Value of immunohistochemistry in the detection of BRAF(V600E) mutations in fine-needle aspiration biopsies of papillary thyroid carcinoma

Combined effects of intermittent fasting with swimming-based high intensity intermittent exercise training in Wistar rats

High caloric intake and physical inactivity are known precursors to the development of several chronic metabolic diseases. For obesity and sedentarism, High Intensity Intermittent Exercise (HIIE) and Intermittent Fasting (IF) have emerged as individual strategies to attenuate their negative effects by improving metabolism. To study their combined effects, Wistar male rats (n = 74, 60 days old) were divided into four groups: Sedentary Control (C), swimming-based HIIE only (HIIE), Intermittent Fasting only (IF), and swimming-based HIIE associated with Intermittent Fasting (HIIE/IF). Over an eight-week period swimming performance, body composition, weight and feeding behavior were analyzed. The final morphology of white adipose tissue showed a significant reduction in adipocyte size consistent with a higher number of cells per area in exercised animals (vs C and IF, p < 0.05), which also displayed characteristics of browning through UCP-1 levels and CD31 staining. These results suggest that the increased performance in the HIIE/IF group is, in part, by modifications of WAT metabolism through the browning process.

Death from COVID-19 in a Fully Vaccinated Subject: A Complete Autopsy Report

A correctly implemented and widely accepted vaccination campaign was the only truly effective weapon to reduce mortality and hospitalizations related to COVID-19. However, it was not 100% effective and has not eliminated COVID-19. Even though more than 60% of the worldwide population is fully vaccinated (meaning that these subjects have completed the recommended vaccine cycle), subjects continue to die from COVID-19, particularly in the presence of comorbidities. In this scenario, autopsies play a crucial role in understanding the pathophysiological mechanisms of SARS-CoV-2 in vaccinated subjects and adapting therapies accordingly. This case report analyzes the death of a fully vaccinated patient who suffered from comorbidities and died from COVID-19; we provide a complete autopsy data set. On microscopic examination, the lungs showed massive interstitial pneumonia, areas of inflammation with interstitial lympho-plasma cell infiltrate, and interstitial edema. The liver showed granulocytes within the hepatic parenchyma. All these elements were consistent with previous published data on unvaccinated patients who had died from COVID-19. The present study is the first that analyzes, through a complete autopsy and a microscopic analysis of all organs, a death related to COVID-19 despite vaccine administration. In this regard, to the best of our knowledge, no other studies have been published reporting a complete autopsy. This study reports, on the one hand, the importance of vaccination programs in the fight against COVID-19, and, on the other hand, it hypothesizes that the vaccine does not offer complete immunity to SARS-CoV-2, particularly in elderly subjects with comorbidities.

Preoperative BRAFV600E mutation detection in thyroid carcinoma by immunocytochemistry

The BRAF^V600E (BRAF) mutation is present in 40-50% of papillary thyroid carcinomas (PTC) and has been associated with more aggressive clinicopathological characteristics of PTC. The aim of this study was to evaluate different methods for preoperative identification of the BRAF mutation in PTC using cytological and histological specimens. Prospectively collected preoperative cytological clots from patients with suspected PTC were tested with BRAF immunocytochemistry (ICC) and the Cobas Test (PCR). In addition, histological specimens were tested with BRAF immunohistochemistry (IHC) and the Cobas Test. All nodules were histologically examined. Fifty-three patients were included in the study. Complete mutation testing was available in 32 patients. The main reason for exclusion was insufficient cell content in the cytological specimen. Twenty-seven nodules were histologically diagnosed as PTC, and 41% (n = 11) of PTCs were BRAF ICC positive. All non-PTC nodules were negative by BRAF ICC. In 26 nodules, all four BRAF tests were concordant, while discordant test results were found in six nodules. ICC was in accordance with the consensus BRAF status in five of these nodules, while BRAF status was undetermined in one nodule. BRAF ICC showed high concordance with the Cobas Test and a low rate of false negative stain. These results indicate that BRAF ICC may be a feasible method for preoperative detection of the BRAF^V600E mutation in patients with PTC.

Diagnostic Efficacy of BRAFV600E Immunocytochemistry in Thyroid Aspirates in Bethesda Category IV and Papillary Thyroid Carcinoma

Background

In papillary thyroid carcinoma (PTC), BRAFV600E is a common mutation and is associated with aggressive clinical behaviour. Immunocytochemistry (ICC) and molecular testing are recommended in the Bethesda System for Reporting Thyroid Cytopathology 2017 (TBSRTC) category III, IV and V.

Aims

The current study aimed to evaluate the diagnostic efficacy of conventional FNAC versus FNAC with BRAFV600E immunostaining in cases of TBSRTC category IV, cases of suspicious for PTC and cases of PTC.

Methods and Material

The study included a prospective case series of 45 patients with clinically palpable thyroid nodules with TBSRTC category IV, category V (suspicious for PTC) and PTC. The corresponding histology specimens of all the 45 cases were also analyzed. Immunostaining for BRAFV600E was performed on FNAC cell blocks and their corresponding histology sections using anti-BRAF (VE1) clone (Ventana). The diagnostic efficacy of the BRAFV600E immunostaining was compared on cytological specimens with histological specimens.

Results

BRAFV600E immunostaining helped to improve the sensitivity of the cytology to confirm the PTC as a diagnostic aid for thyroid FNAs. Cytology alone had a sensitivity of 62.96% and a lower specificity of 60.70%. The combination of both the tests together provided 84.62% sensitivity and much higher specificity of 100%. PPV was also increased to 100% and NPV was raised 94.12%.

Conclusions

The performance of BRAFV600E immunostaining on the cytological specimen is a rapid, simple and cost-effective test and could be considered in TBSRTC category IV and suspicious and malignant cases of PTC.

Immunohistochemical investigation of cytokine expression levels as biomarkers in transrectal ultrasound-guided needle biopsy specimens of prostate adenocarcinoma

Cytokines influence the biological behaviour of prostate cancer (PC) and may influence patient outcome and serve as useful prognostic biomarkers. The aim of the present study was to evaluate cytokine expression levels in prostatic needle biopsy specimens and the association with clinicopathological characteristics of patients with PC. A total of 18 patients with PC who underwent transrectal ultrasound (TRUS) guided prostate biopsy were included in the clinical study. These patients were naïve to radiotherapy (RT) or androgen deprivation therapy prior to TRUS biopsy and clinical follow up data was collected. Cytokine expression levels were analysed by using immunohistochemistry and Spearman's correlation test was used to determine the correlation between cytokine expression and clinicopathological characteristics. Expression levels of pro-inflammatory TNF-α and IL-6 decreased as Gleason score (GS) increased; however, a statistically significant difference was not detected. A statically significant correlation was observed between needle biopsy specimen and pre-RT plasma sample expression levels of pro-inflammatory TNF-α and IL-6 (P=0.01 and P=0.05, respectively) and anti-inflammatory TGF-β1 (P=0.05). However, further studies are needed to confirm these results using a larger sample size to confirm the prognostic value of pro-inflammatory TNF-α and IL-6 and anti-inflammatory TGF-β1 in patients with PC.

