EphB3 protein is a potential ancillary diagnostic biomarker for thyroid cancers

OBJECTIVE

To investigate the expression of ephrin type B receptor 3 (EphB3) in thyroid tumors and its usage as an ancillary diagnostic biomarker for thyroid tumors.

METHODS

Formalin-fixed and paraffin-embedded (FFPE) tissue samples (78 cases) and FNAC samples (57 cases) were assessed with the EphB3 antibody using immunohistochemistry. PTC and other thyroid follicular tumors were compared regarding their EphB3 expression. Sanger sequencing was used to assess for the presence of a BRAF V600E mutation.

RESULTS

EphB3 was positive in 81.8 % (27/33) of papillary thyroid carcinoma (PTC), 83.3 % (5/6) of medullary thyroid carcinoma (MTC), 25 % (1/4) of hyperplastic/adenomatoid nodule (HN), 14.3 % (1/7) of follicular adenoma (FA), and negative in follicular tumors of uncertain malignant potential (FT-UMP) (0/13), noninvasive follicular neoplasm with papillary-like nuclear features (NIFTP) (0/7), thyroid follicular carcinoma (TFC) (0/4), Hashimoto's thyroiditis (0/4), and normal thyroid follicular tissues (0/33). In cellular blocks, EphB3 was positive in 87.1 % (20/23) of PTC, 75 % (3/4) of MTC, 20 % (2/10) of HN, and negative in atypia of undetermined significance/follicular lesion of undetermined significance (AUS/FLUS) (0/20) and normal thyroid follicular cells (0/10).

CONCLUSION

EphB3 is expressed in the majority of PTC, but less so in benign follicular nodules. EphB3 expression in fine needle aspiration cytology (FNAC) specimens can be used as a diagnostic tool to differentiate thyroid cancer from other follicular lesions in its differential diagnosis, especially AUS/FLUS and PTC.

Diagnostic Challenges during Inflammation and Cancer: Current Biomarkers and Future Perspectives in Navigating through the Minefield of Reactive versus Dysplastic and Cancerous Lesions in the Digestive System

In the setting of pronounced inflammation, changes in the epithelium may overlap with neoplasia, often rendering it impossible to establish a diagnosis with certainty in daily clinical practice. Here, we discuss the underlying molecular mechanisms driving tissue response during persistent inflammatory signaling along with the potential association with cancer in the gastrointestinal tract, pancreas, extrahepatic bile ducts, and liver. We highlight the histopathological challenges encountered in the diagnosis of chronic inflammation in routine practice and pinpoint tissue-based biomarkers that could complement morphology to differentiate reactive from dysplastic or cancerous lesions. We refer to the advantages and limitations of existing biomarkers employing immunohistochemistry and point to promising new markers, including the generation of novel antibodies targeting mutant proteins, miRNAs, and array assays. Advancements in experimental models, including mouse and 3D models, have improved our understanding of tissue response. The integration of digital pathology along with artificial intelligence may also complement routine visual inspections. Navigating through tissue responses in various chronic inflammatory contexts will help us develop novel and reliable biomarkers that will improve diagnostic decisions and ultimately patient treatment.

Carcinoma of unknown primary (CUP): an update for histopathologists

Carcinoma of unknown primary (CUP) is a heterogeneous group of metastatic cancers in which the site of origin is not identifiable. These carcinomas have a poor outcome due to their late presentation with metastatic disease, difficulty in identifying the origin and delay in treatment. The aim of the pathologist is to broadly classify and subtype the cancer and, where possible, to confirm the likely primary site as this information best predicts patient outcome and guides treatment. In this review, we provide histopathologists with diagnostic practice points which contribute to identifying the primary origin in such cases. We present the current clinical evaluation and management from the point of view of the oncologist. We discuss the role of the pathologist in the diagnostic pathway including the control of pre-analytical conditions, assessment of sample adequacy, diagnosis of cancer including diagnostic pitfalls, and evaluation of prognostic and predictive markers. An integrated diagnostic report is ideal in cases of CUP, with results discussed at a forum such as a molecular tumour board and matched with targeted treatment. This highly specialized evolving area ultimately leads to personalized oncology and potentially improved outcomes for patients.

Three-dimensional nuclear architecture distinguishes thyroid cancer histotypes

Molecular markers can serve as diagnostic tools to support pathological analysis in thyroid neoplasms. However, because the same markers can be observed in some benign thyroid lesions, additional approaches are necessary to differentiate thyroid tumor subtypes, prevent overtreatment and tailor specific clinical management. This applies particularly to the recently described variant of thyroid cancer referred to as noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP). This variant has an estimated prevalence of 4.4% to 9.1% of all papillary thyroid carcinomas worldwide. We studied 60 thyroid lesions: 20 classical papillary thyroid carcinoma (CPTC), 20 follicular variant of PTC (FVPTC) and 20 NIFTP. We examined morphological and molecular features to identify parameters that can differentiate NIFTP from the other PTC subtypes. When blindly investigating the nuclear architecture of thyroid neoplasms, we observed that NIFTP has significantly longer telomeres than CPTC and FVPTC. Super-resolved 3D-structured illumination microscopy demonstrated that NIFTP is heterogeneous and that its nuclei contain more densely packed DNA and smaller interchromatin spaces than CPTC and FVPTC, a pattern that resembles normal thyroid tissue. These data are consistent with the observed indolent biological behavior and favorable prognosis associated with NIFTP, which lacks BRAFV600E mutations. Of note, next-generation thyroid oncopanel sequencing was unable to distinguish the thyroid cancer histotypes in our study cohort. In summary, our data suggest that 3D nuclear architecture can be a powerful analytical tool to diagnose and guide clinical management of NIFTP.

Performance of ACR TI-RADS and the Bethesda System in Predicting Risk of Malignancy in Thyroid Nodules at a Large Children's Hospital and a Comprehensive Review of the Pediatric Literature

While thyroid nodules are less common in children than in adults, they are more frequently malignant. However, pediatric data are scarce regarding the performance characteristics of imaging and cytopathology classification systems validated to predict the risk of malignancy (ROM) in adults and select those patients who require fine-needle aspiration (FNA) and possibly surgical resection. We retrospectively reviewed the electronic medical records of all patients 18 years of age or younger who underwent thyroid FNA at our institution from 1 July 2015 to 31 May 2022. Based on surgical follow-up from 74 of the 208 FNA cases, we determined the ROM for the American College of Radiology Thyroid Imaging Reporting and Data System (ACR TI-RADS) ultrasound risk stratification system and The Bethesda System for Reporting Thyroid Cytopathology and added our results to those of pediatric cohorts from other institutions already published in the literature. We found the following ROMs for 1458 cases using ACR TI-RADS (TR): TR1. Benign: 2.2%, TR2. Not Suspicious: 9.3%, TR3. Mildly Suspicious: 16.6%, TR4. Moderately Suspicious: 27.0%, and TR5. Highly Suspicious 76.5%; and for 5911 cases using the Bethesda system: Bethesda I. Unsatisfactory: 16.8%, Bethesda II. Benign: 7.2%, Bethesda III: Atypia of Undetermined Significance: 29.6%, Bethesda IV. Follicular Neoplasm: 42.3%, Bethesda V. Suspicious for Malignancy: 90.8%, and Bethesda VI. Malignant: 98.8%. We conclude that ACR TI-RADS levels imply higher ROMs for the pediatric population than the corresponding suggested ROMs for adults, and, in order to avoid missing malignancies, we should consider modifying or altogether abandoning size cutoffs for recommending FNA in children and adolescents whose thyroid glands are smaller than those of adults. The Bethesda categories also imply higher ROMs for pediatric patients compared to adults.

