原发食管炎性肌纤维母细胞肿瘤临床病理分析及鉴别诊断

Clinicopathological characteristics and differential diagnosis of primary esophageal inflammatory myofibroblastic tumor

目的探讨原发于食管的炎性肌纤维母细胞肿瘤(IMT)的临床病理特点、诊断与鉴别诊断的方法。方法对1例手术切除IMT病例大体所见、镜下表现、免疫组化、荧光原位杂交及基因突变检测结果及随访结果进行分析,并总结11例文献报道的原发食管IMT临床病理特点。结果本例食管IMT为老年男性,内镜下显示为隆起性病变,伴黏膜糜烂;镜下显示梭形肿瘤细胞呈紧密束状排列,伴有较多量淋巴细胞、浆细胞及少量中性粒细胞及嗜酸性粒细胞浸润;免疫组化结果显示vimentin、SMA及ALK均(+),β-catenin胞质(+),CD117、CD34、DOG-1、desmin、Calponin、S-100、AE1/AE3等均为(-),Ki-67增殖指数约15%。荧光原位杂交显示ALK(2p23)染色体易位;二代测序未显示c-KIT基因、PDGFRA基因和CTNNB1基因突变。12例食管IMT手术后随访期间均无复发。结论原发于食管的IMT非常罕见,但预后良好,依据形态和免疫组化、荧光原位杂交等可与其它肿瘤相鉴别。

Objective To analyze the clinicopathological features,pathological diagnosis and differential diagnosis of esophageal primary inflammatory myofibroblastic tumor(IMT).Methods A resected esophageal IMT was examined grossly and microscopically.Then the case was investigated with immunohistochemical staining,fluorescence in situ hybridization,next generation sequencing for gene mutation.We also followed up the patient.Another 11 cases of primary esophageal IMTs from the literature were reviewed.Results This patient with esophageal IMT was an old man.His tumor was a protrudent lesion endoscopically.Microscopically,the spindle tumor cells presented as compact fascicular proliferation with infiltration of lymphocytes,plasma cells and small aggregates of neutrophils as well as eosinophils.The tumor cells were immunoreactive to Vim,SMA,ALK andβ-catenin(cytoplasm),but negative to CD117,CD34,DOG-1,desmin,calponin,S-100 and AE1/AE3.The Ki-67 index was about 15%.ALK(2 p23)chromosomal translocation was detected by fluorescence in situ hybridization.Gene mutations of c-KIT,PDGFRA and CTNNB1 were not detected.All the 12 esophageal IMT were free of relapse during the follow-up.Conclusion Primary esophageal IMT is rare,while the prognosis is good.The combination of morphologic characteristics,immunohistochemical staining,and fluorescence in situ hybridization could distinguish IMT from other tumors in esophagus.