Immunohistochemistry is highly sensitive and specific for detecting the BRAF V600E mutation in papillary thyroid carcinoma

The V600E mutation in the B-type Raf kinase (BRAF) gene is a common genetic change in cases of papillary thyroid carcinoma (PTC) that appears to play a key role in the development and progression of this disease. We sought to assess the sensitivity and specificity of immunohistochemical detection of this mutation with a V600E mutated BRAF antibody in a Chinese PTC cohort. In this study, we used fully automated immunohistochemistry (IHC) assay with a BRAF V600E (VE1) mouse monoclonal primary antibody to screen for the BRAF V600E mutation in 556 cases of PTC. Moreover, to verify the IHC staining results, real-time PCR was applied to detect this mutation in the same patient cohort. Among the 556 cases in the examined primary PTC cohort, 414 (74.5%) cases and 419 (75.4%) cases were positive for the BRAF V600E mutation by IHC staining and by real-time PCR, respectively. The real-time PCR results indicated that the sensitivity and specificity of IHC staining for the BRAF V600E mutation were 98.8% and 100%, respectively. The BRAF V600E mutation was common among Chinese patients with primary PTC, and was strongly correlated with older patient age and the conventional subtype of PTC but was not associated with parameters of clinicopathological aggressiveness. The fully automated IHC is a reliable technique that can serve as an alternative to molecular biological approaches for the routine detection of the BRAF V600E mutation in PTC patients.     

分化型甲状腺癌中BRAF V600E突变分析

目的探讨分化型甲状腺癌中BRAF V600E突变与临床病理特征的关系。方法收集甲状腺乳头状癌(papillary thyroid carcinoma,PTC)80例(其中经典型67例、滤泡亚型8例、嗜酸细胞亚型3例、高细胞亚型2例)、滤泡癌5例,其中30例PTC取相应癌旁组织,全部送基因检测室检测BRAF V600E突变情况。结果 80例PTC中BRAF V600E突变率为65.0%,5例滤泡癌及30例癌旁组织中未发现BRAF V600E突变;BRAF V600E突变与患者年龄、肿瘤包膜侵犯、淋巴结转移及TNM分期有关。PTC亚型中,经典型和高细胞亚型的BRAF V600E突变率较高(70.1%、100.0%),滤泡亚型的突变率较低(33.3%)。结论PTC中BRAF V600E突变可能与患者年龄有一定相关性,还与包膜侵犯、淋巴结转移及TNM分期有关,经典型和高细胞亚型的BRAF V600E突变率较高,明显高于滤泡亚型。     

Detection of BRAFV600E mutation on papillary thyroid carcinoma and metastatic malignant melanoma by fine‐needle aspiration cytology

A genetic link between cutaneous melanoma and thyroid cancer (TC) has been identified. A high percentage of both melanomas and papillary carcinomas of the thyroid harbors a recurrent mutation (i.e., BRAF^V600E) in the BRAF oncogene. Herein, we report the case of a 65‐year‐old man with papillary TC and cutaneous malignant melanoma metastatic to masseter muscle, both characterized by BRAF mutation. This is one of the rare reports in which a complete molecular characterization has been performed. As the patients with papillary thyroid carcinoma have a higher risk of malignant melanoma and vice versa, continuous monitoring of such patients, with either of these tumors is necessary. Fine‐needle aspiration cytology is useful as shown in the present case. Diagn. Cytopathol. 2014;42:877–879. © Wiley Periodicals, Inc.     

Cytological features of warthin‐like papillary thyroid carcinoma: A case report with review of previous cytology cases

Warthin‐like papillary thyroid carcinoma (WLPTC) is a rare morphological variant of papillary thyroid carcinoma which mimics various benign and malignant lesions on thyroid aspiration cytology. As correct cytological diagnosis is the cornerstone for appropriate patient management, awareness of the salient cytomorphological characteristics of this tumor is essential. Here, we present cytological features of a case of WLPTC along with discussion of the common differential diagnoses and a brief review of the literature to ascertain the most consistent cytological findings of WLPTC. The present case also harboured BRAFV600E mutation which is the commonest molecular alteration seen in WLPTC.     

