Correlation of thyroid nodule fine-needle aspiration cytology with corresponding histology at Mayo Clinic, 2001-2007: An institutional experience of 1,945 cases

Diagnostic Accuracy of Fine-Needle Aspiration Cytology (FNAC) in Thyroid Nodule Excision Cases

INTRODUCTION

Fine needle aspiration cytology (FNAC) for thyroid nodules has a high diagnostic accuracy, according to several studies worldwide. Patients who experienced preoperative FNAC had more optimal surgical treatment than others who did not perform FNAC. Therefore, achieving an accurate FNAC procedure appears to be an important tool for the proper management of thyroid nodules. We aimed to study the accuracy and challenges of the thyroid FNAC diagnostic tool in the Al-Baha region, Kingdom of Saudi Arabia.

METHODS

The study involves 52 patients with thyroid nodules who underwent preoperative FNAC and postoperative histopathology with the same surgery and pathology team at Al-Baha region in 2022-2023.

RESULTS AND CONCLUSION

The mean age of the included patients was 47.7 years, with a female predominance. The diagnostic accuracy was 90%, and the main cause of inaccurate diagnosis was processing challenges, where the majority of cases were taken on the palpation-only technique, a few cases were ultrasound-guided, and the only technique used in the laboratory was conventional smears. The applied interrater reliability Cohen kappa coefficient (κ) for the clinical-histopathological agreement was "moderate agreement". We recommend using and evaluating more cytological techniques in addition to the currently used conventional smears in pathology laboratories to enhance the efficacy of the FNAC diagnosis of thyroid lesions.

Cadherin-16 (CDH16) immunohistochemistry: a useful diagnostic tool for renal cell carcinoma and papillary carcinomas of the thyroid

Cadherin-16 (CDH16) plays a role in the embryonal development in kidney and thyroid. Downregulation of CDH16 RNA was found in papillary carcinomas of the thyroid. To determine the expression of CDH16 in tumors and to assess the diagnostic utility a tissue microarray containing 15,584 samples from 152 different tumor types as well as 608 samples of 76 different normal tissue types was analyzed. A membranous CDH16 immunostaining was predominantly seen in thyroid, kidney, cauda epididymis, and mesonephric remnants. In the thyroid, CDH16 staining was seen in 100% of normal samples, 86% of follicular adenomas, 60% of follicular carcinomas, but only 7% of papillary carcinomas (p < 0.0001). CDH16 positivity was frequent in nephrogenic adenomas (100%), oncocytomas (98%), chromophobe (97%), clear cell (85%), and papillary (76%) renal cell carcinomas (RCCs), various subtypes of carcinoma of the ovary (16-56%), various subtyped of carcinomas of the uterus (18-40%), as well as in various subtypes of neuroendocrine neoplasms (4-26%). Nineteen further tumor entities showed a weak to moderate CDH16 staining in up to 8% of cases. Our data suggest CDH16 as a potential diagnostic marker-as a part of a panel-for the identification of papillary carcinomas of the thyroid, nephrogenic adenomas, and the distinction of renal cell tumors from other neoplasms.

Diagnostic accuracy of fine-needle aspiration cytology for lymphoma: A systematic review and meta-analysis

BACKGROUND

Fine-needle aspiration cytology (FNAC) has become one of the most useful modalities for diagnosis and staging of lymphoma. However, diagnostic accuracy of this technique has been reported with varying results across several studies around the world. Hence, this meta-analysis was done to assess the accuracy of FNAC for lymphoma diagnosis.

METHODS

We conducted a systematic search for all studies reporting the diagnostic accuracy of FNAC for lymphoma in the databases of PubMed Central, MEDLINE, EMBASE, MEDLINE, SCOPUS and Cochrane library from inception till January 2021. Meta-analysis was performed using STATA software "midas" package.

RESULTS

Forty-seven studies with 7268 patients were included. The pooled sensitivity and specificity of FNAC for diagnosing lymphoma were 93% (95% CI, 90%-95%) and 97% (95% CI, 95%-98%), respectively. Likelihood ratio positive was 33.5 (95% CI, 18.5-60.7) and likelihood ratio negative was 0.07 (0.05-0.11) making the technique to occupy the left upper quadrant in LR scattergram indicating that FNAC can be used for confirmation and exclusion. There was significant heterogeneity with significant chi-square test and I² statistic >75%. There was significant publication bias as per Deek's test and funnel plot.

CONCLUSION

To summarize, our study found that FNAC has a vital role as a diagnostic tool for lymphoma with higher sensitivity and specificity. Further studies assessing the accuracy of FNAC on specific types of lymphoma is required.

Correlation Between Thyroid Fine Needle Aspiration Cytology and Postoperative Histology: A 10-Year Single-Centre Experience

Introduction

Fine needle aspiration cytology (FNAC) forms part of the routine workup for suspicious thyroid nodules. Whilst cytological analysis is less precise than histological assessment, it is quick and easy to perform and may avoid the need for invasive and potentially risky surgery.

Methods

This retrospective study spanned a 10-year period comparing preoperative FNAC with postoperative histology results to establish the accuracy of diagnosis and malignancy rates within our population. These results were then compared to the published figures in the literature.

Results

The histological reports of 659 consecutive cases of thyroid surgery between 2006 and 2015 were retrieved from our hospital database. Among the 471 patients (71.5%) who underwent preoperative FNAC, the postoperative histology was reported as benign in 352 (74.7%) and malignant in 119 cases (25.3%). Papillary thyroid cancer (PTC) was the commonest histological diagnosis. Thy1 grade was reported in 165 (30%) cases, with 19.4% having a final histological diagnosis of malignancy. In the Thy2 group, 85.3% of patients had a benign final histological diagnosis, while 14.7% had malignancy (false-negative results). Malignancy was found in 89% of Thy4 and 100% of Thy5 group patients. 

Conclusions

Rates of malignancy varied considerably from those in the published literature. Each centre should be able to quote a local malignancy rate during patient counselling. It is also prudent for all units performing thyroid diagnostics to investigate the factors that might lead to inaccuracies in reporting.

