Department of Surgery and Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan.
Surg Today. 2011 Sep;41(9):1290-3. doi: 10.1007/s00595-010-4477-8. Epub 2011 Aug 26.
Extra-gastrointestinal stromal tumors (EGISTs) that do not originate in the digestive tract are rare. We report a case of multiple EGISTs, which was monitored closely by KIT gene mutation analysis and other investigations. The patient was a 52-year-old man in whom multiple tumors in the abdominal cavity were diagnosed as EGISTs. Immunohistochemical analysis revealed positive staining for c-kit; however, no mutations were found in the KIT gene. The tumors decreased in size remarkably following treatment with imatinib mesylate, but after 2 years of this treatment, multiple liver metastases and some regrowth of the abdominal masses were found simultaneously. The liver metastasis and the abdominal masses were excised, and further analysis of the KIT gene revealed the same mutation in exon 11 in the KIT gene in the metastatic tumors. We speculate that the treatment might have triggered development of the imatinib mesylate-resistant clone, which may have existed in the primary lesion as a KIT gene mutant. This report provides valuable insight into the mechanisms of recurrent GISTs after treatment with imatinib mesylate.
非胃肠道间质瘤（EGIST）起源于消化道之外的情况非常罕见。我们报告了一例多发性 EGIST 病例，该病例通过 KIT 基因突变分析和其他检查进行了密切监测。患者为 52 岁男性，腹腔内多个肿瘤被诊断为 EGIST。免疫组化分析显示 c-kit 染色阳性；然而，KIT 基因未发现突变。甲磺酸伊马替尼治疗后，肿瘤显著缩小，但治疗 2 年后，同时发现多处肝转移和部分腹腔肿块复发。肝转移和腹部肿块被切除，进一步分析 KIT 基因显示转移瘤中 KIT 基因外显子 11 存在相同的突变。我们推测，治疗可能引发了伊马替尼耐药克隆的发展，而该克隆可能在原发性病变中作为 KIT 基因突变体存在。本报告为伊马替尼治疗后复发性 GIST 的机制提供了有价值的见解。
