具有后肾腺瘤形态的肾母细胞瘤临床病理及分子生物学特征

Clinicopathological and molecular biological characteristics of Wilms tumor with overlapping morphologically features of metanephric adenoma

目的探讨具有后肾腺瘤(MA)形态的肾母细胞瘤(WT)的临床病理特征、诊断、鉴别诊断及预后。方法分析工作中遇到的1例具有MA样形态的WT的临床病理、免疫表型及分子病理特征等,并复习相关文献。结果患者为16岁女性。组织学为三相型WT,以梭形细胞为主,含有与MA形态重叠的分化区域,局灶具有间变特征。免疫组化显示肿瘤细胞弥漫表达WT⁃1。Ki⁃67增殖指数在WT区域明显高于MA样区域。荧光PCR显示BRAF V600E突变阳性。复习相关文献,31例(包括本例)具有MA样特征的WT中28例(87.10%)为成年人。除本例外,其余肿瘤(96.78%)均为上皮型WT。25例(83.3%)具有BRAF基因突变。14例患者获得随访,均存活(随访时间3个月~145个月)。结论具有MA样形态的WT多为上皮型,分子检测具有BRAF V600E基因突变,但并不局限于上皮型,本例为首例出现局灶间变的具有MA样形态的三相型WT,因此拓展了该类肿瘤的形态学谱系。这类肿瘤通常预后较好,可通过靶向治疗方式得到有效治疗结果。

Objective To explore the clinicopathological features,diagnosis,differential diagnosis and prognosis of Wilms tumor(WT)with overlapping morphologically features of metanephric adenoma(MA).Methods The clinicopathological features,immunophenotype and molecular pathological features of WT with overlapping morphologically features of MA were reviewed.Results The patient was a 16⁃year⁃old female.Histological examination revealed that the tumor was triphasic but spindled cells⁃predominant and contained differentiated areas that overlapped morphologically with MA.Focal anaplasia was observed.Immunohistochemical analysis revealed that the tumor cells diffusely expressed WT⁃1.The Ki67 proliferative index was significantly higher in the WT areas than that in the MA⁃like areas.Fluorescence PCR revealed the BRAF V600E mutation.31 cases(including our case)of WTs with overlapping morphologically features of MA were reported,of which 28 cases(87.10%)were adults.Except for our case,all other tumors were epithelial⁃predominant WTs.BRAF mutations were identified in 25 cases(83.3%).The follow⁃up data of 14 patients were analyzed(range,3⁃145 months),and all the patients survived.Conclusion WTs with overlapping morphologically features of MA are mostly epithelial⁃predominant,and harbor BRAF mutations.However,this subtype of tumors is not strictly confined to epithelial⁃predominant WTs.Our case is the first WT with overlapping morphologically features of MA which exhibit focal anaplasia,expanding the morphological spectrum of this subtype of tumors.These tumours may have a favorable prognosis and can be effectively treated with targeted therapy.