Outcomes of the Bethesda system for reporting thyroid cytopathology: Real-life experience

OBJECTIVE

The 2017 revised Bethesda System for Reporting Thyroid Cytopathology (BSRTC) included new malignancy rates for each category as well as new management recommendations. Here, we evaluate the malignancy rate and test performance for BSRTC categories in a middle-sized institution outside the United States (US).

DESIGN

Retrospective single centre case series with chart review.

PATIENTS

All patients who underwent thyroid surgery with a preoperative BSRTC between the years 2010 and 2018 at our institution.

MEASUREMENTS

In order to assess the malignancy rate for each BSRTC, all medical records were reviewed to collect demographics, nodule's size, BSRTC and final pathology.

RESULTS

Three hundred and sixty-four patients were included, with an overall malignancy rate of 34.3%. The malignancy rate for BSRTC categories I-VI was as follows: 13.3%, 5.1%, 25.0%, 24.4%, 91.3% and 95.2%, respectively. The most sensitive test was when BSRTC III-VI were evaluated (91%). Overall best performance (sensitivity, specificity, PPV, NPV and accuracy) was obtained when BSRTC V-VI were grouped together with a substantial decrease when adding BSRTC III-IV (90%, 97%, 94%, 95%, 95% vs, respectively, 91%, 73%, 62%, 95%, 79%, respectively).

CONCLUSIONS

Despite differences from the reported 2017 BSRTC malignancy rates, we demonstrated that the revised 2017 BSRTC management recommendations for thyroid nodules are also valid in smaller non-US centre, supporting its use globally.

Progressively Enlarging Goiter: Case Reports of Primary Thyroid Lymphoma and Literature Review

Primary thyroid lymphoma (PTL) is an exceptionally rare and highly aggressive potentially curable malignant disease. We report three typical cases of PTL referred to our hospital. All three cases had long history of Hashimoto's thyroiditis, and presented with progressively enlarging neck mass. The first two cases were confirmed by surgical biopsy to be diffuse large B cell lymphoma, and received radiotherapy combined with chemotherapy, or received only chemotherapy. The third case was confirmed by core needle biopsy to be mucosa-associated lymphoid tissue lymphoma, and received radiotherapy. In summary, confirmation of PTL diagnosis is essential for further clinical decisions. Core biopsy should be one of the most important methods to make the diagnosis of PTL, while the use of fine needle aspiration cytology alone is still limited in diagnosing PTL.

Pathological diagnosis of thyroid nodules based on core needle biopsies: comparative study between core needle biopsies and resected specimens in 578 cases

BACKGROUND

Pathological diagnosis based on core needle biopsy (CNB) should be different from a resected specimen because it is difficult to apply the histological criteria established for resected specimens to CNB due to sampling limitations. A pathological classification for thyroid nodule on CNB was first proposed by the Korean Group in 2015. The objective of this study was to test the reliability and clinical value of this proposal.

METHODS

According to the Korean proposal, the CNB diagnoses were categorized into unsatisfactory, benign, indeterminate, follicular neoplasm, suspicious for malignancy and malignant. A comparative study between the diagnoses of CNB and resected specimens was performed.

RESULTS

The consistency was moderate (κ = 0.448). Combined indeterminate, suspicious for malignancy and malignant into a single group collectively referred to as "malignant" with the remaining merged into "others", CNB demonstrated a 95.93% sensitivity, 97.30% specificity, 62.07% accuracy, 99.81% positive predictive value (PPV) and 62.07% negative predictive value (NPV) for preoperative malignancy evaluation.

CONCLUSIONS

The Korean proposal for pathological classification of thyroid nodules on CNB is objective, operable and highly valuable.

Thyroid nodules classified as atypia or follicular lesions of undetermined significance deserve further research: Analysis of 305 surgically confirmed nodules

OBJECTIVE

The objective of the present study was to determine the malignancy risk for nodules categorised as atypia or follicular lesions of undetermined significance atypia of undetermined significance/follicular lesion of undetermined significance (AUS/FLUS) and to investigate the predictors of malignancy.

METHODS

All nodules diagnosed as AUS/FLUS on fine needle aspiration (FNAs) performed between January 2011 and December 2015 were retrospectively reviewed. Clinical data, ultrasonographic features, follow-up data and the final pathological results were recorded. After further exclusion, only nodules that underwent surgical excision were included in the final analysis. The malignancy rate and the range of malignancy rates were calculated. Clinical and ultrasound features were examined to determine the predictors of malignancy.

RESULTS

During the study period, FNA was performed on 9938 nodules, and 1019 (10.2%) nodules were diagnosed as AUS/FLUS. After further exclusion, 976 nodules were evaluated. After the initial diagnosis of AUS/FLUS, 139 (14.2%) patients underwent surgery, 518 (53.1%) had repeated FNAs. A total of 305 (31%) had undergone surgical excision at different time points. For surgically confirmed nodules, the malignancy rate after the initial FNA was 34.5% (the lower and upper thresholds for the malignancy rate were 19.3% and 66.3%, respectively), and 37.9% after the repeated FNA. No ultrasound feature was determined as a predictor, whereas age (>55 years) was a predictor for malignancy.

CONCLUSIONS

The overall malignancy rate for nodules diagnosed as AUS/FLUS and the malignancy rate for nodules that underwent repeated FNA after AUS/FLUS were higher than the expected malignancy rates of the National Cancer Institute. It is, therefore, suggested that the current recommendations should be reconsidered.

Metastatic neoplasms to the thyroid diagnosed by fine-needle aspiration/core needle biopsy: Clinicopathologic and cytomorphologic correlation

BACKGROUND

Although thyroid fine-needle aspiration (FNA) and core needle biopsy (CNB) are commonly utilized modalities in the evaluation of thyroid nodules, metastatic tumors to the thyroid are only rarely encountered. We aspired to determine the incidence and primary origin of metastases to the thyroid at our institution and to examine their clinicopathologic and cytomorphologic features.