Investigation of BRAF V600E detection approaches in papillary thyroid carcinoma

Objective

The detection of BRAF V600E mutation in papillary thyroid carcinoma (PTC) may be helpful to offer diagnostic confirmation. Additionally, such detection may provide a targeted therapeutic approach for the radioactive iodine resistant patients to predict adverse outcomes. To compare the results of immunohistochemistry (IHC) method using the anti-BRAF V600E (VE1) antibody with the Quantitative real-time polymerase chain reaction (qPCR) approach in examining BRAF V600E mutation in PTC, we investigated the sensitivity and specificity of BRAF V600E (clone VE1) mouse monoclonal antibody in detecting the BRAF V600E mutation and correlated BRAF V600E mutation with clinicopathologic features in PTC.

Diagnostic value of B‐RAFV600E in difficult‐to‐diagnose thyroid nodules using fine‐needle aspiration: Systematic review and meta‐analysis

Fine‐needle aspiration (FNA) is routinely used in the preoperative evaluation of thyroid nodules. However, approximately 5–20% of thyroid nodules are considered indeterminate or suspicious cases that do not meet clinical standards. The B‐RAF^V600E mutation has been reported in FNA specimens. We conducted a systematic review to evaluate the diagnostic value of testing for B‐RAF^V600E in thyroid nodules that are difficult to diagnose by FNA. A systematic literature search was performed from January 1, 2002 to June 30, 2012. Articles were obtained by searching two electronic databases (MEDLINE and EMBASE), hand searching selected journals, and contacting authors. Article quality was assessed using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS) tool. Sensitivity, specificity, and other measures of accuracy were pooled using random effects models. Summary receiver operating characteristic (SROC) curves were used to summarize overall diagnostic accuracy. A total of 16 studies incorporating 1131 patients were included in a meta‐analysis on diagnostic accuracy of B‐RAF^V600E tests. Pooled sensitivity was 0.60 (95% confidence interval [CI]: 0.556–0.634), pooled specificity was 0.99 (95% CI 0.976–0.997), and the area under the curve of the SROC curve was 0.8376. Q index value was 0.7696. Our data suggest a potentially useful adjunct to evaluating thyroid nodules that are difficult to diagnose. The B‐RAF^V600E test has a high positive predictive value and could help clinicians formulate a more individualized treatment schedule. When supplemented with other noninvasive test methods, the B‐RAF^V600E test could be a powerful adjunct with extensive clinical applications. Diagn. Cytopathol. 2014;42:94–101. © 2013 Wiley Periodicals, Inc.     

TROP‐2 expression in papillary thyroid carcinoma

TROP‐2 is a type I transmembrane glycoprotein which is over‐expressed in various malignancies, and is related to epithelial cell adhesion molecule (EpCAM), also called TROP‐1, gp40, and KSA. In this study, we evaluated TROP‐2 expression in papillary thyroid carcinoma (PTC) and compared it to other thyroid neoplastic and non‐neoplastic lesions. Immunohistochemical (IHC) evaluation for TROP‐2 was performed on 137 thyroid fine needle aspiration (FNA) cell blocks (CB) which included classic PTC (64), follicular variant PTC (FVPTC) (10), anaplastic thyroid carcinoma (AC) (2), medullary carcinoma (MC) (8), follicular neoplasms (FN) (8), Hurthle cell neoplasms (HCN) (9), follicular lesion of uncertain significance (FLUS) (12), and benign thyroid nodule (BTN) (24). IHC for TROP‐2 expression was also performed on 331 BTN and malignant tumor tissue sections in tissue microarray (TMA). Membranous staining in >5% of tumor cells was considered positive. TROP‐2 stained 61 of 64 PTC CB, 7 of 10 FVPTC CB, and 9 of 12 FLUS CB. All other cases were negative for TROP‐2. TROP‐2 showed a sensitivity of 95.31% and specificity of 89% for classic PTC in FNA CB. In TMA samples, TROP‐2 stained 54 of 60 classic PTC cases and hence showed a high sensitivity and specificity. All BTN in CB and TMA were negative. We conclude that TROP‐2 is a highly sensitive and specific IHC marker for identifying classic PTC. TROP‐2 may play an important role in diagnosing classic PTC, especially in equivocal cases. This study also identifies a strong role for TROP‐2 in separating PTC from BTN. Diagn. Cytopathol. 2016;44:26–31. © 2015 Wiley Periodicals, Inc.     

