FNAB of benign thyroid nodules with papillary hyperplasia: A cytological and histological evaluation

Diagnostic Value and Challenges of BRAF V600E Molecular Testing and Thyroid Fine-Needle Aspiration Cytology: A Retrospective Study from a Tertiary Institution in Southern Hunan Province, China

INTRODUCTION

Combined thyroid fine-needle aspiration (FNA) cytology and valine-to-glutamate substitution at codon 600 of B-Raf proto-oncogene, serine/threonine kinase (BRAF V600E) mutation detection are procedures used for diagnosing thyroid nodules in many Chinese tertiary institutions. This retrospective study at our institution aimed to explore the effectiveness and challenges of the combined approach in diagnosing thyroid nodules and the correlation between BRAF V600E mutation status and behavior of papillary thyroid carcinoma.

METHODS

Thyroid FNA cytology and BRAF V600E mutation detection results were reviewed between November 2020 and July 2022. A total of 623 patients, each of whom underwent thyroidectomy and final pathological examination after FNA cytology diagnosis, were included in the study. The relationship between the BRAF V600E mutational status and pathological parameters was analyzed using the χ2 test. The effectiveness and challenges of FNA cytology alone and the combined procedure were also evaluated based on the final pathology.

RESULTS

Of 623 patients, 591 were diagnosed with papillary thyroid carcinoma (PTC), of which 456 were positive for the BRAF V600E mutation. It demonstrated near-perfect specificity for identifying PTC, and its incidence rate showed an age-specific curve with an inverted U-shaped distribution. The final pathological examination showed that the combined procedure had a higher sensitivity (83.91%) than FNA cytology alone (63.45%) for distinguishing PTC from other lesions (p < 0.001). Mutational status was associated with a larger maximum tumor diameter (p = 0.003) and a tendency of capsular invasion (p = 0.0542) but possibly unrelated to central lymph node metastasis (p = 0.1846). Nodular goiters accounted for most benign entities initially designated as Bethesda categories III-V.

CONCLUSION

BRAF V600E mutational analysis complements cytopathology and improves the PTC detection rate in FNA cytology samples due to the high prevalence of the mutation in China. BRAF V600E mutation does not show a statistical correlation with tumor aggressiveness. Morphological pitfalls such as histocyte aggregation, cystic-lining cells in nodular goiters, and oncocytes in Hashimoto's thyroiditis, were overwhelmingly found in BRAF V600E-negative specimens.

A study to evaluate association of nuclear grooving in benign thyroid lesions with RET/PTC1 and RET/PTC3 gene translocation

INTRODUCTION

Papillary thyroid carcinoma (PTC) is the most common malignant lesion of the thyroid characterized by unique histological features like nuclear grooving, nuclear clearing, and intra-nuclear inclusions. However, nuclear grooves are observed even in benign thyroid lesions (BTL) like nodular goiter (NG), Hashimoto's thyroiditis (HT), and follicular adenoma (FA) resulting in diagnostic dilemma of the presence of PTC in such BTL. RET/PTC gene translocation is one of the most common oncogenic rearrangements seen in PTC, known to be associated with nuclear grooving. Among different types of RET/PTC translocations, RET/PTC1 and RET/PTC3 gene translocations are the most common types. These translocations have also been identified in many BTL like hyperplastic nodules and HT. Our study aimed to determine the frequency of nuclear grooving in BTL and evaluate their association with RET/PTC1 and RET/PTC3 gene translocation.

METHODS

Formalin-fixed, paraffin-embedded (FFPE) tissue blocks of NG, HT, and FA were included in the study. The hematoxylin and eosin (H&E) stained sections were evaluated for the presence of nuclear grooving/high power field (hpf) and a scoring of 0 to 3 was used for the number of grooves. Sections of 10 μ thickness were cut and the cells containing the nuclear grooves were picked using Laser-Capture microdissection. About 20 to 50 such cells were microdissected in each of the cases followed by RNA extraction, cDNA conversion, realtime-polymerase chain reaction (RQ-PCR) for RET/PTC1 and RET/PTC3 gene translocation, and the findings were analyzed for statistical significance.

RESULTS

Out of 87 BTL included in the study, 67 (77.0%) were NG, 12 (13.7%) were HT, and 8 (9.2%) were FA. Thirty-two cases (36.8%) had nuclear grooving with 18 out of 67 NG, 6 out of 12 HT, and all 8 cases of FA showing a varying number of nuclear grooves. A significant association between the number of nuclear grooves with RET/PTC gene translocation (p-value of 0.001) was obtained. A significant association of HT with RET/PTC gene translocation (p-value of 0.038) was observed. RET/PTC1 and RET/PTC3 translocation were seen in 5 out of 87 cases, with HT showing positivity in 2 and FA in 1 case for RET/PTC1 and HT in 1 and FA in 2 cases for RET/PTC3 gene translocation with 1 case of FA being positive for both RET/PTC1 and RET/PTC3 gene translocation.

