甲状腺呈胸腺样分化癌病理观察

目的 探讨甲状腺呈胸腺样分化癌（CASTLE）的病理特征、诊断及鉴别诊断。方法 分析2例甲状腺CASTLE的临床表现,对标本进行病理学和免疫组织化学（EnVision^TM法）染色观察。结果 大体检查肿瘤呈质硬灰白色略旱分叶状肿块。光镜下肿瘤组织呈轮廓清楚的巢状,巢间可见丰富的促结缔组织增生性间质。肿瘤细胞呈多边形或梭形,胞质轻度嗜酸,核卵圆形,呈空泡状,有清楚的小核仁,核异型性较轻,核分裂象1～2／10HPF。免疫组织化学肿瘤细胞表达CD5及CD117。结论 CASTLE是一种少见的甲状腺恶性肿瘤,有一定的病理学特征。应与甲状腺未分化癌、甲状腺鳞状细胞癌、转移性淋巴上皮瘤样癌及滤泡树突细胞肉瘤等鉴别。免疫组织化学CD5等标记对鉴别诊断有帮助。     

嗅神经母细胞瘤的病理形态特点及其诊断和鉴别诊断

目的总结嗅神经母细胞瘤(ONB)的病理形态学特点,评价各种方法的诊断价值,并结合其他辅助检查确定与鼻腔鼻窦其他小细胞恶性肿瘤的鉴别诊断依据,提高ONB的病理诊断水平。方法收集ONB34例,鼻腔鼻窦的横纹肌肉瘤(RMS)11例、淋巴瘤76例。对病例基本情况进行了统计,对其活检标本进行了如下处理和观察：(1)常规HE染色、光镜观察。(2)免疫组织化学染色(两步聚合物检测PV6000法)及观察。ONB病例标记了神经元特异性烯醇化酶(NSE),嗜铬素A(CgA),S-100蛋白,细胞角蛋白(AEl／AE3),白细胞共同抗原(LCA),结蛋白,横纹肌肌动蛋白(S-actin)。RMS病例标记了结蛋白、肌球蛋白、S-actin及NSE、CgA及LCA。淋巴瘤病例标记了LCA,T细胞标记物(CD45RO),B细胞标记物(CD20)及NK细胞标记物(CD56)。另对10例NK／T细胞型淋巴瘤、9例B细胞型淋巴瘤标记了NSE、CgA、结蛋白及S-actin。(3)透射电镜观察。对ONB、RMS及淋巴瘤各4例进行了透射电镜观察。结果ONB与RMS及淋巴瘤发病均主要为中青年,临床局部表现有相似之处。ONB的形态学特征是：上皮团巢,血管袢网隔,小圆小梭形细胞及细胞核,腺样及鳞状上皮样细胞,菊形团,神经丝束,深染的细胞核,少、粉染或透明的胞质。免疫组织化学标记结果：NSE及CgA在小细胞100%表达,但在不同病例表达程度不同,S-100蛋白在神经丝束处100％表达,AEl／AE3在鳞状及腺样分化的细胞100％表达,LCA、结蛋白及S-actin均阴性。电镜下可见神经微丝及胞质内少数神经内分泌颗粒。RMS及淋巴瘤光镜下虽与ONB有相似之处,但也各有其形态特点,且免疫组织化学标记结果及电镜下超微结构特征也完全不同。结论ONB在光镜、免疫组织化学标记及电镜下有与RMS和淋巴瘤不同的特征性的形态变化特点,根据组织形态学特点即能够确立ONB的病理诊断,免疫组织化学标记可以进一步印证诊断,并在与RMS和淋巴瘤的鉴别诊断中起重要作用,电镜观察可作为ONB诊断及鉴别诊断中一项非必备的辅助检查。     