Serum Anti-Thyroglobulin Autoantibodies Are Specific in Predicting the Presence of Papillary-like Nuclear Features and Lymphocytic Infiltrate in the Thyroid Gland

(1) Background: Previous studies have reported a correlation between serum anti-Thyroglobulin-antibodies (TgAb) and papillary thyroid carcinoma. The aim of our study was to evaluate whether serum TgAb and anti-thyroid-peroxidase antibody (TPO) positivity was also related to pre-neoplastic histological changes such as papillary-like nuclear features (PLNF) and with the presence of lymphocytic infiltrate (LI) in thyroid surgical specimens. (2) Methods: The study was retrospectively carried out on 70 consecutively recruited patients who underwent thyroidectomy for benign process and whose TgAb and TPOAb values were retrieved from clinical records. Histological sections of thyroid surgical samples were revised, looking for PLNF and lymphocytic infiltrate. HBME1 expression was assessed by immunohistochemistry. (3) Results: Our results showed a significant association between TgAb, PLNF, and lymphocytic infiltrate. The presence of TgAb was highly specific, but less sensitive, in predicting the presence of PLNF (sensitivity = 0.6, specificity = 0.9; positive predictive value (PPV) = 0.88; negative predictive value (NPV) = 0.63). TgAb positivity showed a good association with the presence of lymphocytic infiltrate (sensitivity = 0.62, specificity = 0.9; PPV = 0.88 and NPV = 0.68). HBME1 immunoreactivity was observed in the colloid of follicles showing PLNF and/or closely associated with LI. (4) Conclusions: The presence of PLNF and LI is associated with serum TgAb positivity. The presence of TgAb and of LI could be triggered by an altered thyroglobulin contained in the HBME1-positive colloid, and could be a first defense mechanism against PLNF that probably represent early dysplastic changes in thyrocytes.

Immunohistochemistry in the pathologic diagnosis and management of thyroid neoplasms

The use of immunohistochemistry cannot be underestimated in the everyday practice of thyroid pathology. It has evolved over the years beyond the traditional confirmation of thyroid origin to molecular profiling and the prediction of clinical behavior. In addition, immunohistochemistry has served to implement changes in the current thyroid tumor classification scheme. It is prudent to perform a panel of immunostains, and the immunoprofile should be interpreted in light of the cytologic and architectural features. Immunohistochemistry can also be easily performed in the limited cellularity specimen preparation generated from thyroid fine-needle aspiration and core biopsy; however, it will require laboratory validation of immunostains specific to these preparations to avoid diagnostic pitfalls. This review discusses the application of immunohistochemistry in thyroid pathology with a focus on limited cellularity preparations.

Papillary Thyroid Carcinoma With Breast and Bone Metastasis

Papillary thyroid carcinoma is the most common thyroid malignant tumor and usually has a fine prognosis. The most common metastatic site is the cervical lymph node, and distant metastasis is rare. This report describes a female patient with papillary thyroid carcinoma who presented with multiple metastases in the cervical lymph nodes, breast, and spine. The patient's disease course lasted 11 years, and eventually metastatic cancer led to the patient's death. We also analyzed the survival rate and median survival time of papillary thyroid carcinoma with multiple organ metastases using data in the literature.

Cardioprotective Effects of 6-Gingerol against Alcohol-Induced ROS-Mediated Tissue Injury and Apoptosis in Rats

The present study investigated the cardioprotective properties of 6-gingerol against alcohol-induced ROS-mediated cardiac tissue damage in rats. Experiments were conducted on 4 groups of rats, orally treated with control, 6-gingerol (10 mg/kg body weight), alcohol (6 g/kg body weight) and combination of 6-gingerol plus alcohol for two-month. In the results, we found 6-ginger treatment to alcohol-fed rats substantially suppressed ROS production in cardiac tissue. Alcohol-induced elevated 8-OHDG and protein carbonyls which represent oxidative modification of DNA and proteins were completely reversed by 6-gingerol. This was further endorsed by restored superoxide dismutase and catalase activities with 6-gingerol against alcohol-induced loss. The elevated cardiac biomarkers (CK-MB, cTn-T, cTn-I) and dyslipidemia in alcohol-intoxicated rats was significantly reversed by 6-gingerol. Furthermore, alcohol-induced apoptosis characterized by overexpression of cytochrome C, caspase-8 and caspase-9 was diminished with 6-gingerol treatment. Transmission electron microscope images conferred the cardioprotective properties of 6-gingerol as we have seen less structural derangements in mitochondria and reappearance of myofilaments. Our findings conclude that 6-ginger effectively protect alcohol-induced ROS-mediated cardiac tissue damage, which may be due to its potent antioxidant efficacy. Therefore, 6-gingerol could be a potential therapeutic molecule that can be used in the treatment of alcohol-induced myocardial injury.

Diagnostic and prognostic value of Stanniocalcin 1 expression in papillary thyroid cancer

PURPOSE

To evaluate the potential role of immunohistochemical changes in stanniocalcin 1 (STC1) and stanniocalcin 2 (STC2) expressions in papillary thyroid cancer (PTC) tissues in the disease's diagnosis and to investigate their relationship with classical clinicopathological prognostic factors.

METHODS

The study included 100 patients with PTC. Normal thyroid tissue adjacent to the tumor was taken as the control group. Clinicopathological prognostic features at the time of diagnosis of patients were recorded. STC1 and STC2 expressions of tumor tissue and adjacent normal tissue were determined immunohistochemically.

RESULTS

The sensitivity of STC1 in the diagnosis of PTC was 93%, the specificity was 94%, positive predictive value (PPV) 93.9%, and negative predictive value (NPV) 93.1%. It was determined that the STC1 staining score in tumor tissue was positively correlated with the disease TNM stage score (r = 0.259, p = 0.009) and the increase in STC1 staining score were independent risk factors that increased the risk of lymph node metastasis (R² = 0.398, p < 0.001). While 21% of the tumor tissues were stained with STC2, none of the normal thyroid tissues adjacent to the tumor tissue showed any staining with STC2. No correlation was found between STC2 immunohistochemical staining of tumor tissue and clinicopathological risk factors for the disease.

CONCLUSION

Increased STC1 expression in thyroid lesions may be helpful in diagnosing PTC. In addition, since increased STC1 expression in PTC tissues is associated with the risk of lymph node metastasis, it may be an efficient marker for predicting the prognosis of the disease.

Carcinoma of Unknown Primary Origin: Application of Immunohistochemistry With Emphasis to Different Cytokeratin 7 and 20 Staining Patterns

BACKGROUND

Although the primary origin of some carcinomas may be obscure to clinicians, its identification is crucial as it affects prognosis and treatment (especially novel targeted therapies). Immunohistochemistry (IHC) may be helpful in identifying the primary origin of carcinomas. This retrospective survey aimed to evaluate the frequency and accuracy of each IHC marker used to determine the origin of carcinomas.

METHODS

The review of pathology department archives revealed 307 cases of cancer of unknown primary origin (CUP) between 2015 and 2020, which were accessible in the department archives. Demographic information, site of biopsy, clinical and pathologic diagnoses, and IHC results of the patients were collected.

RESULTS

The patients included 157 (51.15%) men and 150 (48.85%) women. The age of the patients ranged from 14 to 92 years, including 106 (34.5%) expired cases. In 27% of cases, the primary origin of carcinoma remained unknown. The agreement between pathologic and clinical diagnoses was 59%. The most common pattern of cytokeratin (CK) expression in CUP was CK7+/CK20- (55.3%), followed by CK7-/CK20- (19%), CK7+/CK20+ (15%), and CK7-/CK20+ (10.7%), respectively.

CONCLUSION

The IHC analysis may improve the diagnosis of CUPs. However, the origin of some cases remains unknown despite an IHC analysis, thereby necessitating the use of more diagnostic procedures or gene expression studies for reaching a definitive diagnosis.

American Head and Neck Society Endocrine Surgery Section and International Thyroid Oncology Group consensus statement on mutational testing in thyroid cancer: Defining advanced thyroid cancer and its targeted treatment

BACKGROUND

The development of systemic treatment options leveraging the molecular landscape of advanced thyroid cancer is a burgeoning field. This is a multidisciplinary evidence-based statement on the definition of advanced thyroid cancer and its targeted systemic treatment.

METHODS

An expert panel was assembled, a literature review was conducted, and best practice statements were developed. The modified Delphi method was applied to assess the degree of consensus for the statements developed by the author panel.

RESULTS

A review of the current understanding of thyroid oncogenesis at a molecular level is presented and characteristics of advanced thyroid cancer are defined. Twenty statements in topics including the multidisciplinary management, molecular evaluation, and targeted systemic treatment of advanced thyroid cancer are provided.

CONCLUSIONS

With the growth in targeted treatment options for thyroid cancer, a consensus definition of advanced disease and statements regarding the utility of molecular testing and available targeted systemic therapy is warranted.

