BRAFV600E突变型胃肠间质瘤10例临床病理特征

Clinicopathological features of BRAF V600E mutated gastrointestinal stromal tumors

目的探讨BRAF突变型胃肠间质瘤(GIST)分子特征的临床意义。方法用免疫组化测序方法对10例BRAF突变GIST的临床资料、组织学形态、免疫组化及分子遗传学进行分析。结果 BRAF突变型GIST多发生于中老年人(平均年龄54.9岁),男女之比为3∶7。其中7例发生于胃,3例发生于小肠;除1例高风险外,其余为低风险或极低风险。获得随访资料的7例中只有1例术后确诊肠癌,其余均无瘤生存。所有病例的组织形态以梭形细胞结构为主。免疫组化:10例肿瘤细胞CD117、DOG-1大都弥漫强(+),且SMA、desmin和S-100均为(-)。测序检测10例样本C-KIT基因9、11、13、17外显子,PDGFRA基因12、18外显子,均为野生型;BRAF基因均为V600E突变。结论 BRAF突变型GIST是一类具有特殊分子遗传学改变和良好临床预后的特殊肿瘤。

Aim The aims of this study were to examine the status of the BRAF gene in gastrointestinal stromal tumors（GISTs） and to analyze the clinical meaning of these molecular features.Methods The clinical data,morphology,immunohistochemistry and molecular genetics of 10 cases of BRAF-mutationed GIST were analyzed by immunohistochemistry and Sanger sequencing.Results We identified 10 cases（3.5%） of BRAF（exon 15）mutations.The clinical results indicated that BRAF-mutated GISTs tended to occur more frequently in females and stomach（7 of 10 tumors）,in older individuals（mean age,54.9 years）,that these tumors exhibited low risk,recurrence rate and mortality（0%）.All 10 cases exhibited spindle-cell features,and the morphology,and immunophenotype of these cases were strongly positive for CD117 and DOG-1,negative for SMA,desmin and S-100.No mutations was tested in KIT（exons 9,11,13,17） and PDGFRA（exons 12,18） genes in these BRAF-mutated GISTs.Conclusion BRAF-mutanted GIST is a kind tumour of a special molecular genetic change and a good clinical prognosis.