Anatomy, University of Florence, Florence, Italy.
Melanoma Res. 2013 Oct;23(5):414-9. doi: 10.1097/CMR.0b013e32836477d4.
The genotypic profile of rare amelanotic melanomas (AMs) has been poorly investigated, thus preventing either an accurate identification as a distinctive melanoma subtype or therapy stratification. Here, we investigated the presence of the BRAF(V600E) mutation by real-time quantitative PCR and KIT mutations (exons 11 and 17) by sequencing analysis in 33 AMs. AMs included 'truly' amelanotic lesions (n = 19), with no melanin pigmentation upon dermoscopic inspection and hypomelanotic lesions (n = 14), by definition partially pigmented lesions showing a melanin pigmentation area of less than 25% of the total surface area. The frequency of the BRAF(V600E) mutation was 70.3% in the 33 cases, a percentage that increased to 89% when only the subgroup of thin melanomas (≤ 1 mm in thickness, n = 9) was considered. KIT mutations were found in 12.1% of AMs, all of which developed in nonacral sites. The identification of a relatively high frequency of BRAF(V600E) and KIT mutations in AMs may have important consequences for implementation of the novel targeted therapies now available to treat this life-threatening disease.
罕见无色素性黑色素瘤（AM）的基因分型情况尚未得到充分研究，因此既无法准确将其鉴定为一种独特的黑色素瘤亚型，也无法进行治疗分层。在此，我们通过实时定量PCR研究了33例AM中BRAF（V600E）突变的存在情况，并通过测序分析研究了KIT突变（第11和17外显子）。AM包括“真正的”无色素性病变（n = 19），即皮肤镜检查时无黑色素沉着的病变，以及浅色病变（n = 14），根据定义，浅色病变是指黑色素沉着面积小于总面积25%的部分色素沉着病变。在这33例病例中，BRAF（V600E）突变的频率为70.3%，仅考虑薄型黑色素瘤亚组（厚度≤1 mm，n = 9）时，该百分比增至89%。在12.1%的AM中发现了KIT突变，所有这些突变均发生在非肢端部位。AM中BRAF（V600E）和KIT突变相对较高频率的鉴定可能对实施目前可用于治疗这种危及生命疾病的新型靶向治疗具有重要意义。
