小肠的恶性胃肠道间质瘤伴淋巴结转移病理分析

目的 探讨伴淋巴结转移的小肠恶性胃肠道间质瘤的临床病理特征、c-kit基因突变情况,以及对甲磺酸伊马替尼(imatinib mesylate,Glivec)的治疗反应.方法 对2例发生在小肠伴发淋巴结转移的胃肠道间质瘤进行光镜观察、免疫组织化学标志及基因突变分析并随访甲磺酸伊马替尼的治疗效果.结果 2例均为小肠浆膜面肿块,镜下观察肿瘤均以梭形细胞为主,伴有少量上皮样细胞,呈多结节状,并出现大片凝固性坏死;免疫组织化学标志肿瘤细胞CD117阳性,基因突变检测发现均存在c-kit基因第11号外显子的突变.例1显示第11号外显子559～569位点杂合性缺失,伴570、571位点TACATA杂合性突变为GACAGA;例2显示第11号外显子559～565杂合性缺失.结论 小肠胃肠道间质瘤伴淋巴结转移是一种少见病变,需要同发生在此处的其他恶性软组织肿瘤鉴别;该肿瘤对甲磺酸伊马替尼的治疗效果取决于c-kit基因的具体突变类型.     

212例胃肠间质瘤的临床病理特征及预后分析

目的探讨胃肠间质瘤（GIST）的临床特征和分子病理学特点,分析影响GIST预后的相关因素。方法回顾性分析2004年4月至2011年8月南方医院收治的212例GIST患者的临床病理和随访资料,应用生存分析比较不同因素对预后的影响。对接受甲磺酸伊马替尼治疗的53例患者,采用基质辅助激光解析/电离-飞行时间质谱方法检测KIT和PDGFRa基因相关位点的突变情况。结果单因素生存分析显示肿瘤大小、核分裂数、美国国立卫生研究所（NIH）危险度分级、转移、手术及甲磺酸伊马替尼影响GIST患者的生存率。多因素生存分析提示,NIH危险度分级和甲磺酸伊马替尼是影响预后的独立因素。53例GIST患者中,KIT基因突变39例（73.6%）,其中外显子11突变21例（53.8%）,外显子9突变13例（33.3%）。KIT外显子11突变形式主要为5’端第557-558密码子缺失最常见;外显子9突变均为插入串联重复。未检测到PDGFRa基因突变的病例。结论 NIH危险度分级和甲磺酸伊马替尼治疗与GIST患者的生存密切相关,基因突变检测对指导生物靶向治疗和预测其疗效具有重要意义。     

与神经纤维瘤病Ⅰ型伴发的胃肠道间质瘤临床病理学和分子遗传学研究进展

大多数散发性胃肠道间质瘤(gastrointestinal stromaltumors,GIST)具有c-kit基因或血小板衍生的生长因子受体A(PDGFRA)的突变,最常发生于胃,其次是小肠、肛门直肠等。通常单发,偶见多发。部分多发性GIST与Ⅰ型神经纤维瘤病(NF1)有关。NF1可伴发多种病变,GIST被认为是最常见的与NF1相关的胃肠道肿瘤,NF1患者发生GIST的危险性明显提高,多项研究证实:NF1伴发的GIST与散发性GIST在临床病理、c-kit和PDGFRA基因突变状态等方面均有不同,是一种独特的肿瘤,表现为多中心发生、好发于小肠,瘤细胞呈梭形,缺乏KIT及PDGFRA突变,不对甲磺酸伊马替尼的治疗产生应答,大多数临床经过良好。     

胃肠道间质瘤的研究进展

胃肠道间质瘤是消化道内的一种间叶性肿瘤,近年来才逐渐被大家所认识。免疫组织化学研究发现,绝大多数胃肠道间质瘤特征性表达CD117。随着分子生物学技术的发展,发现肿瘤细胞的c-k it基因或血小板衍生生长因子受体α基因存在突变。外科手术是惟一有治愈可能的治疗方法,但药物伊马替尼可以治疗有些不能手术的肿瘤或已经发生转移的肿瘤。但此药物与多种因素有关,包括肿瘤细胞的基因突变类型。     