Immunohistochemistry Critical Assay Performance Controls (ICAPC) Reduce Interobserver Variability in the Interpretation of BRAFV600E Immunohistochemistry

The utility of prognostic and predictive immunohistochemistry biomarkers in the context of cancer is plagued by inconsistent interpretation of results which can lead to poor rates of adoption or inappropriate use of novel therapeutic strategies. To monitor immunohistochemistry assay performance, a new on-slide control motif, Immunohistochemistry Critical Assay Performance Controls (ICAPC) was developed. We hypothesized that the use of these controls by the diagnosing pathologist to interpret BRAFV600E would result in reduced interobserver and intraobserver interpretation errors. A cross-sectional, sequentially obtained sample of surgical pathology cases stained for BRAFV600E was assembled from a single hospital in Vancouver, British Columbia. Half of the cases had normal on-slide controls and the remainder with ICAPC. Results from 6 independent and blinded readers were compared with each other and to the gold-standard pathologic diagnosis with the goal of demonstrating superior interrater agreement with ICAPC relative to standard on-slide controls. Cohen's κ was used to compute pair-wise reader agreements, whereas Fleiss' κ was used to compare to the gold standard. The implementation of ICAPC resulted in statistically significant improvements in the interobserver agreement of BRAF mutation status ascertained by BRAFV600E immunohistochemistry. Half of the readers demonstrated significant improvements in agreement with the gold-standard diagnosis with the addition of ICAPC. Across all readers, the mean increase in κ was 0.14 with a 95% confidence interval of 0.01-0.28 (P=0.04). This study demonstrates that the addition of ICAPC serves to significantly reduce interobserver variability in the assessment of BRAFV600E immunohistochemistry. As such, we recommend that this approach should be used as part of a comprehensive quality management strategy in the setting of histopathology.

Immunocytochemistry for diagnostic cytopathology-A practical guide

Cytological specimens, which are obtained by minimally invasive methods, are an excellent source of diagnostic material. Sometimes they are the only material available for diagnosis as well as for prognostic/predictive markers. When cytomorphology is not straightforward, ancillary tests may be required for a definitive diagnosis to guide clinical management. Immunocytochemistry (ICC) is the most common and practical ancillary tool used to reach a diagnosis when cytomorphology is equivocal, to differentiate entities with overlapping morphological features, and to determine the cell lineage and the site of origin of a metastatic neoplasm. Numerous immunomarkers are available, and some are expressed in multiple neoplasms. To rule out entities within a differential diagnosis, the use of more than one marker, sometimes panels, is necessary. ICC panels for diagnostic purposes should be customised based on the clinical context and cytomorphology, and the markers should be used judiciously to preserve material for additional tests for targeted therapies in the appropriate setting. This review offers a practical guide for the use of ICC for diagnostic cytopathology, covering the most commonly encountered non-hematolymphoid diagnostic scenarios in various body sites.

VE1 immunohistochemistry is an adjunct tool for detection of BRAFV600E mutation: Validation in thyroid cancer patients

Papillary thyroid carcinoma (PTC) is the most common endocrine malignancy among other endocrine tumors, and BRAF^V600E is a frequent genetic mutation occurring in the disease. Although different molecular techniques, most importantly sequencing has been widely recognized as a gold standard but molecular diagnosis remains an expensive, laborious, and time‐intensive process. Recently, immunohistochemistry (IHC) with anti‐BRAF V600E (VE1) antibody has increased practical utility and implemented clinically for the detection of BRAF^V600E mutation. Therefore, the study aimed to evaluate diagnostic accuracy of VE1 IHC for detecting the BRAF^V600E mutation frequency and clinical implementation in diagnostic laboratories. In this study, 72 formalin fixed paraffin‐embedded tissues (FFPE) were used to determine the BRAF^V600E mutation status using IHC and Sanger sequencing. The mutation was found in 29% and 28% cases using IHC and Sanger sequencing, respectively. Furthermore, the results showed 100% sensitivity, 98.07% specificity, 95.2% positive predictive value, and 100% negative predictive value. Notably, significant associations were found between BRAF^V600E status and tumor stage, tumor focality, and extrathyroidal extensions, respectively. VE1 IHC was found to be a highly sensitive, specific, and diagnostically accurate method in this cohort. Therefore, BRAF^V600E detection through IHC has been considered as the best tailored technique for routine pathology laboratories.

Protective effect of cerium oxide nanoparticles on cisplatin and oxaliplatin primary toxicities in male albino rats

Cisplatin and oxaliplatin are widely used anticancer drugs. Their use is restricted by their dose-limiting side effects: nephrotoxicity and neurotoxicity, respectively. Cerium oxide nanoparticles (CONPs) are promising antioxidant and anti-inflammatory agent. To test the possible ameliorative impact of CONPs on the toxic effect of cisplatin and oxaliplatin in male albino rats. Forty eight rats were divided into 6 groups: control group, CONPs group, cisplatin group, cisplatin and CONPs group, oxaliplatin group, and oxaliplatin and CONPs group. After 4 weeks, serum urea and creatinine, renal tissue level of interleukin 10 (IL10), and total antioxidant (TAO) were measured in control, CONPs, and cisplatin groups. The other kidney was used for histopathological and immunohistochemical studies. The right sciatic nerves and the lumbar spinal cord of rats from control, CONPs, and oxaliplatin groups were used for immunohistochemical evaluations of nitrotyrosine, myelin basic protein (MBP), and glial fibrillary acidic protein (GFAP). Cisplatin significantly increased serum urea and creatinine levels, significantly decreased the kidney level of IL10 and TAO with marked tubular necrosis, hemorrhage and renal damage. Also, it decreased IL10 immunohistochemical expression. CONPs significantly decreased the serum urea and creatinine level and increased IL10 and TAO with lower renal damage and strong IL10 expression compared with cisplatin group. Oxaliplatin significantly decreased MBP immunoreactivity and increased nitrotyrosine immunoreactivity. In the lumbar spinal cord, GFAP immunoreactivity was significantly increased. CONPs significantly increased MBP and decreased nitrotyrosine immunoreactivity. GFAP immunoreactivity was significantly decreased. CONPs ameliorated cisplatin and oxaliplatin primary toxicities through anti-inflammatory and antioxidant characteristics.

Preliminary Post-Mortem COVID-19 Evidence of Endothelial Injury and Factor VIII Hyperexpression

(1) Background: The current outbreak of COVID-19 infection is an ongoing challenge and a major threat to public health that requires surveillance, prompt diagnosis, as well as research efforts to understand the viral pathogenesis. Despite this, to date, very few studies have been performed concerning autoptic specimens. Therefore, this study aimed: (i) to reiterate the importance of the autoptic examination, the only method able to precisely define the cause of death; (ii) to provide a complete post-mortem histological and immunohistochemical investigation pattern capable of diagnosing death from COVID-19 infection. (2) Methods: In this paper, the lung examination of two subjects who died from COVID-19 are discussed, comparing the obtained data with those of the control, a newborn who died from pneumonia in the same pandemic period. (3) Results: The results of the present study suggest that COVID-19 infection can cause different forms of acute respiratory distress syndrome (ARDS), due to diffuse alveolar damage and diffuse endothelial damage. Nevertheless, different patterns of cellular and cytokine expression are associated with anti-COVID-19 antibody positivity, compared to the control case. Moreover, in both case studies, it is interesting to note that COVID-19, ACE2 and FVIII positivity was detected in the same fields. (4) Conclusions: COVID-19 infection has been initially classified as exclusively interstitial pneumonia with varying degrees of severity. Subsequently, vascular biomarkers showed that it can also be considered a vascular disease. The data on Factor VIII discussed in this paper, although preliminary and limited in number, seem to suggest that the thrombogenicity of Sars-CoV2 infection might be linked to widespread endothelial damage. In this way, it would be very important to investigate the pro-coagulative substrate both in all subjects who died and in COVID-19 survivors. This is because it may be hypothesized that the different patterns with which the pathology is expressed could depend on different individual susceptibility to infection or a different personal genetic-clinical background. In light of these findings, it would be important to perform more post-mortem investigations in order to clarify all aspects of the vascular hypothesis in the COVID-19 infection.

