Fine-Needle Aspiration of Thyroid Nodules: Past, Present, and Future

Diagnostic accuracy of palpation versus ultrasound-guided fine needle aspiration biopsy for diagnosis of malignancy in thyroid nodules: a systematic review and meta-analysis

Thyroid nodule is a common health problem in endocrinology. Thyroid fine-needle aspiration biopsy (FNAB) cytology performed by palpation guided FNAB (PGFNAB) and ultrasound-guided FNAB (USGFNAB) are the preferred examinations for the diagnosis of thyroid cancer and part of the integration of the current thyroid nodule assessment. Although studies have shown USGFNAB to be more accurate than PGFNAB, inconsistencies from several studies and clinical guidelines still exist.The purpose of this study is to compare the diagnostic accuracy of Palpation versus Ultrasound-Guided Fine Needle Aspiration Biopsy in diagnosing malignancy of thyroid nodules.The systematic review and meta-analysis were prepared based on the PRISMA standards. Literature searches were carried out on three online databases (Pubmed/MEDLINE, Embase, and Proquest) and grey literatures. Data extraction was carried out manually from various studies that met the eligibility, followed by analysis to obtain pooled data on sensitivity, specificity, Diagnostic Odds Ratio (DOR) and Area Under Curve (AUC), and the comparison of the two methods.Total of 2517 articles were obtained, with 11 studies were included in this systematic review. The total sample was 2382, including 1128 subjects using PGFNAB and 1254 subjects using USGFNAB. The risk of bias was assessed using QUADAS-2 with mild-moderate results. The results of sensitivity, specificity, AUC and DOR in diagnosing thyroid nodules using PGFNAB were 76% (95% CI, 49-89%), 77% (95% CI, 56-95%), 0.827 and 11.6 (95% CI, 6-21) respectively. The results of sensitivity, specificity, AUC and DOR in diagnosing thyroid nodules using USGFNAB were 90% (95% CI, 81-95%), 80% (95% CI, 66-89%), 0.92 and 40 (95% CI, 23-69), respectively the results of the comparison test between PGFNAB and USGFNAB; Tsens USGFNAB of 0.99 (p = 0.023), AUC difference test of 0.093 (p = 0.000023).The diagnostic accuracy of USGFNAB is higher than PGFNAB in diagnosing malignancy of thyroid nodules. If it is accessible, the author recommends using USGFNAB as a diagnostic tool for thyroid nodules.

Core Needle Biopsy Can Early and Precisely Identify Large Thyroid Masses

Background

Large thyroid masses, particularly if rapidly growing, are often characterized by compression and infiltration of the vital structures of the neck. Therefore, an early and precise diagnosis, not only of malignancy but also of histotype, is mandatory to set up the right therapy. The aim of this study was to evaluate the diagnostic performance of fine needle aspiration cytology (FNAC) and core needle biopsy (CNB) in this setting.

Patients and Methods

We prospectively evaluated 95 patients with large and rapidly growing thyroid masses admitted to the University Hospital of Pisa between April 2014 and January 2020. All patients were submitted to FNAC and CNB in the same session. The ability of both procedures to diagnose the malignancy of the lesions, particularly the histotype, and to obtain sufficient material to perform molecular analysis was evaluated.

Results

FNAC obtained adequate tumor sample to reach a diagnosis in 76 of 95 (80%) patients, while a higher percentage was obtained with CNB (92/95, 96.8%). FNAC was able to identify the malignancy of the lesion in 74 of 95 (77.9%) cases, but only in 16 of 74 (21.6%) cases was it able to define the histotype. CNB was able to define the malignancy of the lesion in all but three cases (92/95, 96.8%), and in all specimens, the histotype was identified. Moreover, in all cases, the material extracted from CNB was optimal to perform molecular analysis. No surgery-related complications were experienced with both procedures.

Conclusions

CNB is a rapid and safe procedure with higher performance compared to FNAC in identifying the histotype of large and rapidly growing thyroid masses. Moreover, adequate material can be obtained to characterize the molecular profile for the treatment of potentially lethal cancers. In the era of precision medicine, CNB should be introduced in routine clinical practice as a key procedure for an early diagnosis and therapy of these diseases.

Technical feasibility and efficacy of a standard needle magnetization system for ultrasound needle guidance in thyroid nodule-targeting punctures: a phantom study

PURPOSE

The aim of this study was to assess the feasibility and efficacy of an ultrasound needle guidance system (NGS) based on standard needle magnetization in a phantom study of thyroid nodule (TN)-targeting punctures.

METHODS

Six trainees and a staff radiologist performed TN-targeting punctures with or without the NGS in phantom models (group 1, experience <50 cases; group 2, experience ≥50 cases and <100 cases; group 3, experience ≥100 cases of TN-targeting punctures). The feasibility, technical success rate, number of punctures, and procedure time were recorded.

RESULTS

The feasibility of NGS was 98.6% (138/140). In group 1, the technical success rate increased from 60.0%±8.2% to 80.0%±8.2% when the NGS was used (P=0.046), with a reduction in the number of punctures from 2.2 to 1.2 (P=0.005). In group 2, the rate changed from 95.0%±5.8% to 100.0%±0.0% with the NGS (P=0.157), with a minimal decrease in the number of punctures from 1.1 to 1.0 (P=0.157). The procedure time significantly decreased in both groups (P=0.041 and P=0.010, respectively) when the NGS was used. In group 3, there were no significant differences in the technical success rate and the number of punctures according to whether the NGS was used (P=0.317 and P=0.317, respectively).

CONCLUSION

NGS using standard needle magnetization is technically feasible and has potential to improve the efficacy of TN-targeting punctures for less-experienced operators, especially beginners, according to the findings of this phantom study.

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.

Tall Cell Variant versus Conventional Papillary Thyroid Carcinoma: A Retrospective Analysis in 351 Consecutive Patients

Background: The aim of this retrospective study was to investigate clinical and pathological characteristics of the tall cell variant of papillary thyroid carcinoma compared to conventional variants. Methods: The clinical records of patients who underwent surgical treatment between 2009 and 2015 were analyzed. The patients were divided into two groups: those with a histopathological diagnosis of tall cell papillary carcinoma were included in Group A, and those with a diagnosis of conventional variants in Group B. Results: A total of 35 patients were included in Group A and 316 in Group B. All patients underwent total thyroidectomy. Central compartment and lateral cervical lymph node dissection were performed more frequently in Group A (42.8% vs. 18%, p = 0.001, and 17.1% vs. 6.9%, p = 0.04). Angiolymphatic invasion, parenchymal invasion, extrathyroidal extension, and lymph node metastases were more frequent in Group A, and the data reached statistical significance. Local recurrence was more frequent in Group A (17.1% vs. 6.3%, p = 0.02), with two patients (5.7%) in Group A showing visceral metastases, whereas no patient in Group B developed metastatic cancer (p = 0.009). Conclusions: Tall cell papillary carcinoma is the most frequent aggressive variant of papillary thyroid cancer. Tall cell histology represents an independent poor prognostic factor compared to conventional variants.

nPAsym: an open-source plugin for ImageJ to quantify nuclear shape asymmetry

BACKGROUND AND OBJECTIVES

The nucleus is a complex and dynamic organelle enclosing the major part of the cell's genome. A growing body of evidence suggests that changes in the shape of this organelle can influence cell activities. The other way around, altered nuclear shape may be indicative of impaired cell function. Symmetry is an important aspect of nuclear shape not receiving the attention it merits. We address this problem by presenting a software tool allowing to quantify nuclear shape asymmetry in light microscopy images.