CONCLUSIONS

The frequency of nuclear grooving among BTLs in our study was 36.8%. Our study shows, that when BTLs, show nuclear grooves, with an increase in the nuclear size, oval and elongated shape, favors the possibility of an underlying genetic aberration like RET/PTC gene translocation, which in turn supports the reporting pathologist to suggest a close follow up of the patients on seeing such nuclear features on cytology or histopathology sample, particularly in HT.

Challenges in Encapsulated Follicular-Patterned Tumors: How Much Is Enough? Evaluation of Nuclear Atypia, Architecture, and Invasion

Thyroid pathology is notoriously fraught with high interobserver variability, and follicular-patterned tumors are among some of the most challenging to assess accurately and reproducibly. Given that encapsulated or well-circumscribed follicular-patterned tumors often have similar molecular profiles, that is, frequent RAS or RAS-like alterations, the diagnosis usually relies on histopathologic examination alone. Unfortunately, many of the features that are used for diagnosis and prognosis of these tumors have long been controversial and frequently debated topics, both due to their subjectivity and their evolving (or not yet resolved) definitions. In more recent years, the introduction of noninvasive follicular thyroid neoplasm with papillary-like nuclear features has added further complexity to this discussion. In particular, the criteria and significance of nuclear features of papillary thyroid carcinoma, architectural patterns, and invasive growth still pose significant diagnostic challenges and confusion. This review explores some of the challenges in evaluating encapsulated follicular-patterned tumors, focusing on those histologic elements.

A case of papillary hyperplasia of thyroid misdiagnosed as papillary thyroid carcinoma: Case report and review of literature

Overdiagnosis of papillary thyroid hyperplasia which may mimic papillary thyroid carcinoma in fine-needle aspiration and frozen section has a serious impact on the patient. Therefore, it is important to know the difference between them to avoid over or undertreatment.

Interpretive Errors in Fine-Needle Aspiration of Thyroid: A 13-Year Institutional Experience in Lebanon

INTRODUCTION

Fine-needle aspiration (FNA) is a worldwide established diagnostic tool for the assessment of patients with thyroid nodules. All thyroid FNA interpretive errors (IEs) were reviewed at the American University of Beirut Medical Center over a 13-year period, in order to identify and analyze them.

MATERIALS AND METHODS

All FNAs and their corresponding pathology results are correlated yearly for quality assurance. Discrepant cases are segregated into sampling errors and IEs. All thyroid FNAs with IEs were collected from 2005 to 2017. FNA and pathology slides were reviewed by trained, board-certified cytopathologists, adhering to the latest Bethesda criteria. Reasons for erroneous diagnoses were studied.

RESULTS

There was a total of 11 IEs out of 340 thyroid FNAs followed by surgical resection. Five benign follicular nodules (BFNs) were misinterpreted as suspicious for carcinoma. Focal nuclear atypia in cyst-lining or follicular cells and a monotonous population of macrophages misinterpreted as Hurthle cells (HCs) were the causes of IEs in this category. Four Hashimoto's thyroiditis (HT) cases were misinterpreted as suspicious for malignancy. Innate atypia of HCs and sampling misinterpretation were the causes of IEs in HT. One medullary and 1 follicular carcinoma were misinterpreted as suspicious for follicular neoplasm and BFN, respectively. Nine cases were better classified after review.

CONCLUSION

Thyroid FNA IEs can be mitigated by meticulous screening and identification of all elements on FNA smears. Awareness of focal nuclear atypia in reactive cyst-lining and follicular cells in BFN, as well as HCs in HT, is highlighted. Adherence to The Bethesda System for Reporting Thyroid Cytopathology and consulting experienced cytopathologists significantly decrease IEs.

Causes of misdiagnoses by thyroid fine-needle aspiration cytology (FNAC): our experience and a systematic review

Objective

FNA is a simple, safe, cost-effective and accurate diagnostic tool for the initial screening of patients with thyroid nodules. The aims of this study were to determine the diagnostic utility of FNAC performed in our institution, assess the cytomorphologic features that contribute to diagnostic errors and propose improvement measures.

Methods

A total of 2781 FNACs were included in the study, and 1122 cases were compared with their histological diagnoses. We retrospectively reexamined our discordant (both false-negative and false-positive) cases and performed a systematic review of previous studies on causes of misdiagnoses.