VE1 Immunohistochemistry Improves the Limit of Genotyping for Detecting BRAFV600E Mutation in Papillary Thyroid Cancer

Detection of BRAF^V600E is useful for making diagnosis and risk stratification of papillary thyroid carcinoma (PTC). Molecular testing, however, is not always available for routine clinical use. To assess the clinical utility and reliability of VE1 immunohistochemistry (IHC) for detecting BRAF^V600E mutation in PTC, VE1 IHC was performed on the tissue microarrays of 514 patients with PTC and was compared with Sanger sequencing results. Of 514 PTC cases, 433 (84.2%) were positive for VE1 expression. Among 6 discordant cases between VE1 IHC and Sanger sequencing, 3 initial VE1-false negative cases turned out to be true false negative on repeat testing, and 3 VE1-false positive cases showed BRAF^V600E mutation using digital PCR analysis. PTCs with low variant allele fraction were positive for VE1 IHC but were not detected using sequencing. VE1 IHC showed 99.3% sensitivity, 100% specificity, 100% positive predictive value, and 96.4% negative predictive value. The BRAF^V600E mutation was significantly associated with older age, multifocality, extrathyroidal extension, lymph node metastasis, and advanced tumor stage. In conclusion, VE1 IHC is a reliable method for detecting BRAF^V600E mutation in PTC specimens.

Diagnostic accuracy of molecular testing with three molecular markers on thyroid fine-needle aspiration cytology with abnormal category

BACKGROUND

Cases with abnormal category, determined by thyroid fine-needle aspiration (FNA), frequently undergo surgical resection, despite the majority of cases being identified as benign after resection. Additional diagnostic markers are needed to guide the management of patients with abnormal thyroid nodules.

MATERIALS AND METHODS

The retrospective study enrolled 150 cases diagnosed abnormal by FNA cytology that had undergone molecular testing with three markers (BRAF V600E, NRAS, and KRAS) on the cell block. Seventy-one cases had a surgical follow-up.

RESULTS

When NIFTP is not considered as malignant, positive predictive values (PPVs) of cytology and combined cytology and molecular testing (CC-MT) were 67.6% (95% CI: 0.555-0.782) and 89.2% (95% CI: 0.746-0.970) (P = .004), respectively. The sensitivity of the CC-MT was 68.8%, specificity was 82.5%, and the false-positive rate was 17.4%. When NIFTP is considered as malignant, PPVs of cytology and CC-MT were 83.1% (95% CI: 0.743-0.918) and 94.6% (95% CI: 0.873-1.018) (P = .047), respectively. The sensitivity of the CC-MT was 59.3%, specificity was 83.3%, and the false-positive rate was 16.7%.

CONCLUSION

The addition of molecular testing with a small panel to FNA cytology may increase the PPV of cytology in abnormal categories. Small panel (BRAF V600E, KRAS, and NRAS) with high specificity and high PPVs may be used particularly for the detection of thyroid malignancy. Cell blocks can be an especially useful and straightforward method for molecular diagnostic studies.

Cells with ganglionic differentiation frequently stain for VE1 antibody: a potential pitfall

Mitogen-activated protein kinase (MAPK) pathway plays a major role in pediatric low-grade gliomas (pLGGs). Immunohistochemistry with mutant-specific antibody, VE1, has appeared to be the most affordable and rapidly deployable method to identify tumors with aberrant MAPK signaling pathway, by highlighting tumor with BRAF^V600E mutation. Nonetheless, positive staining cases but not associated with BRAF^V600E mutation are also seen. We analyzed 62 pLGGs for the two commonest genetic aberrations in MAPK pathway: KIAA1549-BRAF fusion, using reverse-transcriptase polymerase chain reaction, and BRAF^V600E mutation, using VE1 antibody and Sanger sequencing. We recorded a specificity and accuracy rate of 68.75% and 75%, respectively, for VE1, when strong cytoplasmic staining is observed. Interestingly, we observed that cells with ganglionic features frequently bind VE1 but not associated with BRAF^V600E mutation. Such observation was also confirmed in four cases of differentiating neuroblastoma. This false positive staining may serve as an important confounder in the interpretation of VE1 immunoreactivity with major therapeutic implication. It is important to confirm the presence of BRAF^V600E mutation by DNA-based method, especially in tumor entities not known to, or rarely harbor such mutations.

BRAF mutation in cytologically indeterminate thyroid nodules: after reclassification of a variant thyroid carcinoma

Purpose

Fine-needle aspiration biopsy (FNAB) is regarded by the Bethesda system as the gold-standard investigation for stratifying the risk of malignancy of a thyroid nodule. However, some limitations affect the adequacy of the obtained materials, resulting in 30% of the cytological results remaining in the indeterminate category. We aimed to investigate the diagnostic value of the BRAF mutation in cytologically indeterminate thyroid nodules after the reclassification of a variant thyroid carcinoma.

Patients and methods

In this prospective diagnostic study, 76 patients with FNAB findings of atypia of undetermined significance (AUS) and suspicious for malignancy (SUS) were included. The BRAF V600 mutation from FNAB was confirmed by a PCR-based method (Sanger sequencing combined with allele-specific real-time PCR techniques) and immunohistochemistry (IHC). Pathological specimens and features, including noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP), were reviewed and compared to the FNAB results.

Results

Using the PCR-based method, the BRAF mutation was positive in 13/76 cases (17.1%), with the diagnostic values of 16.7% sensitivity, 100% specificity, 100% positive predictive value (PPV), and 82.8% negative predictive value (NPV) in the AUS compared to 73.3% sensitivity, 100% specificity, 100% PPV, and 20% NPV in the SUS. For the IHC technique, only 20 of the 76 cytological specimens were qualified for testing. The BRAF mutation was positive in 13/20 cases, with the diagnostic values of 100% sensitivity, 63.6% specificity, 42.9% PPV, and 100% NPV in the AUS compared to 100% sensitivity and PPV in the SUS. The BRAF mutation was not found in the pathological reports for NIFTP.

Conclusion

The malignancy rate is high in our data, with specific and acceptable accuracy rates for the BRAF mutation from FNAB found by using the PCR-based method. NIFTP has been introduced after the pathological reclassification. Molecular diagnosis might be useful to establish the nature of the disease.