MATERIALS AND METHODS

A search of our database was undertaken to review all thyroid FNA and/or CNB examined between January 2004 and December 2013.

RESULTS

During our 10 year study period, 7497 patients underwent 13,182 FNA and/or CNB. Four hundred sixty one (6%) patients were diagnosed with neoplasms. Only five (1.1%) were found to have metastatic tumors to the thyroid involving three females and two males. Two were diagnosed by FNA, one by CNB, and two by both FNA and CNB, with rapid on-site evaluation (ROSE) employed in all cases. The primary malignancies in the five cases were pulmonary and nasopharyngeal squamous cell carcinomas, renal cell carcinoma, pancreatic adenocarcinoma, and olfactory neuroblastoma. The cytomorphologic features of these metastases to the thyroid aided in their distinction from primary thyroid carcinoma. Two of these metastases, a renal cell carcinoma and pancreatic adenocarcinoma, were the first clinical manifestations of cancer.

CONCLUSION

Metastases to the thyroid diagnosed by FNA and/or CNB are exceedingly rare in our institution, comprising only 0.04% of total FNA/CNB and only 1.1% of all thyroid neoplasms. We report the first known case of metastatic olfactory neuroblastoma to the thyroid diagnosed by aspiration cytology. In addition, an occult primary may present as a thyroid mass on FNA or CNB as occurred with two of our cases. FNA/CNB proved to be highly effective in the diagnosis of metastases to the thyroid, with ROSE proving valuable in assuring specimen adequacy. Thyroid FNA and CNB demonstrated great utility in the setting of metastatic disease, obviating the need for more invasive procedures.

A Different Perspective on Evaluating the Malignancy Rate of the Non-Diagnostic Category of the Bethesda System for Reporting Thyroid Cytopathology: A Single Institute Experience and Review of the Literature

Objective

To determine the malignancy rate in the non-diagnostic (ND) category of the Bethesda System for Reporting Thyroid Cytopathology (BSRTC) based on a different approach in relation to histopathology diagnoses.

Study Design

All ND fine needle aspirations (FNAs) that were performed under ultrasound guidance by an interventional radiologist with rapid on-site evaluation were included in the study. Slides were reevaluated to identify the cause of inadequacy as “qualitative” or “quantitative.” The malignancy rate of the ND category was assessed. Nodule/patient characteristics were compared between benign and malignant cases within the study cohort.

Results

The study cohort consisted of 192 ND aspirations. Overall there were 156 (81.3%) women and 36 (18.7%) men with a mean age of 50.6 years (range 24–82 years). The malignancy rate was 4.7%. None of the nodules (size, consistency, and number) or patient characteristics (gender and age) were found to be predictive of malignancy.

Conclusion

The malignancy rate of the ND category was high when compared to BSRTC predictions, but at the low end of the reported malignancy rates in the literature. Our results revealed that cyto-histopathologic correlation and method of malignancy rate estimation could have an effect on a wide range of reported malignancy rates. Furthermore, patient/nodule dependent factors were not statistically found to be predictive of malignancy.

Diagnostic value of BRAF (V600E)-mutation analysis in fine-needle aspiration of thyroid nodules: a meta-analysis

Fine-needle aspiration (FNA) is a reliable method for preoperative diagnosis of thyroid nodules; however, about 10%–40% nodules are classified as indeterminate. The BRAF^V600E mutation is the most promising marker for thyroid FNA. This meta-analysis was conducted to investigate the diagnostic value of BRAF^V600E analysis in thyroid FNA, especially the indeterminate cases. Systematic searches were performed in PubMed, Web of Science, Scopus, Ovid, Elsevier, and the Cochrane Library databases for relevant studies prior to June 2015, and a total of 88 studies were ultimately included in this meta-analysis. Compared with FNA cytology, the synergism of BRAF^V600E testing increased the diagnostic sensitivity from 81.4% to 87.4% and decreased the false-negative rate from 8% to 5.2%. In the indeterminate group, the mutation rate of BRAF^V600E was 23% and varied in different subcategories (43.2% in suspicious for malignant cells [SMC], 13.77% in atypia of undetermined significance/follicular lesion of undetermined significance [AUS/FLUS], and 4.43% in follicular neoplasm/suspicious for follicular neoplasm [FN/SFN]). The sensitivity of BRAF^V600E analysis was higher in SMC than that in AUS/FLUS and FN/SFN cases (59.4% vs 40.1% vs 19.5% respectively), while specificity was opposite (86.1% vs 99.5% vs 99.7% respectively). The areas under the summary receiver-operating characteristic curve also confirmed the diagnostic value of BRAF^V600E testing in SMC and AUS/FLUS rather than FN/SFN cases. Therefore, BRAF^V600E analysis can improve the diagnostic accuracy of thyroid FNA, especially indeterminate cases classified as SMC, and select malignancy to guide the extent of surgery.

Comparison of diagnostic yield of core-needle and fine-needle aspiration biopsies of thyroid lesions: Systematic review and meta-analysis

Objectives

Thyroid nodular disease is one of the most commonly observed medical conditions. Cytological evaluation of the specimens obtained with fine-needle aspiration biopsy (FNAB) is the most accurate tool for selecting nodules which should be further surgically removed. A major limitation of this method is the high occurrence of non-diagnostic results. This indicates the need for improvement of the thyroid biopsy technique. The aim of this meta-analysis was to compare the diagnostic value of thyroid core-needle biopsies (CNBs) and FNABs.

Materials and methods

PubMed/MEDLINE, Cochrane Library, Scopus, Cinahl, Academic Search Complete, Web of Knowledge, PubMed Central, PubMed Central Canada and Clinical Key databases were searched. Risk ratios (RRs) of non-diagnostic results were meta-analysed using the random-effects model.

Results

Eleven studies were included in the quantitative analysis. CNB yielded significantly more diagnostic results – the pooled risk ratio (RR) of gaining a non-diagnostic result was 0.27 (p<0.0001). For lesions with one previous non-diagnostic FNAB, RR was 0.22 (p<0.0001).