METHODS

The software named nPAsym is written in Scala and implemented as a plugin to ImageJ making possible to use it in combination with other ImageJ tools. The plugin works with 8-bit images segmented into black nuclear masks and white background. It performs a number of operations allowing to analyze multiple objects within a single image, removing some segmentation artefacts, filtering out objects incomplete and below a specified size. The feature of interest is quantified using the notion of point asymmetry. The performance of nPAsym was tested in a small-scale study comparing nuclear shapes for cells of nodular goiter, follicular thyroid adenoma and papillary thyroid carcinoma.

RESULTS

We present nPAsym, the ImageJ plugin, that measures nuclear shape asymmetry. It works with digital microscopic images segmented using either a raster graphics editor or built-in ImageJ functions. nPAsym is packaged in a single .jar file and does not require installation as well as configuration. It has proved effective in distinguishing between some of the nuclear shape phenotypes.

CONCLUSIONS

nPAsym is the user-friendly, platform-independent and open-source software tool allowing to quantify nuclear shape asymmetry in digital images captured from cytologic and histologic preparations. It has a potential to become useful for both experimental research and diagnostics.

A New Device for Fine-Needle Aspiration Cytology Consisting of a Vibrating Linear Resonant Actuator

OBJECTIVE

To evaluate the efficacy of a new device for fine-needle aspiration cytology (FNAC) consisting of a vibrating linear resonant actuator (LRA).

STUDY DESIGN

Prospective clinical study.

METHODS

The LRA frequency was optimized by visualization of the needle motion using a high-speed camera. The FNAC device consists of a vibrating motor fixed to the stopper of a 5-ml syringe and piston. Upon insertion of the syringe needle into a thyroid nodule (with the stopper attached to the syringe piston), sufficient negative pressure with 1-ml suction was maintained. Subsequently, samples were obtained using vibration generated by an LRA or an eccentric rotating mass (ERM). Surgically resected thyroid specimens from 10 patients were evaluated. The number of follicular groups required for adequate diagnosis and the number of larger follicular groups were counted. Next, 254 thyroid nodules from 187 patients were also evaluated by FNAC. The inadequacy rate was determined, and final cytology was classified according to thyroid Bethesda categories.

RESULTS

The optimized LRA frequency was 155 Hz. Both the LRA and ERM devices resulted in sufficient amounts of diagnostic material and achieved low inadequacy rates. The number of large follicular groups obtained was significantly greater with the LRA device compared with the ERM device.

CONCLUSIONS

The vibrating device using an LRA for thyroid FNAC resulted in sufficient amounts of thyroid follicular groups and achieved low inadequacy rates. In addition, the LRA device allowed for collection of larger follicular groups sufficient to diagnose appropriate thyroid Bethesda categories.

LEVEL OF EVIDENCE

2 Laryngoscope, 131:E1393-E1399, 2021.

Quantitative Analysis of Galectin-3 Expression in Benign and Malignant Thyroid Nodules

In this study, galectin-3 was analyzed as a potential marker for preoperative detection of malignant thyroid lesions. Galectin-3 expression was analyzed by quantitative real-time reverse transcription polymerase chain reaction (RT-PCR) in preoperative thyroid fine-needle aspirates from 245 patients with thyroid nodules. Out of 245 samples, 238 were adequate for analysis by RT-PCR. Galectin-3 was positive in 34 (89.5%) of 38 papillary carcinomas, 3 (89.5%) of 4 follicular carcinomas, 17 (53.1%) of 32 follicular adenomas, 2 (33.3%) of 6 Hurthle cell adenoma, 11 (28.2%) of 39 Hashimoto thyroiditis, and 69 (57.9%) of 119 nodular goiter samples. Galectin-3 showed specificity of 49.5%, sensitivity of 88.1%, positive predictive value of 27.2%, and negative predictive value of 95.1% as a marker for detection of malignant thyroid nodules. Owing to the relatively low positive predictive value due to the relatively high false positive rate, the clinical value of galectin-3 analyzed by quantitative real-time RT-PCR as a marker for preoperative detection of malignant thyroid lesions is limited.

Thyroid carcinoma metastasizing to the submandibular gland: Sonographic findings

Metastases to the submandibular gland are extremely rare; a literature search retuned only three previously reported cases from a thyroid gland primary site. Herein, we report two cases of metastatic thyroid carcinoma to the submandibular gland in a 64-year-old woman with PTC and a 70-year-old-woman with medullary thyroid carcinoma (MTC). The metastases were identified on CT and PET/CT in one case and on CT in the other case, but both were diagnosed with ultrasound-guided fine-needle aspiration. Our cases highlight that while rare, both PTC and MTC can metastasize to the submandibular gland.

Vascular flow on doppler sonography may not be a valid characteristic to distinguish colloid nodules from papillary thyroid carcinoma even when accounting for nodular size

Background

The purpose of this study was to test the hypothesis that there is no significant difference in vascular flow patterns between cytopathologically-proven colloid nodules and papillary thyroid carcinoma (PTC) even when adjusting for nodule size.

Methods

Doppler vascular flow patterns in 200 colloid nodules and 166 nodules with PTC were retrospective reviewed independently by 2 neuroradiologists blinded to the cytopathological results. Absence of vascular flow, perinodular and/or intranodular flow, and diffuse vascular flow were recorded. The vascular flow patterns were compared without (Fisher exact test) and with (Kruskal-Wallis test) an adjustment for nodular size. Using the most common flow pattern as the reference group, multiple logistic regression was used to compare the flow patterns. Sample skewness was calculated to determine degree of symmetry of the size distribution for each vascular flow category.

Results

No significant difference was found in the tested vascular flow patterns between colloid nodules and PTC both without and with an adjustment for nodular size (P>0.05). Intranodular flow only was the largest group (n=111/366) and used as the reference for multiple logistic regression. No significant difference was noted between the vascular flow patterns (P>0.05). Sample skewness showed that nodules were generally smaller in size with outliers of larger size on the opposite end of the spectrum.

Conclusions

Independent of nodule size the absence or presence of vascular flow is not significantly different between colloid nodules and PTC. Therefore, vascular flow may not be useful in distinguishing between colloid nodules and PTC.

Incidence and malignancy rates classified by The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) - An 8-year tertiary center experience in Thailand

Incidence and Malignancy Rates Classified by The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) – An 8-year Tertiary Center experience in Thailand.

Background

Fine-needle aspiration (FNA) of the thyroid is considered the best diagnostic tool for preoperative evaluation of thyroid nodules. The introduction of The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) in 2010 provided the opportunity to establish worldwide standard for reporting and terminology guidelines for diagnostic categories. It is recommended that every institution evaluates the risk of malignancy (ROM) in each category for quality improvement process.

Aim

To assess the effectiveness of TBSRTC method at our institution using cyto-histological correlation.

Method

A retrospective 8-year (2010–2017) audit of thyroid FNA done by thyroid specialists at Theptarin hospital. The FNA results were classified according to TBSRTC. Histopathology reports for operated cases were used to correlate cytology and final histopathology.

Results

A total of 2735 thyroid FNA from 2115 patients (mean age 45.7 ± 13.1 years, female 89.8%) were examined. The rates of non-diagnostic, benign, atypia of undetermined significance (AUS), follicular neoplasm, suspected for malignancy, and malignant cases were 21.1%, 66.6%, 4.7%, 2.4%, 1.8%, and 3.3% respectively. There were 188 patients (9%) who underwent surgical resection with available histopathology. Malignancy rates in operated thyroid nodules were 20.0%, 4.2%, 9.4%, 23.5%, 57.1%, and 90.3% for categories 1 to 6, respectively. The sensitivity, specificity, negative predictive value, and positive predictive value were 96.6%, 88.5%, 95.8%, and 90.3, respectively.

Conclusions

Preoperative diagnosis of thyroid nodules using TBSRTC in our hospital was comparable with other studies. The uniform diagnostic criteria of the Bethesda System help avoid misinterpretation while sharing local experience with international benchmarks.

