Can cytology accurately predict benign follicular nodules?

Role of Ultrasound and Ultrasound-Based Prediction Model in Differentiating Follicular Thyroid Carcinoma From Follicular Thyroid Adenoma

OBJECTIVES

This study aims to identify distinct ultrasound (US) characteristics for distinguishing follicular thyroid carcinoma (FTC) from follicular thyroid adenoma (FTA), and construct a user-friendly preoperative risk stratification model for thyroid follicular neoplasms.

METHODS

In this retrospective study, patients diagnosed with pathologically confirmed FTA or FTC and undergoing US examinations between July 2017 and June 2021 were designated as the training cohort, and those from July 2021 to June 2023 were enrolled as the external validation set. We systematically assessed and compared the sonographic and clinical characteristics of FTC and FTA. Univariable and multivariable logistic regression analyses were used to assess the association of US features with FTC in the training set. A prediction nomogram model, incorporating US features independently associated with FTC, was developed and validated externally to assess its performance.

RESULTS

A total of 645 patients (FTA/FTC = 530/115) were included in the training set, while 197 patients (FTA/FTC = 165/32) constituted the validation set. In the training set, solid composition, hypo-echogenicity, irregular margin, calcification, protrusion sign, trabecular formation, absent or thick halo, and mainly central hypervascularity were identified as independent factors associated with FTC. The prediction nomogram model constructed using these variables showed good performance in differentiating FTC from FTA with an area under the curve of 0.948 in the training set and 0.915 in the validation set.

CONCLUSIONS

The preoperative nomogram model constructed based on US features serves as an effective tool for the risk stratification of thyroid follicular neoplasms.

Thyroid imaging reporting and data system with MRI morphological features for thyroid nodules: diagnostic performance and unnecessary biopsy rate

BACKGROUND

To assess MRI-based morphological features in improving the American College of Radiology Thyroid Imaging Reporting and Data System (ACR-TIRADS) for categorizing thyroid nodules.

METHODS

A retrospective analysis was performed on 728 thyroid nodules (453 benign and 275 malignant) that postoperative pathology confirmed. Univariate and multivariate logistic regression analyses were used to find independent predictors of MRI morphological features in benign and malignant thyroid nodules. The improved method involved increasing the ACR-TIRADS level by one when there are independent predictors of MRI-based morphological features, whether individually or in combination, and conversely decreasing it by one. The study compared the performance of conventional ACR-TIRADS and different improved versions.

RESULTS

Among the various MRI morphological features analyzed, restricted diffusion and reversed halo sign were determined to be significant independent risk factors for malignant thyroid nodules (OR = 45.1, 95% CI = 23.2-87.5, P < 0.001; OR = 38.0, 95% CI = 20.4-70.7, P < 0.001) and were subsequently included in the final assessment of performance. The areas under the receiver operating characteristic curves (AUCs) for both the conventional and four improved ACR-TIRADSs were 0.887 (95% CI: 0.861-0.909), 0.945 (95% CI: 0.926-0.961), 0.947 (95% CI: 0.928-0.962), 0.945 (95% CI: 0.926-0.961) and 0.951 (95% CI: 0.932-0.965), respectively. The unnecessary biopsy rates for the conventional and four improved ACR-TIRADSs were 62.8%, 30.0%, 27.1%, 26.8% and 29.1%, respectively, while the malignant missed diagnosis rates were 1.1%, 2.8%, 3.7%, 5.4% and 1.2%.

CONCLUSIONS

MRI morphological features with ACR-TIRADS has improved diagnostic performance and reduce unnecessary biopsy rate while maintaining a low malignant missed diagnosis rate.

Differentiate Thyroid Follicular Adenoma from Carcinoma with Combined Ultrasound Radiomics Features and Clinical Ultrasound Features

Noninvasive differentiating thyroid follicular adenoma from carcinoma preoperatively is of great clinical value to decrease the risks resulted from excessive surgery for patients with follicular neoplasm. The purpose of this study is to investigate the accuracy of ultrasound radiomics features integrating with ultrasound features in the differentiation between thyroid follicular carcinoma and adenoma. A total of 129 patients diagnosed as thyroid follicular neoplasm with pathologically confirmed follicular adenoma and carcinoma were enrolled and analyzed retrospectively. Radiomics features were extracted from preoperative ultrasound images with manually contoured targets. Ultrasound features and clinical parameters were also obtained from electronic medical records. Radiomics signature, combined model integrating radiomics features, ultrasound features, and clinical parameters were constructed and validated to differentiate the follicular carcinoma from adenoma. A total of 23 optimal features were selected from 449 extracted radiomics features. Clinical and ultrasound parameters of sex (p = 0.003), interior structure (p = 0.035), edge (p = 0.02), platelets (p = 0.007), and creatinine (p = 0.001) were associated with the differentiation between benign and malignant follicular neoplasm. The values of area under curves (AUCs) of the radiomics signature, clinical model, and combined model were 0.772 (95% CI: 0.707-0.838), 0.792 (95% CI: 0.715-0.869), and 0.861 (95% CI: 0.775-0.909), respectively. A final corrected AUC of 0.844 was achieved for the combined model after internal validation. Radiomics features from ultrasound images combined with ultrasound features and clinical factors are feasible to differentiate thyroid follicular carcinoma from adenoma noninvasive before operation to decrease the unnecessary of diagnostic thyroidectomy for patients with benign follicular adenoma.

Ultrasonographic and cytologic assessments of follicular neoplasms of the thyroid: Predictive features differentiating follicular carcinoma from follicular adenoma

Background

The preoperative diagnosis of follicular neoplasm of the thyroid is challenging due to difficulties in the assessment of capsular invasion. This study aimed to identify ultrasonographic (US) and cytopathologic features that are characteristic of follicular adenoma and carcinoma to aid in their differential diagnosis.

Methods

A total of 98 surgically resected nodules diagnosed as follicular neoplasms between 2011 and 2012 were analyzed. US findings were reviewed according to the Korean Thyroid Imaging Reporting and Data System (K-TIRADS). Six cytologic features (high cellularity, abundant microfollicles, cell crowding/nuclear overlapping, isolated cells, homogeneous nuclei, abundant colloid) were reviewed quantitatively. The radiologic findings and quantification of cytologic features were correlated with final diagnoses.

Results

In total, 70 (71.4%) and 28 (28.6%) of the nodules were follicular adenomas and follicular carcinomas, respectively. US findings of a heterogeneous echogenicity, speculated/ill-defined margin, and presence of calcifications were significantly associated with follicular carcinoma (p<0.05). Calcifications had a predilection for pericapsular areas than for stromal areas in follicular carcinomas, whereas their location was more varied in follicular adenomas. No cytologic feature was significantly different between follicular adenomas and carcinomas.

Conclusion

Distinct from follicular adenomas, follicular carcinomas are characterized by heterogeneous echogenicity, speculated/ill-defined margin, and presence of calcifications on US. Thus, US findings can be helpful to differentiate between these two follicular neoplasms.

Logistic regression analysis of contrast-enhanced ultrasound and conventional ultrasound of follicular thyroid carcinoma and follicular adenoma

Background

Follicular thyroid carcinoma (FTC) is prone to recurrence and hematogenous metastasis, preoperative accurate diagnosis is still needed to help clinicians select the best surgical methods to improve the prognosis of patients. The aim of this study was to find specific conventional ultrasound (US) and contrast-enhanced ultrasound (CEUS) characteristics of FTC and to explore their diagnostic value in the differential diagnosis between FTC and follicular adenoma (FA).

