5例胃炎症性肌纤维母细胞瘤的临床病理学分析

Clinicopathology of gastric inflammatory myofibroblastic tumor:An analysis of 5 cases

目的分析5例胃炎症性肌纤维母细胞瘤(inflammatory myofibroblastic tumor,IMT)的临床病理特征,以增加对该类疾病的认识。方法分析5例胃IMTs患者的临床病理资料,进行随访、光镜观察和免疫组化染色。结果患者年龄36-45岁,4例男性,1例女性。肿瘤直径4.5-8cm。镜下主要显示3种组织学类型:以黏液、血管、炎细胞为主的黏液型;以束状排列梭形细胞为主的细胞密集型;以致密成片的胶原纤维为主的纤维型。5例中3例以黏液型为主伴部分细胞密集型区域,2例以细胞密集型为主伴灶状纤维型和黏液型区域。全部病例见淋巴浆细胞浸润。1例局部核分裂数>5个/10HPF,其余核分裂数1-2个/10HPF。未见核异型性或坏死。免疫组化染色显示5例均呈平滑肌蛋白(smooth muscle atin,SMA),Vimentin和间变性淋巴瘤激酶(anaplastic lymphoma kinase,ALK)阳性表达,1例局灶见Desmin阳性表达,而S-100、CD34、CD117、CD21、CD35、CD68均阴性。随访2-5年,1例复发,其余无复发或转移。结论胃IMT是一种具有中间性生物学行为的肿瘤,保守治疗预后良好。

Objective To analyze the clinicopathological characteristics of 5 patients with gastric inflammatory myofibroblastic tumor（IMT） in order to have a deeper understanding of it.Methods Clinicopathological characteristics of 5 patients with gastric IMT were analyzed with immunohistochemical staining and observed under optical microscope.The patients were followed up.Results The age of the 5 gastric IMT patients（4 males and 1 female） was 36-45 years.The diameter of gastric IMT was 4.5-8cm.Optical microscopy showed 3 histological types,including mucous type mainly manifested as mucus,blood vessels and inflammatory cells,dense cell type mainly manifested as spindle cells,and fibrous type mainly manifested as collagenous fibers.Among the 5 cases,predominant mucous type with some dense cell area was found in 3 and predominant dense cell type with focal fibrous and mucous areas was observed in 2.Infiltration of lymph plasma cells was found in all cases.The number of mitosis was 5/10HPF in 1 case and 1-2/10HPF in the other 4 cases.No prominent nuclear atypia or necrosis was found.Immunohistochemical staining showed expression of smooth muscle actin,vimentin and ALK in all cases.Desmin was positively expressed while S-100,CD34,CD117,CD21,CD35 and CD68 were negatively expressed in 1 case.The patients were followed up for 2-5 years during which no relapse or metastasis occurred except recurrence in 1 case.Conclusion Gastric IMT is a tumor characterized by intermediate biological behaviors with a favorable prognosis after conservative therapy.