HMGA2 Gene Expression in Fine-needle Aspiration Samples of Thyroid Nodules as a Marker for Preoperative Diagnosis of Thyroid Cancer

There is a great interest in molecular markers that would help in the preoperative diagnosis of malignant thyroid nodules in cases of indeterminate fine-needle aspiration cytology. The aim of this study was to determine the diagnostic accuracy of HMGA2 gene expression in discriminating benign from malignant thyroid nodules. In this study, 237 preoperative thyroid fine-needle aspiration samples were analyzed prospectively for the expression of the HMGA2 gene by real-time reverse transcription polymerase chain reaction. The results were evaluated against the postoperative histopathologic diagnosis or definitive cytologic diagnosis in cases of nodular goiter and Hashimoto thyroiditis. Among 237 samples from patients with thyroid nodules that were analyzed, 231 were adequate for real-time reverse transcription polymerase chain reaction analysis. With a cutoff value of 8.71 for relative gene expression, HMGA2 was positive in 19 (16.4%) of 116 nodular goiter, 1 (2.6%) of 39 Hashimoto thyroiditis, 9 (28.1%) of 32 follicular adenoma, 0 (0%) of 5 Hurthle cell adenoma, 32 (88.9%) of 36 papillary carcinoma, and 3 (100%) of 3 follicular carcinoma samples. In discriminating between malignant and benign thyroid nodules, HMGA2 has shown specificity of 84.5%, sensitivity of 91.9%, positive predictive value of 53.1%, and negative predictive value of 98.2%. High sensitivity and negative predictive value of HMGA2 for preoperative detection of malignant thyroid nodules shown in this study indicate that it may have a role as an ancillary marker in cytology in the management of patients with thyroid nodules.

Thyroid Fine-Needle Aspiration Practice in the Philippines

Fine-needle aspiration (FNA) is a well accepted initial approach in the management of thyroid lesions. It has come a long way since its introduction for nearly a century ago. In the Philippines, FNA of the thyroid was first introduced 30 years ago and has been utilized until now as a mainstay in the diagnosis of thyroid malignancy. The procedure is performed by pathologists, endocrinologists, surgeons, and radiologists. Most pathologists report the cytodiagnosis using a combination of the aspiration biopsy cytology method that closely resembles the histopathologic diagnosis of thyroid disorders and the six-tier nomenclature of The Bethesda System for Reporting Thyroid Cytopathology. Local endocrinologists and surgeons follow the guidelines of the 2015 American Thyroid Association in the management of thyroid disorders. There is still a paucity of local research studies but available data deal with cytohistologic correlations, sensitivity, specificity, and accuracy rates as well as usefulness of ultrasound-guided FNA. Cytohistologic correlations have a wide range of sensitivity from 30.7% to 73% and specificity from 83% to 100%. The low sensitivity can be attributed to poor tissue sampling since a majority of the thyroid FNA is done by palpation only. The reliability can be improved if FNA is guided by ultrasound as attested in both international and local studies. Overall, FNA of the thyroid has enabled the diagnosis of thyroid disorders with an accuracy of 72.8% to 87.2% and it correlates well with histopathology.

Importance of FNA Technique for Decreasing Non-diagnostic Rates in Thyroid Nodules

To identify potential interventions that may lower the high non-diagnostic rates associated with ultrasound guided (US) fine needle aspiration (FNA) biopsy of the thyroid nodule. A case series of 164 thyroid nodule US-guided FNA was identified retrospectively. The following variables were analyzed in regards to diagnostic and non-diagnostic sampling: patient age, gender, size of nodule, biopsy technique (capillary vs. aspiration), needle gauge (23 vs. 25), and physician experience. The FNA diagnosis, and final pathology, when applicable, was recorded for each sample using the Bethesda criteria. Data was analyzed using the Fisher's exact test or the chi square test. After multivariate logistic regression, capillary action was independently associated with lower non-diagnostic rates (p = 0.01), while increasing patient age was associated with higher non-diagnostic rates (p = 0.018). Physician experience (p = 0.014) was not independently associated with lower non-diagnostic rates. Nodules that were "cystic >50%" were significantly more likely to yield a non-diagnostic result (p < 0.0001). After taking into account confounding variables, including physician experience, our data reveals a statistically significant decrease in non-diagnostic rates with the use of capillary action vs. aspiration technique in US-guided FNA. A major focus in healthcare today is providing cost-effective and minimally invasive care to the patient. In the setting of a rising incidence of thyroid disease, we believe our study demonstrates the need for a prospective analysis of the relationship between technique and non-diagnostic rates.

Comparison of 1869 thyroid ultrasound-guided fine-needle aspiration biopsies between general surgeons and interventional radiologists

BACKGROUND

Thyroid nodules are commonly encountered problems in clinical practice. For patients who have a thyroid nodule, the fine-needle aspiration biopsy (FNAB) is the most important test, as it is the most reliable diagnostic method for distinguishing between benign thyroid nodules and cancerous nodules. FNAB is able to be performed either via an ultrasound (USG) or alone and is the first choice when it comes to diagnosing thyroid nodules, given that it is cheap, safe and provides accurate results.

OBJECTIVE

In this study-a retrospective analysis of FNAB via USG - our aim is to evaluate the multiple variables related to FNAB procedures, including the experience of the person performing the biopsy, the age and gender of the patient, the number of nodules, the size of the nodule(s) and the number of lams recorded from the cytopathology report on non-diagnostic rates, conducted at an invasive radiology clinic and at a general surgery clinic.

MATERIALS AND METHODS

A total of 1062 patients involving 1869 nodules, examined using FNAB via USG, were reviewed retrospectively from records dated between November 2011 and July 2014 and from pathology reports taken from the ANEAH General Surgery clinic and Interventional Radiology clinic. Cytopathology results were classified according to the 2007 Bethesda System for Reporting. Gender, age, number of nodules, diameter of the nodules, biopsied nodules, location of the nodules, number of lams, symptoms and the date of biopsies were the parameters used to examine the factors involved in non-diagnostic cytopathology invasive radiology. These parameters were inspected at both of the clinics (ANEAH General Surgery clinic and Interventional Radiology clinic). In analyzing the results, the statistical significance level was set at 0.05, where in cases that the p value was under 0.05 (p < 0.05), it was determined that no significant relationship existed. In this study, data were analyzed using SPSS 20 software.

RESULTS

Of the nodules reviewed, 1620 were found on females and 249 on males. The age of the patients ranged from 10 to 87 years, with the mean age being 50 years. In the general surgery clinic, 470 nodules of 341 patients were aspirated, and in the interventional radiological clinic, 1399 nodules of 721 patients were aspirated. In the literature review conducted to compare statistical assessments of FNAB via USG, no significant difference was found between the ANEAH General Surgery clinic and the Invasive Radiology clinic (p > 0.05). In the invasive radiology clinic, non-diagnostic rates decreased with the increase in experience of the person who conducted the biopsy (p = 0.001).

CONCLUSION

The results from both of the clinic's rates of non-diagnostic FNAB, performed via USG, were found to be acceptable. Our study also demonstrates that USG-guided FNAB can be performed with a low non-diagnostic rate as experience grows.

A Fatal Case of Cervical Hemorrhage After Fine Needle Aspiration and Core Needle Biopsy of the Thyroid Gland

Fine needle aspiration (FNA) and core needle biopsy (CNB) are recognized to be safe, useful, and inexpensive diagnostic tools for the evaluation of thyroid nodules. However, complications can arise during the procedure, albeit rarely and typically minor in nature. We report here an unusual fatal case of massive hematoma of the neck after FNA and CNB that may have caused airway obstruction. A 68-year-old Japanese woman underwent both procedures and was found dead at home later the same day. Although severe complications of FNA or CNB such as major bleeds or deaths are rarely reported, clinicians and forensic pathologists should be cognizant that complications can arise.