胃肠道间质瘤临床病理及免疫组织化学特征

目的 探讨胃肠道间质瘤的免疫组织化学特征，为其诊断及鉴别诊断和预后提供依据。方法 对消化道内169例间叶源性肿瘤进行免疫组织化学标记和形态学观察，确诊113例胃肠道间质瘤。结果 肿瘤多见于胃，临床常见首发症状为消化道出血及腹部包块。瘤细胞主要有梭形细胞及上皮样细胞两种形态，梭形细胞型70例，上皮样细胞型10例，混合细胞型33例。相对良性33例，交界性26例，恶性54例。免疫表型：CD117阳性112例，CD34阳性102例，阳性率分别为99．1％及90．2％，且呈弥漫强阳性表达。结论 胃肠道间质瘤是消化道最常见间叶源性肿瘤，以胃内多见；主要有2种细胞形态和3种组合形式；确诊需要依靠CD117、CD34等免疫标记物配合。     

肾脏上皮样血管平滑肌脂肪瘤的病理观察

目的对肾脏上皮样血管平滑肌脂肪瘤（epithelioid agiomyolipoma,EAML）的病理诊断、鉴别诊断和预后进行分析。方法2例肾脏EAML（其中1例为复发病例）,复习其临床资料,病理学检查包括常规病理学、免疫组织化学和超微结构,并进行随访。结果光镜下肿瘤均主要由具有多形性和不典型性的上皮样细胞组成,部分区域有明显的血管周上皮样排列;可见出血和坏死;并可见静脉内瘤栓;淋巴结内可见上皮样肿瘤细胞累及。免疫组织化学肿瘤细胞（包括淋巴结内肿瘤）HMB45、平滑肌肌动蛋白（SMA）、神经元特异性烯醇化酶（NSE）和波形蛋白弥漫阳性;S-100、melanpan和CD68散在阳性;而上皮细胞膜抗原（EMA）、AE1／AE3、CK7、CD117、肌肉特异性肌动蛋白（MSA）、结蛋白、白细胞共同抗原（LCA）、CD20、CIM5RO、CD30、CD15、嗜铬素（CgA）、突触素（Syn）、bcl-2、雌孕激素受体（ER、PR）和p53均为阴性。电镜检查可见一些肿瘤细胞内有黑色素小体样的致密颗粒、肌丝、密体,肿瘤细胞外可见不连续的基膜。2例患者手术后10个月状态良好,无肿瘤局部复发和转移征象。结论血管周上皮样排列、寻找经典血管平滑肌脂肪瘤的结构和肿瘤细胞表达HMIM5和SMA对于诊断和鉴别诊断至关重要。而细胞的不典型性、出血坏死和核分裂象可能只表明肿瘤的恶性潜能：淋巴结受累、肾静脉瘤栓不是恶性的诊断依据：只有远处转移才是恶性的证据。     

外阴肌上皮癌1例临床病理分析

目的观察外阴肌上皮肿瘤的形态学改变,探讨其临床病理特征、超微病理和鉴别诊断。方法对1例发生于外阴的肌上皮癌进行光镜、免疫组化、电镜观察,并复习相关文献。结果光镜检查:肿瘤细胞呈3种生长模式,部分细胞呈上皮样、条索状或实性片状排列,部分细胞呈梭形、席纹状排列,且背景黏液样变,可见散在核分裂象,未见坏死。免疫表型:肿瘤细胞Pax-8、ER、EMA均强阳性,Caldesmon、S-100部分阳性。电镜检查:肿瘤细胞大多呈梭形,核形不规则,染色质丰富,核仁明显,部分细胞胞质内可见多少不等的细丝状物质,有的聚集形成密体样结构。结论形态学不典型的肌上皮肿瘤,尤其是发生于少见部位,在免疫组化诊断有困难时,结合电镜下肿瘤细胞的超微结构,对该肿瘤的诊断有重要的提示作用。     