Association of BRAFV600E mutation with clinicopathological features of papillary thyroid carcinoma: a study on a Chinese population

Background: The new finding of the heterogeneous distribution of BRAF^V600E mutation in primary papillary thyroid carcinoma suggested the percentage of BRAF^V600E alleles should be taken into consideration when evaluating its association with clinicopathological features of papillary thyroid carcinoma. The aim of this study was to detect both the presence and the percentage of BRAF^V600E alleles in fine-needle aspiration biopsy samples and to assess its association with clinicopathological characteristics of papillary thyroid carcinoma in a Chinese population. Materials and methods: Fine needle aspiration samples were collected in a total of 182 patients (132 conventional papillary thyroid carcinomas and 50 goiters). The associations of the presence and percentage of BRAF^V600E alleles genotyped by pyrosequencing with clinicopathological characteristics were evaluated in papillary thyroid carcinomas. Results: 80 (60.61%) of papillary thyroid carcinomas exhibited BRAF^V600E mutation in a range of 7.7% to 46.3% of the total BRAF alleles. The presence of BRAF^V600E mutation was significantly associated with extrathyroidal invasion. There was no significant difference between the presence of BRAF^V600E mutation and other clinicopathological features. It was not found that the significant relationship between percentage of BRAF^V600E alleles and clinicopathological characteristics. Conclusion: We concluded that the presence of BRAF^V600E could be preoperatively predictive of extrathyroidal invasion in a Chinese population.     

实时剪切波弹性成像杨氏模量最大值诊断甲状腺乳头状癌BRAF V600E基因突变的价值

目的:探究实时剪切波弹性成像（SWE）杨氏模量最大值诊断甲状腺乳头状癌（PTC）鼠类肉瘤滤过性毒菌致癌同源体B1（BRAF）V600E基因突变的价值。方法:回顾性分析2018年1月~2019年6月宿迁市第一人民医院收治的110例PTC患者共124个结节的临床及超声影像学资料。患者经病理学检查均确诊为PTC,并完成了BRAF V600E基因检测以及SWE检查,临床资料完整。通过比较V600E基因突变型与野生型PTC的SWE检查结果,并绘制患者Emax值的ROC曲线,分析Emax值对PTC患者BRAF V600E基因突变的诊断效能。结果:BRAF基因检测结果显示:124个PTC结节BRAF基因检测V600E野生型共37个,V600E突变型共87个。野生型PTC结节的SWE图像多以蓝色为主,而突变型主要表现为红橙相间彩色混杂的图像。突变组PTC结节Emax、Emean、Eratio值均明显大于野生组,比较差异具有统计学意义（P<0.05）,ROC曲线分析显示:Emax值诊断V600E突变的AUC=0.846>0.5（95%CI:0.808~0.885, P<0.01）;Cut-off值为43.65 kPa,此时敏感度为91.45%,特异性为68.23%。以Emax≥43.65 kPa为临界值对124个结节进行诊断,结果显示:SWE诊断PTC结节为V600E基因突变型90个,野生型34个,正确率为86.29%;SWE诊断结果与基因检测结果一致性显著（Kappa值=0.665, P<0.01）。结论:PTC BRAF V600E基因突变型与野生型的SWE影像学特征具有明显差异,应用SWE的Emax值诊断PTC结节V600E基因突变的正确率和敏感性均较高,诊断价值显著,值得在临床上推广应用。     