Mutation Status and Immunohistochemical Correlation of KRAS, NRAS, and BRAF in 260 Chinese Colorectal and Gastric Cancers

KRAS, NRAS and BRAF are kinases involved in the RAS-RAF-MAPK signaling pathway and also potential tumor-driven genes. Patients with KRAS/NRAS/BRAF mutations are resistant to anti-EGFR monoclonal antibody therapy. The main purpose of this study is to investigate the mutation status and distribution of KRAS/NRAS/BRAF in Chinese colorectal and gastric cancers, and to explore the histopathological changes and related immunohistochemical marker changes caused by these mutations. The mutation status of KRAS (exons 2, codon 12/13), NRAS (exons 2/3/4, codon 12/13/59/61/117/146) and BRAF (exons 15, codon 600) were detected by amplification refractory mutation system polymerase chain reaction (ARMS-PCR) in 86 colon cancer, 140 rectal cancer and 34 gastric cancer tissues. Then, the frequencies and distribution of KRAS/NRAS/BRAF mutations were described in detail. Furthermore, the relationship between KRAS/NRAS/BRAF mutations and the features of histopathological and related immunohistochemical markers were analyzed. The results showed that KRAS/NRAS/BRAF mutation rates in colon cancer were 44.2, 1.2, and 3.5%; in rectal cancer were 37.1, 4.3, and 0.7%; in gastric cancer were none, none and 2.9%. The mutation rate of KRAS in female (48.8%) is significantly higher than that of male (27.8%), and the mutation rate increased with the higher degree of differentiation. Additionally, the mutation rate of BRAF detected by ARMS-PCR (1.77%) was significantly lower than that by immunohistochemistry (4.11%). It also showed that the KRAS/NRAS/BRAF mutation status had a certain relationship with the expression of some immunohistochemical markers. This study provides more data support for clinical research on KRAS/NRAS/BRAF mutation in CRCs or gastric cancers.

Predictive Value of BRAFV600E Mutation for Lymph Node Metastasis in Papillary Thyroid Cancer: A Meta-analysis

BRAF^V600E mutation has been thought to be a valuable molecular marker that may predict a worse prognosis for papillary thyroid cancer (PTC). But whether BRAF^V600E mutation is associated with lymph node metastasis (LNM) remains controversial. Different surgical strategies may bring a bias in demonsstrating the association between them. In order to delineate a risk stratification to guide a tailored initial approach to tumors that express BRAF^V600E mutation, we performed this meta-analysis by using the articles in which total or near-total thyroidectomy plus bilateral central lymph node dissection was routinely performed to avoid the bias from the surgical strategy. We searched the Medline, Embase and CNKI database for eligible studies from January 2003 to May 2018. Meta-analysis was performed using the STATA 12.0 software. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated under fixed-effects or randomeffects models. Fifteen clinical studies were included with a total of 4909 PTC patients. Our meta-analysis results reported that BRAFV600E mutation was associated with LNM (OR=1.34; 95% CI: 1.09-1.65; P=0.005), as well as central LNM (OR=1.59; 95% CI: 1.35-1.88; P<0.00001). Moreover, in patients with papillary thyroid microcarcinoma, we also confirmed the predictive value of BRAF^V600E mutation for LNM (OR=3.49; 95% CI: 2.02-6.02; P<0.00001). This meta-analysis demonstrates that BRAF^V600E mutation is closely related to LNM in PTC patients. The results suggest that BRAF^V600E mutation can be considered as a risk factor for LNM in PTC. Moreover, combining BRAF^V600E mutation with other risk factors to determine the initial surgical treatment may bring benefits for PTC patients.

Neoadjuvant BRAF- and Immune-Directed Therapy for Anaplastic Thyroid Carcinoma

Anaplastic thyroid cancer (ATC) is a devastating disease with a dismal prognosis. Patients who have disease confined to the thyroid and who are able to undergo complete surgery and chemoradiation stand the best chance for survival. Unfortunately, nearly 50% of patients have distant metastases at diagnosis, and most present with locally advanced, unresectable tumors. Nevertheless, BRAF-mutated ATC patients represent a subset of cases who can benefit from a combination therapy with BRAF and MEK inhibitors. Here, a patient is presented with end-stage, locally advanced, unresectable ATC who was treated with this combination. Immunotherapy with pembrolizumab was added at the first sign of progression after which he achieved a partial response to therapy, enabling a complete surgical resection followed by postoperative chemoradiation to be undertaken. This novel neoadjuvant approach to BRAF-mutated ATC should be studied in further in clinical trials.

Utility of the BRAF p.V600E immunoperoxidase stain in FNA direct smears and cell block preparations from patients with thyroid carcinoma

BACKGROUND

The identification of BRAF mutations in thyroid cancer has prognostic and therapeutic implications. Although the gold standard for identifying BRAF mutations is molecular testing, the ability to perform BRAF p.V600E immunostaining on fine-needle aspiration (FNA) samples can facilitate the rapid triaging of patients to treatment options.

METHODS

A total of 50 thyroid carcinoma FNA samples, including papillary (29 samples), poorly differentiated (10 samples), anaplastic (9 samples), and Hurthle cell (2 samples) carcinomas, with a known BRAF p.V600E mutation status were selected for the current study. Immunostaining was performed on smears and cell block sections using an anti-BRAF p.V600E antibody (clone VE1). The results were compared with the known mutation status obtained by molecular testing and/or immunostaining of surgical pathology material from the same patient.

RESULTS

Of the total of 50 cases, 26 cases had smears available for the evaluation of BRAF p.V600E immunostaining; positive immunostaining was noted in 16 samples and negative immunostaining was noted in 4 samples, whereas 6 cases were equivocal. Of the 34 cases for which cell blocks were available for evaluation, BRAF p.V600E immunostaining was positive in 17 cases, negative in 16 cases, and equivocal in 1 case. The overall sensitivity and specificity of BRAF p.V600E immunostaining on the cell block preparation was 94.4% and 100%, respectively, whereas for the smears it was 80% and 63.6%, respectively.

CONCLUSIONS

BRAF p.V600E immunostaining can be performed reliably on thyroid FNA cell block preparations. However, false-positive results on direct smears limit their utility and therefore need to be interpreted with caution. Cancer Cytopathol 2018;126:406-13. © 2018 American Cancer Society.

Concomitant KIT/BRAF and PDGFRA/BRAF mutations are rare events in gastrointestinal stromal tumors

AIM

The BRAF mutation is a rare pathogenetic alternative to KIT/PDGFRA mutation in GIST and causes Imatinib resistance. A recent description of KIT and BRAF mutations co-occurring in an untreated GIST has challenged the concept of their being mutually exclusive and may account for ab initio resistance to Imatinib, even in the presence of Imatinib-sensitive KIT mutations. BRAF sequencing is generally limited to KIT/PDGFRA wild-type cases. Hence, the frequency of concomitant mutations may be underestimated.

METHODS

We screened for KIT (exon 9, 11, 13, 17), PDGFRA (exon 12,14, 18) and BRAF (exon 15) mutations a series of 407 GIST. Additionally, we evaluated the BRAF V600E mutation-specific antibody, VE1, as a surrogate for V600E mutation, on a series of 313 GIST (24 on whole sections, 288 cases on tissue array), including 6 cases molecularly ascertained to carry the BRAF V600E mutation.