Conclusions

CNB seems to be a valuable diagnostic technique yielding a higher proportion of diagnostic results than conventional FNAB. It is also significantly more effective in case of nodules with a prior non-diagnostic result of FNAB results than repeated FNABs.

Key Points

• Core-needle biopsy yields a higher proportion of diagnostic results than fine-needle biopsy.

• Core-needle biopsies may decrease the amount of unnecessary thyroidectomies.

• Probability of gaining non-diagnostic result using core-needle biopsy is almost four times lower.

The cytological diagnosis of a 'benign thyroid lesion': is it a real safe diagnosis for the patient?

OBJECTIVE

In fine needle aspiration cytology (FNAC), the category of benign thyroid lesions (BTL), which constitutes 65-70% of all thyroid FNAC, and can be correctly diagnosed by morphology alone, is an important entity. A diagnosis of BTL denotes a lesion managed with follow-up unless found in conjunction with compressive symptoms. Although this diagnosis can be quite simple, there are cases in which the scant cellular or colloid component may pose diagnostic issues. Herein, we describe the experiences of evaluating BTL at two large academic institutions. We evaluated the clinical importance of a correct diagnosis of BTL to define the exact inherent risk of a false-negative result (FNR).

METHODS

From January 2008 through to June 2013, 506 (3.6%) out of 15 850 patients with BTL underwent surgery. All nodules were sampled under sonographic guidance (US) and processed either with liquid-based cytology (LBC), Diff-Quik® smears or alcohol-Papanicolaou staining methods.

RESULTS

The histological follow-up of 506 BTL series included 493 benign and 13 malignant lesions. The latter group included four follicular carcinomas (FC), two classic variants of papillary thyroid carcinoma (PTC), one macrofollicular PTC and six follicular variants of PTC (FVPC). The malignancy rate for the BTL category was 2.5%.

CONCLUSIONS

When diagnosed by expert cytopathologists, BTL represents a robust diagnosis and might reduce the number of FNR. Additional diagnostic experience and a large case series could enable cytopathologists to recognise all the morphological entities of BTL. An important additional aid is the extensive sampling of the lesions to reduce issues related to a low cellularity.

Survey of cytopathologists and cytotechnologists for the clinical impact of the use of atypia or follicular lesion of undetermined significance

Background:

The cytologic diagnosis of atypia of undetermined significance or follicular lesion of undetermined significance (AUS/FLUS) is controversial because of variation in how it is applied in practice, as well as uncertainty about patient management. We aimed to assess the percentage of thyroid fine-needle aspiration biopsies (FNABs) with AUS/FLUS diagnoses in different North American and European practice settings (e.g. community, academic, etc.), assess whether patients were managed according to current guidelines, and determine patient outcomes.

Materials and Methods:

A detailed questionnaire survey was posted in secure websites used separately by cytopathologists and cytotechnologists. The questionnaire was posted from August 1 through December 31, 2013.

Results:

Endocrinologists and cytopathologists performed 51.7% and 37.1% of thyroid FNABs, respectively. The Bethesda reporting system for thyroid FNAB was used in 90% of practices. The rate of AUS/FLUS varied widely among institutions, with 46.1% of represented institutions reporting AUS/FLUS rates of 3–10%. The median follow-up rate of patients with an initial AUS/FLUS diagnosis was 70% (range, 10–100%). For the majority of represented institutions (86.4%), patients with initial AUS/FLUS diagnosis had follow-up with endocrinologists. Of repeat AUS/FLUS thyroid FNABs, a median of 52% was considered benign, and 18% were suspicious of or positive for malignancy (median, 10% and 7.5%, respectively).

Conclusions:

Reporting of the AUS/FLUS category varied widely among different institutions. The median follow-up rate was lower than published guidelines. The most common follow-up diagnosis was benign thyroid nodule. Improved standardization of cytologic criteria should be adopted to reduce such variation.

Retrospective evaluation of the incidental finding of 403 papillary thyroid microcarcinomas in 2466 patients undergoing thyroid surgery for presumed benign thyroid disease

Background

The aim of our study was to investigate the incidence of papillary thyroid microcarcinoma (PTMC) in patients operated for benign thyroid diseases (BTD) and its relation to age, sex, extent of surgery and type of BTD.

Methods

Retrospective study of 2466 patients who underwent thyroid surgery for BTD from 2008 to 2013. To determine independent predictors for PTMC we used three separate multivariate logistic regression models (MLR).

Results

There were 2128 (86.3%) females and 338 (13.7%) males. PTMC was diagnosed in 345 (16.2%) females and 58 (17.2%) males. Age ranged from 14 to 85 years (mean 54 years). Sex and age were not related to the incidence of PTMC. The overall incidence of PTMC was 16.3%. The highest incidence was in Hashimoto thyroiditis (22.7%, χ² = 10.80, p < 0.001); and in patients with total/near-total thyroidectomy (17.7%, χ² = 7.05, p < 0.008). The lowest incidence (6.6%, χ² = 9.96, p < 0.001) was in a solitary hyperfunctional thyroid nodule (SHTN). According to MLR, Hashimoto thyroiditis (OR 1.54, 95% CI 1.15-2.05, p < 0.003) and SHTN (OR 0.43, 95% CI 0.21-0.87, p < 0.019) are independent predictors. Since the extent of surgery was an independent predictor (OR 1.45, 95% CI 1.10-1.92, p = 0.009) for all BTD, and sex and age were not; when the MLR model was adjusted for them, Graves disease (OR 0.72, 95% CI 0.53-0.99, p < 0.041) also proved to be an independent predictor.

Conclusions

Sex and age are not statistically related to the incidence of PTMC in BTD. The incidence of PTMC is higher in Hashimoto thyroiditis and patients with total/near-total thyroidectomy; and lower in patients with a SHTN and Graves disease.

