102例血管免疫母细胞性T细胞淋巴瘤的临床病理学特征分析

Angioimmunoblastic T-cell lymphoma:a clinicopathological analysis of 102 cases

目的:探究血管免疫母细胞性T细胞淋巴瘤(AITL)的临床病理学特点。方法:分析102例AITL的临床特点以及病理组织学、免疫表型及分子遗传学特征。结果:淋巴结结构被肿瘤细胞全部或部分破坏。高内皮小静脉(HEVs)形成分枝状结构网,其内可见肿瘤细胞、免疫母细胞、组织细胞、浆细胞、嗜酸粒细胞弥漫浸润或浸润于副皮质区。肿瘤细胞胞浆透亮,被滤泡树突细胞(FDC)网围绕。免疫组织化学染色结果显示,肿瘤细胞表达CD3(102/102)、CD4(93/102)、CD5(87/102),并且表达多个滤泡辅助T细胞相关标志物,如BCL6(79/102)、CD10(44/102)、PD1(75/102)、CXCL13(43/102)和诱导型共刺激因子(ICOS)(99/102)。FDC标志物CD21和CD23染色,清晰地显示滤泡外增生的FDC网。NGS检测了40例AITL病例,发现4个特征性基因突变,即TET2(31/40)、DNMT3A(9/40)、IDH2(18/40)和RHOA(23/40)。结论:AITL的临床病理表现复杂,其诊断需要结合临床、组织病理学、免疫组织化学、分子遗传学作综合判断;相较于其他滤泡辅助T细胞标志物,ICOS更有助于AITL的诊断。

Objective:To clarify the clinicopathologic features on angioimmunoblastic T-cell lymphoma(AITL).Methods:The clinical,histomorphological,immunohistochemical,molecular and genetic features of 102 patients with AITL were analyzed.Results:Lymph nodes involved by AITL typically showed partial or complete architectural effacement with perinodal extension.The infiltrate was usually diffuse or paracortical,composed of a polymorphous population of small to medium sized lymphocytes,scattered immunoblasts,histiocytes,plasma cells,and eosinophils amid prominent networks of arborizing high endothelial venules(HEVs).The neoplastic T cells were usually enwrapped by follicular dendritic cell(FDC)meshworks with clear cytoplasm.Immunophenotypically,the neoplastic cells expressed CD3(102/102),CD4(93/102),CD5(87/102),and also expressed multiple T-follicular helper(TFH)related markers,including BCL6(79/102),CD10(44/102),PD1(75/102),CXCL13(43/102),inducible co-stimulator(ICOS)(99/102).FDC markers,CD21 and CD23,typically highlighted extensive FDC meshworks outside of the follicles.Next generation sequencing(NGS)identified the following 4 characteristic molecular mutations in 40 AITL patients,TET2(31/40),DNMT3A(9/40),IDH2(18/40),RHOA(23/40).Conclusion:The diagnosis of AITL is challenging and requires a constellation of clinical,histomorphological,immunohistochemical and genetic findings.ICOS is a more useful TFH cell marker for the diagnosis of AITL than others.