RESULTS

No concomitant KIT/BRAF or PDGFRA/BRAF mutations were detected. BRAF mutation was detected only in one case, wild-type for KIT/PDGFRA. All the 6 BRAF-mutant cases stained positive with the VE1 antibody. A weak VE1 expression was observed in 14/287 (4.9%) BRAF wild-type cases, as observed also in 2/6 BRAF-mutant cases. Overall in our series, sensitivity and specificity of the VE1 antobody were 100% and 95.1%, respectively.

CONCLUSION

The concomitance of BRAF mutation with either KIT or PDGFRA mutation is rare in GIST. In these tumors, moderate/strong VE1 immunoreactivity is a valuable surrogate for molecular analysis. Instead, genotyping is warranted in the presence of weak VE1 staining.

Immunohistochemistry cannot replace DNA analysis for evaluation of BRAF V600E mutations in papillary thyroid carcinoma

INTRODUCTION

The BRAF V600E mutation is the most common genetic event occurring in papillary thyroid cancer (PTC). Recently, the possibility of using immunohistochemistry (IHC) to detect the BRAF V600E mutation has been reported.

MATERIALS AND METHODS

In 140 patients with classical PTC, the status of the BRAF V600E mutation was determined by IHC (using two alternative staining protocols, IHC-1 and IHC-2) and molecular biology methods: Sanger sequencing (SEQ) and real-time PCR (qPCR).

RESULTS

The BRAF V600E mutation was detected in 57.1% (80/140) patients by IHC-1 and 62.9% (88/140) patients by IHC-2. The highest correlation in detecting the BRAF V600E mutation was found between IHC-2 and qPCR (94.2%), and between IHC-1 and qPCR (83.9%). Correlations between IHC-1 and SEQ and between IHC-2 and SEQ were 71.5% and 76.2%, respectively. The IHC-2 protocol had higher sensitivity, PPV, and NPV, and Cohen's kappa than IHC- 1. The presence of BRAF V600E mutation in IHC-2 statistically correlated with age at diagnosis, histopathological stage, and extrathyroidal extension.

CONCLUSIONS

The results obtained in this study indicate a lack of concordance between BRAF V600E detection by IHC and molecular methods. The IHC method cannot replace molecular methods for the detection of the BRAF V600E mutation.

The expression of monocarboxylate transporters in thyroid carcinoma can be associated with the morphological features of BRAF V600E mutation

BRAF ^V600E mutation, usually performed by DNA techniques, is one of the most common diagnostic markers in papillary thyroid carcinoma. Few papers have demonstrated that plump cells (eosinophilic cytoplasms and papillary thyroid carcinoma nuclei) and peculiar sickle-shaped nuclei represent morphological features of BRAF ^V600E on papillary thyroid carcinomas. These features seem to be linked to glycolytic phenotype whereby monocarboxylate transporters 1-4 are hypothesized to have a dominant role as lactate transporters. We investigated the association between these morphological features and monocarboxylate transporters 1 and 4 in 48 cyto-histological samples diagnosed as "positive for malignancy-favoring papillary thyroid carcinoma". These cases were processed with liquid-based cytology and underwent BRAF ^V600E mutational analysis (pyrosequencing) on liquid-based cytology and monocarboxylate transporters immunostaining on histology. The expression of monocarboxylate transporter 1, monocarboxylate transporter 4, glucose trasporter-1 and carbonic anhidrase were scored semi-quantitatively with expression from 0 to 3+ (strong positivity). The 33 mutated and 15 wild type cases showed 100 % cyto-histological concordance. The cytological evaluation revealed plump cells and sickle nuclear shape in 100 % mutated cases. Monocarboxylate transporter 1 yielded 76 % positivity in the mutated cases especially in both the plump cells and sickle-shaped nuclei, whereas the wild types showed 13.3 % positive monocarboxylate transporter 1 (p = 0.00013). Monocarboxylate transporter 4 resulted in 100 % positivity in mutated and 40 % in wild types (p < 0.005). Furthermore, 20 % of the wild types showed weak monocarboxylate transporter 1 nuclear expression associated to a less aggressive behavior. The analysis of glucose trasporter-1 and carbonic anhidrase did not highlight any statistical significance (p > 0.05). This is the first report analyzing the association between monocarboxylate transporter expression and the morphological features of BRAF ^V600E mutated papillary thyroid carcinomas suggesting the possible involvement of lactate in the morphological features.

Cytopathology of Follicular Cell Nodules

The detection of thyroid nodules, consisting of different diseases, represents a common finding in population. Their evaluation and diagnosis are mostly achieved with fine-needle aspiration cytology (FNAC). Even though the majority of thyroid nodules are correctly diagnosed, a total of 25% to 30% of them are classified "indeterminate" comprising lesions with varying risk of malignancy and different types of management. Although the number of thyroid FNACs, including small lesions, is increasing due to the reliance upon sonographic and cytologic interpretations, there are issues concerning cytomorphologic interpretation and interobserver reproducibility. Different classification systems have tried to better define the criteria for inclusion in specific categories and to therefore reduce the rate of indeterminate diagnoses such as atypia of undetermined significance, follicular neoplasms, and suspicious for malignancy. However, the support of ancillary techniques (eg, immunocytochemistry and molecular analysis) are reshaping morphologic diagnoses made on materials obtained from FNAC.

A combination of immunohistochemistry and molecular approaches improves highly sensitive detection of BRAF mutations in papillary thyroid cancer

The optimal method for BRAF mutation detection remains to be determined despite advances in molecular detection techniques. The aim of this study was to compare, against classical Sanger sequencing, the diagnostic performance of two of the most recently developed, highly sensitive methods: BRAF V600E immunohistochemistry (IHC) and peptide nucleic-acid (PNA)-clamp qPCR. BRAF exon 15 mutations were searched in formalin-fixed paraffin-embedded tissues from 86 papillary thyroid carcinoma using the three methods. The limits of detection of Sanger sequencing in borderline or discordant cases were quantified by next generation sequencing. BRAF mutations were found in 74.4 % of cases by PNA, in 71 % of cases by IHC, and in 64 % of cases by Sanger sequencing. Complete concordance for the three methods was observed in 80 % of samples. Better concordance was observed with the combination of two methods, particularly PNA and IHC (59/64) (92 %), while the combination of PNA and Sanger was concordant in 55 cases (86 %). Sensitivity of the three methods was 99 % for PNA, 94.2 % for IHC, and 89.5 % for Sanger. Our data show that IHC could be used as a cost-effective, first-line method for BRAF V600E detection in daily practice, followed by PNA analysis in negative or uninterpretable cases, as the most efficient method. PNA-clamp quantitative PCR is highly sensitive and complementary to IHC as it also recognizes other mutations besides V600E and it is suitable for diagnostic purposes.

Significance of the BRAF mRNA Expression Level in Papillary Thyroid Carcinoma: An Analysis of The Cancer Genome Atlas Data

Background

BRAF^V600E is the most common mutation in papillary thyroid carcinoma (PTC), and it is associated with high-risk prognostic factors. However, the significance of the BRAF mRNA level in PTC remains unknown. We evaluated the significance of BRAF mRNA expression level by analyzing PTC data from The Cancer Genome Atlas (TCGA) database.

Methods

Data from 499 patients were downloaded from the TCGA database. After excluding other PTC variants, we selected 353 cases of classic PTC, including 193 cases with BRAF^V600E and 160 cases with the wild-type BRAF. mRNA abundances were measured using RNA-Seq with the Expectation Maximization algorithm.