肝血管平滑肌脂肪瘤的形态学变异和免疫组织化学特征

目的探讨肝血管平滑肌脂肪瘤(AML)的临床病理学和免疫组织化学特征、诊断和鉴别诊断要点。方法对44例手术切除肝AML的临床病理学特征进行详细分析,并对10种免疫组织化学标志物的表达状况进行检测。结果肿瘤由平滑肌细胞、厚壁血管及脂肪3种成分混合组成,根据瘤组织成分的比例可分为经典型(13例)、肌细胞为主型(25例)、脂肪细胞为主型(4例)、血管瘤型(2例);肌细胞可呈多种形态变异,主要有上皮样细胞型、中间细胞型、梭形细胞型、嗜酸细胞型和多形细胞型5种;8例可见髓外造血。免疫组织化学染色显示,瘤细胞呈HMB45(44／44,100％)、SMA(38／38,100％)和CD117(30／38,78．9％)阳性。结论肝AML形态学变异较大,容易造成误诊,HMB45阳性瘤细胞具有重要的诊断意义,CD117可作为诊断AML的一个有用的辅助标记物。     

表达CD10的非特殊类型乳腺肉瘤3例报道并文献复习

目的 探讨表达CD10的非特殊类型乳腺肉瘤的病理形态学、免疫表型特点以及诊断与鉴别诊断.方法 应用光镜观察、免疫组织化学染色等方法对3例表达CD10的非特殊类型乳腺肉瘤进行分析,并复习文献.结果 肿瘤境界清楚,主要由梭形-胖梭形细胞组成,与数量不等的胶原束交错呈流水样或席纹状排列,胞质红染或空淡,核梭形,染色体粗颗粒状,部分有细小核仁.1例伴大片坏死,1例伴出血及破骨细胞样巨细胞反应.免疫组化染色3例均CD10(+),2例EGFR(+),上皮标记物cK(AEl/AE3)、CK5/6、CK7、CKl4、CK8/18、3413E12及其他肌上皮标记物SMA、p63、ealponin等则(一).结论 表达CD10的非特殊类型乳腺肉瘤是一种罕见而具有独特免疫表型的肉瘤,诊断时须借助免疫组化与化生性癌、叶状肿瘤等鉴别.     

十二指肠间质瘤的临床病理及免疫组织化学研究

目的：研究十二指肠间质瘤临床病理学特点和免疫组织化学表达特征。方法：对18例十二指肠间质瘤作了临床病理形态学观察和免疫组织化学分析。结果：18例肿瘤良性3例，恶性15例，基本细胞类型为梭形细胞，1例肿瘤细胞外基质可见丝团样纤维。免疫表型特征为：C-kit18例（100％）胞质强阳性表达；CD347例（38．9％）阳性；S－100蛋白9例（50％）呈局灶性或散在阳性，其中包括2例良性，7例恶性；SMA仅1例阳性。结论：十二指肠间质瘤恶性发生率较高，细胞类型以梭形细胞为主。C-kit因其敏感性高、特异性强成为十二指肠间质瘤的可靠标记物，但不能作为良恶性判断指标，CD34阳性表达率低；神经化生率较高平滑肌方向分化率低。     