中国胃肠道间质瘤诊断治疗共识

胃肠道间质瘤(gastrointestinal stromal tumors,GIST)是胃肠道最常见的间叶源性肿瘤,免疫组织化学染色大多数呈CD117阳性.传统放疗和化疗对GIST几乎无效.酪氨酸激酶抑制剂甲磺酸伊马替尼的临床应用使GIST的治疗发生了重大的改变,为部分晚期GIST患者带来了延长生存期的疗效.同时由于对GIST基因突变认识的进一步提高,使GIST的诊断率显著提高.     

165例胃肠道间质瘤中c-kit和PDGFRA基因突变的检测和临床诊断意义

目的探讨在中国较大样本的胃肠道问质瘤（GIST）中c-kit基因和PDGFRA基因的突变状况,为进一步的生物靶向治疗提供依据。方法用免疫组织化学EnVision法、聚合酶链反应（PCR）扩增和直接测序的方法,检测165例GIST c-kit基因9、11、13和17号外显子突变以及PDGFRA基因12和18号外显子突变。结果病理组织学诊断的165例GIST病例中有155例（94％）免疫组织化学显示CD117阳性。在CD117阳性的GIST中,c-kit基因总突变率为76．1％（118／155）：分别为11号外显子67．1％（104／155）、9号外显子7．1％（11／155）、13号外显子1．3％（2／155）和17号外显子0．6％（1／155）。绝大多数为杂合性突变,少数为纯合性突变。11号外显子的突变位点多集中在5’端的经典热点,其次为3’端的框内串联重复。后者主要以核分裂象少的老年女性胃部病例多见。9号外显子突变代表一类发生在年轻男性体积较大的小肠病变。13号外显子发现一处新的突变点L641P。PDGFRA基因突变见于50％（5／10）CD117阴性病例,均为18号外显子突变,包括常见的D842V点突变和一个框内843-846处IMHD缺失伴有S847T的新突变。PDGFRA基因突变多见于发生在后腹膜／网膜的具有高度侵袭危险性的病例。结论中国GIST病例大多数存在c-kit基因和PDGFRA基因的突变,且在基因突变类型和肿瘤原发部位问有非随机的联系。除了发现几个新的突变形式外,国人的GIST似乎和西方国家有些不同的突变特点。靶向治疗需要基因突变分型的启示和指导。     

CD117阴性的胃肠道间质瘤的超微结构特点及基因突变检测

目的探讨CD117阴性的胃肠道间质瘤（GIST）的超微结构及c-kit和血小板源性生长因子受体A（PDGFRA）基因的突变情况。方法用免疫组织化学方法（EnVision法和SP法）从101例GIST中筛选到6例CD117阴性的GIST,观察了6例CD117阴性的胃肠道间质瘤的电镜变化,用PCR直接测序的方法检测6例CD117阴性的胃肠道间质瘤的c-kit基因外显子9、11、13、17和PDGFRA基因外显子12和18突变。结果电镜下观察到6例GIST的超微结构特点与卡哈尔细胞相似,通过PCR直接测序检测揭示c-kit基因9、11、13和17外显子均无突变,而3例GIST的PDGFRA有突变,其中2例D842V突变,1例R841S突变。结论PDGFRA基因的突变可能是CD117阴性的胃肠道间质瘤发生的重要分子基础。     