Results

The mean BRAF mRNA level was significantly higher in BRAF^V600E patients than in patients with wild-type BRAF (197.6 vs. 179.3, p = 0.031). In wild-type BRAF patients, the mean BRAF mRNA level was higher in cases with a tumor > 2 cm than those with a tumor ≤ 2.0 cm (189.4 vs. 163.8, p = 0.046), and was also higher in cases with lymph node metastasis than in those without lymph node metastasis (188.5 vs. 157.9, p = 0.040). Within BRAF^V600E patients, higher BRAF mRNA expression was associated with extrathyroidal extension (186.4 vs. 216.4, p = 0.001) and higher T stage (188.1 vs. 210.2, p = 0.016).

Conclusions

A higher BRAF mRNA expression level was associated with tumor aggressiveness in classic PTC regardless of BRAF mutational status. Evaluation of BRAF mRNA level may be helpful in prognostic risk stratification of PTC.

When Morphology Meets Somatic Mutations: The New Possible Scenario in Thyroid Fine-Needle Aspiration

This study points to the analysis of the morphological features suggestive of somatic mutations, mostly the BRAFV600E mutation, on cytological samples of thyroid carcinomas. According to the literature, the application of ancillary techniques on cytology comes in handy as a challenging aid in ruling out a malignant outcome on both conventional and liquid-based cytological preparations. However, the evaluation of somatic mutations, including BRAFV600E, usually performed by DNA techniques, may have some limitations in a worldwide diffusion. In this perspective, few authors emphasized the morphological search for BRAFV600E mutations harbored in papillary thyroid carcinoma (PTC) and characterized by specific architectural and cellular findings (i.e. eosinophilic cells defined as 'plump cells' and sickle-shaped nuclei). Hence, the detection of eosinophilic cytoplasm of mutated PTC cells seems to suggest the possible involvement of the 'Warburg effect' pioneering the ability of cancer cells to convert glucose into lactic acid. The recent yields of immunohistochemical expression of monocarboxylate transporters in mutated PTCs may suggest the accumulation of lactate in these plump cells. Equally importantly, the detection of these morphological findings using fine-needle aspiration cytology may be helpful in triaging thyroid lesions and limiting costs. Additionally, it may lead to the stratification of the malignant risk and personalized management in cases with multifocal lesions.

Morphological features that can predict BRAFV600E -mutated carcinoma in paediatric thyroid cytology

OBJECTIVE

BRAF^V600E represents the most common diagnostic marker in papillary thyroid carcinoma (PTC). A few papers have demonstrated the correlation between BRAF^V600E and specific morphological findings on PTCs in the adult population. This is the first reported series investigating cytological morphological parameters in paediatric thyroid carcinoma.

METHODS

One hundred and nineteen paediatric samples (56 male and 63 female patients), diagnosed in the period between April 2013 and July 2015, were enrolled in the study. Fifteen patients with inadequate results were excluded. Cytological cases were processed with liquid-based cytology (LBC). BRAF^V600E and immunocytochemistry for the VE1 antibody were performed on LBC.

RESULTS

The diagnostic series included 10 mutated and 94 wild-type (WT) cases. Twenty two percent surgical samples showed 96% cytohistological concordance. The morphological analysis revealed plump cells (abundant eosinophilic cytoplasm and PTC nuclei) in all 10 mutated cases with only four cases showing a focal (less than 20% of the cells) plump component. None of the WT showed plump cells. A sickle nuclear shape was seen only in the mutated cases. VE1 yielded 100% positivity on mutated cases with three cytohistological discrepancies.

CONCLUSIONS

The BRAF^V600E mutation is also seen in paediatric cytology and the morphological features showed a high accuracy as both predictive mutational parameters and a helpful aid in management mainly of the aggressive BRAF^V600E mutated carcinomas.

Fine-Needle Aspiration with Immunohistochemistry Using a Modified Scrape Cell Block Technique for the Diagnosis of Thyroid and Parathyroid Nodules

OBJECTIVE

To evaluate the diagnostic accuracy of a modified scrape cell block (SCB) technique in a large series of patients. The technique was especially developed and tested for fine-needle aspiration of thyroid and parathyroid nodules.

STUDY DESIGN

Eighty-two ultrasound-guided fine-needle aspiration specimens with the sonographic aspect of a thyroid (n = 33) or a possible parathyroid nodule (n = 49) were studied. Immunohistochemistry (IHC) was used on cell blocks containing plasma, thromboplastin, and selected 3-dimensional cell aggregates scraped off Papanicolaou-stained smears. Antibodies for chromogranin A, thyroglobulin, parathyroid hormone, calcitonin, and carcinoembryonic antibody (CEA) were used. In cases of reduced immunosensitivity or suspected metastases or rare primary tumors, additional IHC markers were employed.

RESULTS

Chromogranin A was expressed in all 28 parathyroid adenomas (PA), in 7 of 8 hyperplastic parathyroid glands, and in 13 of 14 medullary thyroid carcinomas (MTC). When combining positivity for chromogranin A and calcitonin/CEA, the specificity for the detection of MTC was 100%. Parathyroid hormone was expressed in 26 of 36 parathyroid nodules (72.2%). When combining follicular microarchitecture and expression of chromogranin A, the specificity for the detection of parathyroid tissue was 97%.

CONCLUSION

With the modified SCB technique, accurate cytological diagnoses were obtained in 97.6% of 82 patients.

BRAF V600E detection in cytological thyroid samples: A key component of the decision tree for surgical treatment of papillary thyroid carcinoma

BACKGROUND

Whether preoperative knowledge of the BRAF mutation status would help to determine the extent of surgery for thyroid nodules is still under investigation.

METHODS

We developed a method to state the V600E mutation before surgery on fine-needle aspiration (FNA) stained smears checked to contain tumor cells. We evaluated the interest of the preoperative assessment of the mutation for surgical strategy of nodules, diagnosed as malignant, suspicious for malignancy or follicular neoplasms.

RESULTS

The mutation was found in 81% (79 of 97) malignant, 59% (20 of 34) suspicious nodules, and in none of follicular neoplasms (n = 29). Overall, the mutation was detected in 82% of papillary carcinomas. The sensitivity, specificity, and positive and negative predictive values for the diagnosis of malignancy were 75%, 100%, 100%, and 46%, respectively.

CONCLUSION

The preoperative knowledge of the V600E mutation status is fundamental to plan total thyroidectomy with certainty and should be part of the decision tree for the management of thyroid nodules. © 2016 Wiley Periodicals, Inc. Head Neck 38: 1017-1021, 2016.

DIAGNOSIS OF ENDOCRINE DISEASE: High-yield thyroid fine-needle aspiration cytology: an update focused on ancillary techniques improving its accuracy

Thyroid fine-needle aspiration (FNA) cytology is a fast growing field. One of the most developing areas is represented by molecular tests applied to cytological material. Patients that could benefit the most from these tests are those that have been diagnosed as 'indeterminate' on FNA. They could be better stratified in terms of malignancy risk and thus oriented with more confidence to the appropriate management. Taking in to consideration the need to improve and keep high the yield of thyroid FNA, professionals from various fields (i.e. molecular biologists, endocrinologists, nuclear medicine physicians and radiologists) are refining and fine-tuning their diagnostic instruments. In particular, all these developments aim at increasing the negative predictive value of FNA to improve the selection of patients for diagnostic surgery. These advances involve terminology, the application of next-generation sequencing to thyroid FNA, the use of immunocyto- and histo-chemistry, the development of new sampling techniques and the increasing use of nuclear medicine as well as molecular imaging in the management of patients with a thyroid nodule. Herein, we review the recent advances in thyroid FNA cytology that could be of interest to the 'thyroid-care' community, with particular focus on the indeterminate diagnostic category.