Results

When DC V and DC VI were both considered cytologic-positive, the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and diagnostic accuracy were 98.3, 30.9, 94.9, 58.3 and 93.5%, respectively. If DC VI was considered cytologic-positive, the sensitivity, specificity, PPV, NPV and diagnostic accuracy of FNAC were 98.0, 84.0, 99.4, 58.3, and 97.5% respectively. The main cause of false-negative diagnoses was sampling error (13/15, 86.7%), while interpretation error led to the majority of the false-positive diagnoses (38/47, 80.9%). Overlapping cytological features in adenomatous hyperplasia, thyroiditis and cystic lesions were the major factors contributing to interpretation errors, while the size and number of nodules may have led to false-negative diagnoses because of heterogeneity and unsampled areas.

Conclusions

The sensitivity and PPV of thyroid FNAC in our institution were higher than those in the published data, while the specificity and NPV were lower. Regarding the FNA category DC V, a frozen section analysis during diagnostic lobectomy is necessary. Multiple passes should be performed in various parts of a large nodule or from different nodules to reduce the risk of false-negative findings. Cytopathologists should strengthen their criteria for the identification of adenomatous hyperplasia, thyroiditis and cystic lesions to avoid false-positive diagnoses. NIFTP has little effect on diagnostic accuracy and the distribution of diagnostic errors.

Upregulation of microRNA-143-3p induces apoptosis and suppresses proliferation, invasion, and migration of papillary thyroid carcinoma cells by targeting MSI2

As a tumor-associated biological molecule, microRNA-143-3p (miR-143-3p) is implicated in the progression of papillary thyroid carcinoma (PTC). We conducted this study to elucidate the effects of miR-143-3p mediated by Musashi RNA binding protein 2 (MSI2) on the biological activities of PTC cells. The K1 cells with the lowest miR-143-3p expression were selected for the experiments. The targeting relationship between miR-143-3p and MSI2 was verified. The biological functions of miR-143-3p and MSI2 with respect to K1 cell proliferation, cycle distribution, apoptosis, invasion, migration, and tumorigenesis were studied using gain- and loss-of-function assays both in vitro and in vivo. MSI2 was verified to be a target gene of miR-143-3p. Cells treated with upregulation of miR-143-3p or silencing of MSI2 exhibited significantly decreased the expression of Bcl-2, PCNA, MCM2, Ki67, MSI2, MMP-2, and MMP-9. This was accompanied by inhibited cell proliferation, cell invasion, and migration, as well as a significant increase in Bax expression, cell cycle arrest, and cell apoptosis. More importantly, the tumor inhibitory effects of upregulated miR-143-3p were also confirmed in the tumor xenografts in nude mice. Our results indicate that upregulation of miR-143-3p suppresses the progression of PTC by impeding cell growth, invasion, and migration via downregulation of MSI2, highlighting the potential of miR-143-3p as a target for future PTC treatment.

Diagnostic importance of CD56 with fine-needle aspiration cytology in suspected papillary thyroid carcinoma cases

Background

Palpable thyroid nodules can be found in 4%-7% of the adult population; however, <5% of thyroid nodules are malignant. Immunohistochemical markers, such as CD56, can be used to make a differential diagnosis between benign and malignant lesions. To increase the accuracy of the diagnosis and distinguish the malignant aspirates from the benign ones, chose to evaluate CD56, which is normally found in benign thyroid tissue.

Methods

A total of 53 fine-needle aspirate samples from patients diagnosed with suspected papillary thyroid carcinoma (PTC) were included prospectively. These aspirates were immunocytochemically stained for CD56.

Results

In histopathological examination, the fine-needle aspiration cytopathology specimens suspicious for PTC (after undergoing surgery) showed that 32 (60.4%) were benign and 21 (39.6%) were malignant. Thirty-one of the benign cases (96.87%) were CD56-positive, whereas the last case (3.13%) was CD56-negative. Staining was not seen in any of the malignant cases.

Conclusions

We believe that CD56 is an important marker in the definitive diagnosis of suspected PTC cases, with CD56-positivity being interpreted in favor of benignity.

Incidence and significance of true papillae in thyroid fine needle aspiration

INTRODUCTION

Whether true papillae without nuclear features of papillary carcinoma in thyroid fine needle aspirates should be diagnosed as atypia of undetermined significance (AUS) is unclear.

METHODS

The results of all thyroid FNAs performed from 2014-2016 with corresponding resections as well as aspirates from 2000-2016 with a diagnosis of follicular variant of papillary carcinoma or Noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) were reviewed.

RESULTS

Papillae with fibrovascular cores were identified in 17 of 149 consecutive cases (11%), 3 of which had nuclear features of papillary carcinoma and were papillary carcinoma at resection. All 14 cases of papillae without nuclear features of papillary carcinoma were benign. Of 29 papillary carcinomas, papillae were identified in 8 (28%) and "swirls" were identified in 3 (10%) additional cases, all in cases of papillary carcinoma, NOS. Papillae and swirls were not identified in any cases of NIFTP (13 cases) or follicular variants of papillary carcinoma (15 cases).