Diagnostic Challenges in the Cytology of Thymic Epithelial Neoplasms

Simple Summary

Thymic epithelial neoplasms, including thymoma, thymic carcinoma, and thymic neuroendocrine neoplasms, constitute the majority of anterior mediastinal masses. Fine needle aspirations (FNA) of mediastinal masses are infrequently encountered and are highly challenging to interpret. Thymic neoplasms display a significant degree of histologic diversity and have overlapping morphologic features with tumors from other sites. However, when properly interpreted alongside ancillary studies and radiologic findings, FNAs can yield clinically actionable results. This review aims to illustrate the usefulness and diagnostic pitfalls of thymic FNAs to assist pathologists in analyzing these specimens.

Abstract

Thymic epithelial neoplasms are rare tumors that constitute the majority of anterior mediastinal masses. They are classified as thymomas, thymic carcinomas, and thymic neuroendocrine neoplasms. Biopsy diagnosis is not common, and most tumors are surgically resected. Biopsy, including cytology, is indicated when a non-surgical entity is suspected or in cases of locally advanced disease. Smears of thymomas consist of round or spindle epithelial cells admixed with varying amounts of lymphocytes depending on the type of thymoma. Smears of thymic carcinoma and thymic neuroendocrine neoplasms are often indistinguishable from corresponding tumor types from other organs. Accurate cytological diagnosis can be difficult due to the histological diversity of thymomas, as well as the morphological features that certain thymic tumors share with similar tumors from other organs. However, fine needle aspiration (FNA) of anterior mediastinal masses can provide clinically actionable information and can be used to determine whether lesions require surgical, systemic, or local noninvasive treatments. Ancillary studies, namely, immunocytochemical stains, flow cytometry, and radiology, are important tools in the evaluation of thymic aspirates. This review discusses the utility and limitations of thymic FNAs and illustrates the diagnostic features and pitfalls of these specimens.

Mandibular metastasis of follicular thyroid carcinoma: A case report along with the concise review of literature

Metastasis is one of the most common consequences of malignant tumors, and it is one of the leading causes of morbidity and mortality. Metastatic cancers to oral cavity are extremely rare. Moreover, the true incidence has yet to be determined. Despite their rarity, they are important clinically, since they can be the first and the only evidence of spread in many situations. Breast, kidney, lung, prostate and gastrointestinal tract are the most common sources of metastases in the oral cavity. Thyroid carcinoma is the most prevalent type of endocrine cancer, yet it rarely spreads to the oral cavity. After papillary thyroid carcinoma, follicular thyroid carcinoma is the second-most frequent kind of thyroid cancer. Jawbones are more commonly affected than soft tissues. Literature research revealed that till date, 44 cases of metastatic follicular thyroid cancer to the jawbones have been documented with mandibular preponderance (40 cases). With the rising occurrence of oral metastatic tumors in recent years, it has become increasingly important to diagnose them early to avoid future consequences. We present here an unusual case of metastatic follicular thyroid cancer in the mandible of an elderly adult along with a comprehensive review of the literature.

Can We Predict Differentiated Thyroid Cancer Behavior? Role of Genetic and Molecular Markers

Thyroid cancer is ranked in ninth place among all the newly diagnosed cancer cases in 2020. Differentiated thyroid cancer behavior can vary from indolent to extremely aggressive. Currently, predictions of cancer prognosis are mainly based on clinicopathological features, which are direct consequences of cell and tissue microenvironment alterations. These alterations include genetic changes, cell cycle disorders, estrogen receptor expression abnormalities, enhanced epithelial-mesenchymal transition, extracellular matrix degradation, increased hypoxia, and consecutive neovascularization. All these processes are represented by specific genetic and molecular markers, which can further predict thyroid cancer development, progression, and prognosis. In conclusion, evaluation of cancer genetic and molecular patterns, in addition to clinicopathological features, can contribute to the identification of patients with a potentially worse prognosis. It is essential since it plays a crucial role in decision-making regarding initial surgery, postoperative treatment, and follow-up. To date, there is a large diversity in methodologies used in different studies, frequently leading to contradictory results. To evaluate the true significance of predictive markers, more comparable studies should be conducted.

Accuracy of fine-needle aspiration of lymph nodes: A cancer center's experience

INTRODUCTION

Lymph node fine needle aspiration (LN-FNA) is a minimally invasive method of evaluating lymphadenopathy. Nonetheless, its use is not widely accepted due to the lack of guidelines and a cytopathological categorisation that directly relates to management. We report our experience with LN FNA at a large Cancer Center in Latin America.

METHODS

We retrospectively collected cytological cases of lymph node FNA from the department of pathology at AC Camargo Cancer Center performed over a 2-year period. Data extracted included LN location, age, sex and final cytological diagnosis. Patients that had undergone neoadjuvant chemotherapy and/or cases for which the surgery specimen location was not clearly reported were excluded. For those cases with surgical reports, risk of malignancy was calculated for each diagnostic category, along with overall performance of cytology. False positive cases were reviewed to assess any possible misinterpretation or sampling errors.

RESULTS

A total of 1730 LN-FNA were distributed as follows: 62 (3.5%) non-diagnostic (ND); 1123 (64.9%) negative (NEG), 19 (1.1%) atypical (ATY), 53 (3.1%) suspicious for malignancy (SUS), and 473 (27.3%) positive (POS). Surgical reports were available for 560 cases (32.4%). Risk of malignancy (ROM) for each category was 33.3% for ND, 29.9% for NEG, 25% for ATY, 74.2% for SUS and 99.6% for POS. Overall sensitivity, specificity, negative predictive value (NPV) and positive predictive value (PPV) were 78.5%, 99.4%, 70.2% and 99.6%, respectively.

CONCLUSION

Lymph node FNA is a very specific and accurate exam, which is reliable in the detection of lymph node metastasis and other causes of lymphadenopathy.

Diagnostic challenges in the gray-zone lesions of fine-needle aspiration cytology

Fine-needle aspiration cytology (FNAC) is an excellent technique for rapid diagnosis due to its speed, accuracy, and cost-effectiveness. However, there are many gray-zone areas in cytology that needs attention. These lesions in the aspiration cytology can be overcome by applying the selective use of the series of tests. This review discusses the diagnostic challenges in the gray-zone areas in FNAC. It emphasizes the use of selective ancillary techniques to solve the problems in this area.

Evaluation of E-Cadherin and β-Catenin Immunoreactivity for Determining Undifferentiated Cells in Anaplastic Thyroid Carcinoma

INTRODUCTION

An immunohistochemical study has occasionally been performed to diagnose anaplastic thyroid carcinoma (ATC). However, antibodies to confirm the undifferentiated nature of ATC have not yet been evaluated. The aim of this study was to evaluate E-cadherin and β-catenin expressions in immunoreactivity to determine undifferentiated carcinoma cells in the diagnosis of ATC.

METHODS

We immunohistochemically examined 29 ATCs, 30 poorly differentiated thyroid carcinomas (PDTCs), 22 well-differentiated thyroid carcinomas (WDTCs), and 3 squamous cell carcinomas. Antibodies for thyroid transcription factor-1 (TTF-1), paired-box gene 8 (PAX8), β-catenin, and E-cadherin were used.

RESULTS

All WDTCs tested positive for TTF-1, PAX8, and E-cadherin. The positive rates of TTF-1, PAX8, and E-cadherin were 93.3, 93.3, and 100%, respectively, in PDTCs and 17.2, 51.7, and 10.3%, respectively, in ATCs. WDTC expressed the lateral cell membrane staining for β-catenin and E-cadherin, whereas PDTC showed circumferential cell membranous expression (fishnet pattern). β-catenin cell membrane expression in ATCs is lost or discontinuous. Carcinoma cells with β-catenin nuclear expression without cell membranous expression were scattered in 72.4% of ATCs but were not observed in the other carcinomas.

CONCLUSION

We propose 3 immunohistochemical findings to determine undifferentiated carcinoma cells in the diagnosis of ATC: (1) β-catenin nuclear expression with no or reduced cell membranous expression, (2) the loss or discontinuous pattern of E-cadherin expression, and (3) the loss of PAX8 nuclear expression.

