Radiofrequency ablation is an effective treatment for Bethesda III thyroid nodules without genetic alterations.

Background: Radiofrequency ablation (RFA) is effective in the treatment of thyroid nodules, leading to a 50-90% reduction with respect to baseline. Current guidelines indicate the need for a benign cytology prior to RFA, though, on the other side, this procedure is also successfully used for the treatment of papillary microcarcinomas. No specific indications are available for nodules with an indeterminate cytology (Bethesda III/IV). Aim: To evaluate the efficacy of RFA in Bethesda III nodules without genetic alterations as verified by means of a custom panel. Methods: We have treated 33 patients (mean delivered energy 1069 ± 1201 J/mL of basal volume) with Bethesda III cytology, EU-TIRADS 3-4, and negative genetic panel. The mean basal nodular volume was 17.3 ± 10.7 mL. Results: Considering the whole series, the mean volume reduction rate (VRR) was 36.8 ± 16.5% at 1 month, 59.9 ± 15.5% at 6 months, and 62 ± 15.7% at 1-year follow-up. The sub-analysis done in patients with 1 and 2 years follow-up data available (n = 20 and n = 5, respectively) confirmed a progressive nodular volume decrease. At all-time points, the rate of reduction was statistically significant (P < 0.0001), without significant correlation between the VRR and the basal volume. Neither cytological changes nor complications were observed after the procedure. Conclusion: RFA is effective in Bethesda III, oncogene-negative nodules, with reduction rates similar to those obtained in confirmed benign lesions. This procedure represents a good alternative to surgery or active surveillance in this particular class of nodules, regardless of their initial volume. A longer follow-up will allow to evaluate further reduction or possible regrowth.

Preoperative neck ultrasound combined with pathological data can significantly impact the outcome of medullary thyroid carcinoma.

The diagnosis of medullary thyroid carcinoma (MTC) is challenging since the accuracy of ultrasound (US) and fine-needle aspiration cytology are suboptimal. As a result, MTC has a generally poor prognosis. The aim of this study was to analyze whether perioperative data can modify the risk of relapse in these patients. The institutional database of Turin Mauriziano Hospital was searched to extract records of MTCs diagnosed between 2000 and 2021. Kaplan-Meier curves and Cox and logistic regression analyses were performed, and the hazard ratio (HR) was calculated. Seventy-three MTC patients (median age 58 yr) were found. Disease-free survival was significantly different according to staging (HR: 9.12; p = 0.037), capsular status (HR: 5.49; p = 0.02), and neck US (HR: 9.19; p = 0.04). In the logistic regression analysis, CEA level (ß: -0.01; p = 0.043), histological multifocality (OR: 7.4; p = 0.034), and metastatic lymph nodes at histology (ß: -0.13; p = 0.006) were significantly associated with structural recurrence. Two logistic multivariate models best explained the variance in recurrence: 1) neck US presentation plus histological multifocality (AIC: 27; r2: 0.37; x2: 12.4; p = 0.002) and 2) number of neck metastases plus capsular invasion (AIC: 26; r2: 0.40; x2: 13.7; p = 0.001). Pathological data are associated with MTC prognosis. Preoperative neck US can significantly help to predict MTC outcome.

Image-guided thermal ablation in autonomously functioning thyroid nodules. A retrospective multicenter three-year follow-up study from the Italian Minimally Invasive Treatment of the Thyroid (MITT) Group.

OBJECTIVES: To report the results of a multicenter retrospective evaluation of the clinical outcomes of thermal ablation (TA) in a large series of autonomously functioning thyroid nodules (AFTN) with a follow-up protracted up to 3 years. METHODS: Patients treated with single TA for an AFTN in Italy were included. Changes in nodule volume, TSH values, and ongoing anti-thyroid therapy were assessed at the 2-, 6-, 12-, 24-, and 36-month follow-up controls. Complications and need of any additional therapy after TA were also registered. RESULTS: A total of 361 patients (244 females, 117 males, median age 58 years, IQR 46-70 years) were included. Nodule volume was significantly reduced at all time points (p < 0.001) (median volume reduction 58% at 6-month and 60% at 12-month). Serum TSH values increased significantly at all time points. After TA, anti-thyroid therapy was withdrawn in 32.5% of patients at 2 months, in 38.9% at 6 months, and in 41.3% at 12 months. A significant difference in the rate of patients who withdrawn medical therapy at 12 months was registered between small (< 10 mL) (74%), medium (49%), or large (> 30 mL) nodules (19%). A single major complication occurred (0.25%). Additional treatments were needed in 34/361 (9.4%) of cases including 4 (1.1%) surgical treatment. CONCLUSIONS: Image-guided thermal ablation offers a further safe and effective therapeutic option in patients with AFTN. Clinical outcomes are significantly more favorable in small than in large size AFTN. KEY POINTS: • Thermal ablations (TA) can be safely and effectively used in patients with autonomously functioning thyroid nodules (AFTN). • TA results in a clinically significant nodule volume reduction that is paralleled by TSH level normalization and anti-thyroid drug therapy discontinuation (after TA anti-thyroid therapy was withdrawn in 41.3% at 12 months). • Clinical outcomes after TA are more favorable in small nodules, and when a large amount of thyroid nodule tissue is ablated.