Well-Differentiated Thyroid Cancer: The Philippine General Hospital Experience

BACKGROUND

Well-differentiated thyroid cancer (WDTC) is the most common form of thyroid malignancy. While it is typically associated with good prognosis, it may exhibit higher recurrence and mortality rates in selected groups, particularly Filipinos. This paper aims to describe the experience of a Philippine Hospital in managing patients with differentiated thyroid cancer.

METHODS

We performed a retrospective cohort study of 723 patients with WDTC (649 papillary and 79 follicular), evaluating the clinicopathologic profiles, ultrasound features, management received, tumor recurrence, and eventual outcome over a mean follow-up period of 5 years.

RESULTS

The mean age at diagnosis was 44±13 years (range, 18 to 82), with a majority of cases occurring in the younger age group (<45 years). Most tumors were between 2 and 4 cm in size. The majority of papillary thyroid cancers (PTCs, 63.2%) and follicular thyroid cancers (FTCs, 54.4%) initially presented as stage 1, with a greater proportion of FTC cases (12.7% vs. 3.7%) presenting with distant metastases. Nodal metastases at presentation were more frequent among patients with PTC (29.9% vs. 7.6%). A majority of cases were treated by complete thyroidectomy, followed by radioactive iodine therapy and thyroid stimulating hormone suppression, resulting in a disease-free state. Excluding patients with distant metastases at presentation, the recurrence rates for papillary and FTC were 30.1% and 18.8%, respectively.

CONCLUSION

Overall, PTC among Filipinos was associated with a more aggressive and recurrent behavior. FTC among Filipinos appeared to behave similarly with other racial groups.

Combined papillary and mucoepidermoid carcinoma of the thyroid gland: a possible collision tumor diagnosed on fine-needle cytology. Report of a case with immunocytochemical and molecular correlations

Fine-needle cytology (FNC) is frequently used to diagnose thyroid nodules discovered by palpation or imaging studies. Molecular tests on FNC material may increase its diagnostic accuracy. We report a case of a classic papillary thyroid carcinoma combined with a mucoepidermoid carcinoma correctly identified on FNC. The papillary component had a classic immunophenotype (CK19+, TTF1+), while the mucoepidermoid one was only focally CK19+. Point mutations (BRAF and RAS) and rearrangements (RET/PTC) of the papillary component have been also investigated on FNC samples, with resulting concurrent rearrangements of RET/PTC1 and RET/PTC3, but no point mutations. The histogenesis of combined papillary and mucoepidermoid carcinoma of the thyroid still remains partly unsettled, and further genomic studies are needed to shed some more light on this peculiar neoplasm.

BRAF mutation analysis in thyroid nodules with indeterminate cytology: our experience on surgical management of patients with thyroid nodules from an area of borderline iodine deficiency

PURPOSE

Fine-needle aspiration (FNA) with cytologic evaluation is the most reliable tool for malignancy prediction in thyroid nodules, but cytologic diagnosis remains indeterminate for 12-18 % of nodules. BRAF V600E mutation has been reported to show a high specificity for malignant thyroid nodules and the use of this marker to refine indeterminate FNA cytology results may be a useful diagnostic adjunctive tool in the pre-operative evaluation of thyroid nodules. The aim of this study was to estimate the prevalence of BRAF exon 15 mutation (V600E) and its clinical value as a diagnostic tool in a series of thyroid nodules with indeterminate cytology from an area of borderline iodine deficiency.

SUBJECTS AND METHODS

One hundred and fifty-three thyroid samples obtained by FNA of thyroid nodules from 151 patients were subjected to the analysis of BRAF V600E mutation by direct sequencing. In the study 54 nodules with indeterminate cytology, 56 benign and 43 malignant thyroid nodules were included.

RESULTS

V600E BRAF gene mutation was demonstrated in 19/43 malignant nodules, in 0/56 benign nodules and in only 1/54 indeterminate nodules that, after histology, turned out to be at a papillary thyroid carcinoma.

CONCLUSIONS

The application of BRAF exon 15 analysis showed limitations when applied to discriminate thyroid nodules with indeterminate cytology if wild-type BRAF is found, and there is no role for avoiding diagnostic thyroid surgery.

Detection of RAS mutation by pyrosequencing in thyroid cytology samples

INTRODUCTION

Fine-needle aspiration cytology (FNAC) is the primary means to distinguish benign from malignant thyroid nodules. However, adjunctive diagnostic tests are needed as 20-40% of FNAC are inconclusive. RAS mutations have been described in differentiated thyroid cancer and they could be used as tumor markers. However, their prevalence varies widely among studies, probably as a result of the detection methods used. We investigated whether the pyrosequencing method can be applied to detect NRAS and KRAS mutations in thyroid aspirates.

PATIENTS AND METHODS

A total of 37 thyroid aspirates, including benign hyperplastic nodules (HBN, N = 16) and follicular thyroid carcinomas (FTC, N = 21) were analyzed for the presence of NRAS(61) and KRAS(13) mutations.

RESULTS

A RAS mutation was found in 31% and 62% of BN and FTC respectively. Most samples displayed a percentage of mutated alleles lower than 50% (median = 30.8% and 15.3% in FTC and HBN respectively), a result compatible with the presence of extra-nodular cells contaminating the FNA or with the subclonal nature of both types of thyroid nodules.

DISCUSSION

Pyrosequencing is a reliable assay to detect RAS mutations in fine-needle thyroid aspirates.

CONCLUSIONS

The low specificity and sensitivity limit the power of this test to distinguish between FTC and benign nodules in inconclusive FNACs.

BRAF(V600E) assessment by pyrosequencing in fine needle aspirates of thyroid nodules with concurrent Hashimoto's thyroiditis is a reliable assay

Detection of BRAF mutation in cytology specimens has been proposed as a diagnostic adjunctive tool in evaluation of thyroid nodules with indeterminate cytology findings. Concurrent papillary thyroid carcinoma and Hashimoto's thyroiditis (HT), a disease characterized by thyroid lymphocytic infiltration, is a frequent occurrence. A large lymphocytic infiltrate might reduce the sensitivity of methods employed to detect BRAF mutation in thyroid cytology specimens. To determine whether testing for BRAF mutational status in fine needle aspirates (FNA) is reliable also in the presence of HT lymphocytic infiltration, we assessed the BRAF status by direct sequencing and pyrosequencing in a series of FNAs with and without concomitant HT lymphocytic infiltration. We also performed the same assessment by pyrosequencing in the corresponding tissue samples. Pyrosequencing demonstrated to be more sensitive than direct sequencing. The percentage of mutant BRAF(V600E) alleles was higher in FNAs than in the corresponding tissues, probably because of the lower stromal contamination in FNA than in the sections. In the presence of lymphocytic infiltration, the percentage of mutant BRAF(V600E) alleles determined by pyrosequencing was higher in FNAs than in the corresponding tissue samples (P < 0.0001), indicating a minor lymphocytic contamination in FNA. The diagnostic value of BRAF(V600E) in inconclusive FNAs was not hampered by thyroid lymphocytic infiltration. These results indicate that BRAF(V600E) assessment by pyrosequencing is a reliable assay useful to refine inconclusive cytology of thyroid nodules also in the presence of concurrent HT.