Evaluation of the VE1 Antibody in Thyroid Cytology Using Ex Vivo Papillary Thyroid Carcinoma Specimens

Background:

Recently, VE1, a monoclonal antibody against the BRAFV600E mutant protein, has been investigated in terms of its detection of the BRAFV600E mutation. Although VE1 immunostaining and molecular methods used to assess papillary thyroid carcinoma in surgical specimens are in good agreement, evaluation of VE1 in thyroid cytology samples is rarely performed, and its diagnostic value in cytology has not been well established. In present study, we explored VE1 immunoexpression in cytology samples from ex vivo papillary thyroid carcinoma specimens in order to minimize limitations of low cellularity and sampling/targeting errors originated from thyroid fineneedle aspiration and compared our results with those obtained using the corresponding papillary thyroid carcinoma tissues.

Methods:

The VE1 antibody was evaluated in 21 cases of thyroid cytology obtained directly from ex vivo thyroid specimens. VE1 immunostaining was performed using liquid-based cytology, and the results were compared with those obtained using the corresponding tissues.

Results:

Of 21 cases, 19 classic papillary thyroid carcinomas had BRAFV600E mutations, whereas two follicular variants expressed wild-type BRAF. VE1 immunoexpression varied according to specimen type. In detection of the BRAFV600E mutation, VE1 immunostaining of the surgical specimen exhibited 100% sensitivity and 100% specificity, whereas VE1 immunostaining of the cytology specimen exhibited only 94.7% sensitivity and 0% specificity.

Conclusions:

Our data suggest that VE1 immunostaining of a cytology specimen is less specific than that of a surgical specimen for detection of the BRAFV600E mutation, and that VE1 immunostaining of a cytology specimen should be further evaluated and optimized for clinical use.

BRAF Immunohistochemistry Using Clone VE1 is Strongly Concordant with BRAF(V600E) Mutation Test in Papillary Thyroid Carcinoma

The aim of this study was to investigate the concordance between BRAF(V600E) mutation test and immunohistochemistry (IHC) and determine the diagnostic accuracy of IHC for papillary thyroid carcinoma (PTC) through a systematic review, meta-analysis, and diagnostic test accuracy review. The current systematic review and meta-analysis included 1141 PTCs in 11 eligible studies. We investigated the concordance rate and performed subgroup analysis using tissue and cytologic samples. Diagnostic test accuracy review was conducted and calculated using the value of area under curve (AUC) on the summary receiver operating characteristic (SROC) curve. The positive rate of BRAF IHC was 79.1% (903 of 1141 cases), and the BRAF(V600E) mutation was found in 76.6% (874 of 1141 cases). The concordance rates were 0.921 (95% confidence interval (CI) 0.877-0.950) and 0.894 (95% CI 0.801-0.946) in IHC positive and negative subgroups, respectively. In the diagnostic test accuracy review, the pooled sensitivity and specificity were 0.97 (95% CI 0.95-0.98) and 0.78 (95% CI 0.72-0.83). The value of AUC on SROC curve was 0.983, and diagnostic odds ratio was 164.28 (95% CI 57.69-467.80). Our results showed that BRAF IHC was strongly concordant with BRAF mutation test and had high diagnostic accuracy in BRAF mutation analysis of PTC.

Mutant-specific BRAF and CD117 immunocytochemistry potentially facilitate risk stratification for papillary thyroid carcinoma in fine-needle aspiration biopsy specimens

The study aims to test whether combination of mutant-specific BRAF and CD117 immunocytochemical (ICC) staining stratifies probability for papillary thyroid carcinoma (PTC) in thyroid fine-needle aspiration biopsy (FNAB) specimens. A consecutive cohort of cases diagnosed as atypia of undetermined significance (AUS) or suspicious for malignancy-suspicious for papillary thyroid carcinoma (SM-SPTC) from 30 December, 2011 to 23 October, 2014 in a single institute was enrolled. Forty cytologically benign and 50 cytologically diagnosed PTC within the same time span were also included. CD117 and mutant-specific BRAF (BRAF VE1) ICC staining was performed. Association of BRAF VE1 and CD117 expression with final diagnosis was analyzed. Both BRAF VE1 and CD117 showed good performance in distinguishing PTC from benign nodules. Combination of BRAF VE1 and CD117 stratified 180 cases into three categories: BRAF VE1 positive regardless of CD117 expression (ICC-malignant), BRAF VE1 negative plus low level of CD117 expression (ICC-intermediate), and BRAF VE1 negative plus high level of CD117 expression (ICC-benign), which was associated with 100, 75.6, and 0 % of malignancy. Combination of mutant-specific BRAF and CD117 ICC may potentially facilitate the PTC risk stratification in FNAB thyroid nodule specimens.

VE1 immunohistochemical detection of the BRAF V600E mutation in thyroid carcinoma: a review of its usefulness and limitations

The BRAF V600E mutation is a valuable prognostic factor in thyroid carcinoma despite lingering debate. Successful immunohistochemical (IHC) detection of the BRAF V600E mutation using a VE1 antibody was introduced recently. The objective of this study was to verify the usefulness of IHC detection of the BRAF V600E mutation in thyroid carcinoma using the VE1 antibody. IHC detection of BRAF V600E was performed on various thyroid carcinoma subtypes. IHC results were compared with those obtained from real-time polymerase chain reaction (PCR) detection. Discordant cases were re-examined using a direct sequencing method following nested PCR amplification. The BRAF V600E mutation was detected in 68 % (71/104) of papillary carcinoma cases and 78 % (7/9) of anaplastic carcinoma cases. The mutation was not detected in patients with follicular carcinoma (0/18) or in medullary carcinoma (0/21). The overall sensitivity and specificity of IHC using the VE1 antibody were 100 and 94 %, respectively, suggesting that molecular-based results were indeterminable in four VE1-positive cases. IHC using the VE1 antibody is a highly sensitive and specific method for BRAF V600E mutation detection and may represent a future replacement for DNA-based molecular tests.

Detection of BRAF mutations on direct smears of thyroid fine-needle aspirates through cell transfer technique

OBJECTIVES

To determine the utility of the cell transfer technique (CTT) for BRAF molecular testing on thyroid fine-needle aspiration (FNA) specimens.

METHODS

Polymerase chain reaction (PCR)-based BRAF molecular testing was performed on tissues obtained through CTT from both air-dried and ethanol-fixed direct smears of thyroid FNA specimens and then compared with the corresponding thyroidectomy formalin-fixed, paraffin-embedded (FFPE) tissues on 30 cases.