HBME1 and CK19 expression in non-invasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) vs other follicular patterned thyroid lesions

BACKGROUND

Thyroid neoplasms with follicular architecture can have overlapping morphologic features and pose diagnostic confusion among pathologists. Various immunohistochemical stains have been investigated as potential diagnostic markers for PTC, among which HBME1 and CK19 have gained popularity. Non-invasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) poses similar diagnostic challenges with interobserver variability and is often misdiagnosed as adenomatoid nodule or follicular adenoma. This study aims to evaluate expression of HBME1 and CK19 in NIFTPs in comparison to other well-differentiated thyroid neoplasms and benign mimickers.

METHOD

Seventy-three thyroid cases diagnosed over a period of 3 years at Methodist University Hospital, Memphis, TN, USA, were included in this study: 9 NIFTP; 18 papillary thyroid carcinoma (PTC); 11 follicular variant of papillary thyroid carcinoma, invasive (I-FVPTC); 24 follicular adenomas (FA); and 11 multinodular goiters/adenomatoid nodules (MNG). A tissue microarray (TMA) was constructed and HBME1 and CK19 immunohistochemistry was performed.

RESULTS

77.8% of NIFTPs, 88.9% of PTCs, 81.8% of I-FVPTCs, 16.7% of FAs, and 18.2% of MNGs showed HBME-1 expression. 66.7% of NIFTPs, 83.3% of PTCs, 81.8% of I-FVPTCs, 33.3% of FAs, and 45.4% of MNGs expressed CK19. Difference in expression of HBME1 and CK19 was statistically significant for NIFTP vs FA (qualitative; p < 0.05) and NIFTP vs MNG (p < 0.05). No statistically significant difference was found for HBME1 in NIFTP vs PTC (conventional and FVPTC), p ≥ 0.2. Sensitivity of HBME1 and CK19 for NIFTP were 78% and 67%, ~ 88% each for PTC, and 89% and 100% for FVPTC, respectively, while specificity of HBME1 and CK19 for NIFTP were 53% each, ~ 62% each for PTC, and ~55% each for FVPTC.

CONCLUSION

Our study indicated that HBME1 and CK19 are valuable markers in differentiating NIFTPs from morphologic mimics like follicular adenoma and adenomatoid nodules/multinodular goiter. While HBME1 and CK19 are both sensitive in diagnosing lesions with PTC-like nuclear features, CK19 stains a higher number of benign lesions in comparison to HBME1. No increase in sensitivity or specificity in diagnosis of NIFTP, PTC, or FVPTC was noted on combining the two antibodies.

Contribution of Glycation and Oxidative Stress to Thyroid Gland Pathology-A Pilot Study

The patho-mechanism of changes in the thyroid gland, including carcinogenesis, is a complex process, which involves oxidative stress. The goal of our investigation was to verify the extent of stress in the thyroid gland related to glycation. The study samples were comprised of blood sera, thyroid, and adipose tissue sections probed from 37 patients diagnosed with thyroid cancers and goiter. Using immuno-enzymatic and fluorometric assays we analyzed the content of advanced glycation end-products (AGEs), pentosidine, receptors for advanced glycation end-products (RAGE), scavenger receptor class (SR)-A, SR-B, glutathione, malondialdehyde and nitric oxide synthase. In addition to classic AGEs, a recent study detected the melibiose-derived glycation (MAGE) product. We demonstrated the presence of AGEs, MAGE and their receptors of the RAGE and SR-A. In addition, in the control samples of thyroid glands SR-B groups were detected as well as of pathological groups without noticeable tendency to antigen concentration in the area of carcinogenesis. Fluorescent AGEs correlate positively with glutathione, which supports the assumption that glycation stress leads to augmentation of oxidative stress and increase of the intensity of antioxidant mechanisms.

ESMO recommendations on the standard methods to detect RET fusions and mutations in daily practice and clinical research

Aberrant activation of RET is a critical driver of growth and proliferation in diverse solid tumours. Multikinase inhibitors (MKIs) showing anti-RET activities have been tested in RET-altered tumours with variable results. The low target specificity with consequent increase in side-effects and off-target toxicities resulting in dose reduction and drug discontinuation are some of the major issues with MKIs. To overcome these issues, new selective RET inhibitors such as pralsetinib (BLU-667) and selpercatinib (LOXO-292) have been developed in clinical trials, with selpercatinib recently approved by the Food and Drug Administration (FDA). The results of these trials showed marked and durable antitumour activity and manageable toxicity profiles in patients with RET-altered tumours. The European Society for Medical Oncology (ESMO) Translational Research and Precision Medicine Working Group (TR and PM WG) launched a collaborative project to review the available methods for the detection of RET gene alterations, their potential applications and strategies for the implementation of a rational approach for the detection of RET fusion genes and mutations in human malignancies. We present here recommendations for the routine clinical detection of targetable RET rearrangements and mutations.

Clinicopathological Features of Thyroid-Like Low-Grade Nasopharyngeal Papillary Adenocarcinoma: A Case Report and Review of the Literature

Thyroid-like low-grade nasopharyngeal papillary adenocarcinoma (TL-LGNPPA) is an extremely rare neoplasm of the nasopharynx. Accordingly, its clinical and pathological characteristics are not well-known. We report a case of TL-LGNPPA and review the relevant literature on TL-LGNPPA. A 38-year-old Japanese woman presented with a history of nasal obstruction that had persisted for 1 month after symptoms of a common cold (e.g., low-grade fever, sore throat, and fatigue). A pedunculated tumor of ~20 mm in diameter was found on the posterior edge of the nasal septum. The tumor was endoscopically resected. Based on careful histopathological and immunohistochemical examinations, it was diagnosed as TL-LGNPPA. At 5 years after surgery, the patient remained disease-free. TL-LGNPPA has a very good prognosis, and complete resection with a sufficient safety margin is recommended as the first-line treatment. The morphological characteristics and immunohistochemical findings, especially TTF-1 positivity and thyroglobulin negativity, are important for the diagnosis.

Patient-Derived Papillary Thyroid Cancer Organoids for Radioactive Iodine Refractory Screening

Patients with well-differentiated thyroid cancer, especially papillary thyroid cancer (PTC), are treated with surgical resection of the thyroid gland. This is followed by post-operative radioactive iodine (I131), resulting in total thyroid ablation. Unfortunately, about 15-33% of PTC patients are unable to take up I131, limiting further treatment options. The aim of our study was to develop a cancer organoid model with the potential for pre-treatment diagnosis of these I131-resistant patients. PTC tissue from thirteen patients was used to establish a long-term organoid model. These organoids showed a self-renewal potential for at least five passages, suggesting the presence of cancer stem cells. We demonstrated that thyroid specific markers, a PTC marker, and transporters/receptors necessary for iodine uptake and thyroid hormone production were expressed on a gene and protein level. Additionally, we cultured organoids from I131-resistant PTC material from three patients. When comparing PTC organoids to radioactive iodine (RAI)-refractory disease (RAIRD) organoids, a substantial discordance on both a protein and gene expression level was observed, indicating a treatment prediction potential. We showed that patient-derived PTC organoids recapitulate PTC tissue and a RAIRD phenotype. Patient-specific PTC organoids may enable the early identification of I131-resistant patients, in order to reduce RAI overtreatment and its many side effects for thyroid cancer patients.

Bone metastasis of papillary thyroid carcinoma simulating a pulmonary origin. Unusual immunohistochemistry leading to misdiagnosis

Immunophenotypical features from tumors can be variable and, sometimes, confusing. We herein report a 61 year old woman with two foci of papillary thyroid microcarcinoma who developed a bone lesion four months after total thyroidectomy/central lymphadenectomy (mpT1aN0), with an immunohistochemical pattern suggestive of a pulmonary rather than a thyroid origin (CK7, napsin-A and TTF1 positive; and negative thyroglobulin). Further biomarkers (HBME-1 and PAX8) were performed in order to confirm primary tumor, leading to conclusion of a bone metastasis from thyroid papillary carcinoma. We believe it is always advisable to perform more than one biomarker as part of a panel to get a more reliable diagnosis.

A Rare Case of Uterine Leiomyosarcoma with Metastasis to the Thyroid Gland

Uterine leiomyosarcomas are aggressive tumors associated with a poor prognosis. These neoplasms have high metastatic potential, more frequently affecting the lungs, liver, and peritoneum. There are very few cases of metastasis to the thyroid described in the literature. We present the case of a 47-year-old female diagnosed with uterine leiomyosarcoma metastatic to the thyroid gland. In this case report, we want to emphasize the utility of ancillary studies to help differentiate a leiomyosarcoma from anaplastic thyroid carcinoma since cytologic evaluation alone can be challenging.