Impact of molecular testing in the diagnosis of thyroid fine needle aspiration cytology: data from mainland China

Background. The molecular work-up of thyroid nodules from fine needle aspiration samples has given clinicians a new level of diagnostic information. The aim of the present study was to evaluate the utility of molecular analysis in thyroid fine needle aspiration samples from a Chinese population. Methods. Specimens were collected from thyroid nodules by fine needle aspiration. Cytology diagnosis and genes analysis were performed and correlated with histology outcome. Results. A total of 83 patients with thyroid nodules were enrolled, including 20 benign lesions and 63 papillary carcinomas. BRAF and RAS mutations and RET/PTC gene rearrangements were found in 65.1%, 0%, and 1.6% of papillary carcinomas, respectively. No gene alterations were found in benign lesions. The combination of BRAF testing and cytology improved the accuracy of cytology from 69.9% to 89.2% (P < 0.05). Moreover, BRAF testing confirmed 82.4% of papillary carcinomas with suspicious cytology and identified 33.3% of papillary carcinomas with atypia cytology. Conclusions. Of the three candidate markers, BRAF testing showed diagnostic utility in fine needle aspiration. Combining BRAF testing with cytology improves the accuracy of fine needle biopsy. Those who have positive BRAF and malignant or suspicious malignant cytology can undergo thyroidectomy without a frozen section.

Pathologic diagnosis of papillary thyroid carcinoma: today and tomorrow

Papillary thyroid carcinoma is the most common malignancy of the thyroid. It is a well-differentiated tumor and the majority behaves in an indolent fashion. The pathologic diagnosis of papillary carcinoma in both cytology and histologic specimens is based upon demonstration of typical nuclear morphology. Using these morphologic criteria, most papillary cancers can be diagnosed with ease, except cases in which there is a paucity of diagnostic nuclear features. Despite advances in the treatment of thyroid cancer, disease recurrences and metastasis can be observed in 20% of cases. Recently, many advances have been made in the pathogenesis of papillary thyroid carcinoma. The notable genetic events include Ret/PTC rearrangements, Ras and BRAF gene mutations. The identification of these has also led to their use in diagnosis and predicting prognosis of papillary thyroid carcinoma. In addition, these involved genes may also serve as targets for cancer chemotherapy in patients where standard thyroid cancer treatment is not effective.

Implementation of the Bethesda System for Reporting Thyroid Cytopathology: observations from the 2011 thyroid supplemental questionnaire of the College of American Pathologists

CONTEXT

Although information about the Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) has been widely disseminated since its inception in 2007, the extent of its implementation and impact on daily practice has not been formally evaluated.

OBJECTIVES

To assess the extent of uptake of TBSRTC across pathology laboratories and to evaluate its impact on daily practice by collating participant responses to the 2011 supplemental thyroid questionnaire of the College of American Pathologists.

DESIGN

A questionnaire was designed to gather information about various aspects of TBSRTC and mailed in June 2011 to 2063 laboratories participating in the College of American Pathologists cytopathology interlaboratory comparison program. The participating laboratories' answers were collated and summarized.

RESULTS

Seven hundred and seventy-seven laboratories (37.6%) returned the survey. Although 60.9% (n = 451) and 17.1% (n = 127) of laboratories reported using TBSRTC or planning to use it in the near future, respectively, 22% (n = 163) had no plans to implement TBSRTC. Of the latter, 32% (n = 70) stated that they were unaware of this classification system. The majority (78.3%, n = 343) of the laboratories used TBSRTC as published in the Thyroid Bethesda System atlas, whereas 21.7% (n = 95) used it with minor modifications. Most reported that the use of TBSRTC had caused either no change (n = 67, 15.2%) or only minor changes (n = 353, 80.2%) in the terminology and diagnostic criteria previously used in their laboratories.

CONCLUSIONS

According to the collected data, TBSRTC is generally well implemented in pathology laboratories. However, because approximately a third of those not using this terminology are not aware of it, additional educational efforts regarding TBSRTC are warranted.

RAS mutations in thyroid cancer

In recent years, our understanding of the genetic alterations underlying thyroid oncogenesis has greatly expanded. The use of molecular markers, including RAS, in the management of thyroid carcinoma is also increasing. This review summarizes the current literature surrounding RAS and discusses its potential as a diagnostic and prognostic indicator in the management of thyroid cancer.

The impact of implementing The Bethesda System for reporting of thyroid FNA at an academic center

Recently, a six-tiered diagnostic risk classification system was created based on the recommendations of the National Cancer Institute (NCI) sponsored NCI Thyroid Needle Aspiration State of the Science Conference at Bethesda, MD in October 2007. The objective of the current study was to compare the frequency distribution of the various diagnostic categories to evaluate its diagnostic performance before and after implementation of The Bethesda System (TBS). A total of 5,897 thyroid Fine needle aspirations (FNAs) were reviewed; 3,207 were from 2008 after TBS implementation, and 2,690 were from 2007 immediately before TBS implementation. Follow-up consisted of reviewing corresponding histologic results. The rates of "Nondiagnostic" specimens and cases with a diagnosis of "Follicular Neoplasm" decreased from 13.1 to 11.1% and 8.6 to 5.5%, respectively, after implementation of TBS, while the rate of negative specimens increased from 68.2 to 73.8%. The other categories remained relatively stable. In addition, there also was a significant decrease in the use of noncommittal descriptive diagnoses. The diagnostic performance of thyroid FNA in identifying a neoplastic process as measured by area under the receiver operating characteristic curve increased from 0.88 to 0.89; the difference was statistically significant (P=0.03). Implementation of TBS showed a significant reduction of: nondiagnostic thyroid FNAs, of FNAs with a diagnosis of "Follicular Neoplasm," as well as cases with descriptive noncommittal diagnoses. TBS results in improved diagnostic performance and therefore more consistent and uniform reporting of thyroid FNA.

MicroRNA expression profile helps to distinguish benign nodules from papillary thyroid carcinomas starting from cells of fine-needle aspiration

OBJECTIVE

MicroRNAs (miRNAs) are small endogenous noncoding RNAs that pair with target messengers regulating gene expression. Changes in miRNA levels occur in thyroid cancer. Fine-needle aspiration (FNA) with cytological evaluation is the most reliable tool for malignancy prediction in thyroid nodules, but cytological diagnosis remains undetermined for 20% of nodules.

DESIGN

In this study, we evaluated the expression of seven miRNAs in benign nodules, papillary thyroid carcinomas (PTCs), and undetermined nodules at FNA.

METHODS

The prospective study included 141 samples obtained by FNA of thyroid nodules from 138 patients. miRNA expression was evaluated by quantitative RT-PCR and statistical analysis of data was performed. Genetic analysis of codon 600 of BRAF gene was also performed.

RESULTS

Using data mining techniques, we obtained a criterion to classify a nodule as benign or malignant on the basis of miRNA expression. The decision model based on the expression of miR-146b, miR-155, and miR-221 was valid for 86/88 nodules with determined cytology (97.73%), and adopting cross-validation techniques we obtained a reliability of 78.41%. The prediction was valid for 31/53 undetermined nodules with 16 false-positive and six false-negative predictions. The mutated form V600E of BRAF gene was demonstrated in 19/43 PTCs and in 1/53 undetermined nodules.

CONCLUSIONS

The expression profiles of three miRNAs allowed us to distinguish benign from PTC starting from FNA. When the assay was applied to discriminate thyroid nodules with undetermined cytology, a low sensitivity and specificity despite the low number of false-negative predictions was obtained, limiting the practical interest of the method.