伴有神经内分泌分化的乳腺梭形细胞癌

目的探讨乳腺伴有神经内分泌分化的梭形细胞癌的病理形态学和免疫表型特点及鉴别诊断。方法复习2500例乳腺癌切片,找出以梭形细胞占主要优势（〉80％）的癌5例,其中2例梭形细胞型导管内癌和3例梭形细胞型浸润癌。采用HE、阿辛蓝（AB）／PAS和网织染色,以及用癌胚抗原（CEA）、上皮膜抗原（EMA）、细胞角蛋白（CK7、3413E12、AE1／AE3）、神经元特异性烯醇化酶（NSE）、突触素、嗜铬蛋白（cg）A、Lue-7、波形蛋白,S-100、平滑肌肌动蛋白（SMA）、calponin、雌激素受体（ER）、孕激素受体（PR）、c—erbB-2、E-钙黏素、Ki-67、p53抗体进行免疫组织化学观察。其中4例有随访信息。结果患者平均年龄在68岁。镜下：5例癌细胞形态主要为长梭形的上皮样细胞,3例有少数胞质内空泡状细胞,4例可见散在AB阳性细胞。免疫组织化学5例均表达AE1／AE3、EMA、CEA、E-钙黏素和突触素,CK7有4例表达,NSE阳性3例,CgA和Lue7阳性2例,ER阳性4例,PR阳性2例,1例表达c-erbB-2,1例有灶状波形蛋白阳性。免疫组织化学结果显示2例梭形细胞型导管内癌和1例梭形细胞型浸润性癌是梭形细胞型的神经内分泌癌,另外2例梭形细胞型浸润性癌是伴有神经内分泌分化的化生性癌。随访3例存活（24～58个月）,1例27个月内死亡。结论上皮样梭形细胞和细胞内黏液的出现是乳腺伴有神经内分泌分化癌的一个形态学特点。梭形细胞神经内分泌型导管内癌需要和普通导管增生及导管内乳头状瘤鉴别。梭形细胞型的神经内分泌癌和伴神经内分泌分化的梭形细胞浸润性癌需要与梭形细胞肌上皮肿瘤、恶性黑色素瘤及某些软组织肿瘤鉴别。     

中枢神经系统非典型畸胎样/横纹肌样瘤临床病理及免疫表型特征

目的 探讨中枢神经系统非典型畸胎样／横纹肌样瘤的临床病理特征、诊断及鉴别诊断。方法 对2例非典型畸胎样／横纹肌样瘤应用光镜行HE、网状纤维染色及免疫组织化学染色观察,并结合文献复习。结果 非典型畸胎样／横纹肌样瘤具有特征性的横纹肌样细胞,伴有不同程度的原始神经外胚叶、上皮和间质分化。肿瘤组织富于网状纤维,免疫组织化学标记示波形蛋白、CD99、上皮细胞膜抗原、细胞角蛋白、胶质纤维酸性蛋白、S-100蛋白、神经微丝蛋白、结蛋白、平滑肌肌动蛋白阳性,突触素、肌调节蛋白、胎盘碱性磷酸酶和HMB45阴性。结论 非典型畸胎样／横纹肌样瘤是中枢神经系统一种罕见的高度恶性肿瘤,好发于儿童,偶见于成人,呈异源性组织学和免疫组织化学表型。其诊断需与脑内其他多形性肿瘤鉴别。     

74例胃肠道间质瘤临床病理与生物学行为评价

目的　探讨在胃肠道间质瘤(GIST)的病理诊断和预后分析上采用一种简单实用且重复性好的病理学“标准”,以利于GIST的日常病理诊断和生物学行为评价及指导治疗,并对Fletcher等推荐的GIST生物学行为评价表进行评估。方法　85例消化道间叶组织肿瘤,复习其病理形态学并应用CD117、CD34、平滑肌肌动蛋白(SMA)、结蛋白、S 100等进行免疫组织化学标记,结合 31例随访资料进行分析。结果　85例消化道间叶组织肿瘤中,GIST74例,平滑肌瘤和交界性平滑肌瘤 8例(食管),平滑肌肉瘤 1例(直肠 ),神经鞘瘤 1例 (胃 ),恶性纤维组织细胞瘤 1例 (肠系膜 )。74例GIST中,发生在胃和小肠的分别为 34例和 30例,占 86. 5%,食管 3例,胃肠道外(肠系膜、网膜、后腹膜)7例。年龄 23~80岁,平均 52 5岁, 40岁以上者占 85%,男性 45例,女性 29例。镜下观察:梭型细胞型 48例,上皮样细胞型 10例,混合细胞型 16例。瘤细胞呈长、短梭形和圆形,胞质丰富弱嗜酸性,排列呈旋涡状、栅栏状或弥漫巢状。免疫组织化学: 85例消化道间叶组织肿瘤波形蛋白均阳性,其中 74例表达CD117,诊断为GIST,表达形式有弥漫胞膜 /胞质强阳性、散在阳性、胞质点状着色等,其中 54例同时表达CD34 (阳性率 72. 9% ), 25例表达SMA, 5例表达结蛋白, 5例表达S 100蛋白。在 85例     