Molecular testing in diagnosis of indeterminate thyroid cytology: Trends and drivers

Fine needle aspiration (FNA), the cornerstone of diagnosis in thyroid swellings, fails to render a definitive diagnosis in about 20% to 30% of cases that are reported as indeterminate on cytology. Since the clinical management in thyroid rests on the risk of malignancy (ROM) in a given nodule, this distinction between "benign" and "possibly malignant" assumes paramount clinical importance. Over the last two decades, tremendous progress has been achieved in our understanding of the molecular basis of thyroid pathologies leading to identification of several genetic alterations that could potentially be exploited for diagnostic, prognostic and therapeutic purposes. An array of molecular tests has hit the markets aiming to predict the ROM in thyroid nodules. A deeper understanding of the strengths and limitations of these tests is imperative to be able to judiciously choose the right molecular test in a given case for maximum clinical benefit. This narrative review provides an overview of current status of molecular testing in the evaluation of thyroid nodules encompassing the current status and applications of these tests in diagnostic, prognostic and therapeutic areas along with a brief insight into the future developments in this field.

A case report of papillary thyroid carcinoma dedifferentiated to squamous cell carcinoma presenting as a lung metastasis: A potential diagnostic pitfall

Papillary thyroid carcinoma (PTC) tall cell variant (TCV) with squamous dedifferentiation is a rare entity. We present a case of 90-year-old woman who initially had a 2.8 cm conventional PTC in right lobe of thyroid who, couple decades later, had metastatic dedifferentiated PTC to right neck lymph nodes level II and IV with tall cell features; to right level IV and V lymph nodes with tall cell and squamous components, which recently presented exclusively as squamous cell carcinoma (SCC) metastasizing to lung. The squamous component in the lymph node and SCC in the lung were both positive for squamous marker p63 and PTC markers TTF1, PAX-8 and BRAF V600E while negative for thyroglobulin and p16. The papillary component was positive for TTF-1, BRAF V600E and P63 (majority); negative for thyroglobulin and p16. Final diagnoses were rendered based on combination of cytological features and immunohistochemical profiles. This report highlights the utilization of current biomarkers to distinguish between metastatic dedifferentiated PTC with squamous features and primary lung SCC, as well as the importance of recognizing this rare entity.

Enhanced expression of Cyclin D1 and C-myc, a prognostic factor and possible mechanism for recurrence of papillary thyroid carcinoma

A direct association has been shown between Cyclin D1 and C-myc gene expressions and the proliferation of human thyroid tumor cells. Our previous study showed that increased β catenin led to a reduction in disease-free probability in patients with papillary thyroid cancer. This study was designed to investigate Cyclin D1 and C-myc genes as targets for β catenin function in PTC and to determine the association between genes expression and staging, recurrence, metastasis, and disease-free survival of PTC. This study was conducted via a thorough investigation of available data from medical records as well as paraffin blocks of 77 out of 400 patients over a 10-year period. Cyclin D1 and C-myc gene expression levels were measured using real-time polymerase chain reaction (RT-PCR) and the Kaplan-Meier method was used to evaluate disease-free survival. Higher levels of Cyclin D1 and C-myc gene expressions were observed in patients with recurrence by 8.5 (P = 0.004) and 19.5 (p = 0.0001) folds, respectively. A significant positive correlation was found between Cyclin D1 expression and the cumulative dose of radioactive iodine received by patients (r = −0.2, p value = 0.03). The ten-year survival rate in the patients included in this study was 98.25% while disease-free survival was 48.1%. Higher Cyclin D1 and C-myc gene expression levels were observed in patients with recurrence/distant metastasis. Inversely, lower expression of Cyclin D1 and C-myc genes were associated with better survival of patients (SD, 0.142-0.052) (Mantel-Cox test, P = 0.002). The enhancement of Cyclin D1 and C-myc gene expression may be a potential mechanism for recurrence and aggressiveness of PTC.

Epithelial-Mesenchymal Transition in a Case of Metastatic Thyroid Carcinoma in a Brown Bear (Ursus arctos)

A 20-year-old male brown bear (Ursus arctos) with a 20 × 25 cm necrotic mass adjacent to the trachea was diagnosed as having an anaplastic thyroid carcinoma. Metastases were observed in the lungs and one adrenal gland and, histologically, these had anaplastic and follicular carcinoma patterns, respectively. E-cadherin labelling was observed in the adrenal mass only, while N-cadherin immunolabelling was detected in the thyroid gland and lung masses. Thyroid-specific markers (thyroid transcription factor-1, thyroglobulin) were expressed in the adrenal gland metastasis. This case illustrates an example of a primary epithelial-mesenchymal transition (EMT) enabling metastasis to distant organ sites, followed by a mesenchymal-epithelial transition within the adrenal gland microenvironment, allowing invasion and reacquisition of thyroid epithelial cell features. EMTs help to understand the phenomenon of carcinoma cell plasticity in enabling colonization and growth of metastases.

Role of matrix metalloproteinases and their inhibitors in the development of cervical metastases in papillary thyroid cancer

OBJECTIVE

To investigate the role of matrix metalloproteinases (MMPs) and their inhibitors (TIMPs) in the development of cervical metastases in papillary thyroid cancer. Our hypothesis is that level of expression of MMPs and TIMPs is associated with the development of cervical metastases and the pattern of metastatic process in papillary thyroid cancer.

DESIGN

This research retrospectively investigates the expression of MMP-1, -2 and -9 as well as TIMP-1 and -2 in papillary thyroid carcinoma tissue. Tissue specimens were immunohistochemically treated with primary monoclonal antibodies against MMP-1, MMP-2, MMP-9, TIMP-1 and TIMP-2.

SETTING

Single-centre study.

PARTICIPANTS

In total, samples of 159 patients were analysed. In all patients, total thyroidectomy was performed, whereas 102 patients underwent selective neck dissection of either central (level VI) or lateral neck (level II-V). Subjects were divided into four groups.

MAIN OUTCOME MEASURES

Matrix metalloproteinases and TIMPs expression values were analysed in each group, and groups were compared to each other.

RESULTS

Total number of patients was 159, of which 125 were women and 34 men. Comparing expression levels of MMPs and TIMPs in metastatic (study groups) and non-metastatic (control group), papillary thyroid carcinomas yielded significant differences in MMP-1 and TIMP-1 expression levels, where the highest expression values were found in the group with metastasis in lateral neck. Expression levels of MMP-2, MMP-9 and TIMP-2 did not differ statistically significant among the groups.

CONCLUSION

Elevated expression of MMP-1 and TIMP-1 in tumour tissue can be considered a predictive factor for the development of metastases.

Application of GATA 3 and TTF-1 in differentiating parathyroid and thyroid nodules on cytology specimens

BACKGROUND

Differentiating parathyroid from thyroid lesions can be difficult on fine-needle aspiration (FNA) due to overlapping cytomorphologic features. While the traditional parathyroid hormone (PTH) assays can help in the distinction, these tests may be cumbersome, particularly when the lesion is unexpected clinically and a needle wash is not collected at the time of FNA. Therefore, we chose to investigate the application of immunohistochemical staining (IHC) with GATA 3 and thyroid transcription factor-1 (TTF-1) on air-dried cytology smears to distinguish parathyroid and thyroid lesions.

METHODS

Air-dried touch preparation (TP) slides were prepared from consecutively selected parathyroid and thyroid specimens. Thirteen FNA cases with the clinical concern for parathyroid lesions were also included in the study. IHC was performed on unstained and ultrafast Papanicolaou (UFP) stained air-dried slides.

RESULTS

On TP slides, GATA 3 expression was observed in all cases of parathyroid origin but no immunoreactivity was present in thyroid lesions. TTF-1 expression was observed in all cases of thyroid origin but not in parathyroid lesions. GATA 3 and TTF-1 expression of 13 FNA cases were consistent with the clinical impression or concurrent PTH tests.

CONCLUSIONS

IHC with GATA 3 and TTF-1 on air-dried cytology smears is a simple and effective way to differentiate parathyroid vs thyroid lesions on FNA. Air-dried unstained and UFP-stained slides perform equally well with IHC, but UFP-stained slides provide the added benefit of morphologic evaluation and assessment of smear cellularity prior to IHC.