RET/PTC rearrangement in benign and malignant thyroid diseases: a clinical standpoint

Cytological examination of fine needle aspiration biopsy is the primary means for distinguishing benign from malignant nodules. However, as inconclusive cytology is very frequent, the introduction of molecular markers in the preoperative diagnosis of thyroid nodules has been proposed in recent years. In this article, we review the clinical implications of preoperative detection of rearrangements of the RET gene (RET/papillary thyroid carcinoma (PTC)) in thyroid nodules. The prevalence of RET/PTC in PTC depends on the histological subtypes, geographical factors, radiation exposure, and detection method. Initially, RET/PTC was considered an exclusive PTC hallmark and later it was also found sporadically in benign thyroid lesions. More recently, the very sensitive detection methods, interphase fluorescence in situ hybridization (FISH) and Southern blot on RT-PCR amplicons, demonstrated that the oligoclonal occurrence of RET rearrangement in benign thyroid lesions is not a rare event and suggested that it could be associated with a faster enlargement in benign nodules. For this reason, RET/PTC cannot be considered as an absolute marker of PTC, and its diagnostic application must be limited to assays able to distinguish between clonal and oligoclonal expression. Detection of RET/PTC by quantitative assays will be useful for diagnostic purposes in cytology specimens when a precise cutoff will be fixed in a clinical setting. Until that time, less sensitive RET/PTC detection methods and FISH analysis remain the most appropriate means to refine inconclusive cytology. Future studies with a long follow-up will further clarify the clinical significance of low level of RET rearrangements in benign nodules.

The impact of using defined criteria for adequacy of fine needle aspiration cytology of the thyroid in routine practice

The fine needle aspiration cytology (FNAC) of the thyroid is the predominant method of preoperative tissue diagnosis of thyroid lesions. The routine use of FNAC has reduced the rate of unnecessary surgery for thyroid nodules. However, there are overlaps in the existing criteria for defining adequacy in thyroid aspirates. In this study, we aimed to explore the reasons for high percentage of inadequate thyroid FNAC samples and to reevaluate those samples by applying clearly defined criteria suggested in the literature to reduce the proportion of inadequate aspirates. The results of 550 smears reported as inadequate FNAC samples are presented over a period of 15 years extending from 1986 to 2000 (18.8%). For the purpose of the study, only those patients with subsequent histological or cytological analysis were included (279). The original FNA samples were reviewed by two cytopathologists, unaware of the subsequent repeat cytology or histology results. Specific criteria for adequacy of specimens were used which include the presence of six or more groups of follicular cells, each having more than 10 discernable viable cells or 60 isolated viable follicular cells. Out of 279, 82 (29%) FNAC samples originally reported as inadequate met our criteria and were considered adequate on review. Of these 82 cases, subsequent surgical excision showed malignancy in 5 cases (6%), adenoma in 7 (9%), and benign hyperplasia and thyroiditis in 70 cases (85%). In addition, 16 (5%) cases were classified as cysts. The slide preparation error was noticed in 26 (14%) and the sampling error was observed in 160 (86%) cases. The use of well-defined criteria for adequacy is helpful because it improves the diagnostic efficiency of thyroid FNA and avoids unnecessary surgery for benign nonneoplastic thyroid lesions. However, since application of these criteria has also resulted in an increase in the false-negative diagnoses, they should be applied in the multidisciplinary context.

Fine-Needle Aspiration and Intraoperative Consultation in Thyroid Pathology: When and How?

Fine-needle aspiration (FNA) and frozen section evaluation are traditional components of the management of thyroid lesions. Their role and usefulness are dictated by some basic facts about thyroid pathology: ( a) nodules are very common; ( b ) they are benign in the majority of cases; and ( c) the diagnosis of malignancy is primarily based on cytologic features in the case of papillary carcinoma, and on the presence of invasion of the tumor capsule or of blood vessels in the case of follicular carcinoma. The common occurrence of benign thyroid nodules mandates a cost-effective effective method for preoperative screening. Since, as already stated, the diagnosis of papillary thyroid carcinoma (by far the most common thyroid malignancy) is based on the identification of characteristic cytologic features, FNA has easily emerged in the past 30 years as the most accurate and cost-effective tool—indeed a true cornerstone—for the preoperative management of thyroid nodules. Standardized terminology to report cytologic diagnoses is highly recommended and is being implemented worldwide. Conversely, the importance of intraoperative frozen section diagnosis has been constantly decreasing over the past years, as a direct consequence of the widespread application of FNA. It may, however, be very useful in cases that are suspicious for papillary carcinoma on FNA and in selected cases with an indeterminate cytologic diagnosis.

Prevalence of RET/PTC rearrangement in benign and malignant thyroid nodules and its clinical application

Fine-needle aspiration cytology (FNAC) is the primary means to distinguish benign thyroid nodules from malignant ones. About 20% of FNAC yields indeterminate results leading to unnecessary or delayed surgery. Many studies of tissue samples, the majority of which are retrospective advocate testing for RET rearrangements as a diagnostic adjunctive tool in thyroid nodules with indeterminate cytological findings. Because of the uncertain prevalence of RET rearrangements, its utility as a tumor marker is still controversial. The goal of this study was to establish the prevalence and the utility of testing for RET rearrangements in FNAC suspicious of cancer in a clinical setting. In this prospective study, we analysed a large series of thyroid aspirates by RT-PCR only and Southern blot on RT-PCR products for type 1 and 3 RET rearrangements. Results were compared with clinical findings, cytological diagnosis and final histopathology. By the higher sensitive Southern-blot on RT-PCR method, RET rearrangements were present in 36% of papillary thyroid carcinomas (RET/PTC-1, 12%; RET/PTC-3, 20%; both, 4%) and of 13.3% of benign nodules. By means of RT-PCR only, RET rearrangements were disclosed only in 14.3% of PTC and in 3.6% of benign nodules. No significant correlation was found between RET rearrangements and clinicopathological features of patients. These results indicate that molecular testing of thyroid nodules for RET/PTC must take into account of its high prevalence in benign nodules, inducing false positive diagnoses when the highly sensitive assay Southern-blot on RT-PCR is used. Its searching by means of RT-PCR only, has a specificity superior of conventional cytology and can be used to refine inconclusive FNAC.

Old and new insights in the treatment of thyroid carcinoma

Thyroid cancer is the endocrine tumor that bears the highest incidence with 33 550 new cases per year. It bears an excellent prognosis with a mortality of 1530 patients per year (Jemal et al.; 2007). We have been treating patients with thyroid carcinoma during many years without many innovations. Recently, we have assisted to the development of new agents for the treatment of this disease with unexpected good results. Here we present a review with the old and new methods for the treatment of this disease.

First report of a case with needle track sinus after aspiration biopsy of a benign thyroid nodule resulted in an unexpected postoperative complication

Fine needle aspiration biopsy is the most feasible, safe, and accurate diagnostic tool for thyroid nodule diagnosis. The development of a sinus tract between thyroid gland and the skin through needle tract after fine needle aspiration biopsy is an extremely uncommon phenomenon. In this paper, a 71-year-old man presenting with a swelling and discharge on the anterior neck wall was reported. Similar complaints were present 15 to 20 days after fine needle aspiration biopsy of thyroid gland four years ago. Bilateral total thyroidectomy was performed considering a thyroid malignancy infiltrating the skin. Histopathologic examination confirmed a sinus tract between the thyroid gland and skin and thyroid nodule was benign in nature. It must be kept in mind that inflammatory reactions might also occur after fine needle aspiration biopsy of benign thyroid nodules. In patients with needle biopsy-related inflammation, surgery may be delayed until the inflammation subsides.

Impact of proto-oncogene mutation detection in cytological specimens from thyroid nodules improves the diagnostic accuracy of cytology

CONTEXT

Fine-needle aspiration cytology (FNAC) is the gold standard for the differential diagnosis of thyroid nodules but has the limitation of inadequate sampling or indeterminate lesions.

OBJECTIVE

We aimed to verify whether search of thyroid cancer-associated protooncogene mutations in cytological samples may improve the diagnostic accuracy of FNAC.

STUDY DESIGN

One hundred seventy-four consecutive patients undergoing thyroid surgery were submitted to FNAC (on 235 thyroid nodules) that was used for cytology and molecular analysis of BRAF, RAS, RET, TRK, and PPRgamma mutations. At surgery these nodules were sampled to perform the same molecular testing.