RESULTS

BRAF testing was successfully performed on 29 of 30 air-dried CTT, 27 of 30 ethanol-fixed CTT, and 27 of 30 FFPE tissues. The results exhibited 11, 13, and 13 BRAF mutations and 18, 14, and 14 wild types for the air-dried CTT, the ethanol-fixed CTT, and the FFPE tissues, respectively. The concordance rate was 96% between air-dried and ethanol-fixed CTT tissues, 88% between air-dried CTT and FFPE tissues, and 92% between ethanol-fixed CTT and FFPE tissues.

CONCLUSIONS

PCR-based BRAF mutational testing can be reliably performed on the direct smears of the thyroid FNA specimens through the application of CTT.

Thyroid core needle biopsy: taking stock of the situation

Recently, the microhistologic evaluation by core needle biopsy (CNB) has been reported as high accurate to diagnose thyroid nodules with previous indeterminate or not adequate fine-needle aspiration cytology. In addition, sparse data have been reported regarding the use of CNB in other conditions. Aim of this review was to furnish the state of the art of this topic by summarizing published data about the diagnostic performance of CNB in thyroid lesions, and provide an easy to use reference for clinical practice. Sources encompass studies published through May 2014. Original articles were investigated and following specific aspects were discussed: 1. The "large" needle biopsy in 90's; 2. Complications by and patient's comfort with thyroid CNB; 3. Advantages provided by examination of a microhistologic sample of thyroid nodule; 4. Use of CNB in thyroid nodules with previous not adequate (Thy 1/Class 1/Category I) cytology; 5. Use of CNB in thyroid neoplasms (Thy 3/Class 3/Category III-IV) cytology; 6. Use of CNB in specific ultrasonographic presentations of thyroid nodules or in patients with peculiar clinical contexts; 7. First-line approach by CNB in thyroid nodules; 8. Immunohistochemistry and molecular tests on CNB samples; and 9. Future perspective.

Liquid-based cytology and cell block immunocytochemistry in veterinary medicine: comparison with standard cytology for the evaluation of canine lymphoid samples

Liquid-based Cytology (LBC) consists of immediate wet cell fixation with automated slide preparation. We applied LBC, cell block (CB) and immunocytochemistry to diagnose canine lymphoma and compare results with conventional cytology. Samples from enlarged lymph nodes of 18 dogs were collected and fixed in preservative solution for automated slide preparation (LBC), CB inclusion and immunophenotyping. Two CB techniques were tested: fixed sediment method (FSM) and agar method (AM). Anti-CD79a, anti-Pax5, anti-CD3 and anti-Ki67 were used in immunocytochemistry. LBC smears showed better nuclear and nucleolar definition, without cell superposition, but presented smaller cell size and worse cytoplasmic definition. FSM showed consistent cellular groups and were employed for immunocytochemistry, while AM CBs presented sparse groups of lymphocytes, with compromised analysis. Anti-Pax-5 allowed B-cell identification, both in reactive and neoplastic lymph nodes. Our preliminary report suggests that LBC and FSM together may be promising tools to improve lymphoma diagnosis through fine-needle aspiration.

BRAF V600E mutation-specific antibody: A review

The significance of BRAF mutations in neoplasia was first recognized in 2002 when mutations were discovered in a broad range of cancers. Numerous subsequent studies expanded our understanding of BRAF V600E as a critical diagnostic, prognostic, and predictive biomarker in many cancers. Additionally, the advent of small-molecule inhibitors of BRAF V600E rendered assessment of BRAF mutation status essential in tumors such as melanoma. In clinical practice, evaluation of BRAF mutation status has routinely been performed by DNA-based assays utilizing polymerase chain reaction (PCR). However, molecular testing is not available at many hospitals since it is time-consuming, expensive, and requires expertise in molecular techniques. The first BRAF V600E-specific antibody was reported in 2011 (clone VE1). A purified version of this antibody as well as a second monoclonal antibody targeted to BRAF V600E is now commercially available. In this review, clinicopathologic characteristics associated with BRAF-mutant tumors will be highlighted, and the prognostic and predictive implications of a BRAF V600E mutation will be discussed with a focus on melanoma, thyroid carcinoma and colorectal carcinoma. Additionally, we will review the correlation between immunohistochemistry and molecular results and deliberate how BRAF immunohistochemistry might be utilized in the evaluation of these tumors.

Different approaches for interpretation and reporting of immunohistochemistry analysis results in the bone tissue - a review

BACKGROUND

Immunohistochemistry (IHC) is a well-established, widely accepted method in both clinical and experimental parts of medical science. It allows receiving valuable information about any process in any tissue, and especially in bone. Each year the amount of data, received by IHC, grows in geometric progression. But the lack of standardization, especially on the post-analytical stage (interpreting and reporting of results), makes the comparison of the results of different studies impossible.

METHODS

Comprehensive PubMED literature search with a combination of search words "immunohistochemistry" and "scoring system" was performed and 773 articles describing IHC results were identified. After further manual analysis 120 articles were selected for detailed evaluation of used approaches.

RESULTS

Six major approaches to the interpretation and presentation of IHC analysis results were identified, analyzed and described.

CONCLUSIONS

The overview of the existing approaches in evaluation and interpretation of IHC data, which are provided in the article, can be used in bone tissue research and for either better understanding of existing scoring systems or developing a new one. Standard multiparametric, semiquantitative IHC scoring systems should simplify and clarify the process of interpretation and reporting of received data.

VIRTUAL SLIDES

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/13000_2014_221.

Clinicopathologic correlations of the BRAFV600E mutation, BRAF V600E immunohistochemistry, and BRAF RNA in situ hybridization in papillary thyroid carcinoma

BACKGROUND

The BRAF(V600E) mutation is the most common genetic alteration in papillary thyroid carcinoma (PTC). The aim of this study is to analyze the clinicopathologic correlations of the BRAF(V600E) mutation, BRAF V600E immunohistochemistry (IHC) and BRAF RNA in situ hybridization (ISH) in PTC.

METHODS

This study included 467 patients with PTC who underwent surgical resection. We studied the BRAF(V600E) mutation using real-time PCR and BRAF V600E and BRAF RNA ISH using tissue microarray (TMA).

RESULTS

The frequencies of a positive BRAF(V600E) mutation by real-time PCR, positive BRAF V600E IHC, and high BRAF RNA ISH were 84%, 86%, and 70%, respectively, in PTC. Conventional PTC had higher positive rates in all three tests than other histologic types. The BRAF(V600E) mutation, BRAF V600E IHC, low ΔCt, and high BRAF RNA ISH were significantly associated with lymph node metastasis. The BRAF(V600E) mutation was significantly associated with positive immunostaining for BRAF V600E mutant protein (P<0.001) overall, with high BRAF RNA ISH only in the follicular variant (P=0.035). No significant correlation was noted between BRAF V600E IHC and BRAF RNA ISH. The sensitivity of BRAF V600E IHC for the BRAF(V600E) mutation was 95%, and the specificity was 61% overall, 96% and 54% in the conventional type, and 85% and 70% in the follicular variant.

CONCLUSIONS

Our results showed that positive BRAF V600E IHC significantly correlated with the BRAF(V600E) mutation. This suggests its clinical utility as a screening tool for the BRAF(V600E) mutation. In addition, a high BRAF RNA ISH score could be a candidate marker of aggressive behavior in BRAF(V600E) mutation-positive cases of PTC.