Peptide Profile Differences of Noninvasive Follicular Thyroid Neoplasm with Papillary-Like Nuclear Features, Encapsulated Follicular Variant, and Classical Papillary Thyroid Carcinoma: An Application of Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry Imaging

Introduction: The lack of papillary structures and faint and/or unclear core features of follicular variant of papillary thyroid carcinoma (FV-PTC) may hamper the definitive fine needle aspiration biopsy -based diagnosis. Recently, the nomenclature of noninvasive encapsulated FV-PTC was revised to "noninvasive follicular thyroid neoplasms with papillary-like nuclear features" (NIFTP). However, it remains inconclusive whether or not the peptide patterns differ between NIFTP and encapsulated FV-PTC. The main objectives of this study were to investigate the viability of matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI MSI) in the pathological assessment of NIFTP and to evaluate the discriminatory power of MALDI MSI for the classification of classical variant of PTC (CV-PTC), NIFTP, and encapsulated FV-PTC. Methods: MALDI MSI was employed to investigate the changes in peptide profiles from 21 formalin-fixed paraffin-embedded (FFPE) tissue samples (n = 7 from each group of CV-PTC, NIFTP, and FV-PTC). Six out of seven FV-PTC FFPE tissue samples were encapsulated FV-PTC; only one was infiltrative FV-PTC. Liquid chromatography-tandem mass spectrometry was used for the identification of the peptide signals detected in MALDI MSI. Results: Using receiver operating characteristics analysis, 10 peptide signals distinguished NIFTP from normal thyroid parenchyma (area under the curve [AUC] >0.80). To evaluate the discriminatory power of MALDI MSI, statistically significant peptide signals (n = 88) within three groups were used for hierarchical clustering. The method had high discriminatory power for distinguishing CV-PTC from NIFTP and FV-PTC (encapsulated and infiltrative). The majority of the NIFTP and encapsulated FV-PTC were clustered together, indicating that NIFTP could not be distinguished from encapsulated FV-PTC. However, infiltrative FV-PTC FFPE tissue samples had the furthest distance from all the NIFTP cases. High signal intensities of S100-A6, vimentin, and cytoplasmic actin 1 were detected in FV-PTC, prelamin A/C in CV-PTC, and 60S ribosomal protein L6 and L8 in NIFTP tissues. Conclusions: MALDI MSI, a powerful tool combining histological and mass spectrometric data, enabled the differentiation of NIFTP from normal thyroid parenchyma. Although NIFTP is a recent definition that replaces noninvasive encapsulated FV-PTC, the peptide profiles of NIFTP and encapsulated FV-PTC were found to be similar.

[Tumors of the thyroid gland. Proposal for the management and study of samples from patients with thyroid neoplasms]

The recent changes in the classification and staging of thyroid tumors have arisen from the need to provide an adequate response to the exponential increase of thyroid cancer, which, however, has not been accompanied by an increase in mortality. These changes pretend to reduce overdiagnoses of malignancy, unnecessary treatment, side effects as well as cost for the health system. To this end, this article reviews recommendations for the management of thyroid surgical pathology samples with emphasis on the new terminology of the WHO classification. The basic criteria for the diagnosis of malignancy in well-differentiated thyroid carcinomas are reviewed and the criteria for NIFTP (non-invasive follicular tumor with papillary-like nuclear features) diagnosis are updated. Recommendations for the elaboration of the pathological report are also included.

New and Emerging Biomarkers in Endocrine Pathology

Significant advances in genomics and molecular genetics in recent years have reshaped the practice of endocrine pathology. Pan-genomic studies, including the pioneering ones on papillary thyroid carcinoma, phaeochromocytoma/paraganglioma, and adrenal cortical carcinoma from the Cancer Genome Atlas (TCGA) project, provided a comprehensive integrated genomic analysis of endocrine tumors into distinct molecularly defined subtypes. Better understanding of the molecular landscape and more accurate definition of biological behavior has been accordingly achieved. Nevertheless, how any of these advances are translated into routine practice still remains a challenge in the era of precision medicine. The challenge for modern pathology is to keep up the pace with scientific discoveries by integrating novel concepts in tumor classification, molecular genetics, prognostication, and theranostics. As an example, pathology plays a role in the identification of hereditary disease, while it offers the tools for complementing molecular genetics, for example, validation of variants of unknown significance deriving from targeted sequencing or whole exome/genome sequencing approach. Immunohistochemistry has arisen as a cost-effective strategy in the evaluation either of somatic mutations in tumors and/or germline mutations in patients with familial cancer syndromes. Herein, a comprehensive review focusing on novel and emerging biomarkers is presented in order pathologists and other endocrine-related specialists to remain updated and become aware of potential pitfalls and limitations in the field of endocrine pathology.

A novel microfluidic device capable of maintaining functional thyroid carcinoma specimens ex vivo provides a new drug screening platform

BACKGROUND

Though the management of malignancies has improved vastly in recent years, many treatment options lack the desired efficacy and fail to adequately augment patient morbidity and mortality. It is increasingly clear that patient response to therapy is unique to each individual, necessitating personalised, or 'precision' medical care. This demand extends to thyroid cancer; ~ 10% patients fail to respond to radioiodine treatment due to loss of phenotypic differentiation, exposing the patient to unnecessary ionising radiation, as well as delaying treatment with alternative therapies.

METHODS

Human thyroid tissue (n = 23, malignant and benign) was live-sliced (5 mm diameter × 350-500 μm thickness) then analysed or incorporated into a microfluidic culture device for 96 h (37 °C). Successful maintenance of tissue was verified by histological (H&E), flow cytometric propidium iodide or trypan blue uptake, immunohistochemical (Ki67 detection/ BrdU incorporation) and functional analysis (thyroxine [T4] output) in addition to analysis of culture effluent for the cell death markers lactate dehydrogenase (LDH) and dead-cell protease (DCP). Apoptosis was investigated by Terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL). Differentiation was assessed by evaluation of thyroid transcription factor (TTF1) and sodium iodide symporter (NIS) expression (western blotting).

RESULTS

Maintenance of gross tissue architecture was observed. Analysis of dissociated primary thyroid cells using flow cytometry both prior to and post culture demonstrated no significant change in the proportion of viable cells. LDH and DCP release from on-chip thyroid tissue indicated that after an initial raised level of release, signifying cellular damage, detectable levels dropped markedly. A significant increase in apoptosis (p < 0.01) was observed after tissue was perfused with etoposide and JNK inhibitor, but not in control tissue incubated for the same time period. No significant difference in Ki-67 positivity or TTF1/NIS expression was detected between fresh and post-culture thyroid tissue samples, moreover BrdU positive nuclei indicated on-chip cellular proliferation. Cultured thyroid explants were functionally viable as determined by production of T4 throughout the culture period.

CONCLUSIONS

The described microfluidic platform can maintain the viability of thyroid tissue slices ex vivo for a minimum of four days, providing a platform for the assessment of thyroid tissue radioiodine sensitivity/adjuvant therapies in real time.

Evaluation of Diagnostic Utility of Immunohistochemistry Markers of TROP-2 and HBME-1 in the Diagnosis of Thyroid Carcinoma

OBJECTIVE

The diagnosis of thyroid tumors is based on histologic features, but the distinction between benign and malignant thyroid lesions is somehow difficult, especially in lesions with a follicular pattern. Thus, ancillary studies, such as immunohistochemistry (IHC), may be helpful. In this study, we aimed to evaluate the diagnostic value of 2 IHC markers, TROP-2 and HBME-1, in the diagnosis of thyroid cancers.

STUDY DESIGN

A total of 102 cases of thyroid lesions, including papillary thyroid carcinoma (classic variant) (29 cases), follicular variant of papillary thyroid carcinoma (21 cases), multinodular goiter (22 cases), follicular adenoma (24 cases), and follicular carcinoma (6 cases) were selected. The hematoxylin-eosin slides were reviewed for confirmation of diagnosis, and IHC examination for TROP-2 and HBME-1 was performed.

RESULT

HBME-1 had 84% sensitivity and 98% specificity with a positive predictive value (PPV) of 98% and a negative predictive value (NPV) of 83%. TROP-2 had 93% sensitivity and 74% specificity with a PPV of 81% and an NPV of 90% in malignant thyroid lesions.