RESULTS

Mutations were found in 67 of 235 (28.5%) cytological samples. Of the 67 mutated samples, 23 (34.3%) were mutated by RAS, 33 (49.3%) by BRAF, and 11 (16.4%) by RET/PTC. In 88.2% of the cases, the mutation was confirmed in tissue sample. The presence of mutations at cytology was associated with cancer 91.1% of the times and follicular adenoma 8.9% of the time. BRAF or RET/PTC mutations were always associated with cancer, whereas RAS mutations were mainly associated with cancer (74%) but also follicular adenoma (26%). The diagnostic performance of molecular analysis was superior to that of traditional cytology, with better sensitivity and specificity, and the combination of the two techniques further contributed to improve the total accuracy (93.2%), compared with molecular analysis (90.2%) or traditional cytology (83.0%).

CONCLUSIONS

Our findings demonstrate that molecular analysis of cytological specimens is feasible and that its results in combination with cytology improves the diagnostic performance of traditional cytology.

Growing thyroid nodules with benign histology and RET rearrangement

Some benign thyroid nodules are stationary in size over time while others grow progressively, indicating that there is a broad individual variability within benign nodules. To date, it is very difficult to predict if a benign thyroid nodule will grow in size and which will be its trend over time. While BRAF(V600E) is a highly specific marker of thyroid cancer, RET rearrangements have been disclosed also in non malignant thyroid lesions and their biological significance is debated. We compared the clinical history of three histologically benign thyroid nodules harboring RET rearrangements with that of 6 benign nodules bearing wild type RET. The nodules negative for RET rearrangements were followed for 10 years by ultrasonographic evaluation, showing a slow, constant enlargement. Three patients with benign nodules diagnosed at FNAC, were followed for 11, 9 and 7 years by annual ultrasonographic evaluation. After several years of latency, the nodules had an unexpected and gradual increase in their dimensions, reaching a large final size. A second FNAC confirmed the previous cytologic diagnosis of benign lesion. Because of the increasing size of the nodules, the patients were advised to surgery. Before undergoing thyroidectomy, we performed molecular diagnostic tests that revealed the absence of BRAF(V600E) and the presence of RET/PTC-1 in one nodule and RET/PTC-3 in the two others. Despite the presence of this oncogene, the samples were histologically classified as benign hyperplastic nodules. These findings lead us to speculate that histologically benign hyperplastic thyroid nodules containing RET rearrangements might represent a subgroup of nodules with a rapid size increase.

The Bethesda thyroid fine-needle aspiration classification system: year 1 at an academic institution

BACKGROUND

Fine-needle aspiration (FNA) may be the procedure of choice in the preoperative evaluation of thyroid nodules, yet it suffers as a modality both because of its inherent limitations as well as variability in its diagnostic terminology. The National Cancer Institute recently proposed a classification system. The objective of this study was to report our experience in using this new reporting system to review the distribution of diagnosis categories and to evaluate the specificity of the system based on the cytologic-histologic correlation.

PATIENTS AND METHODS

A total of 3207 thyroid nodules underwent FNA, that is, 3207 FNAs from 2468 patients were examined at our institution between January 1, 2008 and December 31, 2008. All FNAs were classified prospectively into unsatisfactory, benign, indeterminate (cells of undetermined significance), follicular neoplasm (FN), suspicious for malignancy, and positive for malignancy.

RESULTS

The distribution of these categories from 3207 evaluated nodules was as follows: 11.1% unsatisfactory, 73.8% benign, 3.0% indeterminate, 5.5% FN, 1.3% suspicious, and 5.2% malignant. Of the 2468 sampled patients, 378 (15%) underwent thyroidectomy. The distribution of diagnoses of patients who underwent surgery was as follows: 10% unsatisfactory, 4.6% benign, 30.3% indeterminate, 61.4% FN, 76.9% suspicious, and 77.2% malignant. There was an excellent association between the categories and in predicting benign versus malignant thyroid nodules (p < 0.0001). However, the false-negative rate cannot be calculated because only a small number of patients with benign diagnosis underwent surgery. The false-positive rate was 2.2%; all were diagnosed as suspicious cytologically. Given that only 15% of the patients underwent surgery, at this time the sensitivity of thyroid FNA for diagnosing malignant thyroid nodules cannot be calculated, nor can the sensitivity of thyroid FNA as a screening test for all neoplasms be accurately estimated. The specificity for diagnosing malignant thyroid nodules was 93%, whereas the specificity as a screening test for all neoplasms was 68%. The positive predictive values for an FN, suspicious, and positive cytologic diagnosis were 34%, 87%, and 100%, respectively.

CONCLUSIONS

These data demonstrate that the recently proposed classification system is excellent for reporting thyroid FNAs. Each diagnostic category conveys specific risks of malignancy, which offers guidance for patient management.

Development of a clinical decision model for thyroid nodules

Background

Thyroid nodules represent a common problem brought to medical attention. Four to seven percent of the United States adult population (10–18 million people) has a palpable thyroid nodule, however the majority (>95%) of thyroid nodules are benign. While, fine needle aspiration remains the most cost effective and accurate diagnostic tool for thyroid nodules in current practice, over 20% of patients undergoing FNA of a thyroid nodule have indeterminate cytology (follicular neoplasm) with associated malignancy risk prevalence of 20–30%. These patients require thyroid lobectomy/isthmusectomy purely for the purpose of attaining a definitive diagnosis. Given that the majority (70–80%) of these patients have benign surgical pathology, thyroidectomy in these patients is conducted principally with diagnostic intent. Clinical models predictive of malignancy risk are needed to support treatment decisions in patients with thyroid nodules in order to reduce morbidity associated with unnecessary diagnostic surgery.

Methods

Data were analyzed from a completed prospective cohort trial conducted over a 4-year period involving 216 patients with thyroid nodules undergoing ultrasound (US), electrical impedance scanning (EIS) and fine needle aspiration cytology (FNA) prior to thyroidectomy. A Bayesian model was designed to predict malignancy in thyroid nodules based on multivariate dependence relationships between independent covariates. Ten-fold cross-validation was performed to estimate classifier error wherein the data set was randomized into ten separate and unique train and test sets consisting of a training set (90% of records) and a test set (10% of records). A receiver-operating-characteristics (ROC) curve of these predictions and area under the curve (AUC) were calculated to determine model robustness for predicting malignancy in thyroid nodules.

Results

Thyroid nodule size, FNA cytology, US and EIS characteristics were highly predictive of malignancy. Cross validation of the model created with Bayesian Network Analysis effectively predicted malignancy [AUC = 0.88 (95%CI: 0.82–0.94)] in thyroid nodules. The positive and negative predictive values of the model are 83% (95%CI: 76%–91%) and 79% (95%CI: 72%–86%), respectively.

Conclusion

An integrated predictive decision model using Bayesian inference incorporating readily obtainable thyroid nodule measures is clinically relevant, as it effectively predicts malignancy in thyroid nodules. This model warrants further validation testing in prospective clinical trials.

Impact of a reporting template on thyroid fine needle aspiration cytology reporting and cytohistologic concordance

BACKGROUND

Reporting templates are increasingly common in all fields of pathology. In this paper, we present an assessment of the impact of a thyroid fine needle aspiration cytology (FNAC) template on diagnostic classification and cytohistologic concordance.

MATERIALS AND METHODS

A thyroid FNAC reporting template was developed and introduced at a university teaching hospital. We examined FNAC reports for a five-month period before introduction of the template and compared these to the five month period after the template introduction. We recorded diagnostic categorization as well as cytohistologic correlation.