The diagnostic accuracy of ultrasound-guided fine-needle aspiration biopsy for thyroid nodules three centimeters or larger in size

BACKGROUND AND PURPOSE

Whether under ultrasonography (US) guidance or not, fine-needle aspiration biopsy (FNAB) has some limitations, particularly in larger nodules. In this study, we aimed to evaluate the diagnostic value of US-guided fine-needle aspiration biopsy (US-FNAB) in thyroid nodules equal to or larger than 3 cm.

MATERIALS AND METHODS

Data of 267 patients operated for nodular goiter in the period of January 2006 and March 2012 were reviewed retrospectively. The study group (40 males, 104 females; mean age 42.3 ± 12.3, between 17 and 71) consisted of patients with nodules with a diameter of 3 cm or larger. Patients with nodules less than 3 cm in diameter were considered as the control group (27 males, 96 females; mean age 44.4 ± 11.9, between 18 and 71).

RESULTS

For nodules smaller than 3 cm, US-FNAB had an accuracy rate of 60% and a false negativity rate of 21.9%. In nodules equal to or larger than 3 cm, the accuracy rate of US-FNAB was 80%, with a false negativity rate of 6.7%. Malignancy was observed in 16% of the study group and 42.3% of the control group.

CONCLUSION

This study showed that increased nodule diameter is not associated with limitations in the diagnostic value of US-FNAB. We also found that the malignancy rate was smaller for larger nodules. This finding reflects the importance of accurate and rational diagnostic work-up and clinical management for detecting malignancy and surgical decision-making.

Detection rate of FNA cytology in medullary thyroid carcinoma: a meta-analysis

BACKGROUND

The early detection of medullary thyroid carcinoma (MTC) can improve patient prognosis, because histological stage and patient age at diagnosis are highly relevant prognostic factors. As a consequence, delay in the diagnosis and/or incomplete surgical treatment should correlate with a poorer prognosis for patients. Few papers have evaluated the specific capability of fine-needle aspiration cytology (FNAC) to detect MTC, and small series have been reported. This study conducts a meta-analysis of published data on the diagnostic performance of FNAC in MTC to provide more robust estimates.

RESEARCH DESIGN AND METHODS

A comprehensive computer literature search of the PubMed/MEDLINE, Embase and Scopus databases was conducted by searching for the terms 'medullary thyroid' AND 'cytology', 'FNA', 'FNAB', 'FNAC', 'fine needle' or 'fine-needle'. The search was updated until 21 March 2014, and no language restrictions were used.

RESULTS

Fifteen relevant studies and 641 MTC lesions that had undergone FNAC were included. The detection rate (DR) of FNAC in patients with MTC (diagnosed as 'MTC' or 'suspicious for MTC') on a per lesion-based analysis ranged from 12·5% to 88·2%, with a pooled estimate of 56·4% (95% CI: 52·6-60·1%). The included studies were statistically heterogeneous in their estimates of DR (I-square >50%). Egger's regression intercept for DR pooling was 0·03 (95% CI: -3·1 to 3·2, P = 0·9). The study that reported the largest MTC series had a DR of 45%. Data on immunohistochemistry for calcitonin in diagnosing MTC were inconsistent for the meta-analysis.

CONCLUSIONS

The presented meta-analysis demonstrates that FNAC is able to detect approximately one-half of MTC lesions. These findings suggest that other techniques may be needed in combination with FNAC to diagnose MTC and avoid false negative results.

Thyroid nodules with macrocalcification: sonographic findings predictive of malignancy

PURPOSE

To analyze which sonographic features of thyroid nodules with macrocalcifications were predictable of thyroid malignancy.

MATERIALS AND METHODS

We reviewed sonographic findings of 854 macrocalcified thyroid nodules in patients who underwent fine needle aspiration biopsy between December 2009 and January 2011. There were 171 non-diagnostic aspirations, 34 nodules with category 3, 4, 5 based on Bethesda system, which were not confirmed by surgery, and these nodules were excluded from the analysis. Sonographic characteristics of the macrocalcifications including its thickness, interruption, and existence of soft tissue rim outside the macrocalcification were analyzed. Other sonographic characteristics of nodules such as shape, margin, composition, echo pattern, vascularity, and underlying parenchymal echogenicity were also evaluated. The correlation of sonographic features with cytopathologic results and the diagnostic performance of sonographic features for the prediction of malignancy were analyzed.

RESULTS

Among 649 nodules, 179 (27.6%) nodules were malignant and 470 (72.4%) nodules were benign. Among the features of the macrocalcification, interruption, irregular thickness, or the presence of soft tissue outside calcification rim were associated with malignancy (p<0.001). A high sensitivity and negative predictive values for the prediction of malignancy was found in sonographic characteristics of irregular thickness (92.2% and 91.0%, respectively) and the presence of soft tissue (88.5% and 88.8%, respectively).

CONCLUSION

Sonographic characteristics of macrocalcification such as interruption, irregular thickness and the presence of soft tissue rim were associated with malignancy in thyroid nodules with macrocalcifications.

'Suspicious for papillary thyroid carcinoma' before and after The Bethesda System for Reporting Thyroid Cytopathology: impact of standardized terminology

BACKGROUND

The high-risk 'suspicious for papillary thyroid carcinoma' (SPTC) is a clinically relevant diagnosis in the cytological interpretation of thyroid aspirates. While The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) has provided invaluable terminology standardization, a performance comparison for this diagnostic category has not been performed. Therefore, this study evaluates the SPTC diagnosis before and after the introduction of TBSRTC in a large meta-analysis and at a single institution.

MATERIALS AND METHODS

The meta-analysis analyzed publications of SPTC or similar diagnoses before and after the introduction of TBSRTC. Similarly our own institutional experience was analyzed for the 8 years surrounding the introduction of TBSRTC. A correlation of the cytopathology and surgical pathology diagnoses was performed.