CONCLUSION

IHC panel consisting of TROP-2 and HBME-1 can be used in equivocal follicular patterned lesions for the diagnosis of thyroid carcinomas.

Cystic Papillary Thyroid Carcinoma: A Case Report

Cystic nodule is an unusual presentation of Papillary Thyroid Carcinoma (PTC), seen in less than 10% of cases. Even by ultrasound, finding a thyroid cyst carries a less than 5% chance of malignancy. We present a case of a 45-year-old male, who came in for incidental finding of a palpable thyroid mass with no significant predisposing history. Thyroidectomy was done and immunohistochemical staining confirmed it to be papillary thyroid cancer. He underwent high dose radiation therapy with post therapy whole body scan showing no evidence of radioavid foci aside from the thyroid bed. The malignant potential of cystic nodule(s) should never be overlooked in certain select patients even if it carries a low chance of malignancy. The diagnosis of PTC relies primarily on the typical nuclear features, however in cases of histologic uncertainty, immunohistochemical stains such as HBME-1 may be used to help classify unusual presentations of PTC. Treatment and monitoring of Cystic Papillary Thyroid Carcinoma follows the conventional guideline on solid PTC.

Update on: proteome analysis in thyroid pathology - part II: overview of technical and clinical enhancement of proteomic investigation of the thyroid lesions

INTRODUCTION

An accurate diagnostic classification of thyroid lesions remains an important clinical aspect that needs to be addressed in order to avoid 'diagnostic' thyroidectomies. Among the several 'omics' techniques, proteomics is playing a pivotal role in the search for diagnostic markers. In recent years, different approaches have been used, taking advantage of the technical improvements related to mass spectrometry that have occurred. Areas covered: The review provides an update of the recent findings in diagnostic classification, in genetic definition and in the investigation of thyroid lesions based on different proteomics approaches and on different type of specimens: cytological, surgical and biofluid samples. A brief section will discuss how these findings can be integrated with those obtained by metabolomics investigations. Expert commentary: Among the several proteomics approaches able to deepen our knowledge of the molecular alterations of the different thyroid lesions, MALDI-MSI is strongly emerging above all. In fact, MS-imaging has also been demonstrated to be capable of distinguishing thyroid lesions, based on their different molecular signatures, using cytological specimens. The possibility to use the material obtained by the fine needle aspiration makes MALDI-MSI a highly promising technology that could be implemented into the clinical and pathological units.

The diagnostic value of TROP-2, SLP-2 and CD56 expression in papillary thyroid carcinoma

OBJECTIVE

The study aimed to explore some novel diagnostic biomarkers for papillary thyroid carcinoma (PTC) by identifying the different expression of TROP-2, SLP-2 and CD56 in benign and malignant thyroid lesions.

METHODS

We evaluated the mRNA expressions of TROP-2 and SLP-2 in fine needle aspirates (FNAs) which contained 10 PTCs and 10 benign follicular adenomas (FAs) using quantitative real-time PCR (qRT-PCR). Immunohistochemical (IHC) staining of TROP-2, SLP-2 and CD56 was also performed on postoperative samples of 30 PTCs and 29 FAs. Membranous or cytoplasmic staining in > 10% of cells was considered as positive. Diagnostic sensitivity, specificity, positive predictive value, negative predictive value (NPV) and diagnostic accuracy of these three biomarkers were carried out. We further analyzed the associations between the clinical features and the expressions of markers in PTCs.

RESULTS

The mRNA expressions of both TROP-2 and SLP-2 were increased substantially in PTCs in comparison with those in FAs (P < 0.05). Similarly, IHC for these two proteins demonstrated higher positive staining in PTCs than in FAs (96.5% vs. 12.5% for TROP-2, 83.3% vs. 20.7% for SLP-2, P < 0.05). Conversely, CD56 expression was lost with 86.7% of PTCs. In identifying malignancy, TROP-2 was the most sensitive marker and CD56 was the most specific one. When the markers were combined, the sensitivity and NPV increased to 100% and had better diagnostic accuracy. However, no association was found between biomarker expressions and clinicopathological factors in PTCs.

CONCLUSIONS

We found that TROP-2, SLP-2 and CD56 were effective diagnostic markers for PTC, especially when they were combined to use.

Immunohistochemical Biomarkers in Thyroid Pathology

The application of immunohistochemistry to the diagnosis of thyroid lesions has increased as new biomarkers have emerged. In this review, we discuss the biomarkers that are critical for accurate diagnosis, prognosis, and management. Immunohistochemical markers are used to confirm that an unusual tumor in the thyroid is indeed of thyroid origin, either of follicular epithelial or C-cell differentiation; the various mimics include nonthyroidal lesions such as parathyroid tumors, paragangliomas, thymic neoplasms, and metastatic malignancies. Tumors of thyroid follicular epithelial cells can be further subclassified using a number of immunohistochemical biomarkers that can distinguish follicular-derived from C-cell lesions and others that support malignancy in borderline cases. The use of mutation-specific antibodies can distinguish papillary carcinomas harboring a BRAF^V600E mutation from RAS-like neoplasms. Immunostains have been developed to further identify molecular alterations underlying tumor development, including some rearrangements. Altered expression of several biomarkers that are known to be epigenetically modified in thyroid cancer can be used to assist in predicting more aggressive behavior such as a propensity to develop locoregional lymphatic spread. Immunohistochemistry can assist in identifying lymphatic and vascular invasion. Biomarkers can be applied to determine dedifferentiation and to further classify poorly differentiated and anaplastic carcinomas. The rare tumors associated with genetic predisposition to endocrine neoplasia can also be identified using some immunohistochemical stains. The application of these ancillary tools allows more accurate diagnosis and better understanding of pathogenesis while improving prediction and prognosis for patients with thyroid neoplasms.

The Potential Diagnostic Utility of TROP-2 in Thyroid Neoplasms

Objectives:

Human trophoblast cell-surface marker (TROP-2) has been reported to be overexpressed in various human carcinomas (CAs) and suggested to be a prognostic marker for some CAs. The diagnostic utility of TROP-2 in CAs has not been explored.

Methods:

Immunohistochemical evaluation of TROP-2 expression on tissue microarray sections of 136 thyroid neoplasms, surgical specimens of 61 atypical thyroid follicular-patterned lesions [including 33 papillary thyroid carcinomas (PTCs), 17 atypical follicular neoplasms (AFNs), and 11 adenomatoid nodules with focal nuclear atypia (ANFNA)], and 20 benign thyroid lesions, as well as 10 cytology specimens of PTCs was performed. For comparison, immunoassay for Hector Battifora mesothelial-1 (HBME-1), galectin-3, and cytokeratin 19 was performed on the 61 atypical thyroid follicular-patterned lesions.

Results:

Strong membranous staining with TROP-2 was seen in 94% (33/35) of classic PTCs and 81% (30/37) of confirmed follicular variant PTCs on tissue microarray and routine surgical sections, as well as 100% (10/10) of PTCs on cytology specimens; it was not observed in follicular adenomas (n=51) or CAs (n=37), AFNs or ANFNA (n=28), benign (n=20) or normal (n=15) thyroid tissue. In contrast, the expression of HBME-1 and galectin-3 was identified in 100% (33/33) of surgical cases of PTCs and in 57% (16/28) and 50% (14/28) of AFNs and ANFNA, respectively.

Conclusions:

Our findings demonstrate that a membranous TROP-2 staining pattern is highly specific for PTC, which may serve as a potential diagnostic marker aiding in the accurate classification of morphologically equivocal thyroid follicular-patterned lesions.

Identification of metastatic papillary thyroid carcinoma in FNA specimens using thyroid peroxidase immunohistochemistry

INTRODUCTION

We evaluated immunohistochemical staining for thyroid peroxidase (TPO), a glycoprotein found in the apical plasma membrane of thyroid follicular cells, as a marker for metastatic PTC in FNA samples and compared results with thyroglobulin (Tg) and thyroid transcription factor 1 (TTF1) staining.

METHODS

Cell block sections prepared from 100 FNA specimens were stained with a rabbit monoclonal antibody to TPO (EP159). The FNAs included 64 metastatic malignancies from non-thyroid primary sites, including 18 lung, and 36 cases of thyroid tumours (29 PTC, six cases of medullary thyroid carcinoma and one thyroid anaplastic carcinoma). Thyroid tumours were stained with TTF1 and Tg in addition to TPO. All cases of metastatic lung carcinoma also had TTF-1 staining results.

