58例胃肠道间质瘤的病理学观察

目的观察胃肠道间质瘤（GISTs）的病理学特点并探讨其概念和诊断标准。方法在光镜观察胃肠道非上皮性梭形细胞肿瘤的基础上，运用免疫组织化学方法检测vimentin、CD34、actin和S－100。结果1988～1997年10年间共有消化道原发的非上皮性肿瘤121例，其中GISTs58例，占47．9％。GISTs由梭形细胞和上皮样细胞构成，vimentin阳性，CD34阳性，少部分病例可以表现灶性或个别细胞actin和／或S－100阳性。HE染色与平滑肌瘤、神经鞘瘤、神经纤维瘤难以鉴别，须依靠免疫组化染色。本组研究按Lewin提出的标准判断GIST的良恶性，结果为良性GIST23例，潜在恶性GIST8例，恶性GIST27例。经初步观察，此标准是可行的。结论GISTs是胃肠道的最常见非上皮性肿瘤，缺乏定向分化，根据其免疫组化特征可与平滑肌瘤、神经鞘瘤、神经纤维瘤鉴别。

A clinicopathologic study of gastrointestinal stromal tumors

Objective To investigate the clinicopathologic features of gastrointestinal stromal tumors (GISTs) and discass theirconcepts and diagnostic criteria. Method In addition to light microscopic observations immunohistochemical assays of vimentin, CD34, actin and S-- 100 were used . Results There were totally 121 cases with non - epithelioid tumors of gastrointestinal tract from 1988 to 1997. Among them, 58 cases were GISTs (47.9%). The GISTs showed two basic cell types -spindle and epithelioid. Vimentin and CD34 were of positive reaction in most specimens . A few of GISTs were actin and /or S-100 positive, usually in single cell or focal areas . Some of them were difficult to be differentiated from leiomyomas , sohwannomas and neurofibromas without immunohistochemical aids. In thes study, the Lewin's criteria for the diagnoses of benign and malignant GISTs were applied. In the 58 cases, there were 23 cases benign, 8 potential malignant and 27 malignant GISTs. From our experiences ,it was demonstrated that the criteria were available and practical . Conclusion GISTs which have no evidence of specific differentiation constitute the largest category of nonethelial neoplasms of gastrointestinal tract . They can be differentiated from leiomyomas, Schwannomas and neurofibromas depending on their immunohistochemical features .