Kawanowa Kaori, Sakuma Yuji, Sakurai Shinji, Hishima Tsunekazu, Iwasaki Yoshiaki, Saito Kana, Hosoya Yoshinori, Nakajima Takashi, Funata Nobuaki
Department of Pathology, Tokyo Metropolitan Komagome Hospital, Tokyo, Japan.
Hum Pathol. 2006 Dec;37(12):1527-35. doi: 10.1016/j.humpath.2006.07.002. Epub 2006 Sep 25.
Gastrointestinal stromal tumors (GISTs) are rare mesenchymal neoplasms with an annual incidence of approximately 10 to 20 per 1 million cases. Although pathologists have often observed incidental small GISTs in the stomach resected from patients with gastric cancer, no report on the real incidence of gastric GISTs is available. In this study, 100 whole stomachs resected from patients with gastric cancer were sectioned at 5-mm intervals and hematoxylin and eosin-stained slides (a mean of 130 slides for each case) were examined for microscopic GISTs. KIT (CD117), CD34, and desmin expression of the incidental tumors was evaluated by immunohistochemistry, and genomic DNA extracted from formalin-fixed and paraffin-embedded tumor tissues was analyzed for c-kit gene mutations in exon 11. In 35 of the 100 whole stomachs, we found 50 microscopic GISTs, all of which were positive for KIT and/or CD34 and negative for desmin. Most microscopic GISTs (45/50, 90%) were located in the upper stomach. Two of the 25 (8%) microscopic GISTs had c-kit gene mutations. Fifty-one leiomyomas with positive expression for desmin were observed in 28 of the 100 stomachs. Both leiomyomas and GISTs were found in 12 stomachs. These results indicate that microscopic GISTs are common in the upper portion of the stomach. Considering the annual incidence of clinical GISTs, only few microscopic GISTs may grow into a clinical size with malignant potential. Further studies are required to clarify the genetic events responsible for the transformation of microscopic GISTs to clinical GISTs.
胃肠道间质瘤（GISTs）是罕见的间叶组织肿瘤，年发病率约为每100万例中有10至20例。尽管病理学家常在胃癌患者切除的胃中偶然观察到小的GISTs，但尚无关于胃GISTs实际发病率的报道。在本研究中，将从胃癌患者切除的100个全胃以5毫米间隔切片，并对苏木精和伊红染色的切片（每个病例平均130张切片）进行显微镜检查以寻找微小GISTs。通过免疫组织化学评估偶然发现的肿瘤的KIT（CD117）、CD34和结蛋白表达，并对从福尔马林固定石蜡包埋的肿瘤组织中提取的基因组DNA进行第11外显子c-kit基因突变分析。在100个全胃中的35个中，我们发现了50个微小GISTs，所有这些均对KIT和/或CD34呈阳性，对结蛋白呈阴性。大多数微小GISTs（45/50，90%）位于胃上部。25个微小GISTs中的2个（8%）有c-kit基因突变。在100个胃中的28个中观察到51个结蛋白表达阳性的平滑肌瘤。12个胃中同时发现了平滑肌瘤和GISTs。这些结果表明微小GISTs在胃上部很常见。考虑到临床GISTs的年发病率，只有少数微小GISTs可能生长为具有恶性潜能的临床大小肿瘤。需要进一步研究以阐明导致微小GISTs转变为临床GISTs的遗传事件。
