摘要目的 探讨消化道平滑肌瘤的临床病理特征,以及Cajal间质细胞(interstitial cells of Cajal,ICC)在消化道平滑肌瘤中的分布特点.方法 收集郑州大学第二附属医院2012年6月至2017年6月147例消化道平滑肌瘤临床及病理资料,光镜下观察HE切片,免疫组织化学及奥辛蓝-沙红染色,Sanger测序检测C-KIT和PDGFRA基因突变状态.结果 患者年龄13～82岁,平均年龄52岁.男女比例接近1:2.发生于食管100例,胃20例,小肠12例,结直肠15例.组织学上卵圆形或梭形肿瘤细胞呈条束状或编织状排列.肿瘤细胞弥漫阳性表达平滑肌肌动蛋白、结蛋白及h-caldesmon,CD117与DOG1阳性且奥辛蓝-沙红染色阴性的分支状细胞散在分布于肿瘤内,该类细胞见于100％(100/100)食管平滑肌瘤、80％(16/20)胃平滑肌瘤、3/12的小肠平滑肌瘤,所占比例1％ ～30％不等,而不存在于结直肠平滑肌瘤中.16例CD117与DOG1阳性且奥辛蓝-沙红染色阴性细胞比例≥20％的平滑肌瘤均未检测到C-KIT及PDGFRA基因突变.结论 ICC普遍存在于食管、胃及小肠平滑肌瘤中,不能因为肿瘤细胞表达CD117与DOG1而误诊为胃肠道间质瘤,必要时可借助分子检测进行鉴别.

abstractsObjective To study clinical and pathologic characteristics of leiomyomas of the gastrointestinal tract, and to investigate the distribution characteristics of interstitial cells of Cajal ( ICCs ) in gastrointestinal leiomyomas. Methods One hundred and forty-seven cases of leiomyomas of gastrointestinal tract were collected at the Second Affiliated Hospital of Zhengzhou University from June 2012 to June 2017. Clinical and pathologic findings were analyzed, combined with immunohistochemistry, Alcian blue-osafranin staining and molecular study. Results The age of patients ranged from 13-82 years with mean age of 52 years. Male to female ratio was about 1:2. Histologically, all tumors were composed of ovoid to spindle cells arranged in short intersecting fascicles. All tumors were diffusely and strongly positive for smooth muscle antibodies, desmin and h-caldesmon by immunohistochemical staining. A prominent interspersed subpopulation of elongated/ dendritic-like cells with CD117 and DOG1 positivity (accounting for 1％ to 30％ of all tumor cells) and negative for Alcian blue-osafranin staining was identified in all esophageal leiomyomas, 16 of 20 (80％) gastric leiomyomas and 3 of 12 small bowel leiomyomas, but none in colonic/rectal leiomyomas. Mutational analysis in 16 cases showed absence of mutation in exons 9,11,13 or 17 of C-KIT and exons 12 or 18 of PDGFRA. Conclusions ICCs are identified in esophageal and gastric leiomyomas, as well as in small percentage of intestinal leiomyomas. Such findings may bring significant diagnostic pitfalls for misdiagnosis as gastrointestinal stromal tumor. Careful attention to the distribution of CD117 and DOG1 positive cells and molecular mutation analysis of C-KIT and PDGFRA may be necessary to establish the correct diagnosis.