Methods

This retrospective study included 258 thyroid follicular neoplasms (172 FAs and 86 FTCs) in 244 consecutive patients who underwent preoperative conventional US, and 72 of them underwent both conventional US and CEUS. Sonograms were reviewed in consensus by two experienced radiologists for various conventional US and CEUS features. Multivariate logistic regression analysis was performed to determine independent risk factors for FTC.

Results

Independent risk factors of conventional US for FTC were heterogenicity (OR =7.477, 95% CI: 2.848-19.629), unevenly thick halo (OR =5.643, 95% CI: 3.234-9.848) and calcifications (OR =1.748, 95% CI: 1.098-2.783). While independent risk factors determined with the combination of CEUS and conventional US were unevenly thick halo (OR =5.770, 95% CI: 1.310-25.409) and absent or irregular rim enhancement (OR =27.000, 95% CI: 2.445-298.178). The area under the receiver operating characteristic curve of the final two logistic regression models was 0.835 and 0.838.

Conclusions

Conventional US is an efficient diagnostic tool in the differential diagnosis of FTC and FA to help clinicians in making appropriate decisions while CEUS failed to provide additional diagnostic value in the study, thus the value of CEUS remains to be verified by further studies with larger sample sizes.

The Value of Sonography in Distinguishing Follicular Thyroid Carcinoma from Adenoma

Purpose

Differentiation between follicular thyroid carcinomas (FTCs) and follicular thyroid adenomas (FTAs) is difficult and the sonographic features of FTC are not yet fully established. The purpose of this study is to explore the sonographic features of FTC and the value of sonography in differentiating FTCs from FTAs.

Patients and Methods

A total of 28 pathologically proven FTCs and 53 FTAs in 78 patients who were performed thyroid surgery were included in this retrospective study. The sonographic features of each tumor including an interrupted halo, satellite nodule(s) with or without halo ring, local irregularity of margin and cluster of grapes sign were evaluated. A mode image of FTC halo was built up in our study. The frequencies of the sonographic features were compared by chi-square test or Fisher exact test between FTCs and FTAs. The relative risk of malignancy was assessed by logistic regression analysis.

Results

Logistic regression analysis showed that a thick, irregular and/or interrupted halo with or without satellite nodule(s), hypoechoic or marked hypoechoic echogenicity, a predominantly solid pattern, cluster of grapes sign, micro-or macro-calcifications, rim calcifications correlated with significant increases in relative risk for FTCs (odds ratio 11.48 (1.37-96.56), 6.74 (1.05-43.30), 17.51 (1.78-172.53), 9.55 (1.44-63.46), 9.36 (1.25-70.15) and 17.45 (1.04-292.65), respectively, p<0.05). Two new sonographic features, an interrupted halo and satellite nodule(s) with or without halo ring, can only be found in FTCs.

Conclusion

An interrupted halo and satellite nodule(s) with or without halo ring are specific sonographic features for FTCs. Sonography could play a role in differentiating follicular thyroid carcinoma from adenoma.

Multiparametric Ultrasound Evaluation of the Thyroid: Elastography as a Key Tool in the Risk Prediction of Undetermined Nodules (Bethesda III and IV)-Histopathological Correlation

The purpose of this study was to select thyroid nodules most at risk for malignancy among those cytologically undetermined by fine-needle aspiration biopsy (FNAB), using B-mode, color duplex Doppler and 2-D shear wave shear wave elastography (2-D-SWE). This was a prospective diagnostic accuracy study with 62 Bethesda III/IV nodules according to FNAB (atypia/follicular lesion of undetermined significance or follicular neoplasia/Hürthle cell neoplasm). Ultrasonography (US) data were compared with resection histologic results, revealing 35 of 62 benign nodules (56.4%) and 27 of 62 carcinomas (43.6%). Conventional US was uses to evaluate nodule echogenicity, dimensions, contours, presence of halo and microcalcifications. Doppler US was used to assess the vascularization (exclusively or predominantly peripheral or central) and mean resistance index of three nodule arteries. Elastography was used to evaluate the nodule elastographic pattern; mean nodule deformation index; deformation ratio between nodule and adjacent thyroid parenchyma; and mean deformation ratio between nodule and pre-thyroid musculature (MDR). Statistical analysis included χ², Fisher's exact, Student's t, Mann-Whitney tests and multivariable analysis by multiple logistic regression. Areas under the receiver operating characteristic curves (AUC-ROCs) were used for accuracy analysis. Fifty-eight participants (54.7 ± 14.0 y, 51 women) were studied. The parameters that were statistically significant to the univariate analysis were hypo-echogenicity, nodule diameter greater than width and all parameters analyzed from Doppler and elastography. Multivariate analysis revealed that the MDR (in kPa) was the best parameter for risk analysis of indeterminate nodules. Nodules with MDRs >1.53 exhibited a greater chance of malignancy (AUC-ROC = 0.98). We conclude that 2-D-SWE is able to select malignant nodules among those cytologically indeterminate, thus avoiding unnecessary surgery in these cytologic groups.

Strategy to reduce unnecessary surgeries in thyroid nodules with cytology of Bethesda category III (AUS/FLUS): a retrospective analysis of 667 patients diagnosed by surgery

PURPOSE

Fine-needle aspiration (FNA) is widely used for the diagnosis of thyroid nodules detected by ultrasonography. However, the cytology of atypia of undetermined significance/follicular lesion of undetermined significance (AUS/FLUS) often leads to unnecessary thyroid surgery. This study aimed to identify a strategy to reduce unnecessary surgeries in patients with AUS/FLUS nodules.

METHODS

Medical records of 667 patients with the cytology of AUS/FLUS who underwent surgery from January 2007 to December 2017 were retrospectively reviewed. Clinicopathological data were analyzed to identify malignant factors in thyroid nodules with AUS/FLUS. Factors were compared between patients with thyroid cancer and those with benign thyroid nodules, using stepwise multivariate logistic regression and decision tree model.

RESULTS

Pathological thyroid cancer was identified in 193 (43.3%) patients. There was a significant difference in malignancy incidence with respect to family history, number of nodules, number of FNAs, ultrasonographic finding, lymphocytic thyroiditis, and BRAFV600E mutation. Multivariate analysis showed that ultrasonography (K-TIRADS 5) was the most influential independent predictor of malignancy in AUS/FLUS (odds ratio = 11.02, p < 0.001), followed by possessing BRAFV600E mutation (odds ratio = 4.54, p < 0.001). This strategy enabled 226 (89.3%) patients to avoid unnecessary surgeries based on the decision tree model. There was no node of repeated FNA in the decision tree model, which reduced the risk of malignancy (odds ratio = 0.35, p = 0.029).

CONCLUSION

K-TIRADS 5 and BRAFV600E mutation were predictive of malignancy in nodules of AUS/FLUS. These factors should be considered in strategies to reduce unnecessary surgeries for AUS/FLUS.

Differentiation of follicular carcinomas from adenomas using histogram obtained from diffusion-weighted MRI

AIM

To evaluate the role of histogram analysis of apparent diffusion coefficient (ADC) maps from diffusion-weighted imaging (DWI) in the differentiation of follicular thyroid carcinoma (FTC) from follicular adenoma (FA) in nodules indeterminate on ultrasound-guided core needle biopsy (USCNB).