RESULTS

The introduction of TBSRTC coincided with a significant decrease in the fraction of cases called SPTC in the meta-analysis (4.5-3.1%, p < 0.00001) and in the institutional review (1.7-0.9%, p = 0.005). Meanwhile, the malignancy risk for those cases increased significantly in the meta-analysis from 62.5 to 80.5% (p < 0.00001) and trended upwards in the institutional review from 69 to 79% (p = 0.4). The follow-up rate was similar in both time periods in the meta-analysis and the institutional review.

CONCLUSIONS

The introduction of TBSRTC coincided with a decrease in the fraction of cases called SPTC and an increase in the malignancy risk associated with that diagnosis.

Low nondiagnostic rate for fine-needle capillary sampling biopsy of thyroid nodules: a singular experience

OBJECTIVES

This study examined the hypothesis that sonographically guided fine-needle capillary thyroid biopsies performed by an experienced operator and with constant technique on nodules that meet the Society of Radiologists in Ultrasound criteria warranting biopsy can result in a nondiagnostic rate that is significantly lower than prior published reports.

METHODS

We retrospectively reviewed the sonographic and pathologic reports from 228 consecutive sonographically guided fine-needle capillary thyroid biopsies performed during a 3-year interval by a single operator with more than 15 years of experience performing fine-needle capillary thyroid biopsies. There were no exclusion criteria. Sonographic and pathologic reports from all nodules biopsied were included in the analysis. The radiologist's protocol included 6 fine-needle capillary biopsies, each with 20 passes of the needle into the periphery and/or solid components of the nodule. The cytologic specimens were reviewed off-site in adherence with the Bethesda system for reporting thyroid cytopathologic findings and classified as diagnostic or nondiagnostic. The nondiagnostic rate in this study was compared with the nondiagnostic rates in prior published reports.

RESULTS

Among the 228 fine-needle capillary thyroid biopsies performed during the study interval, cytologic analysis showed 1 nondiagnostic biopsy, yielding a nondiagnostic rate of 0.4%. This rate was significantly lower than previously published reports (P < .001).

CONCLUSIONS

Sonographically guided fine-needle capillary biopsies of the thyroid performed by an experienced radiologist can result in a nondiagnostic rate of less than 1%. This finding warrants further investigation into the reasons for the discrepancy between the results of this study and other previous reports.

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

BACKGROUND

Fine-needle aspiration biopsy (FNAB) is important in the diagnostic establishment of suspicious thyroid nodules. In thyroid neoplasms, mutation of the BRAF gene occurs rather exclusively in papillary thyroid carcinoma (PTC) and results in>98% of the cases in V600E amino acid substitution. In the current study, the authors investigated the diagnostic value of a recently described monoclonal antibody that detects this specific mutation on FNAB specimens from patients with PTC.

METHODS

BRAF(V600E) status of FNAB cell blocks from 55 patients with PTC was analyzed by immunohistochemistry (IHC) with the new BRAF(V600E) antibody (clone VE1) and by Sanger sequencing (SaS). In discrepant cases, ultra-deep sequencing was also performed. Available corresponding histological specimens were investigated by IHC and, in selected cases, with SaS as well.

RESULTS

All cases yielded evaluable IHC staining results of the cell block sections with good interobserver agreement (kappa value, 0.650). Ten tumors (18.2%) demonstrated no staining, 10 tumors (18.2%) demonstrated equivocal staining, 25 tumors (45.4%) demonstrated moderate staining, and 10 tumors (18.2%) demonstrated strong staining. SaS was able to be performed in 48 cases. Nineteen cases demonstrated wild-type BRAF and 29 cases were found to have the BRAF(V600E) mutation. After performing ultra-deep sequencing 1 false-positive and 2 false-negative VE1 IHC cases remained, resulting in a sensitivity of 93.8% and a specificity of 93.8%.

CONCLUSIONS

BRAF(V600E) mutations in FNAB specimens from patients with PTC can be reliably detected in most cases by IHC with a new mutation-specific antibody. Interpretation of VE1 IHC staining results on cell block slides of PTC can be difficult in some cases.

Clinicopathologic predictors of thyroid bed recurrence of differentiated thyroid cancer using ultrasound-guided fine-needle aspiration biopsies

BACKGROUND

Monitoring changes in the thyroid bed (TB) is one of the clinical mainstays for surveillance of recurrent thyroid carcinoma. Fine-needle aspiration (FNA) is a diagnostic tool that is commonly used to aid in the identification of residual or recurrent disease. The aim of our study was to evaluate the efficacy of ultrasound-guided FNA of the TB in detecting recurrent thyroid cancer and to correlate the findings with clinicopathologic parameters to identify predictors of TB recurrence.

METHODS

We retrieved cases of soft tissue masses within the TB that were evaluated for recurrence between January 1, 2006, and February 1, 2011. All ultrasound-guided FNA biopsies clinically suspected to indicate a lymph node metastasis and specimens with lymphocytes were excluded from the data.

RESULTS

Of the 291 patients identified for evaluation of recurrence, 250 had papillary thyroid carcinoma (PTC), 10 had follicular carcinoma, 22 had medullary carcinoma, 7 had Hürthle cell carcinoma, and 2 had a previous thyroidectomy for an unknown type of thyroid carcinoma. For all FNAs that were clinically suspicious or intermediate for recurrence, the rate of positivity was 71.8% (209 patients). All cases diagnosed as "positive for PTC" or "suspicious for PTC" on TB FNA were found to have soft tissue metastasis on follow-up surgical resection. This resulted in a negative predictive value of 88.4% and a positive predictive value of 100%. The average time between thyroidectomy and TB FNA was 73.5 months. Of the patients with a previous diagnosis of PTC, those with suspicious/positive cytology were more likely to be women, to be older at thyroidectomy, to have documented metastasis to other sites as well as extrathyroidal extension and multifocal primary disease as compared with nondiagnostic/negative cytology cases. Patient age ≥45 years, primary tumor size at thyroidectomy, and surgical resection margin status had no statistical significance for predicting risk of TB recurrence.