Gastrointestinal spindle cell tumours of the dog: histological and immunohistochemical study

To assess the relevance of spindle cell tumours in the canine gastrointestinal (GI) tract and to classify them, a retrospective study was carried out on haematoxylin and eosin-stained sections from formalin-fixed paraffin wax-embedded samples of 105 primary GI tumours. Seventeen out of 105 (16%) GI tumours were mesenchymal, 48% were epithelial and 36% were round cell tumours. Spindle cell tumours were stained by Masson trichrome, Orcein-Van Gieson and labelled immunohistochemically (vimentin, desmin, smooth muscle actin, protein S100, glial fibrillar acid protein, CD117 and MIB-1) and the histological grade, mitotic index, nuclear size and cellular density were also assessed. The 17 gastrointestinal mesenchymal tumours were classified as 10 leiomyomas (10/10 positive for desmin and smooth muscle actin; 6/10 positive for vimentin) 2 leiomyosarcomas (2/2 positive for desmin, smooth muscle actin and vimentin) and 5 gastrointestinal stromal tumours (GISTs) (5/5 positive for CD117 and vimentin; 3/5 positive for smooth muscle actin). Canine GISTs appeared as densely packed spindle cell tumours, with a diffuse, strong, cytoplasmic immunopositivity for c-kit protein (CD117). GISTs, defined as CD117-positive spindle cell or epithelioid or pleomorphic neoplasms that presumably derive from interstitial cells of Cajal, are reported in recent medical studies as the most common mesenchymal tumours of the GI tract. Our data suggest that GISTs represent a significant portion of canine GI spindle cell tumours, which can be definitely distinguished from leiomyosarcomas only by their expression of CD117.     

Histopathological and immunohistochemical features of gastrointestinal stromal tumors

Gastrointestinal stromal tumors (GISTs) are the most frequent mesenchymal tumors of the gastrointestinal tract. Major advances in their definition and classification and the understanding of their molecular mechanisms have recently been made. These advances have become a model of targeted therapy in oncology. The diagnosis of GISTs relies on histological arguments - proliferation of spindle cells, seldom of epithelioid cells or both spindle and epithelioid cells - and on immunohistochemical arguments - expression of CD117 usually associated with CD34 expression. The evaluation of the prognosis is essential and based on a simple algorithm using two prognostic parameters, tumor size and mitotic index. The aim of this paper is a complex histopathological assessment, using both classic and modern (immunohistochemistry) techniques, of the GISTs comprised in the study. GISTs occur mainly in older adults (median age 60-69 years), anywhere along the gastrointestinal tract but also retroperitoneal. Most of them were nodular (75%), tumor necrosis and mucosal ulceration being the most frequent encountered secondary alterations; these modifications proved to be significantly correlated with large tumor size and high malignancy. Immunohistochemical evaluation revealed that 77 (97%) cases of GISTs presented a positive reaction for CD117, 50 (63%) cases were positive for CD34, 19 (24%) were positive for SMA and only 10 (13%) were positive for S100. Immunohistochemical evaluation remains an important tool of pathology in the diagnosis of GISTs, in the differential diagnosis from other gastrointestinal mesenchymal tumors and represents the gold standard for diagnosis of these tumors and an eligibility criterion for imatinib therapy.     