RESULTS

TPO staining was negative in all non-thyroid malignancies. Ninety percent (26/29) of PTC were positive. All positive cases showed strong cytoplasmic staining, although 54% (14/26) showed positivity in less than half of the cells. By comparison, Tg staining of TPC cases was present in 62% and TTF-1 in 100%. In addition to showing higher sensitivity, interpretation of staining results with TPO was generally easier with than Tg. All metastatic lung adenocarcinomas were positive for TTF-1 and TPO negative. The six medullary cancers showed positivity in 17%, 0% and 83% with TPO, Tg and TTF-1, respectively.

CONCLUSIONS

TPO (mAb EP159) may be a useful addition to immunohistochemical panels for FNA specimens where metastatic PTC is a consideration, particularly in cases where metastatic lung carcinoma features in the differential diagnosis.

Circulating epithelial cell counts for monitoring the therapeutic outcome of patients with papillary thyroid carcinoma

Loco-regional recurrence or distant metastasis usually leads to the death of patients with papillary thyroid carcinoma (PTC). Whether or not circulating epithelial cells (CECs) count is a valuable marker in monitoring the therapeutic outcome of PTC was investigated. Patients with PTC (n=129) were treated in our medical center and were categorized into 4 groups with excellent (n=45), biochemical incomplete (n=15), indeterminate (n=37), and structural incomplete (n=32) responses. CECs were enriched from the peripheral blood by the PowerMag negative selection system. Three subtypes of CECs expressing epithelial cell adhesion molecule (EpCAM), thyroid-stimulating hormone receptor (TSHR, a marker for thyroid cells), and podoplanin (PDPN, a marker related to poor prognosis in patients with PTC) were defined by immunofluorescence staining, respectively. The median number of CECs (cells/mL of blood) expressing EpCAM, TSHR, and PDPN was 23 (interquartile range 10-61), 19 (interquartile range 8-50), and 8 (interquartile range 3-22), respectively, for patients enrolled in this study. The number of EpCAM+-CECs, TSHR+-CECs, and PDPN+-CECs was statistically different among patients in different treatment response groups without interference from anti-thyroglobulin antibody (P<0.0001). Patients with structural incomplete response had higher counts for all three CECs subtypes when compared to other patients. EpCAM+-CECs was better in distinguishing patients with excellent response from structural incomplete response among the three subtypes of CECs. The sensitivity and specificity of the assay was 84.4% and 95.6%, respectively, when the cut off value was 39 EpCAM+-CECs/mL. CECs testing can supplement the current standard methods for monitoring the therapeutic outcome of PTC.

Clinical and Morphologic Features of ETV6-NTRK3 Translocated Papillary Thyroid Carcinoma in an Adult Population Without Radiation Exposure

The ETV6-NTRK3 translocation characterizes a subset of radiation associated and pediatric papillary thyroid carcinomas (PTCs). We now describe the clinicopathologic features of ETV6-NTRK3 translocated PTC in an adult population without radiation exposure. Twelve cases were identified by next-generation sequencing (ThyroSeq version 2). The mean patient age was 37 years with a female predilection (10:2). Preoperative fine needle aspiration was performed on 6 patients of which 4 were classified as "malignant," whereas 2 were classified as "follicular lesion of undetermined significance." One third (4/12) of patients demonstrated extrathyroidal extension and one half of patients (5/10) demonstrated lymph node metastases. One patient presented with brain metastasis. Tumors typically (8/12) demonstrated an admixture of follicular and papillary patterns and were usually infiltrative and multinodular (6/12 cases). Tumors often showed clear cell or oncocytic foci and demonstrated overt nuclear features of PTC, though characteristically, interspersed bland areas were common, even in metastases. Cytoplasmic vacuolization resembling that of mammary analog secretory carcinoma was also common but focal. TTF-1 was positive and S100 was negative in all tested cases confirming a thyroid phenotype. Unique morphologies included glomeruloid follicles, reverse polarization of nuclei. Survey of the TCGA datasets revealed similar findings. Thus, ETV6-NTRK3 translocated PTC are locoregionally aggressive and can metastasize distantly. They are characterized by mixture of papillary and follicular architecture and may show cytoplasmic vacuolization akin to other ETV6 translocated carcinomas. Although nuclear features are typically overt, interspersed bland regions may cause diagnostic difficulty in metastatic sites, and may explain discordance on fine needle aspiration.

Tumor-to-tumor metastases: papillary thyroid carcinoma into a clear cell renal cell carcinoma

Background

Thyroid metastases to distant sites are uncommon incidents, most often metastasizing to the lungs and bones. Rates of metastasis to the kidney are particularly low, ranging from 2.8–3.8% for papillary and 6–20% for follicular variants of well-differentiated thyroid cancers (WDTCs). In rare instances, tumor-to-tumor metastasis between two true primary neoplasms can occurs. This medical phenomenon has previously occurred as a clear cell renal cell carcinoma (CCRCC) spreading to a WDTC. To our knowledge, this is the first report of a tumor-to-tumor metastasis of a thyroid cancer metastasizing to a primary renal neoplasm.

Case presentation

A 72 year old male presented to the urology clinic with complaints of flank pain. Computed tomography (CT) imaging of the abdomen and pelvis revealed a 5.7 cm solid enhancing mass from the lateral aspect of the right kidney, suspicious for renal cell carcinoma (RCC). The patient subsequently underwent a right laparoscopic radical nephrectomy, and immunohistochemical staining of the 5.5 cm lesion revealed a positive RCC marker to establish a diagnosis of a pT1b ISUP Grade 2 CCRCC. The tumor contained a 3 mm focus of a lesion staining positive for TTF1 and Thyroglobulin, and negative for RCC marker. This finding established a diagnosis of a tumor-to-tumor metastasis of PTC to CCRCC. Subsequent ultrasound and CT of the head and neck revealed a heterogeneously hypodense 3.3 cm mass in the right thyroid lobe, prompting a total thyroidectomy and level VI neck dissection. Pathology revealed a classic variant multifocal PTC and two ipsilateral lymph nodes positive for metastatic PTC. Ultimately, the thyroid specimen was positive for lymphatic vascular invasion, extrathyroidal extension with invasion of the tracheal cartilage, staging as T4aN1aM1. On follow up examination the patient was recovering well, without signs of dysphagia or dysphonia, and showed bilateral mobile vocal cords on laryngoscope examination.

Conclusions

Tumor-to-tumor metastasis between the thyroid and kidney is an extremely rare occurrence, reports of RCC metastases from a WDTC has not yet been reported in the literature. Corroboration of diagnostic imaging findings with immunohistochemistry staining can consolidate a diagnosis of thyroid neoplasm tumor-to-tumor metastasis to a RCC, thereby prompting surgical excision.

Values of molecular markers in the differential diagnosis of thyroid abnormalities

INTRODUCTION

Thyroid cancer (TC), follicular adenoma (FA) and Hashimoto's thyroiditis (HT) are three of the most frequently reported abnormalities that affect the thyroid gland. A frequent co-occurrence along with similar histopathological features is observed between TC and FA as well as between TC and HT. The conventional diagnostic methods such as histochemical analysis present complications in differential diagnosis when these abnormalities occur simultaneously. Hence, the authors recognize novel methods based on screening genetic defects of thyroid abnormalities as viable diagnostic and prognostic methods that could complement the conventional methods.

METHODS

We have extensively reviewed the existing literature on TC, FA and HT and also on three genes, namely braf, nras and ret/ptc, that could be used to differentially diagnose the three abnormalities. Emphasis was also given to the screening methods available to detect the said molecular markers.

RESULTS AND CONCLUSION

It can be conferred from the analysis of the available data that the utilization of braf, nras and ret/ptc as markers for the therapeutic evaluation of FA and HT is debatable. However, molecular screening for braf, nras and ret/ptc mutations proves to be a conclusive method that could be employed to differentially diagnose TC from HT and FA in the instance of a suspected co-occurrence. Thyroid cancer patients can be highly benefited from the screening for the said genetic markers, especially the braf gene due to its diagnostic value as well as due to the availability of personalized medicine targeted specifically for braf mutants.