MATERIALS AND METHODS

This study was performed with institutional review board approval. Seventeen patients who were planned to undergo diagnostic lobectomy for an indeterminate thyroid nodule (atypical of unknown significance/follicular lesion of undetermined significance [AUS/FLUS] or suspicious for follicular neoplasm/follicular neoplasm [SFN]) on USCNB were enrolled prospectively. All patients underwent DWI on the day before surgery. Histogram parameters were derived from ADC values obtained from the whole extent of the tumours. The parameters were compared with the final diagnosis based on histopathological examination after surgery. The accuracy of the parameters in differentiating FTC from FA was evaluated using receiver operating characteristic (ROC) curve analysis.

RESULTS

Twelve patients were confirmed as having FA and five patients as having FTC. Histogram parameters including the 10^th (ADC₁₀), 25^th (ADC₂₅), and 50^th (ADC₅₀) percentiles of the ADC values were significantly lower in FA than in FTC (p < 0.05, all). ROC curve analysis revealed that ADC₂₅ resulted in the highest AUC (0.867; confidence interval, 0.616-0.980), with a cut-off value of 0.352×10^-3 mm²/s.

CONCLUSION

Histogram parameters from ADC maps could differentiate FTC from FA effectively in indeterminate nodules on USCNB, with ADC₂₅ being the most promising parameter.

Intranodular Vascularity May Be Useful in Predicting Malignancy in Thyroid Nodules with the Intermediate Suspicion Pattern of the 2015 American Thyroid Association Guidelines

The aim of the study described here was to determine whether vascularity patterns on Doppler ultrasonography (US) differentiate benign and malignant thyroid nodules with the intermediate suspicion pattern based on the 2015 American Thyroid Association guidelines. A total of 411 benign or malignant thyroid nodules from 406 patients with intermediate-suspicion US features were retrospectively collected. Univariate and multivariate logistic regression analyses with the generalized estimating equation were used to identify factors predicting malignancy, and odds ratios with 95% confidence intervals were calculated. The vascularity patterns significantly differed between the benign (353 of 411, 85.9%) and malignant (58 of 411, 14.1%) nodules (p = 0.005). Only intranodular vascularity was significantly associated with malignancy on univariate analysis (p = 0.006) and was an independent predictor of malignancy on multivariate analysis (p = 0.004). In conclusion, intranodular vascularity on Doppler US may be useful for predicting malignancy in thyroid nodules with the intermediate-suspicion pattern.

Positive central lymph-nodes are underdiagnosed in patients with Bethesda V cytology in an endemic goiter region

Background

Fine needle aspiration (FNA) is a significant diagnostic procedure for detecting malignancy in patients with nodular thyroid disease. A high proportion of patients with cytological diagnosed follicular neoplasia (Bethesda IV and V) ultimately have thyroid cancer. The aim of this study was to evaluate the incidence of preoperatively undiagnosed central lymph node metastasis in patients with multinodular goiter (MNG).

Methods

Patients who underwent FNA and were classified as Bethesda IV/V were included. Applying a radical approach, all patients underwent (hemi)thyroidectomy and prophylactic unilateral central neck dissection.

Results

During our study period 2009-2013, 60 patients (19.7%) were classified as Bethesda IV and 21 (6.9%) Bethesda V. Final histopathological results revealed malignancy in 35 (43.2%) of 81 Bethesda IV/V nodules. Of the nodules classified as Bethesda IV, 20 (33.3%) showed malignancy in the final histology. Ten patients (16.7%) had papillary micro-carcinoma (mPTC, <10 mm), 4 (6.6%) PTC and 6 (10%) follicular thyroid cancer. Fifteen of 21 (71.4%) Bethesda V nodules were revealed as PTC of whom seven (33.3%) patients also had lymph-node metastases.

Conclusions

While 33.3% of the patients with PTC, preoperatively classified as Bethesda V, had previously undetected positive lymph-nodes, only one patient with Bethesda IV had lymph-node metastasis.

Role of phospho-ezrin in differentiating thyroid carcinoma

Comprehensive theory explaining the relationship between estrogen (E2) and ezrin in metastasis of thyroid cancer remains non-elicited. In vitro results revealed that E2 could stimulate the expression and phosphorylation of ezrin in a time and dose dependent manner. Our data clearly showed that E2 enhanced the migration and invasion of cells, which was reversed by the transfection of cells with ezrin specific siRNA. Further, we observed that Phosphoinositide 3-kinase (PI3K) ROCK-2 are among the kinases responsible for E2 induced phosphorylation of ezrin. Clinical validation of ezrin/phospho-ezrin revealed that phospho-ezrin was intensely expressed in follicular thyroid carcinoma (FTC) and follicular variant of papillary thyroid carcinoma (FVPTC), while it was completely absent in follicular adenoma (FA) lesions in which the differentiation of the follicular neoplasms remains subtle. When histology of different carcinomas is correlated with benign FA with respect to phospho-ezrin, we observed that the marker was highly significant (p = 0.0001). 100% sensitivity, specificity and diagnostic accuracy of the above marker in the histological association of FTC, FVPTC with FA, enables us to suggest phospho-ezrin as a diagnostic marker to differentiate the follicular neoplasms. These data are the first to suggest the dynamic regulation of ezrin phosphorylation during metastasis in FTC.

Spectroscopic identification of benign (follicular adenoma) and cancerous lesions (follicular thyroid carcinoma) in thyroid tissues

Thyroid follicular nodules are quite common in the population, however only a small proportion is malignant. Thyroid cancer differs from adenoma by features of cellular atypia, angioinvasiveness and possibility of metastasis via blood vessels mainly in the lungs and bones. Pathomorphological examination of the postoperative material plays a significant role in the diagnosis of cystic thyroid lesions. De facto, there is no possibility to determine with certainty whether the lesion is benign or malignant before surgery, therefore new methods are being sought to meet clinical needs. The study aimed to investigate if Fourier-transform infrared spectroscopy (FTIR) spectroscopy and Raman spectroscopy combined with multidimensional analysis can be a useful tool in distinguishing between thyroid adenomas and carcinomas. The obtained results indicate quantitative and qualitative alterations within proteins and fats derived from patients' tissues samples. Raman spectroscopy additionally shows significant changes in the amount of tissue collagen due to the pathogenic process. In the spectra of the second FTIR derivative, shifts of vibrations corresponding to the β-sheet and α-helix structure are observed towards the lower rates of wave numbers in the case of neoplastic tissues. Using the leave-one-out cross-validation, sensitivity and specificity calculated with Principal Component Analysis-Linear Discriminant Analysis (PCA-LDA) clearly shows the possibility to distinguish between pathologically changed and normal thyroid tissue as well as differentiate follicular thyroid adenoma (FTA) from widely invasive follicular thyroid carcinoma (WI-FTC) tissues.

Controversy regarding when clinically suspicious thyroid nodules should be subjected to surgery: Review of current guidelines

BACKGROUND

The work-up of a thyroid nodule to diagnose malignancy is not always straightforward. There are various international thyroid societies each with their own guidelines on the approach to a thyroid nodule. The aim is therefore to determine whether a clinically suspicious thyroid nodule should be subjected to surgery.

METHOD

A review of various international thyroid society guidelines on their approach to a suspicious thyroid nodule.

RESULTS

Sixty-two relevant articles were identified of which 4 current international thyroid guidelines, consisting of 6 different international societies, were reviewed. The commonalities of each of the thyroid society guidelines are imaging, with ultrasound, and cytopathology as the main diagnostic investigations. The description and the size of the nodule are the 2 most important factors on ultrasound; however, the guidelines vary in their recommendations whether to biopsy a suspicious thyroid nodule. An indeterminate group exists whereby thyroid nodules cannot be confirmed as malignant even with fine needle aspiration cytology (FNA). Although further investigations (Technetium-99m -sestamethoxyisobutylisonitryl scan, 18F-fluorodeoxyglucose positron emission tomography/computed tomography scan, and molecular testing) may assist in the diagnosis, there are limitations. There are differences in the guidelines whether suspicious nodules should be subjected to surgery.