CD117阴性胃肠道间质瘤的临床病理及免疫组织化学研究

目的 探讨免疫组织化学在形态学典型、免疫组织化学CD117阴性胃肠道间质瘤(GIST)诊断中的意义.方法 对10例CD117阴性、形态学典型的GIST进行c-kit基因第9、11、13、17号外显子及血小板源性生长因子受体α(PDGFRA)基因第12和18号外显子的基因检测,同时所有病例均进行CD117、CD34、平滑肌肌动蛋白(SMA)、结蛋白、S-100蛋白、WT-1、DOG-1 的免疫组织化学染色(EnVision法).结果 10例中8例完成c-kit及PDGFRA基因的检测,仅1例有c-kit基因第9号外显子突变,余未发现基因突变.10例CD117阴性的病例9例CD34阳性,2例SMA局灶阳性.结蛋白和S-100蛋白均阴性.DOG1弥漫阳性者5例,1例弥漫弱阳性,2例局灶阳性,2例阴性.4例WT-1弥漫阳性,2例局灶阳性,1例有散在肿瘤细胞阳性,3例阴性.结论 对胃肠道及胃肠道外形态学典型、但CD117阴性的GIST病例,联合应用多种免疫组织化学标记有助于诊断.DOG-1和WT-1可作为补充加入到CD117阴性GIST的诊断中.     

食管间质瘤与平滑肌肿瘤对照性研究

目的 探讨食管间质瘤与平滑肌肿瘤临床病理、免疫组织化学及分子生物学特点。方法 24例食管间叶源性肿瘤用CD117、CD34等一组抗体重新进行分类,部分病例同时测定c-kit基因11外显子序列。结果 此组肿瘤分别为间质瘤3例（交界性1例、恶性2例）,年龄71、56、60岁,均为男性,瘤体直径4、8、14cm,源于固有肌层。瘤细胞梭形,上皮样多角形及印戒样,呈交叉束状、栅栏状及弥漫片状排列,免疫表型为CD117、CD34弥漫强阳性。平滑肌瘤20例,年龄30－60岁,平均41.6岁,男性12例,女性8例,15例源于固有肌层,直径0.8-10.5cm（平均4.5cm),5例源于黏膜肌层,直径为0.2-1.0cm(平均0.6cm)。平滑肌肉瘤1例,男性,61例,瘤体直径5cm,源于黏膜肌层。平滑肌（肉）瘤胞质丰富,嗜伊红,交叉束状排列,免疫表型为平滑肌肌动蛋白、肌特异性肌动蛋白、结蛋白弥漫强阳性。恶性间质瘤有c-kit基因11外显子的突变,平滑肌瘤无突变。结论 食管间叶源性肿瘤仍以平滑肌瘤多见,可发生与胃肠道间质瘤相同形态与免疫表型的间质瘤,典型平滑肌肉瘤极为罕见,食管间质瘤与平滑肌瘤具有不同的临床病理学及分子生物学特征。     

胃肠道间质瘤c-Kit及PDGFRA基因突变与临床病理特征、免疫表型及预后的关系

目的探讨胃肠道间质瘤(gastrointestinal stromal tumors,GIST)中c-Kit/PDGFRA基因突变与临床病理特征、免疫表型及预后的关系。方法采用直接测序法检测185例GIST标本中c-Kit和PDGFRA基因突变类型。结果 c-Kit基因突变中,外显子11突变最常见,以缺失突变、点突变及混合突变为主,并见3例双外显子突变。外显子9在小肠GIST中的突变率显著高于胃GIST,且均为A502-Y503串联重复突变,提示小肠GIST有独特的基因型。PDGFRA在上皮样细胞型和混合细胞型GIST中的突变率显著高于梭形细胞型GIST。c-Kit基因外显子11缺失突变的中高危GIST易出现术后复发转移,且复发转移患者中发生二次突变率较高,表现为c-Kit基因外显子13、14、17或18点突变,以13号外显子V654A最为常见。CD117和DOG1的表达与基因突变之间无相关性,不能作为预测疾病基因突变的指标。单因素分析结果显示,肿瘤直径、核分裂象、Ki-67增殖指数、危险程度分级、术后复发和转移是影响GIST预后的重要因素,术后靶向药物治疗可一定程度改善预后。c-Kit基因外显子11缺失突变和外显子9突变的GIST患者预后较差。结论 c-Kit基因9号外显子在小肠GIST中突变率较高,PDGFRA基因在上皮样细胞型和混合细胞型GIST中突变率较高。c-Kit基因外显子11缺失突变的中高危GIST易发生二次突变导致术后复发转移,外显子11缺失突变可作为GIST预后不良的独立影响因素之一。     