A valuable adjunct to FNA diagnosis of papillary thyroid carcinoma: In‐house PCR assay for BRAF T1799A (V600E)

The diagnostic approach to thyroid nodules generally starts with FNA cytology. However, approximately one‐fifth of cytologic evaluations yield indeterminate cytological findings but only 20% of cases with indeterminate thyroid nodule cytology have a cancer diagnosis, emphasizing the need for an effective ancillary test based on FNA material to help prevent unnecessary surgery. Detection of BRAFV600E mutation, the genetic signature of papillary thyroid carcinoma (PTC) in FNA material provides an invaluable diagnostic adjunct to overcome the limitations of FNA cytology. There are many ways to detect V600E, such as direct DNA sequencing, allele‐specific PCR and hybridization‐based colorimetric methods. In this study, a newer simple PCR method is presented that removes requirements for sequencing special equipment and commercial kits. Two forward primers including the mutant sequence specific (F2), and one common reverse (R) primer were optimized to generate a 241 bp fragment (F1R), an internal PCR control, and a 141 bp fragment (F2R) denoting the presence of V600E. Sensitivity studies revealed that the assay is capable of detecting V600E even in 1 ng of DNA. Direct sequencing data of 241 bp F1R fragment proved the specificity of the assay. For validation studies of the sequence specific multiplex PCR assay, archival FNA slides were used in a group of thyroid lesions including PTC, follicular carcinoma, follicular adenoma, Hashimoto thyroiditis, and benign thyroid nodules. The newer PCR‐based method presented in this study is a practical, inexpensive one‐step assay to detect the BRAF T1796A mutation on FNA samples. Diagn. Cytopathol. 2011;39:424–427. © 2010 Wiley‐Liss, Inc.     

甲状腺乳头状癌中TROP-2表达的临床意义及其诊断价值

目的观察人类滋养层细胞表面抗原2(TROP-2)在甲状腺乳头状癌(papillary thyroid carcinoma,PTC)中的表达,探讨TROP-2在PTC中表达的临床意义及其诊断价值。方法采用免疫组化EnVision法检测100例甲状腺恶性病变(PTC 75例、滤泡性癌10例、髓样癌10例、差分化癌5例)、45例良性病变(正常甲状腺10例、结节性甲状腺肿10例、桥本甲状腺炎15例、滤泡性腺瘤10例),5例具有乳头样核特征的非浸润性甲状腺滤泡性肿瘤(non-invasive folliculaRthyroid neoplasms with papillary-like nucleaRfeatures,NIFTP)中TROP-2的表达;ARMS法检测PTC中BRAF V600E基因突变。分析TROP-2对PTC诊断的敏感性和特异性,及其与PTC临床病理特征以及BRAF V600E基因突变的关系。结果TROP-2在PTC中的阳性率为81.3%(61/75),在其他甲状腺恶性肿瘤和良性病变中均阴性,TROP-2对PTC诊断的敏感性为81.3%,特异性为100%。TROP-2表达与PTC淋巴结转移有关(P<0.05),与患者年龄、性别、肿瘤部位及临床分期无关(P>0.05),经典型PTC中TROP-2表达高于滤泡亚型PTC(P<0.05)。PTC中TROP-2表达与BRAF V600E基因突变呈正相关(P<0.05)。结论TROP-2是一种具有高度特异性和敏感性的诊断PTC的标志物,TROP-2检测可预测PTC的临床生物学行为和BRAF V600E基因突变状态,并对于形态学变形的PTC、微小型PTC和PTC的甲状腺内扩散的诊断和识别具有重要价值。     

