胃肠道炎性肌纤维母细胞瘤的临床病理学分析

Gastrointestinal inflammatory myofibroblastic tumor：a clinicopathologic study

目的探讨胃肠道炎性肌纤维母细胞瘤（IMT）的临床病理学特征、免疫表型和分子遗传学改变，提高对该病的认识。方法回顾性分析浙江省台州医院2005年1月至2016年12月诊断的胃肠道IMT病例7例的临床资料、病理形态学特征及免疫表型特点，并运用荧光原位杂交（FISH）检测IMT中间变性淋巴瘤激酶（ALK）基因的易位情况。结果7例IMT患者中女性4例，男性3例；年龄1～72岁，中位年龄53岁，平均年龄40岁。4例发生在胃，1例在左半结肠，1例在右半结肠，1例在直肠。组织学显示梭形纤维母细胞和肌纤维母细胞束状混杂排列伴淋巴细胞、浆细胞等炎性细胞浸润。免疫组织化学显示梭形细胞波形蛋白（7/7）、平滑肌肌动蛋白（7/7）阳性，CD34、广谱细胞角蛋白、CD117、DOG1、S－100蛋白、结蛋白均阴性；其中2例免疫组织化学ALK阳性，FISH检测证实此2例肿瘤中存在ALK分离信号，为阳性病例。7例均完整切除肿瘤，随访6～135个月，术后均无瘤生存。结论胃肠道IMT少见，临床及组织学表现多样，容易误诊，手术切除是治疗IMT的可靠方式。ALK可能是IMT潜在的分子治疗靶点。

ObjectiveTo study the clinicopathologic characteristics, immunophenotype and ALK gene alterations of gastrointestinal inflammatory myofibroblastic tumor.MethodsClinical data, histological features and immunohistochemical results were analyzed in 7 cases of gastrointestinal inflammatory myofibroblastic tumor at Zhejiang Province Taizhou Hospital from January 2005 to December 2016. ALK gene status was investigated by ALK fluorescence in situ hybridization.ResultsThere were 4 female and 3 male patients. The age of patients ranged from 1 to 72 years （median age=53 years and mean age=40 years）. The tumor was located in stomach （n=4）, left hemicolon （n=1）, right hemicolon （n=1） and rectum （n=1）. Histologically, the tumors consisted of spindle fibroblast and myofibroblast cells growing in bundles with inflammatory infiltration primarily composed of plasma cells and lymphocytes. Immunohistochemical study showed spindle tumor cells were positive for vimentin （7/7）, SMA （7/7）, but were negative for CD34, CKpan, CD117, DOG1, S-100 and desmin. Two cases expressed ALK protein and fluorescence in-situ hybridization revealed the presence of ALK gene rearrangement in the both cases.ConclusionsGastrointestinal inflammatory myofibroblastic tumor is a rare neoplasm that is easily misdiagnosed. Its surgical removal is a reliable treatment. ALK may be a potential novel therapeutic target for inflammatory myofibroblastic tumor.