胃肠道间质瘤的病理学特征及诊断

Pathological characters and diagnosis of gastrointestinal stromal tumor

目的探讨胃肠道间质瘤(G IST)的病理学特征及鉴别诊断。方法常规HE染色及免疫组织化学(S-P法)染色观察51例原发性胃肠道间质瘤的病理组织学形态及抗体CD117、CD34、V im entin、S-100、Syn、NSE、SMA、ACT免疫组织化学表达特点,并对其形态学特征及生物学行为进行分析。结果本组51例G IST中,梭形细胞型27例,上皮样细胞型9例,混合型15例。良性14例,交界性10例,恶性27例。瘤细胞CD117、CD34和V im entin多为弥漫性强阳性,阳性率分别为100.0%、72.5%和100.0%;部分病例SMA、ACT、S-100、SY-N、NSE呈局灶性阳性。结论本组病例组织形态变化多样,有些特征容易误诊为其他肿瘤。免疫组化CD117(c-k it蛋白)和CD34阳性表达是确诊G IST最有诊断价值的依据。诊断时主要是同消化道的其他梭形细胞肿瘤进行鉴别。依据肿瘤生长的大小、细胞核异形性及核分裂相活性来判断肿瘤的恶性程度,恶性度高的肿瘤往往伴有明显的出血及坏死。

Objective To analyze the morphologic findings of gastrointestinal stromal tumors in order to delineate diagnostic features. Methods H＆E staining and immunohistochemical （S-P method） studies of antibodies such as CD117, CD34, vimentin,S-100, Syn, NSE, SMA and ACT were performd in 51 cases of gastrointestinal stromal tumor（GIST）, and their morphologic and biologic behaviors were analyzed. Results Among 51 cases of GISTs, the tumors were composed of spindle cells in 27 cases, epithelioid cells in 9 cases and both cells in 15 cases. Fourteen cases showed a benign trend, 10 cases borderline, and 27 cases malignant. CDllT, CD34 and vimentin showed diffuse strong expression and the positive rates were 100%, 72.5% and 100% respectively. In some cases, SMA, ACT,S-100, Syn and NSE showed focal expression. Conclusions GISTs have various cell types and different arrangements. Some characteristics are apt to lead to misdiagnosis with other tumors. CD117 and CD34 positivity are the most valuable factors in diagnosing stromal tumors. According to the pathological appearance and immunological expression, accurate diagnosis and differential diagnosis of the GIST can be established. The differential diagnosis is primarily with other spindle cell tumors in digestive tract. The malignant degree of stromal tumors is judged by tumor size, abnormal cellular morphology and mitotic activity. Malignant tumor is usually accompanied by obvious hemorrhage and necrosis.