101例胃肠道间质性肿瘤的免疫组织化学研究——组织发生学的探讨

IMMUNOHISTOCHEMICAL STUDY ON 101 CASES OF GASTROINTESTINAL STROMAL TUMORS-AN ATTEMPT TO EVALUATE THE HISTOGENESIS

本文通过101例胃肠道间质性肿瘤(GIST)的免疫组化研究,以探讨其组织发生学问题。所有病例均作Vimentin,HHF—35,Desmin和S—100蛋白的检测。在HHF—35和Desmin均阴性的29例,加染Neurofilament和GFAP。并选择了12例胃肠道外的平滑肌肿瘤对比。101例中,94％Vimentin阳性(良性94.6％,恶性93.8％),65.3％HHF—35阳性(良性67.6％,恶性64％),23.8％Desmin阳性(良性37.8％,恶性15.6％)和22.8％S—100蛋白阳性(良性27％,恶性20.9％)。在HHF—35和Desmin均阴性的29例Neurofilament和GFAP均阴性。支持大多数GIST是平滑肌来源的肿瘤。对比正常胃肠道壁和血管壁的平滑肌以及胃肠道外的平滑肌肿瘤,其对HHF—35和Desmin的反应明显较弱,可能是因瘤细胞分化处于早期阶段有关。文中分析了各部位和各组织学类型的GIST与其抗原表达的差异,发现与肿瘤分化有关,亦与部位有关,食道发生的常是分化很好的平滑肌肿瘤,胃、肠的分化差异较大,即使组织学上为典型的平滑肌瘤,其对HHF—35和Desmin的表达较食道的差。部分GIST对HHF—35反应阳性而Desmin阴性,尤以恶性者。提示HHF—35对发现分化较差的肌肉源性肿瘤较Desmin为敏感。

Gastrointestinal stromal tumors (GISTs) have generated considerablecontroversy about histogenesis, particularly whether the tumor cells are smooth muscle cells or Schwann cells. In order to characterize these tumors, the immunohistochemical staining patterns of vimentin, HHF-35 (muscle-actins), desmin and S-100 protein were studied in 101 cases of GIST (including 37 benign and 64 malignant). The results are also compared with normal host smooth muscle and 12 cases of extra-gastrointestinal smooth muscle tumors. Of these tumors, 94% were marked with vimentin (94.6% benign and 93.8% malignant), 65.3% were marked with HHF-35 (67.6% benign and 64% malignant), 23.8% were marked with desmin (37.8% benign and 15.6% malignant) and 22.8% were marked with S-100 protein (27% benign and 20. 9% malignant). There were 29 cases, neither marked with HHF-35 nor desmin, which showed also negative staining with neurofilament and GFAF. The reactivity of the tumor tissues to HHF-35 and desmin is much less than normal smooth muscle and tissues from extra-gastrointestinal smooth muscle tumors. These tumors are often diffuse and strongly stained with vimentin, a more primitive messenchymal marker. The finding indicates that most of the GISTs are of smooth muscle origin, but relatively undifferentia-ted. Esophageal GISTs tend to be most advanced in terms of smooth muscle differentiation. The morphology resemble uterine leiomyomas and expression of HHF-35 and desmin. On the other hand, gastric and intestinal GISTs are of varied differentiation in tumors. HHF-35 revealed positivity in some cases of GISTs in which desmin was not observed, especially in malignant tumors, suggesting that this antibody might detect less differentiated states of muscle cells better than anti-desmin antibody does.