CONCLUSION

Ultrasound and cytopathology are the 2 most appropriate investigations to diagnose whether a suspicious thyroid nodule is benign or malignant. The clinician needs to be aware of the differences between the guidelines from the various international thyroid societies, specifically concerning the indeterminate group of patients where a definitive diagnosis cannot be made. Management decisions should be discussed with a thyroid multidisciplinary team for a consensus decision whether or not to subject a patient with a suspicious thyroid nodule to surgery.

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.

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.

Controversies in the surgical management of thyroid follicular neoplasms. Retrospective analysis of 721 patients

The most appropriate surgical management of "follicular neoplasm/suspicious for follicular neoplasm" lesions, is still controversial. Analysing and comparing the experience of two units for endocrine surgery, we retrospectively evaluated 721 patients, surgically treated after a follicular neoplasm diagnosis. Total thyroidectomy was routinely performed in one Institution, while in the other one it was selectively carried out. The main criteria leading to hemythyroidectomy were a single nodule, the age ≤45 years, the absence of thyroiditis or clinical/intraoperative suspicion of malignancy. Total thyroidectomy was performed in 402/721 patients (55.7%), hemythyroidectomy in 319/721 cases (44.2%) and a completion thyroidectomy in 51/319 cases (15.9%). The overall malignancy rate was 24% (176/721 patients), respectively 16% (51/319 patients) following hemythyroidectomy, and 31% (125/402 patients) following total thyroidectomy. Definitive recurrent laryngeal nerve paralysis and permanent hypoparathyroidism were not reported in hemythyroidectomy patients in which lower mean hospitalization and costs were observed. Considering the low-risk of follicular neoplasm solitary lesions, hemythyroidectomy is still the safest standard of care with lower hospitalization and costs. In case of multiglandular disease or thyroiditis, that might be associated with a higher risk of cancer, total thyroidectomy should be recommended. Further investigation is warranted to achieve a better preoperative follicular neoplasm diagnostic accuracy in order to reduce the amount of unnecessary surgical operations with a diagnostic aim.

Clinical characteristics as predictors of malignancy in patients with indeterminate thyroid cytology: a meta-analysis

Indeterminate thyroid nodules (ITN) constitute the gray zone of thyroid fine-needle aspiration cytology (FNAC). About 70-80 % of ITN are later diagnosed as benign; therefore, it is very important to identify the predictors of malignancy. Aim of the study was to summarize published data about clinical risk factors for malignancy in patients with ITN and thereby provide more robust estimates of the effect of these risk factors. Sources comprised studies published through December 2012. Original articles that investigated clinical parameters as potential predictors of malignancy in ITN were identified. Two authors performed the data extraction independently. A meta-analysis of 19 relevant studies was conducted that included 3,494 patients with ITN according to FNAC. The pooled prevalence of malignancy was 28 % (95 % CI 23-33), 26 % in females and 34 % in males. The pooled OR was 1.51 (95 % CI 1.2-1.83) for males and 0.68 (95 % CI 0.53-0.88) for females. Regarding the nodule's size, the pooled OR was 2.10 (95 % CI 1.26-3.50) for nodules >4 cm in diameter. Analysis of the patient age as a risk factor was not feasible because of marked difference found between the studies. In patients with indeterminate thyroid nodules diagnosed at FNAC, the pooled rate of malignancy from 19 studies was 28 %. Patients that are male and have ITN greater than 4 cm in diameter should be considered at higher risk of cancer.

Sonographic features of thyroid follicular carcinoma in comparison with thyroid follicular adenoma

OBJECTIVES

The purpose of this study was to determine the sonographic features of thyroid follicular carcinoma in comparison with thyroid follicular adenoma.

METHODS

This retrospective study included 36 pathologically proven follicular carcinomas (5 widely invasive and 31 minimally invasive) and 52 follicular adenomas in 88 patients who underwent thyroid surgery. We analyzed the sonographic features of each tumor, including maximum diameter, peripheral halo, echogenicity, echo texture, calcifications, and nodularity. The frequencies of the sonographic features were compared by χ(2) and Fisher exact tests between follicular adenomas and carcinomas. The relative risk of malignancy was evaluated by logistic regression analysis.

RESULTS

Predominantly solid contents, hypoechoic echogenicity, a heterogeneous echo texture, the presence of calcifications, and an absent or irregular thick halo were associated with follicular carcinoma (P < .05). Logistic regression analysis demonstrated that predominantly solid contents, a heterogeneous echo texture, and the presence of calcifications were associated with significant increases in the relative risk of follicular carcinoma (odds ratios, 9.4, 24.9, and 25.6, respectively; P < .01).

CONCLUSIONS

Sonography could provide useful information for differentiating follicular carcinoma from follicular adenoma.

Better understanding in the differentiation of thyroid follicular adenoma, follicular carcinoma, and follicular variant of papillary carcinoma: a retrospective study

Background. To evaluate the role of ultrasonography (US), US-guided fine-needle aspiration (USFNA) and intraoperative frozen section (FS) in follicular neoplasm. Methods. US features, USFNA cytology, and FS results were compared based on the pathology results of patients with follicular adenoma (FA), follicular carcinoma (FC), and follicular variant of papillary thyroid carcinoma (FVPTC). Results. FC and FVPTC showed significantly higher rates of suspicious US features (P < 0.05) and positive findings on either US or cytology, 80.0% and 90.7%, compared to FA, 64.5% (P = 0.001). Intraoperative FS showed higher malignant rates in FVPTC and FC (81.8% and 75.0%, resp.), compared to FA (3.8%, P < 0.001). Conclusion. Suspicious US features were more significantly seen in FC and FVPTC compared to FA. Intraoperative FS is useful in the differential diagnosis of these lesions and supplements cytology results of USFNA.

Lobectomy in follicular thyroid neoplasms' treatment

BACKGROUND

The purpose of this study is to evaluate the suitability of lobectomy with isthmectomy (LwI) in treatment of Follicular Thyroid Neoplasms (FTN), considering malignancy incidence and postoperative complications.

METHODS

192 patients (165 females; 27 males) who underwent LwI for FTN from 01/2005 to 12/2007 were retrospectively evaluated: clinical and pathological features, surgical complications and five year outcome. Inclusion criteria were cytological Bethesda category III and IV or histological follicular adenoma/carcinoma or follicular variant of papillary carcinoma). Metastatic disease or previous thyroidal surgery patients were excluded.

RESULTS

Mean age was 48.68 ± 14.93 yrs. Overall malignancy occurred in 88 patients (45.83%) and 80 (41.67%) underwent thyroidectomy completion (TC), mainly by index lesion's malignancy. Forty-one (21.35%) in LwI and 31 (38.75%) in TC specimens had associated malignancy, mainly papillary microcarcinomas. High preoperative Thyroid-Stimulating Hormone (TSH), histological multinodularity and, in cytology category IV, younger age, were significantly associated to malignancy. Permanent recurrent laryngeal nerve lesion occurred in 0.58% in Lwl and 1.52% in TC, and temporary dysphonia occurred in 9.25% and 6.06% (LwI and TC respectively). No LwI patients presented hypoparathyroidism whereas 3.03% in TC had temporary symptoms. In LwI, 36.70% developed hypothyroidism. Higher preoperative TSH was associated with hypothyroidism development.

