胃肠道间质瘤40例临床病理分析

Clinicopathological analysis of gastrointestinal stromal tumor

目的探讨胃肠道间质瘤(GIST)的基本临床病理、良恶标准、组织学类型、预后的判断以及组织发生等问题。方法对我院1999～2004年曾被诊断为胃肠道间质瘤的40例患者进行临床和病理分析。结果40例中胃恶性间质肿瘤16例,小肠恶性间质肿瘤15例,大肠肿瘤3例,盆腔肿瘤3例,后腹膜肿瘤2例,食道肿瘤1例。肿瘤大小0.2～25cm,平均7.8cm。其中4例发生了转移。免疫组化的阳性表达结果:CD117阳性率为90.0%,CD34阳性率45.0%,S100阳性率10.0%,VEGF阳性率70.0%,VEGFR2阳性率80.0%。其中CD117与CD34共表达率为40.0%(1640),CD117与S100共表达率为7.5%(340),CD34与S100共表达率为2.5%(140)。结论GIST的主要恶性指标有肿瘤最大径、核分裂像(HPF)。在GIST的诊断中,只要CD117表达即可诊断为狭义的GIST,并将真正的平滑肌肿瘤与雪旺细胞瘤区别出来。VEGF也是一种衡量肿瘤生长和转移的重要指标。

Objective To investigate the problems of clinicopathologic features,criteria of malignancy, histological type, prognosis,histogenesis,and treatment option of the gastrointestinal stromal tumor(GIST).Method Forty cases of GIST (including 4 benign and 36 malignant)of GI tract from 1999 to 2004 in this department were analyzed clinically and pathologically.In addition to light microscopic observation, immunohistochemical assay of CD117, CD34, S-100, VEGF(vascular endothelial growth factor)and VEGFR-2(VEGF receptor 2)was carried out. The follow-up information was obtained from 37 patients and 3 patients were lost to follow-up.Follow-up was carried out for 3-65months (median follow-up 23.7 months).Results The 40 GISTs occurred in 17 women ((42.5%))and 23 men (57.5%).The median age was 57.98 years(range 39-78). 40.0%(16/40)of the tumors occurred in the stomach,37.5%(15/40)in the small intestine,7.5%(3/40) in the colon, 7.5%(3/40) in the pelvic cavity,5.0%(2/40) in the retroperitoneum and 2.0%(1/40) in the esophagus.The sizes of the tumors were from 0.2 to 25 cm (average 7.8 cm). Four patients had metastasis(4/40,10.0%).In light microscopic observation, morphologic criteria of malignancy were tumor size 5 cm and mitotic figures 5/50HPF. Immunohistochemical staining results: CD117 positive 90.0%(36/40),CD34 positive 45.0%(18/40),S-100 positive 10.0%(4/40), VEGF positive 70.0%(28/40),VEGFR-2 positive 80.0%(32/40),CD117 and CD34 coexpression 40.0%(16/40),CD117 and S-100 coexpression (7.5%)(3/40),CD34 and S-100 coexpression 2.5%(1/40). All benign cases are alive.Conclusions Morphologic criteria of malignancy of GIST are tumor size≥5 cm, mitotic figures≥5/50 HPF and ulcer formation.CD117 positive is the special criterion for diagnosing GIST in narrow sense and can differentiate GIST from true leiomyoma/leiomyosarcoma and Schwannoma.(3)VEGF and VEGFR-2 are highly positive in GIST,and are important indexes for judging growth and metastasis of the tumors.