Predictive factors of malignancy in pediatric patients with thyroid nodules and performance of the Italian classification (SIAPEC 2014) in the outcome of the cytological FNA categories.

PURPOSE: The rate of malignancy (ROM) among pediatric studies using the Bethesda System is 39.5% and 41.5% for atypia of undetermined significance/follicular lesion of undetermined significance and for suspected follicular neoplasm, respectively. Data reported on the basis of Bethesda System showed lower ROM in adults with indeterminate nodules (30.5 and 28.9% respectively). Studies on adults based on the Italian Society of Anatomic Pathology and Cytology (SIAPEC) classification, report ROM of 14.2% for TIR3a and 44.6% for TIR3b category, showing greater sensitivity in detecting malignancy. To date, no performance data are available about SIAPEC classification in pediatric age. METHODS: Retrospective data were collected from 200 pediatric subjects with thyroid nodules in the period 2000-2020. RESULTS: The distribution of cytological categories after fine needle aspiration biopsy (FNAB) was 7 TIR1, 4 TIR1c, 22 TIR2, 14 TIR3a, 9 TIR3b, 3 TIR4, and 16 TIR5. The surgical approach was performed in 40/200 subjects, with total ROM of 65% (0% for TIR1-TIR3a, 77.8% for TIR3b, and 100% for TIR4-TIR5). Total FNAB accuracy was 95%, while the sensibility and specificity were 92.3 and 92.6%, respectively. CONCLUSIONS: The reported data seem to confirm a greater sensitivity of SIAPEC classification to identify malignancy within the indeterminate category also in pediatric age and not only in adulthood. This finding may orient clinicians toward clinical follow-up for the indeterminate TIR3a group and toward surgical approach with total thyroidectomy in the indeterminate TIR3b group, although this indication should be confirmed in further national multicenter studies including larger cohorts.

Determining an energy threshold for optimal volume reduction of benign thyroid nodules treated by radiofrequency ablation.

OBJECTIVES: Radiofrequency ablation (RFA) is effective in reducing the volume of benign thyroid nodules. However, what parameters can influence the response to RFA is still unclear. The present study aimed to (1) investigate which ultrasound and technical parameters are potential determinants of the volumetric reduction; (2) develop a dose-response model, and (3) analyze the effects of RFA on ultrasound features. METHODS: In this retrospective study, three institutions treated patients with benign thyroid nodules according to the same protocol. The technical parameters were power and energy. The 1-year volume reduction ratio (VRR) was the reference standard of the response. The correlations of different parameters with VRR were analyzed and the association between several parameters and a VRR above 50% studied by uni- and multivariate analyses. The probit regression estimated the probability to achieve an effective response. RESULTS: One hundred fifteen patients were enrolled. The median power was 50 W and median total delivered energy 27,531 J. At 1-year follow-up, the median VRR was 64.0% and 87 (75.7%) nodules showed a VRR above 50%. Among all parameters, only baseline volume, total energy, and energy per volume were independently associated to a VRR > 50% (p = 0.001, p = 0.0178, p < 0.001 respectively). The probit regression analysis demonstrated that delivering 756 J/ml and 2670 J/ml gave a probability of VRR > 50% in 50% and 99% of patients, respectively. CONCLUSIONS: Considering the baseline nodular volume and delivering the adequate energy per volume allow optimizing technical and clinical success. KEY POINTS: • The effectiveness of radiofrequency ablation in treating benign thyroid nodules is negatively correlated to the volume of the nodule and positively correlated to the energy delivered per volume. • When planning the treatment, the total energy to deliver can be calculated by using a simple formula: nodular volume × 2670 J.