新疆地区甲状腺乳头状癌中BRAF V600E基因的表达及意义

目的探讨新疆地区BRAF V600E基因点突变在甲状腺乳头状癌(papillary thyroid carcinoma,PTC)中的表达,及其与临床病理特征的关系。方法收集原发性PTC 178例,石蜡包埋组织经QIAGEN试剂盒提取DNA,经Taq Man探针荧光定量PCR技术检测PTC中BRAF基因点突变。结果 178例原发性PTC中BRAF V600E基因点突变142例,突变率为79.8%(142/178)。患者年龄(≥45岁)、肿瘤直径(≤1 cm)、被膜外侵犯BRAF V600E基因点突变率高(P均0.05),而BRAF V600E基因点突变与患者性别、多灶性及淋巴结转移灶和肿瘤部位均无相关性(P均0.05)。结论新疆地区PTC中BRAF V600E基因点突变与临床病理特征密切相关,且具有一定特异性,可作为PTC诊断提供依据。     

An immunohistochemical and genetic study of BRAFV600E mutation in Japanese patients with ameloblastoma

Ameloblastoma is an odontogenic tumor of the jaw. It most frequently occurs in the mandible, and less often in the maxilla. Mandibular ameloblastoma harbors a BRAF mutation that causes a valine (V) to glutamic acid (E) substitution at codon 600 (BRAF^V600E). We examined specimens from 32 Japanese patients to detect the prevalence of the BRAF^V600E mutation, and to evaluate the relationship between immunohistochemical (IHC) expression and genetic results, of BRAF^V600E+ ameloblastoma. Among the 32 cases, 22 (69%) were IHC positive for BRAF^V600E protein, and 10 (31%) were IHC negative; and polymerase chain reaction showed 16 of 21 tested cases (76%) carried the BRAF^V600E mutation. Our findings indicate that that samples that stain IHC positive for BRAF^V600E protein are more likely to carry the BRAF^V600E mutation. These results support assessments for BRAF mutations, and the use of BRAF inhibitors as targeted therapy for ameloblastoma in Japanese patients.     

Occult oncocytic papillary thyroid carcinoma with lymphoid stroma (Warthin-like tumor): report of a case with concomitant mutations of BRAF V600E and V600K

Warthin-Like tumor of the thyroid is a recently described rare variant of papillary thyroid cancer. The distinct histological feature of this variant is papillary architecture lining oncocytic epithelial cells with nuclear characteristics of papillary carcinoma, accompanied by prominent lymphocytic infiltration in the papillary stalks. Here, we present a case of occult Warthin-like papillary thyroid carcinoma, 0.5-cm in maximum dimension, underwent left thyroid lobectomy in a 65 years old Chinese woman. In this case, there was no extrathyroid extension, vascular invasion and lymphatic metastasis, as well as no complication of lymphocytic thyroiditis. Immunohistochemistry staining revealed that the tumor cells were positive for Leu-M1, HBME-1, 34βE12, and MIB-1 labeling index was low. RET/PTC expression was absent in tumor cells. Furthermore, activated point mutations of BRAF V600E and V600K were concurrently detected by DNA sequencing. Further studies are needed to elucidate the prevalence and role of BRAF^V600K mutation in papillary thyroid carcinoma, and long-term follow-up for the patient is needed to clarify the biological behavior of this variant with dual BRAF mutations.     

甲状腺乳头状癌BRAF基因突变的检测及临床意义

目的 了解甲状腺乳头状癌(papillary thyroid carcinoma,PTC)BRAF基因T1799A点突变的情况与临床病理学特征的关系.方法 应用聚合酶链反应及DNA直接测序法对43例PTC患者,20例非PTC甲状腺病变患者及40份正常甲状腺组织对照的新鲜标本进行BRAF基因检测.分析BRAF基因突变与性别、发病年龄、原发灶大小、甲状腺包膜外浸润、颈淋巴结转移及远处转移等临床病理学特征的关系.结果 43例PTC中1 7例检出BRAF基因T1799A点突变.检出率为39.5%,而在非PTC甲状腺病变患者和40份正常甲状腺组织未发现T1799A点突变.BRAF基因突变与PTC甲状腺包膜外浸润及颈淋巴结转移密切相关(P<0.05及P<0.05),与性别、发病年龄、原发灶大小及远处转移无关.结论 BRAF基因突变与颈淋巴结转移和甲状腺包膜外浸润密切相关,突变可能增加PTC的侵袭性并影响预后.