胃肠道间质瘤156例临床病理学特征与预后的分析

目的探讨胃肠道问质瘤（GIST）的生物学行为,分析临床病理特征对于GIST患者生存率的影响,同时检测c—kit基因11号外显子的突变,试图发现对GIST预后判断有意义的指标。方法收集解放军总医院病理科156例发生于胃与小肠的GIST,总结临床病理特征包括年龄、临床分期、肿瘤直径、核分裂象计数、坏死、风险分级等,并进行统计学分析。套式PCR扩增c—kit基因11号外显子,变性高效液相色谱法筛查,并进行DNA直接测序检测突变。结果胃GIST83例,平均年龄55．4岁,62例获得随访,17例复发或转移,5年生存率为66．5％±17．1％。小肠GIST73例,平均年龄50．6岁,43例获得随访,22例发生复发或转移,5年生存率为61．8％4-18．3％。对于胃GIST患者,年龄小于50岁（P=0．046）,临床分期晚（P=0．0001）,肿瘤直径大（P=0．0001）,核分裂象计数多（P=0．0001）,肿瘤组织出现坏死（P=0．0001）和风险分级高（P=0．004）提示生存率低。COX风险比例模型发现临床分期晚（P=0．001）、肿瘤直径大（P=0．001）、核分裂象计数多（P=0．002）、风险分级高（P=0．018）与患者预后差相关。在小肠GIST中,肿瘤组织坏死（P=0．036）、临床分期晚（P=0．010）与患者生存率低相关,其中临床分期为独立的预后提示因子。c—kit基因11号外显子突变检测发现共25例患者存在突变,胃GIST的突变率为32．0％,主要发生于50岁以上患者,小肠GIST的突变率为22．5％,主要发生于40～49岁患者。结论根据临床病理特征可以对GIST患者的预后进行判断,其中胃GIST患者可以根据临床分期、肿瘤直径、核分裂象计数、风险分级来判断预后,小肠GIST患者可依据临床分期及肿瘤组织坏死来判断预后。小肠GIST比胃GIST更易复发或转移。胃与小肠GIST基因的突变可能与患者的年龄相关。     

Epithelioid gastrointestinal stromal tumor with PDGFRA activating mutation and immunoreactivity.

The authors report a unique case of an intra-abdominal, epithelioid mesenchymal tumor that had an activating mutation of PDGFRA and a strong PDGFRA immunoreactivity but lacked both c-kit mutation and c-kit protein (CD117) expression. IHC study showed that the tumor cells were diffusely and strongly positive for PDGFRA, vimentin, CD34, and Bcl-2 but completely negative for CD117 as well as for muscle, epithelial, endothelial, endocrine, mesothelial, neural, and melanocytic cell markers. Molecular study revealed a mutation at the juxtamembrane domain of exon 12 in PDGFRA gene with GTC to GAC transition at codon 561 (V561D), as shown in the previous mutational studies on gastrointestinal stromal tumor (GIST). This case likely represents an example of GIST with PDGFRA activating mutation and PDGFRA immunoreactivity without CD117 positivity, which has not been documented in the literature. STI 571 (imatinib mesylate [Gleevec]) might be an effective therapy in this case, since Gleevec targets both PDGFRA and c-kit oncoproteins.     

Mutations in Exon 11 of c-Kit Occur Preferentially in Malignant versus Benign Gastrointestinal Stromal Tumors and Do Not Occur in Leiomyomas or Leiomyosarcomas