CONCLUSIONS

LwI was inappropriate in 40.10% patients with malignancy who required TC and 23.12% had no functional benefit because post-LwI hypothyroidism. Nodular relapse was reported in at least 23/113 LwI patients (20.35%). We propose total thyroidectomy for patients with FTN preoperative TSH higher than 2.16 mU/L and, in Bethesda category IV, less than 39.5yrs.

A histological assessment of the Bethesda system for reporting thyroid cytopathology (2010) abnormal categories: a series of 219 consecutive cases

OBJECTIVE

The purposes of this study were to establish the distribution of thyroid lesions that were seen in Hatay (a province of southern Turkey), to review the accuracy of fine needle aspiration cytology (FNAC) in the diagnosis of thyroid nodules and to correlate the FNAC results with the histopathology of the excised specimens, especially in indeterminate cases.

METHODS

Data on patient cytology were retrieved by a retrospective search of all thyroid FNAC specimens that had been evaluated at the Department of Pathology, Antakya Public Hospital, Hatay, Turkey between January 2009 and February 2011; 1021 thyroid FNAC samples were reviewed and interpretations were recorded according to the Bethesda system for reporting thyroid cytopathology (TBSRTC). The results of adequate FNAC samples were compared with the histological diagnoses in the cases in which surgery was performed, and the malignancy rates, especially in indeterminate categories, were calculated.

RESULTS

Of the 1021 FNAC samples, 697 (68.3%) were benign, 122 (11.9%) were non-diagnostic, 100 (9.8%) were atypia of undetermined significance/follicular lesion of undetermined significance (AUS/FLUS), 41 (4%) were follicular neoplasm/suspicious for follicular neoplasm (FN/SFN), 36 (3.5%) were suspicious for malignancy (SM) and 25 (2.4%) were malignant. In 219 cases, there was follow-up histology. Rates of malignancy were as follows: benign, 0%; AUS/FLUS, 12.7%; FN/SFN, 35.0%; SM, 91.4%; malignant, 100%.

CONCLUSIONS

In our study, the cytohistological correlation of benign and malignant lesions was 100%. In the indeterminate categories, we recommend that clinicians should evaluate both the clinical and radiological findings of patients in addition to the FNAC results.

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.

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.

STT3A, C1orf24, TFF3: putative markers for characterization of follicular thyroid neoplasms from fine-needle aspirates

OBJECTIVES/HYPOTHESIS

The goals of this study were to characterize gene expression using fine-needle aspirates (FNAs) from follicular neoplasms to distinguish follicular adenomas (FAs) from follicular thyroid carcinomas (FTCs) and follicular variant of papillary thyroid carcinomas (FVPTCs); and to use FNA material to distinguish benign from malignant follicular neoplasms.

STUDY DESIGN

Retrospective expression analysis of diagnosed follicular neoplasms (level of evidence 2b); prospective cohort of FNA from the operating room after thyroid lobectomy (level of evidence 1b).

METHODS

Gene expression analysis via reverse-transcription polymerase chain reaction (rt-PCR) of nine genes previously noted to be differentially expressed in follicular neoplasms was performed on formalin-fixed, paraffin-embedded archived normal thyroid tissue (n = 63) and follicular neoplasms as diagnosed on preoperative FNA: FA (n = 16), FTC (n = 13), FVPTC (n = 24), and papillary thyroid carcinomas (PTCs) (n = 10). All cases were originally read as follicular neoplasms on preoperative FNA. To determine if these results could be translated into fresh tissue, ex vivo FNA was performed on follicular neoplasms (n = 17) in the operating room after thyroidectomy.

RESULTS

Quantitative gene analysis detected differential TFF3 expression in FA versus FTC, FVPTC, and PTC (P = .02). Rt-PCR of FNA samples demonstrated that malignant nodules overexpress STT3A as compared with benign disease (P = .046). The combination of STT3A overexpression/Clorf24 underexpression identified malignant disease (P = .03) on FNA samples.

CONCLUSIONS

Gene-expression data suggest a difference in expression between STT3A, Clorf24, and TFF3 in FAs versus carcinomas that may be detected from an FNA sample. Findings must be validated from preoperative FNAs in larger numbers.

Thyroid nodules; interpretation and importance of fine-needle aspiration (FNA) for the clinician - practical considerations

Thyroid nodules are very common lesions. Despite that the great majority is benign, in a significant percentage of them there is an underlying malignancy. Malignant thyroid nodules should be managed surgically, while the more common benign thyroid nodules may be managed conservatively. A systemic and careful diagnostic evaluation is needed to recognize nodules (overtly malignant or with malignant potential), and to avoid unnecessary surgery in a large percentage of patients with benign disease. Fine-needle aspiration (FNA) has a central role in the diagnostic investigation of the patient with thyroid nodules. FNA is a safe, useful, and cost-effective procedure. To increase accuracy, FNA can be performed under ultrasonographic guidance (if needed). Its results may be particularly helpful in determining the indication for surgery. In contrast, the role of FNA in selecting the extent of surgery is limited today. This is due to the fact that during the last decade there is a clear trend toward radical surgical management of thyroid nodular disease (both benign and malignant) by total/near-total thyroidectomy.

Fine-needle aspiration of follicular patterned lesions of the thyroid: Diagnosis, management, and follow-up according to National Cancer Institute (NCI) recommendations

The National Cancer Institute (NCI) State of the Science Conference on thyroid fine-needle aspiration (FNA) proposed that follicular patterned lesions can be divided into two diagnostic categories; follicular lesion of undetermined significance/Atypia of undetermined significance (FLUS/AUS) and suspicious for follicular neoplasm/follicular neoplasm (SFON/FON). The former group can benefit from repeat FNA (RFNA) to achieve a more definitive diagnosis and the latter should undergo surgical excision for histologic characterization (adenoma vs. carcinoma). In this study, we report the combined experience from our institutions with thyroid FNA cases that can be placed into NCI-designated thyroid FNA diagnostic categories for follicular patterned lesions.The case cohort comprised of 857 cases in 645 females and 212 males; 509 cases could be classified as FLUS/AUS and 348 as SFON/FON. Histologic follow-up was available in 273/509 (54%) cases diagnosed as FLUS/AUS and 251/348 (72%) cases diagnosed as SFON/FON.RFNA was performed in 203/509 (40%) patients classified as FLUS/AUS. RFNA diagnoses were: benign (125 cases), FLUS (46 cases), SFON/FON (20 cases), suspicious for papillary carcinoma (7 cases), papillary carcinoma (3 cases) and non-diagnostic (2 cases). The malignancy rate on surgical excision in the FLUS/AUS group was 27 and 15% with and without RFNA, respectively; and 25% in cases diagnosed as SFON/FON.RFNA is effective in managing thyroid nodules diagnosed as FLUS/AUS since the malignancy rates are different in cases with or without RFNA (27% vs. 15%). The malignancy rate (25%) in cases diagnosed as SFON/FON is similar to reported by other authors.

Real-time elastosonography: useful tool for refining the presurgical diagnosis in thyroid nodules with indeterminate or nondiagnostic cytology

BACKGROUND

Indeterminate and nondiagnostic patterns represent the main limitation of fine-needle aspiration (FNA) cytology of thyroid nodules, clinical and echographic features being poorly predictive of malignancy. The newly developed real-time ultrasound elastography (USE) has been previously applied to differentiate malignant from benign lesions. The aim of this study was to get further insights into the role of USE in the presurgical diagnosis of nodules with indeterminate or nondiagnostic cytology.