Machine Learning Prediction of Radiofrequency Thermal Ablation Efficacy: A New Option to Optimize Thyroid Nodule Selection.

BACKGROUND: Radiofrequency (RF) is a therapeutic modality for reducing the volume of large benign thyroid nodules. If thermal therapies are interpreted as an alternative strategy to surgery, critical issues in their use are represented by the extent of nodule reduction and by the durability of nodule reduction over a long period of time. OBJECTIVE: To assess the ability of machine learning to discriminate nodules with volume reduction rate (VRR) < or ≥50% at 12 months following RF treatment. METHODS: A machine learning model was trained with a dataset of 402 cytologically benign thyroid nodules subjected to RF at six Italian Institutions. The model was trained with the following variables: baseline nodule volume, echostructure, macrocalcalcifications, vascularity, and 12-month VRR. RESULTS: After training, the model could distinguish between nodules having VRR <50% from those having VRR ≥50% in 85% of cases (accuracy: 0.85; 95% confidence interval [CI]: 0.80-0.90; sensitivity: 0.70; 95% CI: 0.62-0.75; specificity: 0.99; 95% CI: 0.98-1.0; positive predictive value: 0.95; 95% CI: 0.92-0.98; negative predictive value: 0.95; 95% CI: 0.92-0.98). CONCLUSIONS: This study demonstrates that a machine learning model can reliably identify those nodules that will have VRR < or ≥50% at 12 months after one RF treatment session. Predicting which nodules will be poor or good responders represents valuable data that may help physicians and patients decide on the best treatment option between thermal ablation and surgery or in predicting if more than one session might be necessary to obtain a significant volume reduction.

Five-Year Results of Radiofrequency and Laser Ablation of Benign Thyroid Nodules: A Multicenter Study from the Italian Minimally Invasive Treatments of the Thyroid Group.

Background: Radiofrequency ablation (RFA) and laser ablation (LA) are effective treatments for benign thyroid nodules. Due to their relatively recent introduction into clinical practice, there are limited long-term follow-up studies. This study aimed to evaluate technique efficacy, rate of regrowth, and retreatment over 5 years after RFA or LA and to identify predictive factors of outcome. Methods: In this multicenter retrospective study, the rates of technique efficacy, regrowth, and retreatment were evaluated in 406 patients treated with either RFA or LA, and followed for 5 years after initial treatment. Propensity score matching was used to compare treatments. Cumulative incidence studies with hazard models were used to describe regrowth and retreatment trends, and to identify prognostic factors. Logistic regression models and receiver operating characteristic analyses were used for risk factors and their cutoffs. Results: RFA and LA significantly reduced benign thyroid nodule volume, and this reduction was generally maintained for 5 years. Technique efficacy (defined as a reduction ≥50% after 1 year from the treatment) was achieved in 74% of patients (85% in the RFA and 63% in the LA group). Regrowth occurred in 28% of patients (20% in the RFA and 38% in the LA group). In the majority of cases, further treatment was not required as only 18% of patients were retreated (12% in the RFA and 24% in the LA group). These data were confirmed by propensity score matching. Cumulative incidence studies showed that RFA was associated with a lower risk of regrowth and a lower risk of requiring retreatment over time. Overall, technique inefficacy and regrowth were associated with low-energy delivery. Retreatments were more frequent in young patients, in large nodules, in patients with lower volume reduction at 1 year, and in cases of low-energy delivery (optimal cutoff was 918 J/mL for RFA). Conclusions: Both thermal ablation techniques result in a clinically significant and long-lasting volume reduction of benign thyroid nodules. The risk of regrowth and needing retreatment was lower after RFA. The need for retreatment was associated with young age, large baseline volume, and treatment with low-energy delivery.

Long-Term Efficacy of a Single Session of RFA for Benign Thyroid Nodules: A Longitudinal 5-Year Observational Study.