77例胃肠道间质肿瘤的病理形态学及免疫组化研究

目的：研究胃肠道间质瘤（GIST）的病理形态及免疫组化特点,方法：应用光镜观察77例GIST的形态特征,用免疫组化S－P法检测c-kit(CD117),CD34,vimentin,SMA及S－100蛋白在GIST中的表达情况。结果：GIST的瘤细胞较经典的平滑肌瘤更丰富,胞质嗜酸较弱,瘤细胞为酸形或上皮样,或酸形与上皮样细胞混合存在,胞质内常见空泡形成;排列成交织刺状、弥散片状、栅栏状或轮辐状、较为特征的是细胞团巢形成。常见间质或见管壁玻变。原发于肠系膜者恶性潜力较高。CD117和CD34的阳性率分别为90％和92％,结论：胃肠道间质肿瘤有较为特独的组织学形态,CD117和CD34联合使用可协助鉴别诊断。     

Clinicopathologic study of 275 cases of gastrointestinal stromal tumors: the experience at 3 large medical centers in Mexico

It is important to distinguish gastrointestinal (GI) stromal tumors (GISTs) from other GI mesenchymal tumors (GIMTs) because of the availability of molecular-targeted therapy for GISTs. The aim of the study was to reclassify GIMTs and to determine the clinicopathologic features of GISTs in Mexico. Cases of GIMT identified from the database of 3 large diagnostic centers in Mexico between 1995 and 2004 were reclassified according to current criteria. Hematoxylin and eosin-stained sections and clinical histories were reviewed, and immunohistochemistry was performed using anti-CD117, CD34, smooth muscle actin, and S-100 protein. A total of 275 GISTs were identified. The tumors were located in the stomach (40%), small intestine (35%), colorectum (12%), abdominal cavity (11%), and esophagus (2%). There were equal numbers of men and women with a mean age at diagnosis of 61 years. The tumors ranged in size from 3.5 to 34 cm (mean, 9.1 cm); 95 tumors (34%) were larger than 10 cm. Colorectal and omental tumors were the largest. The cell types included pure spindle (68%), pure epithelioid (16%), and mixed epithelioid/spindle (14%). Whereas 17.8% of tumors were regarded as low risk, 43% of tumors were in the high-risk category. CD117 positivity was detected in most of the tumors (96%). In addition to CD117, 255 cases (92%) were positive for CD34, 82 cases (32%) were positive for smooth muscle actin, and 13 cases (4.7%) were positive for desmin. Gastrointestinal stromal tumors in Mexico have the same clinicopathologic and immunohistochemical features as those reported in other countries. It is not always easy to distinguish GISTs from other soft tissue lesions. The diagnosis can be difficult even for experienced pathologists.     

Immunohistochemical spectrum of GISTs at different sites and their differential diagnosis with a reference to CD117 (KIT).

Gastrointestinal (GI) stromal tumor (GIST) is the designation for the major subset of GI mesenchymal tumors and encompasses most tumors previously classified as GI smooth muscle tumors. Although GISTs typically express CD117 (KIT), often express CD34, and sometimes express alpha-smooth muscle actin (SMA), the relative frequency of these markers has not been characterized in large series of GISTs of different sites, and the CD117 expression has not been fully characterized in intra-abdominal tumors. In this study, we immunohistochemically analyzed 292 GISTs throughout the GI tract, including omentum and mesentery, and compared the immunoreactivities with 211 other tumors that may enter in the differential diagnosis. GISTs were defined in this study as CD117-positive primary spindied or epithelioid mesenchymal tumors of the GI tract, omentum, or mesentery. The CD34 positivity of GISTs varied from 47% in small bowel to 96 to 100% in rectum and esophagus, whereas SMA expression showed the opposite patterns and was most frequent in the GISTs of small bowel (47%) and rarest in the GISTs of rectum and esophagus (10-13%). Desmin was seen only occasionally. S100 positivity was rare but was seen most frequently in small intestinal GISTs (15%). True leiomyomas from esophagus, muscularis mucosae of colorectum, and pericolic leiomyomas similar to uterine leiomyomas were negative for CD117 and CD34 and positive for SMA and desmin (46 of 46). Inflammatory fibroid polyps of stomach and small intestine were negative for CD117 but were often positive for CD34 (6 of 8) and variable for SMA (3 of 8). Inflammatory myofibroblastic tumors involving gastric or colonic wall were negative for CD117 but some showed CD117-positive endothelia. GI schwannomas were all negative for CD117 and positive for S100 protein (11 of 11). Extremely focal CD117 positivity was seen in the neoplastic cells of some retroperitoneal leiomyosarcomas and liposarcomas. Among other CD117-positive tumors were intestinal metastatic melanomas (8 of 11) and extraskeletal Ewing's sarcomas (5 of 11), two of which were abdominal. In conclusion, strong CD117 expression defines most primary GI mesenchymal tumors as GISTs, which show different patterns for CD34 and SMA in various parts of the GI tract. Some unrelated CD117-positive tumors (melanomas, Ewing's sarcomas) should not be confused with GISTs.     