CONCLUSION

True papillae are relatively common. Both papillae with nuclear atypia and swirls are highly specific for papillary carcinoma, NOS and are not seen in NIFTP. True papillae with fibrovascular cores but without cytologic features of papillary carcinoma are benign and should not be diagnosed as AUS. Diagn. Cytopathol. 2017;45:689-692. © 2017 Wiley Periodicals, Inc.

Investigation of thyroid nodules in the female population in Cyprus and in Romania

Background and aims

The most common thyroid disorders, with an increasing detection worldwide, are the thyroid nodules and thyroiditis, which leads to an increase of thyroid cancer incidence . In two different countries with a different exposure to risk factors for thyroid cancer, such as Cyprus and Romania, the rank of thyroid cancer among other neoplasms is very different: the 3^rd most prevalent cancer among females in Cyprus and the 12^th in Romania, respectively. Environmental chemicals, such as bisphenol A have a proven effect on the thyroid function. However, the relation between the exposure to the endocrine disruptor and the development of thyroid nodules, with a potential of malignant transformation has not been previously studied. The aim of the study was to investigate the potential factors that lead to the difference of thyroid nodules incidence in the mentioned countries.

Methods

A pilot case-control study has been conducted in 2014–2015 in the “Prof. Dr. Ion Chiricuţă” Institute of Oncology, Cluj-Napoca, Romania and the Endocrinology Department of Archbishop Makarios III Hospital, Nicosia, Cyprus. Females older than 20 years with no medical history were recruited. Cases were women with ultrasound-confirmed thyroid nodules of size >3mm. Controls were women without thyroid nodules after ultrasound confirmation. All participants provided blood samples for measurements of the thyroid stimulating hormone (TSH), free thyroxin (FT4), anti-thyroglobulin (ATg) and anti-thyroid peroxidase (ATPO); urine samples. Demographics, anthropometrics and other relevant information were provided through the administration of a questionnaire.

Results

In Romania we selected 51 patients with thyroid nodules (case group) and 41 without thyroid nodules (control group) and in Cyprus 57 cases, respectively 65 controls. After the statistical analysis of the data collected we observed statistically significant differences between the populations of the two countries regarding BMI and the value of the thyroid hormones and antibodies.

Conclusions

Using the data observed in this study, differences were found between Cyprus and Romania among females with thyroid nodules the BMI, and the level of thyroid hormones had statistically significant differences. This study reports preliminary data, further analysis of environmental exposures to chemical factors that might have a certain influence over the thyroid in the two countries will follow.

The Role of CD56 in Thyroid Fine Needle Aspiration Cytology: A Pilot Study Performed on Liquid Based Cytology

Background

Fine needle aspiration Cytology (FNAC) fulfills a reliable role in the evaluation of thyroid lesions. Although the majority of nodules are quite easily diagnosed as benign or malignant, 30% of them represent an indeterminate category whereby the application of ancillary techniques (i.e. immunocytochemistry-ICC and molecular testing) has been encouraged. The search for a specific immunomarker of malignancy sheds light on a huge number of ICC stains although none of them attempt to yield 100% conclusive results. Our aim was to define in a pilot study on thyroid FNAC whether CD56 might be a valid marker also in comparison with HBME-1 and Galectin-3.

Materials and Methods

Inasmuch as this is the largest pilot study using only liquid based cytology (LBC), we selected all the cases only in the categories of benign nodules (BN) and positive for malignancy (PM) for validation purposes. Eighty-five consecutive (including 50 PM and 35 BN) out of 950 thyroid FNACs had surgical follow-up. The ICC panel (HBME-1, Galectin-3 and CD56) was carried out on LBC and histology.

Results

All BNs and PMs were histological confirmed. CD56 was negative in 96% of the PM while 68.5% of the BNs showed cytoplasmic positivity for this marker, with an overall high sensitivity (96%) but lower specificity (69%). In specific, our 96% of the PMs did not show any follicular cell with CD56 expression. Different ICC combinations were evaluated showing that the panel made up of CD56 plus HBME-1 and Galectin-3 had the highest sensitivity (98%) and specificity (86%).

Conclusions

Our pilot study suggests that CD56 may be a good marker for ruling out PTC and its variants. The low specificity suggests that an immunopanel including also HBME-1 and Galectin-3 could obtain the highest diagnostic accuracy in thyroid lesions. Our results suggest that CD56 may be a feasible additional marker for identifying malignancies also in the FNs and SMs.