CONCLUSION

TB recurrence of PTC is most likely to occur in patients who have the following clinicopathologic parameters: documented metastasis to any site, extrathyroidal extension, and increased number of primary cancer foci.

Thyroid nodule as a first manifestation of Hodgkin lymphoma-report of two cases and literature review

Lymphomas account for less than 5% of thyroid malignant lesions. Vast majority of them are B-cell non-Hodgkin lymphomas (NHL), while Hodgkin lymphoma (HL) is extremely rare. Here we present two cases of HL, at baseline manifesting as a thyroid lesion. First patient, 29-year-old pregnant female, initially suspected for metastatic medullary thyroid cancer, was eventually diagnosed with mixed cellularity type of thyroid HL. Second patient, 22-year-old woman with suspicion of advanced thyroid cancer, was in the end diagnosed with an extra-lymphatic classical HL of the thyroid. In both cases, despite repeated fine-needle aspiration biopsy, cytological examination gave inconclusive or misleading results. On histopathological examination, thyroid tumor cells were positive for CD15 and CD30 antigen, which is typical for Reed-Sternberg cells. In the report authors also discuss difficulties in management as well as potential importance of novel methods such as FISH, PCR and other molecular techniques in diagnostics of thyroid lymphomas.

VIRTUAL SLIDES

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/2896947559559648.

[Medullary thyroid carcinoma in children]

Medullary thyroid carcinoma (MTC) is rare in children. MTC is almost always inherited and occurs as part of a multiple endocrine neoplasia type 2A and B, due to germline mutation in the RET proto-oncogene. MTC in the pediatric population is most often diagnosed in the course of a familial genetic investigation. But when the child is the proband, a de novo mutation is most often founded. The main aim is to treat MTC before extrathyroidal extension occurs because when distant metastases are present, it is rarely curable. Treatment is based on total thyroidectomy with cervical lymph node dissection.

Thyroid nodule surgery: predictive diagnostic value of fine-needle aspiration cytology and frozen section

OBJECTIVES

The authors analyse the predictive diagnostic accuracy of fine-needle aspiration cytology (FNAC) and frozen section examination in adult patients operated for thyroid nodules.

PATIENTS AND METHODS

The same pathologist performed macroscopic and cytological examination, followed by frozen section examination on each operative specimen. FNAC results were classified into three groups: benign, malignant or suspicious of malignancy. Frozen section examination was also classified into three categories: benign, malignant or suspicious of malignancy when not all criteria of malignancy were present.

RESULTS

One hundred and sixty-six (82%) of the 202 patients included in the study were females. Patients had a mean age of 51 years. Thyroid carcinoma was diagnosed on final pathology in 22% of women and 25% of men. FNAC results were benign in 85% of cases, malignant in 9% of cases and atypical or suspicious in 6% of cases, with a specificity of more than 99% and a sensitivity, including and excluding microcarcinomas, of 36% and 48%, respectively. The diagnostic accuracy of FNAC was 84% and 89%, after excluding micro-carcinomas. Frozen section was benign in 85% of cases, malignant in 13% of cases and suspicious in 2% of cases, with a specificity of more than 99% and a sensitivity, including and excluding microcarcinomas, of 56% and 68%, respectively. The diagnostic accuracy of frozen section was 89% and 90%, after excluding microcarcinomas. The diagnostic accuracy of the combination of the two examinations was 94% after excluding microcarcinomas.

CONCLUSION

FNAC and frozen section have a comparable predictive diagnostic accuracy. Frozen section is requested by the surgeon not only on the basis of preoperative FNAC, especially when it is suspicious, or even indeterminate, but also in the light of the macroscopic surgical findings.

False negatives in thyroid cytology: impact of large nodule size and follicular variant of papillary carcinoma

OBJECTIVES/HYPOTHESIS

Fine-needle aspiration (FNA) cytology is well established in the diagnosis of thyroid nodules. However, false-negative rates for malignancy of 3% to 10% are reported. The purpose of the present study was to investigate the impact of nodule size and follicular variant of papillary carcinoma (FVPTC) on false-negative FNA rates in thyroid nodules and on malignancy rates in nodules with indeterminate cytology.

STUDY DESIGN

Retrospective study.

METHODS

A total of 765 consecutive ultrasound-guided FNAs were reviewed. Histological correlation was available in 262 cases.

RESULTS

The overall sensitivity of FNA for malignancy was 84%, and the false-negative rate 9.1%. Nodules ≥ 3 cm were significantly more likely to ultimately be diagnosed as cancer by histology than nodules <3 cm (14% vs. 6.8%, P = .006); however, they were also significantly more likely to undergo surgery than smaller nodules (P < .0001). Among the surgical series, the false-negative rate was 10.9% in nodules ≥ 3 cm and 6.1% in nodules <3 cm (P = .71). Most false negatives were due to FVPTC. FVPTC was significantly more likely to be missed by preoperative cytology than conventional or other variants of papillary carcinoma (P < .001). Among cases with indeterminate cytology, nodule size and Thy-3f versus Thy-3a subclassification did not have any significant impact on likelihood of malignancy.

CONCLUSIONS

The sensitivity of FNA for detection of FVPTC is reduced compared to conventional papillary carcinoma. The impact of nodule size is not significant.

LEVEL OF EVIDENCE

4.

'Suspicious for a follicular neoplasm' before and after the Bethesda System for Reporting Thyroid Cytopathology: impact of standardized terminology

BACKGROUND

The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) standardized the terminology for indeterminate diagnoses, but the performance of the indeterminate categories before and after TBSRTC has not been compared. This study evaluates the 'suspicious for a follicular or Hürthle cell neoplasm' (SFN/HCN) category before and after the introduction of TBSRTC at a single institution and in a meta-analysis of the literature.

METHODS

A meta-analysis compiled findings from publications on SFN/HCN or similar diagnoses before and after the introduction of TBSRTC. The pathology database at our institution identified all SFN/HCN or similar diagnoses in the 8 years surrounding the introduction of TBSRTC, and those cases were correlated with the surgical follow-up.