Differential diagnosis of gastrointestinal stromal tumor and other spindle cell tumors in the gastrointestinal tract based on immunohistochemical analysis

To confirm the usefulness of an immunohistochemical panel of antibodies for KIT (c-kit/CD117), CD34, desmin, smooth-muscle actin (SMA), h-caldesmon (HCD), S-100 protein, neuron-specific enolase (NSE), and beta-catenin, 297 mesenchymal and peripheral nerve-sheath tumors of the gastrointestinal tract and intra-abdominal locations including 211 gastrointestinal stromal tumors (GISTs), 12 leiomyomas, 18 leiomyosarcomas, 17 solitary fibrous tumors (SFTs), 14 schwannomas, and 25 desmoid-type fibromatoses (DTFs) were analyzed immunohistochemically. Consistent (100%) immunoreactivity for KIT, CD34, desmin and S-100, and nuclear accumulation of beta-catenin were detected in GISTs, SFTs, smooth-muscle tumors, schwannomas, and DTFs, respectively. Immunoreactivity for SMA, HCD, and NSE was observed in a wide range of these tumors. In addition, 418 bone and soft tissue tumors were enrolled in this study for KIT immunostaining. As a result, a limited number of these tumors were KIT positive, including synovial sarcoma that showed morphological similarity to GISTs. These findings suggest that KIT, CD34, desmin, S-100, and beta-catenin are key markers for clinical diagnosis of GISTs and other spindle cell tumors that may involve the gastrointestinal tract, whereas SMA, HCD, and NSE have only limited value.     

Gastrointestinal stromal tumor (GIST) in southern Taiwan: a clinicopathologic study of 93 resected cases

The purpose of this study was to determine the clinicopathologic features of gastrointestinal stromal tumor (GIST) in southern Taiwan. The pathology files from a medical center in southern Taiwan (1993 to 2003) were searched for primary mesenchymal tumors of the gastrointestinal tract. Hematoxylin/eosin sections and history were reviewed, and immunohistochemistry was performed using anti-CD 117, CD34, smooth muscle actin (SMA), and S-100 protein. Only primary resected GISTs were included in this study. Univariate and multivariate analyses were carried out using the T-test to evaluate the significance of primary tumor size and mitotic activity for the prediction of recurrence and metastasis. A total of 121 surgically resected primary mesenchymal tumors were identified, and 93 of these were GISTs. These 93 patients showed a slight female predominance (male: female = 1:1.2). The clinical presentations were variable and site-dependent. The most common tumor locations were the stomach (57%) and the small intestine (39%). Microscopically, 88 tumors (95%) were composed of spindle cells, the remaining five (5%) consisted of mixed epithelioid and spindle cells. No pure epithelioid type GIST was found. In addition to CD117, 66 cases (71%) were positive for CD34, 23 cases (25%) were positive for SMA, and 19 cases (21%) were positive for S-100. In a mean follow-up time of 27.3 months (median: 26 months), 19 cases (20.6%) were clinically malignant and mainly manifested as liver metastases (seven cases, 37% of malignant GISTs). Univariate analysis revealed that both primary tumor size and mitotic activity were significantly increased in the group affected by recurrence and/or metastasis (p = 0.001 and 0.035, respectively). Compared to GISTs in the western countries, those in southern Taiwan are characterized by a slight female predominance, a relatively higher frequency of small intestinal localization, a higher rate of S-100 protein expression, and a less aggressive behavior. Tumor size and mitotic activity were useful predictors of malignancy.     