PATIENTS

The study included 176 patients who had one (n=138) or multiple (n=38) nodules with indeterminate or nondiagnostic cytology on FNA, for whom histology was available after thyroidectomy. A total of 195 nodules (142 indeterminate, 53 nondiagnostic) were submitted to USE, and elasticity was scored as 1 (high), 2 (intermediate), or 3 (low).

RESULTS

In indeterminate lesions, the score 1, describing high elasticity, was strongly predictive of benignity, being found in 102 of 111 benign nodules and in only one of 31 carcinomas (P<0.0001). By combining the scores 2 and 3, USE had a sensitivity of 96.8% and a specificity of 91.8%. In nodules with nondiagnostic cytology, score 1 was found in 39 of 45 benign nodules and in only one of eight carcinomas (P<0.0001). By combining the scores 2 and 3, USE had a sensitivity of 87.5% and a specificity of 86.7%.

CONCLUSIONS

USE may represent an important tool for the diagnosis of thyroid cancer in nodules with indeterminate or nondiagnostic cytology and may prove useful in selecting patients who are candidates for surgery.

Indeterminate thyroid nodules: a challenge for the surgical strategy

BACKGROUND

Because no clinical parameter can establish the final status of a cytologically indeterminate thyroid nodule (ITN) or nodal-metastases in case of malignancy, the initial surgical strategy should define an oncologically adequate procedure with low morbidity.

METHODS

The prognostic relevance of sex, age, tumor sizes, multifocality, thyroid function, and recurrence was analyzed in 156 consecutive patients according to the presence of malignancy and nodal metastases. The accuracy of frozen sections to reveal malignancy was determined. Clinical parameters were compared with regard to their ability to identify malignancy and nodal metastases in an ITN to determine an appropriate initial operative strategy.

RESULTS

One hundred and eighteen (75.6%) patients underwent (total) thyroidectomy, 37 (23.7%) patients underwent hemithyroidectomy, and 1 patient underwent isthmus resection. Fifty-five (35.3%) patients showed malignancy. First step lymphadenectomy (lymph node dissection along the recurrent laryngeal nerve before removing the thyroid lobe) was performed in 142 patients documenting 10 nodal metastases. Comparing benign and malignant ITN, no association was found for sex (P = .17), age (P = 1.0), tumor sizes (P = .33, P = .12, P = .19 for < or =30 mm, < or =40 mm, and < or =50 mm, respectively), or thyroid function (P = .26). The determination of malignancy by frozen section showed a sensitivity of 30.9% and a specificity of 100%. No permanent hypoparathyroidism or recurrent laryngeal nerve palsy was observed postoperatively.

CONCLUSION

Because of the failure of available clinical parameters to predict malignancy in cytologically ITN, hemithyroidectomy in unilateral goiter and thyroidectomy in bilateral goiter is recommended. Ipsilateral "first step central neck dissection" on the side of ITN offers the advantages of oncologically adequate resection and staging with a low morbidity, as well as avoids reoperation.

How to approach thyroid nodules with indeterminate cytology

BACKGROUND

Ultrasound (US)-guided fine-needle aspiration biopsy (FNAB) is an accurate, reliable, and simple procedure to perform, and it is nowadays accepted as a standard diagnostic method for the differential diagnosis of thyroid nodules. However, a major limitation of US-FNAB is indeterminate cytology results at a thyroid nodule. This study investigated the clinical and US characteristics that predict malignancy, as well as the role of intraoperative frozen sections (FS) in the treatment of thyroid nodules with indeterminate cytology.

METHODS

From September 2002 to December 2007, the medical records of 181 patients (185 nodules) with indeterminate FNAB cytology results were retrospectively reviewed. Among them, 99 patients (M:F = 13:86; mean age, 43.71 years) with 99 thyroid nodules underwent subsequent surgery with pathologic confirmation. Seventy-eight patients (78.8%) underwent intraoperative FS. US findings of the surgically proven thyroid nodules were retrospectively reviewed. US features, clinical characteristics, and FS results were compared to the surgically proven pathologic results.

RESULTS

Nineteen nodules (19.2%) with indeterminate FNAB cytology were diagnosed as malignant. Lesion size varied from 4 to 70 mm (mean, 27.0 mm). Male patients (46.2%) were more significantly associated with malignancy than female patients (15.1%, P < 0.05). Microlobulated or ill-defined margins (87.5%), microcalcifications (50.0%), and taller-than-wide shape (80.0%) were US features showing correlations with malignancy (P < 0.05). Intraoperative FS significantly predicted malignancy (P < 0.05). Of the 78 cases with FS, 29 cases (37.2%) were deferred. Among the remaining 49 cases, 4 (5.1%) were malignant on FS and subsequent surgical pathology. Forty-five cases (57.7%) were diagnosed as benign on FS, but only two cases were diagnosed as malignant on surgical pathology.

CONCLUSIONS

Ultrasound is a feasible method in predicting malignancy in thyroid nodules with indeterminate FNAB cytology. Also, intraoperative FS is a supportive method with high specificity that may guide the treatment of thyroid nodule with indeterminate cytology.

Evaluation of a new method for the diagnosis of alterations of Lens culinaris agglutinin binding of thyroglobulin molecules in thyroid carcinoma

BACKGROUND

The measurement of serum thyroglobulin (Tg) is widely used as a marker for recurrence of thyroid carcinoma following total thyroidectomy. However, this method cannot differentiate between benign and malignant disease. We focused on the sugar chain in the Tg molecule and investigated the usefulness of Lens culinaris agglutinin (LCA)-reactive Tg ratios in sera and wash fluids obtained during fine-needle aspiration (FNA) for the detection of thyroid carcinoma.

METHODS

The study was performed using 203 serum samples (115 from patients with benign thyroid disease and 88 from patients with thyroid carcinomas) and 176 wash fluid samples (143 benign, 21 malignant, and 12 inconclusive). LCA-reactive Tg ratios were determined using an enzyme-linked immunosorbent assay, and a comparison was made between malignant and benign lesions.

RESULTS

In serum, the ratio in patients with malignancy was 79.5+/-6.0 [mean+/-standard deviation (SD)], significantly lower than in patients with benign lesions (84.9+/-3.5). The ratios in wash fluid from malignant lesions (75.8+/-18.9) were also significantly lower than those from benign lesions (85.6+/-3.9).

CONCLUSIONS

These results suggest that this method could distinguish between benign and malignant lesions and may be useful for screening serum and wash samples.

Comparison of cytological results obtained by repeated US-guided fine-needle aspiration biopsies of thyroid nodules: focus on the rate of malignancy and diagnostic concordance

The debate still continues on the repeated fine-needle aspiration biopsies (FNABs) for thyroid nodule in clinical practice. In this study, we determined the rate of cytological change to malignancy and the diagnostic concordance of repeated FNABs when the same nodules were targeted under US-guidance. We retrospectively reviewed data for 187 thyroid nodules (173: twice, 14: three times) from 160 patients who underwent repeated US-guided FNABs, which were performed by one skillful radiologist targeting for the same nodules at a mean interval of 7.5 months. Their initial cytological findings were compared with second or third results and histopathologic follow-up. The initial FNABs findings of 187 nodules were unsatisfactory, benign, and indeterminate in 56, 52, and 79 cases, respectively. The rate of a second cytological diagnosis changed to malignancy was significantly higher in the unsatisfactory aspirates (10.7%; 6/56), when compared with those of the benign (0.0%; 0/52) or of indeterminate aspirates (3.8%; 3/79) (P = 0.022). However, there was no change to malignancy at third cytological findings of all 14 nodules. After the second US-guided FNABs, 30.8% (16/52) of the initially diagnosed as benign aspirates were reclassified as indeterminate, while 26.6% (21/79) of the initially diagnosed as indeterminate were reclassified as benign. In conclusion, to identify malignancies, repeated US-guided FNABs are recommended for thyroid nodules initially classified as unsatisfactory aspirates. However, although US-guidance is applied, a discrepancy might be unavoidable in the cytological interpretation of the nodules classified as benign or as indeterminate aspirates because of overlapping cytological criteria.