RESULTS

In the meta-analysis, the fraction of cases called SFN/HCN or the equivalent increased from 6.1 to 7.4% (p = 0.0002); the surgical follow-up rate increased from 55 to 61% (p < 0.00001), and the histological malignancy rate among the cases that were resected increased from 22 to 28% (p = 0.03) after TBSRTC. In our institutional experience, the introduction of TBSRTC did not coincide with any significant changes.

CONCLUSION

Standardized terminology clearly coincided with increases in follow-up and the malignancy rate of SFN/HCN. A change in the same statistics was not seen in our institutional experience.

Prognosis of thyroid nodules in individuals living in the Zhitomir region of Ukraine

Objective

After the accident at the Chernobyl Nuclear Power Plant (CNPP), the incidence of thyroid cancer increased among children. Recently, a strong relationship between solid thyroid nodules and the incidence of thyroid cancer was shown in atomic bomb survivors. To assess the prognosis of benign thyroid nodules in individuals living in the Zhitomir region of Ukraine, around the CNPP, we conducted a follow-up investigation of screening data from 1991 to 2000 in the Ukraine.

Patients and Methods

Participants of this study were 160 inhabitants with thyroid nodules (nodule group) and 160 inhabitants without thyroid nodules (normal control group) intially identified by ultrasonography from 1991 to 2000. All participants were aged 0 to 10 years old and lived in the same area at the time of the accident. We performed follow-up screening of participants and assessed thyroid nodules by fine needle aspiration biopsy.

Results

Among the nodule group participants, the number and size of nodules were significantly increased at the follow-up screening compared with the initial screening. No thyroid nodules were observed among the normal control group participants. The prevalence of thyroid abnormality, especially nodules that could be cancerous (malignant or suspicious by fine needle aspiration biopsy), was 7.5% in the nodule group and 0% in the normal control group (P<0.001).

Conclusions

Our study indicated that a thyroid nodule in childhood is a prognostic factor associated with an increase in the number and size of nodules in individuals living in the Zhitomir region of Ukraine.

Incidence of malignancy in thyroid nodules determined to be follicular lesions of undetermined significance on fine-needle aspiration

BACKGROUND

Fine-needle aspiration (FNA) for thyroid nodules is the most important method for determining a diagnosis. The system for reporting results is based on a cytopathologic classification that stratifies the risk of malignancy.

METHODS

We retrospectively studied 197 patients who underwent FNA for diagnostic evaluation of a thyroid nodule and had their results reported as a follicular lesion of undetermined significance (FLUS) using the Bethesda classification system. The objective of the study was to analyze the incidence and histopathologic types of malignancy in these cases.

RESULTS

The final histopathologic breakdown is as follows: 65 cases (32.9%) of follicular adenoma, 81 cases (41.1%) of microfollicular adenomatoid nodule, 19 cases (9.6%) of microfollicular adenomatoid nodule on the background of thyroiditis, 17 cases (8.6%) of follicular carcinoma, 9 cases (4.6%) of follicular variant papillary carcinoma, and 6 cases (3.1%) of classic papillary carcinoma, for a 16.2% incidence of malignancy. Beyond these diagnoses in the FNA-biopsied nodules, we observed 29 cases (14.7%) of incidental ipsilateral papillary thyroid microcarcinoma (PTM) and 13 cases (6.6%) of incidental contralateral thyroid lobe PTM.

CONCLUSIONS

This study observed a 16.2% incidence of thyroid cancer in the nodule designated FLUS compared to the 5 to 15% rate reported by the Bethesda FNA classification. The overall incidence of incidental PTM in the thyroid gland was 21.3%. These data support considering surgical intervention for at least diagnostic purposes in a patient with the FNAB diagnosis of FLUS.

Predictors of malignancy in patients with cytologically suspicious thyroid nodules

BACKGROUND

Fine needle aspiration (FNA), although very reliable for cytologically benign and malignant thyroid nodules, has much lower predictive value in the case of suspicious or indeterminate nodules. We aimed to identify clinical predictors of malignancy in the subset of patients with suspicious FNA cytology.

METHODS

We reviewed the electronic medical records of 462 patients who had FNA of thyroid nodules at our institution with a suspicious cytological diagnosis, and underwent surgery at Mayo Clinic between January 2004 and September 2008. Demographic data including age, gender, history of exposure to radiation and use of thyroid hormone was collected. The presence of single versus multiple nodules by ultrasonography, nodule size, and serum thyroid-stimulating harmone (TSH) level before thyroid surgery were recorded. Analysis of the latter was limited to patients not taking thyroid hormone or antithyroid drugs at the time of FNA.

RESULTS

Of the 462 patients, 327 had lesions suspicious for follicular neoplasm (S-FN) or Hürthle cell neoplasm (S-HCN), 125 had cytology suspicious for papillary carcinoma (S-PC) and 10 had a variety of other suspicious lesions (medullary cancer, lymphoma and atypical). Malignancy rate for suspicious neoplastic lesions (FN+HCN) was ∼15%, whereas malignancy rate for lesions S-PC was 77%. Neither age, serum TSH level, or history of radiation exposure were associated with increased malignancy risk. The presence of multiple nodules (41.1% vs. 26.4%, p=0.0014) or smaller nodule size (2.6±1.8 cm vs. 2.9±1.6 cm, p=0.008) was associated with higher malignancy risk. In patients with cytology suspicious for neoplasm (FN, HCN) malignancy risk was higher in those receiving thyroid hormone therapy than in nonthyroid hormone users (37.7% vs. 16.5%, p=0.0004; odds ratio: 3.1), although serum TSH values did not differ significantly between thyroid hormone users and nonusers.

CONCLUSION

In patients with cytologically suspicious thyroid nodules, the presence of multiple nodules or smaller nodule size was associated with increased risk of malignancy. In addition, our study demonstrates for the first time, an increased risk of malignancy in patients with nodules suspicious for neoplasm who are taking thyroid hormone therapy. The reason for this association is unknown.