RESULTS

A total of 168 cases were identified in the five month period prior to the introduction of the reporting template and 172 cases in the five month period after the introduction of the reporting template. The template appeared to improve the diagnostic precision of benign conditions without altering the proportion of cases classified as unsatisfactory, benign or abnormal. There was no significant difference in the rate of cytohistologic concordance before and after the template introduction.

CONCLUSIONS

The introduction of a reporting template for thyroid FNAC improved diagnostic precision of benign conditions and did not alter the general diagnostic classification or cytohistologic concordance.

US-guided fine-needle aspiration of thyroid nodules: indications, techniques, results

Fine-needle aspiration (FNA) biopsy of thyroid nodules is minimally invasive and safe and is usually performed on an outpatient basis. However, the optimal application of FNA requires not only technical skill but also an awareness of the limitations of the procedure, the indications for its use, the factors that affect the adequacy of the biopsy specimen, and the postprocedural management strategy. Ultrasonographic (US) features that are considered indications for FNA include single and multiple thyroid nodules. The results of FNA biopsy are operator dependent. In addition, the results may be affected by the lesion characteristics, the accuracy of lesion and needle localization, the method of guidance, the number of aspirated samples, the needle gauge, the aspiration technique, and the presence or absence of on-site facilities for immediate cytologic examination. With regard to postprocedural management, nodules that are diagnosed as benign on the basis of an adequate FNA specimen should be monitored with follow-up US. Circumstances that necessitate repeat FNA include sample inadequacy, nodule enlargement, cyst recurrence, or clinical or imaging findings that arouse suspicion about the presence of a malignancy even when cytologic findings in the biopsy specimen indicate benignity. Supplemental material available at radiographics.rsnajnls.org/cgi/content/full/28/7/1869/DC1.

Routine serum calcitonin measurement in the evaluation of thyroid nodules

Calcitonin (CT) is secreted mainly by parafollicular C cells. In normal subjects, serum CT (sCT) levels are low and barely detectable by commonly used assays. Increased sCT levels are highly suggestive of medullary thyroid carcinoma (MTC). Since the clinical manifestation of MTC is a thyroid nodule, either single or in the context of a multinodular goitre, the routine measurement of sCT in the evaluation of thyroid nodule(s) facilitates the diagnosis of MTC. sCT measurement is indeed more sensitive than cytology in finding MTC. There are two major benefits from this clinical practice: (a) the surgeon is alerted to the need to perform total thyroidectomy and central compartment lymphadenectomy, which is the minimal surgical treatment for MTC; and (b) the outcome of MTC is favourably affected because it is usually identified at a less advanced stage. However, other non-MTC causes of hypercalcitoninaemia and false sCT positivity do exist and must be recognized. The differential diagnosis is possible using previously validated assays against possible sources of interference, and performing stimulation tests with pentagastrin or, eventually, calcium infusion.

Thyroid disorders: evaluation and management of thyroid nodules

Although thyroid nodules are a common clinical entity, few (5% to 10%) are malignant and require surgical treatment. Most nodules are discovered incidentally in patients undergoing surveillance for medical reasons unrelated to thyroid disorders. Therefore, a systematic approach to their evaluation is important to avoid unnecessary surgery. High-resolution ultrasonography and fine-needle aspiration have resulted in substantial improvements in diagnostic accuracy, cost reductions, and higher malignancy yield at the time of surgery. In this article, the authors present practical guidelines and a suggested management strategy for the effective diagnosis and management of incidentally discovered thyroid nodules.

Techniques for thyroid FNA: a synopsis of the National Cancer Institute Thyroid Fine-Needle Aspiration State of the Science Conference

The National Cancer Institute (NCI) sponsored the NCI Thyroid fine-needle aspiration (FNA) State of the Science Conference on October 22-23, 2007 in Bethesda, MD. The 2-day meeting was accompanied by a permanent informational website and several on-line discussion periods between May 1 and December 15, 2007 (http://thyroidfna.cancer.gov). This document summarizes matters addressing manual and ultrasound guided FNA technique and related issues. Specific topics covered include details regarding aspiration needles, devices, and methods, including the use of core needle biopsy; the pros and cons of anesthesia; the influence of thyroid lesion location, size, and characteristics on technique; the role of ultrasound in the FNA of a palpable thyroid nodule; the advantages and disadvantages of various specialists performing a biopsy; the optimal number of passes and tissue preparation methods; sample adequacy criteria for solid and cystic nodules, and management of adverse reactions from the procedure. (http://thyroidfna.cancer.gov/pages/info/agenda/)

Thyroid fine-needle aspiration samples inadequate for reverse transcriptase-polymerase chain reaction analysis

BACKGROUND

Analysis of different tumor markers by reverse transcriptase-polymerase chain reaction (RT-PCR) in fine-needle aspiration samples of thyroid nodules has been studied with the objective of improving the accuracy of the preoperative diagnosis of thyroid lesions. The aim of the current study was to investigate thyroid fine-needle aspiration samples inadequate for RT-PCR analysis and to determine whether there is a correlation between their proportion and the method of sampling used or the greatest dimension of the nodules.

METHODS

A total of 350 fine-needle aspiration samples from patients with thyroid nodules were analyzed. After the aspirate was smeared for conventional cytology, the leftover material in the needle was used for RT-PCR analysis in 1 group of 175 patients. In another group of 175 patients, a separate puncture was performed to obtain material for RT-PCR analysis only. Samples were considered adequate for RT-PCR analysis if the expression of both glyceraldehyde-3-phosphate dehydrogenase and thyroglobulin was found by RT-PCR.

RESULTS

In total, 61 (17.4%) samples inadequate for RT-PCR were detected. All 12 samples that were inadequate for cytologic diagnosis were also found to be inadequate for RT-PCR analysis. The proportion of inadequate samples for RT-PCR was found to be significantly higher in samples taken from leftover material in the needle (21.7%) then in samples from a separate puncture (13.1%) (P = .049). No statistically significant correlation between the adequacy of samples for RT-PCR and the largest dimension of the nodule was found.

CONCLUSIONS

The proportion of samples inadequate for RT-PCR was found to be higher in samples taken from leftover material in the needle than in samples obtained from a separate puncture.

The role of ultrasound in thyroid nodules with a cytology reading of "suspicious for papillary thyroid carcinoma"

BACKGROUND

Irrespective of ultrasound (US) features, surgery is usually recommended for patients who have a fine-needle aspiration biopsy (FNAB) read as suspicious for papillary carcinoma (PTC). The aim of the present study was to evaluate the role of US in the management of thyroid nodules with a FNAB reading suspicious for PTC.

METHODS

Between August 2002 and May 2006, 303 patients who had thyroid nodules with a FNAB reading suspicious for PTC underwent surgery. The sonographic findings in the patients were classified as suspicious for malignancy or probably benign based on the US reading. The US readings and final pathological diagnoses of thyroid nodules were analyzed in these patients.

RESULTS

The malignancy rate was 84.2% in patients with a FNAB specimen suspicious for PTC. Sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of the US were 96.4%, 74.5%, 92.7%, 94.9%, and 80.9%, respectively, in nodules read as suspicious for PTC on FNAB. Whereas 243 (96.4%) lesions were found to be malignant at surgery, in the 252 lesions that had ultrasound findings suspicious for malignancy, only 13 (25.5%) lesions were malignant out of the 51 that had US readings of probably benign (p < 0.05).

CONCLUSIONS

The probability of malignancy is much lower in thyroid nodules with benign US findings even if the FNAB is read as suspicious for PTC. Therefore, US may be useful in planning the extent of surgery in patients with a FNAB reading of suspicious for PTC. As thyroid malignancy occurs in approximately 26% of patients with cytology readings suspicious for PTC and benign-appearing US, the US reading alone is not sufficient to determine the need for surgery. The US and FNAB are complementary to each other and should be useful when providing informed consent before thyroid surgery.