Sentinel node biopsy for follicular tumours of the thyroid gland

BACKGROUND

It is difficult to differentiate histologically between benign and malignant follicular-type tumours of the thyroid gland. The present study evaluated whether sentinel lymph node (SLN) biopsy was helpful in obtaining the correct diagnosis of malignant follicular-type tumours, as metastasis to the lymph nodes is sufficient evidence for a diagnosis of cancer.

METHODS

SLN biopsy was performed for 37 follicular-type tumours suspected to be malignant on the basis of preoperative examinations, but for which the diagnosis had not been confirmed.

RESULTS

SNs were identified in 32 of 37 procedures. SLN metastases were found in four of 12 patients with a malignant tumour identified by intraoperative frozen-section analysis. There was one false-negative but no false-positive diagnoses. Frozen-section analysis of the tumour itself identified only one follicular cancer. The accuracies of preoperative imaging methods were lower than that of SLN detection.

CONCLUSION

Detection of SLN metastasis was helpful in diagnosing follicular thyroid cancer and thus enabling one-stage surgery.

Diagnostic terminology and morphologic criteria for cytologic diagnosis of thyroid lesions: 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 two-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 regarding diagnostic terminology/classification scheme for thyroid FNA interpretation and cytomorphologic criteria for the diagnosis of various benign and malignant thyroid lesions. (http://thyroidfna.cancer.gov/pages/info/agenda/).

Thyroid fine needle aspiration: how to improve clinicians' confidence and performance with the technique

Studies from single institutions report an acceptable accuracy rate for thyroid fine needle aspiration (FNA). However, FNA accuracy is much lower in many other centers in Europe and the USA and large multicenter studies indicate that the clinicians' confidence in the FNA technique remains low. One explanation for this is that there is an excess of inadequate and indeterminate findings for a follicular nodule at FNA cytology. In a University Hospital with large and qualified experience on thyroid nodule diagnosis, a review of 320 slides with an FNA diagnosis of indeterminate follicular nodule from different minor Italian Hospitals led to a different diagnosis in 61%. Since ancillary thyroid imaging may be overutilized and only a few authors report a proportion of excised nodules lower than 10%, we suspect that use of the FNA procedure is suboptimal. Several techniques are reported to improve the performance of thyroid FNA. Among these are tumor markers and large needle aspiration biopsy (LNAB). Immunodetection of the tumor marker galectin-3 has been evaluated by large multinational studies. Analysis of LNAB specimens reduces the number of inadequate FNA findings, improves the diagnostic determination of indeterminate follicular FNA findings and represents a better substrate for the determination of galectin-3. Therefore, we propose that clinical practice guidelines reflect these adjuvant techniques to thyroid FNA in order to improve selection criteria for thyroid nodule surgery.

Upregulation of HMGA2 in thyroid carcinomas: a novel molecular marker to distinguish between benign and malignant follicular neoplasias

The identification of molecular markers allowing to differentiate between benign and malignant thyroid tumors remains a diagnostic challenge. Herein, we have used the expression of the high mobility group protein gene HMGA2 and its protein, respectively, as a possible marker detecting malignant growth of thyroid tumors. HMGA2 belongs to the high mobility group proteins, i.e. small, highly charged DNA-binding proteins. While HMGA2 is highly expressed in most embryonic tissues, its expression in adult tissues is very low. However, a reactivation of HMGA2 expression has been described for various malignant tumors and often correlates with the aggressiveness of the tumors. The aim of this study was to investigate whether the HMGA2 expression can be used to detect malignant thyroid tumors. RNA from 64 formalin-fixed paraffin-embedded thyroid tissues including normal tissue (n = 3), thyroiditis (n = 2), and follicular adenomas (n = 19) as well as follicular (n = 9), papillary (n = 28), and anaplastic (n = 3) carcinomas was reverse transcribed. Finally, real-time quantitative RT-PCR was performed. Expression differences of up to 400-fold were detected between benign and malignant thyroid tumors. Based on HMGA2 expression alone, it was possible to distinguish between benign and malignant thyroid tissues with a sensitivity of 95.9% and a specificity of 93.9%. There was a highly significant (P < 0.001) difference with histology of the tumors being the gold standard between the benign lesions and malignant tumors. Our results show that even as a stand-alone marker HMGA2 expression has a high potential to improve diagnoses of follicular neoplasms of the thyroid.

Fine-needle aspiration of thyroid nodules: a study of 4703 patients with histologic and clinical correlations

BACKGROUND

The Papanicolaou Society of Cytopathology recently proposed 6 diagnostic categories for the classification of thyroid fine-needle aspiration (FNA) cytology. Using these categories, the experience with FNA from 2 institutions was studied with emphasis on cytologic-histologic correlation, source of errors, and clinical management.

METHODS

Patient cytology data were retrieved by a retrospective search of thyroid FNA in the institutional databases. Cytologic diagnoses were classified as unsatisfactory, benign, atypical cellular lesion (ACL), follicular neoplasm (FN), suspicious for malignancy, and positive for malignancy. Samples with a histologic discrepancy were re-evaluated, and clinical follow-up information was recorded.

RESULTS

Of 4703 FNA samples, 10.4% were classified as unsatisfactory, 64.6% were classified as benign, 3.2% were classified as ACL, 11.6% were classified as FN, 2.6% were classified as suspicious, and 7.6% were classified as malignant. Five hundred twelve patients had at least 1 repeat FNA, mainly for results in the unsatisfactory and ACL categories. One thousand fifty-two patients had surgical follow-up, including 14.9% of patients with unsatisfactory FNA results, 9.8% of patients with benign results, 40.6% of patients with ACL results, 63.1% of patients with FN results, 86.1% of patients with suspicious results, and 79.3% of patients with malignant results. The rates for histologically confirmed malignancy in these categories were 10.9%, 7.3%, 13.5%, 32.2%, 64.7%, and 98.6%, respectively. The cytologic-histologic diagnostic discrepancy rate was 15.3%. Sources of errors included diagnoses on inadequate specimens, sample errors, and overlapping cytologic features between hyperplastic nodules and follicular adenoma. The sensitivity and specificity of thyroid FNA for the diagnosis of malignancy were 94% and 98.5%, respectively.

CONCLUSIONS

The current results indicated that FNA provides an accurate diagnosis of thyroid malignancy. The 6 diagnostic categories were beneficial for triaging patients for either clinical follow-up or surgical management.

Diagnosis of suspicious thyroid nodules using four protein biomarkers

PURPOSE

Fine-needle aspiration (FNA) cytology, a standard method for thyroid nodule diagnosis, cannot distinguish between benign follicular thyroid adenoma (FTA) and malignant follicular thyroid carcinoma (FTC). Previously, using expression profiling, we found that a combination of transcript expression levels from DDIT3, ARG2, C1orf24, and ITM1 distinguished between FTA and FTC. The goal of this study was to determine if antibody markers used alone or in combination could accurately distinguish between a wider variety of benign and malignant thyroid lesions in fixed sections and FNA samples.