CONTEXT: Radiofrequency ablation (RFA) of benign thyroid nodules has been gaining consensus. However, no solid information on its long-term efficacy is available. OBJECTIVE: To analyze the long-term results of single-session RFA. DESIGN: Retrospective longitudinal observational study. SETTING: Primary care center. PATIENTS OR OTHER PARTICIPANTS: Adult outpatients who underwent a single-session RFA and posttreatment follow-up of least 3 years. INTERVENTION: Ultrasound-guided RFA was performed after local anesthesia by "moving-shot" technique. RFA was performed with a median power of 55W and a median time of 14 minutes with an internally cooled 18-gauge electrode with an active 10-mm tip. MAIN OUTCOME MEASURES: Objective (trend of nodule volume) and subjective (compressive and cosmetic concerns) response to RFA were evaluated. Continuous variables were analyzed by the Wilcoxon and ANOVA test and their correlations by using the Spearman test. Categorical variables were compared by Pearson χ2 test. RESULTS: Two hundred and fifteen patients were included. An early significant reduction of nodule volume was found at 1 year, lasting up to 5 years. A 67% nodule shrinkage was observed at the end of the observation period. The best response was recorded in nodules below 10 mL (79% reduction early and 81% at 5 years). Patients' symptoms were significantly reduced. CONCLUSIONS: This study, by demonstrating a durable shrinkage of benign thyroid nodules treated by RFA with an improvement of subjective symptoms, establishes the reliability of RFA as alternative to surgery in the management of thyroid nodules, thus representing a remarkable novelty for clinical practice.

Quantitative analysis of thyroid tumors vascularity: A comparison between 3-D contrast-enhanced ultrasound and 3-D Power Doppler on benign and malignant thyroid nodules.

PURPOSE: To perform a comparative quantitative analysis of Power Doppler ultrasound (PDUS) and Contrast-Enhancement ultrasound (CEUS) for the quantification of thyroid nodules vascularity patterns, with the goal of identifying biomarkers correlated with the malignancy of the nodule with both imaging techniques. METHODS: We propose a novel method to reconstruct the vascular architecture from 3-D PDUS and CEUS images of thyroid nodules, and to automatically extract seven quantitative features related to the morphology and distribution of vascular network. Features include three tortuosity metrics, the number of vascular trees and branches, the vascular volume density, and the main spatial vascularity pattern. Feature extraction was performed on 20 thyroid lesions (ten benign and ten malignant), of which we acquired both PDUS and CEUS. MANOVA (multivariate analysis of variance) was used to differentiate benign and malignant lesions based on the most significant features. RESULTS: The analysis of the extracted features showed a significant difference between the benign and malignant nodules for both PDUS and CEUS techniques for all the features. Furthermore, by using a linear classifier on the significant features identified by the MANOVA, benign nodules could be entirely separated from the malignant ones. CONCLUSIONS: Our early results confirm the correlation between the morphology and distribution of blood vessels and the malignancy of the lesion, and also show (at least for the dataset used in this study) a considerable similarity in terms of findings of PDUS and CEUS imaging for thyroid nodules diagnosis and classification.

American Thyroid Association ultrasound system for the initial assessment of thyroid nodules: Use in stratifying the risk of malignancy of indeterminate lesions.

BACKGROUND: The ultrasound risk stratification system of the American Thyroid Association (ATA) is frequently adopted in clinical practice. Here, we evaluated its performance in a series of nodules with indeterminate fine-needle aspiration cytology (FNAC) report. METHODS: Indeterminate thyroid nodules diagnosed at 2 medical centers were retrospectively screened, ultrasound images were reevaluated, and lesions were classified according to the ATA. Single ultrasound parameters were also analyzed. RESULTS: One hundred seventy-three indeterminate lesions were included with 24.8% of malignancy. The high suspicion class showed a cancer rate (75%) significantly (P < .001) higher than that recorded in the other categories (16.8%). Between ultrasound parameters, halo and microcalcifications were the most sensitive and specific ones. The most accurate receiver operating characteristic (ROC)-derived cutoff of nodule's diameter was >4.1 cm. At multivariate analysis, only the ATA class of high suspicion and size >4.1 cm were significantly associated with cancer (odds ratios [ORs] 19.4 and 5.4, respectively). CONCLUSION: The ATA ultrasound system is reliable in the risk stratification of indeterminate thyroid lesions.

A comparison of laser with radiofrequency ablation for the treatment of benign thyroid nodules: a propensity score matching analysis.