Gastrointestinal stromal tumors (GISTs) comprise the largest subset of mesenchymal tumors of the gastrointestinal tract. These neoplasms differ histologically and immunohistochemically from typical leiomyomas and leiomyosarcomas. Most GISTs express CD34 and CD117 (c-kit protein) but not desmin. Recently, gain-of-function mutations of c-kit proto-oncogene have been shown in five solitary GISTs and in tumors and leukocytes from a family with multiple GISTs. An in-frame deletion or a point mutation in exon 11 of c-kit was detected in these cases. Stable transfection of the mutant c-kit complementary DNA was also shown to induce malignant transformation of murine lymphoid cells, suggesting that the c-kit mutations contribute to tumor development. In this study, we evaluated 43 GISTs and 14 smooth muscle tumors for mutations in the exon 11 of c-kit by a PCR-assay. Half of the malignant GISTs (12/24) and only one benign GIST (1/19) revealed mutant bands. No mutant bands were found in 3 leiomyomas and 11 leiomyosarcomas. Sequence analysis confirmed the presence of an in-frame deletion of 3–21 bp in all 13 GISTs with mutant bands. Wild-type bands from 8 malignant and 11 benign GISTs and 7 smooth muscle tumors without mutant bands were cloned and sequenced. Additional mutations were found in 3 malignant and 2 benign GISTs. There were no mutations in 3 leiomyomas and 4 leiomyosarcomas. The mutation status of exon 11 did not correlate with immunohistochemically detectable expression of the CD117, as virtually all GISTs with or without such mutations showed CD117 immunoreactivity. The c-kit mutations occur preferentially in malignant GISTs and might be a clinically useful adjunct marker in the evaluation of GISTs. The conservation of the c-kit mutation pattern, observed in consecutive lesions from the same patients, suggests that these mutations might be useful tumor markers in monitoring recurrence or minimal residual disease.     

Gastrointestinal stromal tumors in children and young adults: a clinicopathologic and molecular genetic study of 22 Korean cases

Studies on gastrointestinal stromal tumors (GISTs) in young patients are limited due to their rarity, and none have been conducted in Asian populations. GISTs from patients under the age of 30 were retrospectively reviewed and were analyzed for clinicopathologic features, immunohistochemistry for SDHB (succinate dehydrogenase subunit B), and mutations for exon 9, 11, 13, and 17 of KIT gene and exon 12, 14, and 18 of PDGFRA gene. We found two pediatric (<18 years old) and 20 young adult (18–30 years old) GIST cases. Pediatric GISTs occurred in two girls, both as solitary masses with epithelioid histology in the stomach. Both GISTs were wild type for KIT and PDGFRA genes, were negative for SDHB, and there was no recurrence during follow‐up. Of the 20 GISTs in young adults, 12 (60%) were from extra‐gastric locations (six duodenum, five jejunum, and one esophagus), and 16 (80%) showed a spindle cell morphology. Mutations of KIT or PDGFRA genes were identified in 14 (78%) of the 18 cases. One patient with multiple gastric GISTs with perigastric lymph node metastases at presentation developed multiple distant metastases and died of the disease 7.3 years after diagnosis. Of the 19 R0‐resected young adult patients, one patient with small intestinal GIST harboring KIT exon 11 deletion mutation developed recurrence and showed partial responses for imatinib. In summary, compared with pediatric GIST cases, young adult GISTs are heterogeneous and share the characteristics of both pediatric and adult GISTs. When a mesenchymal tumor is clinically suspected in the small intestine of young adults, a GIST should be included in the differential diagnoses. Further mutation studies and extensive treatments are recommended for these cases.     

Analysis of clinicopathologic features and gene mutations in gastrointestinal stromal tumor: a series of 58 patients