EXPERIMENTAL DESIGN

Immunohistochemistry was done on 27 FTA, 25 FTC, and 75 other benign and malignant thyroid tissue sections using custom antibodies for chromosome 1 open reading frame 24 (C1orf24) and integral membrane protein 1 (ITM1) and commercial antibodies for DNA damage-inducible transcript 3 (DDIT3) and arginase II (ARG2). FNA samples were also tested using the same antibodies. RNA expression was measured by quantitative PCR in 33 thyroid lesions.

RESULTS

C1orf24 and ITM1 antibodies had an estimated sensitivity of 1.00 for distinguishing FTA from FTC. For the expanded analysis of all lesions studied, ITM1 had an estimated sensitivity of 1.00 for detecting malignancy. Because all four cancer biomarkers did well, producing overlapping confidence intervals, not one best marker was distinguished. Transcript levels also reliably predicted malignancy, but immunohistochemistry had a higher sensitivity. Malignant cells were easily detected in FNA samples using these markers.

CONCLUSIONS

We improved this diagnostic test by adding C1orf24 and ITM1 custom antibodies and showing use on a wider variety of thyroid pathology. We recommend that testing of all four cancer biomarkers now be advanced to larger trials. Use of one or more of these antibodies should improve diagnostic accuracy of suspicious thyroid nodules from both tissue sections and FNA samples.

Cytohistologic correlation of thyroid nodules

BACKGROUND

Fine-needle aspiration (FNA) is widely used as a diagnostic tool to assess thyroid nodules. This study correlates FNA cytology results with surgical pathologic findings.

METHODS

All thyroidectomies performed between 1994 and 2004 were reviewed, identifying 242 patients. Data were obtained for FNA diagnosis, demographics, findings on ultrasound, and histologic findings.

RESULTS

Among 89 patients with a carcinoma on FNA, 89% of cases were verified on final histopathology. Of 78 patients with "follicular lesion" on FNA, only 36% of cases were verified to be malignant at surgery. Only 13% of the 75 cases diagnosed as benign, mostly colloid nodules, on FNA were found to have a carcinoma on histopathology.

CONCLUSION

A cytologic diagnosis of papillary carcinoma has a highly predictive of thyroid cancer. When dealing with follicular lesions the predictive value of FNA drops considerably. However, we found a 13% false positive result to occur in FNA declared benign lesions.

Nódulos com diagnóstico de padrão folicular: marcadores biológicos são o futuro?

Com o uso da ultra-sonografia de alta resolução, a prevalência de nódulos tem aumentado e, conseqüentemente, o número de punção aspirativa por agulha fina (PAAF), que é o método de escolha para diagnóstico inicial. Um dos maiores dilemas clínicos para o citologista é o diagnóstico diferencial das lesões foliculares comumente agrupadas na classe padrão folicular. Neste artigo de revisão, discutiremos quais são as lesões que podem ser assim classificadas e os marcadores moleculares, identificados por nós ou por outros grupos, que são capazes de distinguir as lesões benignas das malignas.

Inter- and intraobserver reproducibility of thyroid fine needle aspiration cytology: an analysis of discrepant cases

OBJECTIVE

To determine the inter- and intraobserver reproducibility and analyse the discrepant cases of fine needle aspiration cytology (FNAC) of the thyroid.

METHODS

Cases of thyroid FNAC with a corresponding histological diagnosis were reviewed regarding the original cytological diagnoses by two observers. The final cytological diagnoses (FCD) included both concordant and consensus diagnoses. The inter- and intraobserver reproducibility and efficacy of thyroid FNAC were calculated based on the FCD.

RESULTS

A total of 97 FNAC cases with corresponding histopathological specimens were analysed. Although inter- and intraobserver disagreement in the cytological diagnoses occurred in about one-quarter of the cases analysed (24.7% and 23.7%, respectively), a substantial level of diagnostic interobserver (kappa = 0.71) and intraobserver (kappa = 0.66) reproducibility was observed. The efficacy of the method was 94.4%. Disagreement in the diagnosis was detected in 24 cases (24.7%), most of them (41.7%) for follicular lesions. Discordant cytological diagnoses between the two observers were represented by six (16.2%) of the 37 cases with an FCD of colloid nodule, five (41.7%) of the 12 cases of cellular follicular lesion, all three cases of follicular neoplasm, in two (6.3%) of the 32 cases of PTC, one (16.7%) of six cases of follicular neoplasm with a predominance of Hürthle cells and in one case of poorly differentiated neoplasia. Similarly, major disagreement in intraobserver cytological diagnoses was observed for the diagnosis of follicular lesions: 18 (78.3%) of a total of 23 discordant cases.

CONCLUSION

As discrepancies in the cytopathological diagnosis can have repercussions in the management of patients, all cases with a cytological diagnosis of follicular lesions/neoplams should be reviewed in multidisciplinary meetings thus minimizing interobserver variability.

Combined clinical, thyroid ultrasound and cytological features help to predict thyroid malignancy in follicular and Hupsilonrthle cell thyroid lesions: results from a series of 505 consecutive patients

OBJECTIVE

The cytological patterns of follicular and Hupsilonrthle cell nodules are included among the indeterminate results of fine-needle aspiration cytology, because distinction between benign and malignant lesion can only be made on histological criteria. The diagnostic value of atypia at cytology, clinical parameters and echographic patterns were examined to establish the risk of malignancy in 505 patients with follicular and Hupsilonrthle cell thyroid nodules at cytology.

DESIGN AND PATIENTS

The study included 505 consecutive patients who had undergone thyroidectomy from the period 2002-2005.

RESULTS

Histological diagnosis of malignancy was carried out in 125 of 505 (25%) patients, the follicular variant of papillary carcinoma being the most frequent histotype. Only atypia at cytology (P < 0.0001) and spot microcalcifications at ultrasound (P = 0.009) were predictive of malignancy. Male gender, normal thyroid volume, single nodularity, nodule hypoechogenicity, size and blurred margins were associated with malignancy, although not significantly. An arbitrary clinical score allowed the identification of patients with high (41%, 110 patients) and low (16%, 242 patients) risk of malignancy. Combining the clinical score with the presence of atypia at cytology we could identify 30 patients (6%) in whom the risk of malignancy was as high as 63%.

CONCLUSIONS

Twenty-five per cent of patients with a cytological result of follicular and Hupsilonrthle cell thyroid lesion had a final diagnosis of malignancy. Only atypia at cytology and spot microcalcifications at thyroid ultrasound were significantly associated with malignancy. Other clinical parameters and thyroid ultrasound patterns can be used to set up a clinical score useful for predicting the individual risk of malignancy before surgery.

Progress in the preoperative diagnosis of thyroid nodules: managing uncertainties and the ultimate role for molecular investigation

The preoperative evaluation of thyroid nodules currently relies on a clinical assessment of risk factors and an algorithm based on imprecise tests. With serum TSH, thyroid ultrasound and fine-needle aspiration (FNA) with or without ultrasound guide, accounting for the routine initial evaluation, indeterminate aspirates remain the major obstacle for confidently advising patients whether to have surgery or not. Recent clinical guidelines have attempted to settle various controversies but many inherent errors of clinical testing result in delayed diagnosis and unnecessary surgery. A better solution may ultimately involve the use of molecular markers of thyroid carcinogenesis but further research is still needed regarding the basic biology of thyroid cancer.