胃肠、泌尿、会阴部间质瘤临床病理及免疫组织化学分析

目的 探讨胃肠道间质瘤(GIST)与胃肠道外GIST型间质瘤的组织学起源与病理特征。方法 对46例胃肠道及13例泌尿道、会阴部原诊断平滑肌瘤、平滑肌肉瘤、许旺瘤的病例作回顾性研究,观察其病理特点,应用免疫组织化学方法观察4种抗体(CD117、CD34、平滑肌肌动蛋白、S—100)的表达,对发生于不同部位的间质瘤进行对比分析。结果 45例为GIST组,CD117阳性表达率为93．3％,CD34阳性率88．9％;12例为胃肠道外GIST型间质瘤组,CDll7阳性表达率为83．3％,CD34阳性率75．0％;2例(其中1例为胃肠道)平滑肌瘤组,CDll7和CD34均为阴性,平滑肌肌动蛋白瘤细胞呈弥漫性强阳性表达。结论 CDll7和CD34标记阳性是确诊间质瘤最具有诊断价值的依据。推测GIST和胃肠道外GIST型间质瘤均系起源于一种非定向分化的、原始间充质干细胞。     

Gastrointestinal stromal tumor: consistent CD117 immunostaining for diagnosis,and prognostic classification based on tumor size and MIB-1 grade

Gain-of-function c-kit gene mutations and immunoreactivity of the c-kit protein CD117 in many gastrointestinal stromal tumors (GISTs) seem to support the idea that GISTs form a biologically distinct entity. In this study, the clinicopathologic features of 171 cases of GIST at a single institution were investigated for accurate diagnosis, and their relative risk for mortality was estimated by multivariate analysis. A GIST was defined diagnostically as a mesenchymal spindle or epithelioid cell lesion arising in the wall of the gastrointestinal tract with consistent immunoreactivity for CD117. The 171 patients with GISTs comprised 96 males (56.1%) and 75 females (43.9%), with a mean age of 59.4 years. One hundred and forty-five tumors (84.8%) occurred in the stomach, 18 (10.5%) in the small intestine, 6 (3.5%) in the rectum, and 2 (1.2%) in the esophagus. The median tumor size was 4.5 cm (range, 1.2 to 38 cm). Spindle-cell GISTs were present in 132 cases (77.2%); mixed GISTs, in 25 cases (14.6%); and epithelioid GISTs, in 14 cases (8.2%). Ten cases (55.6%) of spindled small intestine GIST contained eosinophilic skeinoid fibers. Immunoreactivity for CD34, h-caldesmon, alpha-smooth-muscle actin (SMA), desmin, and S-100 was observed in 156 (91.2%), 131 (76.6%), 46 (26.9%), 7 (4.1%), and 14 (8.2%) tumors, respectively. The percentage of CD34 positivity (38.8%) was low, in contrast with the high percentage of reactivity for SMA (77.8%) and S-100 (44.4%) in small intestine GISTs. By our histologic grading system using tumor differentiation, MIB-1 score, and necrosis, 129 tumors (75.4%) were classified as low grade and 42 tumors (24.6%) were classified as high grade. With a median follow-up period of 83.5 months for 122 living patients, the 5-year and 10-year survival rates were 81.7% and 67.4%, respectively. Multivariate analysis showed that both tumor size >10 cm and high grade were significantly associated with a poor outcome. As a result, GISTs >10 cm or high grade, 5 to 10 cm and low grade, and < or =5 cm and low grade were regarded as high risk, intermediate risk, and low risk for mortality, respectively. In conclusion, it is important to recognize GISTs that have a specific molecular pathogenesis and to separate them from other mesenchymal tumors with optimal immunostaining for CD117 when making a diagnosis and prognostic classification based on tumor size and MIB-1 grade.