Background: In gastrointestinal stromal tumor (GIST), mutually exclusive gain-of-function mutations of c-kit and PDGFRα are associated with different mutation-dependent clinical features. We analyzed clinico-pathologic features and genotypes of GIST among patients in China. Methods: Adult patients with GIST in the stomach, small intestine, colorectum, or extra-gastrointestinal areas were enrolled in this study. These patients had been subjected to surgical resection without imatinib (Gleevec) treatment at the Cancer Hospital, Chinese Academy of Medical Sciences from January 2009 to January 2019. Samples were obtained for histopathologic examination. Mutations in c-kit and PDGFRα genes were analyzed by PCR and next generation sequencing (NGS). Clinico-pathologic characteristics of each gene were also analyzed. Results: A total of 58 GIST patients was enrolled in this study. In terms of genotypes, there were 51 (87.9%) c-kit mutations, 5 (8.6%) PDGFRα mutations, and 2 (3.4%) wild-type mutations. In terms of cell types, there were 40 cases (69.0%) with spindle cell type, 3 cases (5.2%) with epithelioid cell type and 3 cases (5.2%) with mixed spindle-epithelioid cell type. Among the 4 mutant forms of c-kit exon-11, the most common were point mutations in 16 cases (38.1%), deletion mutations in 13 cases (31.0%), insertion mutations in 4 cases (9.5%), and mixed mutations in 9 cases (21.4%). Based on risk grade classification of the National Institutes of Health (NIH), 3 cases (5.2%) were very-low risk, 9 cases (15.5%) were low risk, 19 cases (32.8%) were medium risk, and 23 cases (39.7%) were high risk. Significant differences in cell type were identified across different gene types (P = 0.022). Similarly, differences in tumor risk were found among different mutant forms of c-kit gene exon-11 (P = 0.039). Conclusion: With c-kit mutations, spindle cell type prevalence exceeded that of the epithelioid cell type and mixed spindle-epithelioid cell type. Spindle and mixed spindle-epithelioid cell types were the most prevalent in the category of PDGFRα mutations. In wild type cases, spindle and epithelioid cell types were the most common. A high risk of deletion and mixed mutations, and intermediate risk of point and insertion mutations were observed in c-kit exon-11 mutation type.     

Pathology of gastrointestinal stromal tumors

Gastrointestinal stromal tumors (GIST) are the most common mesenchymal tumors in the gastrointestinal tract. It was found that most GIST expressed KIT, a receptor tyrosine kinase encoded by protooncogene c-kit. In normal gastrointestinal wall, KIT is expressed by interstitial cells of Cajal (ICC), which are a pacemaker for autonomous gastrointestinal movement. Because both GIST and ICC are double-positive for KIT and CD34, and because familial and multiple GIST appear to develop from diffuse hyperplasia of ICC, GIST are considered to originate from ICC or their precursor cells. It was also found that approximately 90% of the sporadic GIST have somatic gain-of-function mutations of the c-kit gene, and that the patients with familial and multiple GIST have germline gain-of-function mutations of the c-kit gene. These facts strongly suggest that the c-kit gene mutations are a cause of GIST. Approximately half of the sporadic GIST without c-kit gene mutations were demonstrated to have gain-of-function mutations in platelet-derived growth factor receptor-alpha (PDGFRA) gene that encodes another receptor tyrosine kinase. Because KIT is immunohistochemically negative in a minority of GIST, especially in PDGFRA gene mutation-harboring GIST, mutational analyses of c-kit and PDGFRA genes may be required to diagnose such GIST definitely. Imatinib mesylate was developed as a selective tyrosine kinase inhibitor. It inhibits constitutive activation of mutated KIT and PDGFRA, and is now being used for KIT-positive metastatic or unresectable GIST as a molecular target drug. Confirmation of KIT expression by immunohistochemistry is necessary for application of the drug. The effect of imatinib mesylate is different in various types of c-kit and PDGFRA gene mutations, and the secondary resistance against imatinib mesylate is often acquired by the second mutation of the identical genes. Mutational analyses of c-kit and PDGFRA genes are also significant for prediction of effectiveness of drugs including newly developed agents.     

A lethal mesenteric gastrointestinal stromal tumor: a case report and review of the literature

Gastrointestinal stromal tumors (GISTs) arising from the mesentery are very rare. Here, we report a 53-year old man with a huge lobulated cystic-solid tumor in the left lower quadrant of the abdomen, which had been proved clinically and radiographically. Surgical resection showed that the large mass was noted at the mesentery of small intestine. Grossly, the largest diameter of the mass were measured up to 23 cm, and poorly circumscribed. Histological observation demonstrated it as a malignant GIST with positive CD117 (c-kit) staining. Mitotic figures were frequently observed up to 110 per 50 high power fields. Soon after the surgery, the patient experienced local recurrence with quick growth. The patient received targeted therapy (imatinib mesylate) but had no ideal effect. The patient died nine months after the operation because of rapid disease progression.