PURPOSE: To compare technique efficacy and safety of laser ablation (LA) and radiofrequency ablation (RFA) in treatment of benign thyroid nodules. MATERIALS AND METHODS: Institutional review board approval was obtained, and patients' consent was waived. 601 nodules were treated from May 2009 to December 2014 at eight centres, 449 (309 females, age 57 ± 14 years) with LA and 152 (107 females, age 57 ± 14 years) with RFA. A matched cohort composed of 138 patients from each group was selected after adjustment with propensity score matching. Factors influencing volume reduction at 6 and 12 months and complications were evaluated. RESULTS: No significant differences were observed in the baseline characteristics between groups after propensity score matching adjustment. Mean nodule reduction at 6 and 12 months was -67 ± 19% vs. -57 ± 21% (p < 0.001) - 70 ± 19% vs. -62 ± 22% (p = 0.001) in LA group and in RFA group, respectively. Nodules with volume >30 mL had significantly higher percentage volume reduction at 6 and 12 months (-69 ± 19 vs. -50 ± 21, p = 0.001) and (-73 ± 18 vs. -54 ± 23 8, p = 0.001) in the LA group than in the RFA group, respectively. In both groups, operator's skills affected the results. Major complications occurred in 4 cases in each group (p = 0.116) Conclusions: LA and RFA showed nearly similar outcome but LA was slightly more effective than RFA in large nodules. Operator's skills could be crucial in determining the extent of nodule volume reduction regardless of the used technique.

Predictors of Malignancy in Children with Thyroid Nodules.

OBJECTIVE: To evaluate the diagnostic accuracy of clinical, laboratory, and ultrasound (US) imaging characteristics of thyroid nodules in assessing the likelihood of malignancy. STUDY DESIGN: Data from 184 children and adolescents with thyroid nodules were evaluated and compared with respective cytologic/histologic outcomes. A regression model was designed to assess the predictors associated with malignancy and to calculate ORs. RESULTS: Twenty-nine malignant neoplasms (25 papillary, 1 medullary, 3 Hurtle-cell carcinomas), 8 follicular adenomas, and 147 goitrous nodules (92 based on cytology, 55 on follow-up) were diagnosed. Fine-needle aspiration biopsy diagnostic accuracy, sensitivity, and specificity were 91%, 100%, and 88%, respectively. Male sex, compression symptoms, palpable lymphopathy, thyroid stimulating hormone concentration, microcalcifications, indistinct margins, hypoechoic US pattern, pathologic lymph node alterations, and increased intranodular vascularization were associated with malignancy. Regular margins, mixed echoic pattern, and peripheral-only vascularization were associated with benignity. During follow-up, nodule growth was associated with malignant disease, especially with levothyroxine therapy. A multivariate analysis confirmed that microcalcifications, hypoechoic pattern, intranodular vascularization, lymph node alterations, and thyroid stimulating hormone concentration were independent predictors of malignant outcome. For each predictor, we provide sensitivity, specificity, and positive/negative predictive values. CONCLUSIONS: Clinical, laboratory, and US features of nodules can be used as predictors of malignancy in children. Although none has diagnostic accuracy as high as that of fine-needle aspiration biopsy, these predictors should be considered in deciding the diagnostic approach of children with thyroid nodules.

Efficacy and Safety of Radiofrequency Ablation Versus Observation for Nonfunctioning Benign Thyroid Nodules: A Randomized Controlled International Collaborative Trial.

BACKGROUND: Percutaneous radiofrequency thermal ablation (RFA) has been reported as an effective tool for the management of benign thyroid nodules (BTN). However, large, randomized controlled trials (RCTs) are lacking. OBJECTIVE: The aims of this study were to assess the volume reduction of BTN after a single RFA performed using the moving-shot technique and to compare the volume reduction obtained in patients treated in two centers with different experience of the moving-shot technique. METHOD: This study was an international prospective RCT. It was carried out at the Mauriziano Hospital (Turin, Italy) and the Asan Medical Center (Seoul, Korea). Eighty patients harboring solid, compressive, nonfunctioning BTN (volume 10-20 mL) were enrolled. Twenty patients in each country were treated by RFA using a 18-Gauge internally cooled electrode (group A); 20 nontreated patients in each country were followed as controls (group B). RESULTS: At six months, BTN volume significantly decreased in group A (15.1±3.1 mL vs. 4.2±2.7 mL; p<0.0001), whereas it remained unchanged in group B (14.4±3.3 mL vs. 15.2±3.5 mL). The baseline volume was larger in the Italian series (16.4±2.5 mL vs. 13.9±3.3 mL, p=0.009). However, at six months, there was no significant difference between the Korean group and the Italian group (3.7±2.9 mL vs. 5.5±2.2 mL). Both cosmetic and compressive symptoms significantly improved (3.6±0.5 vs. 1.7±0.4 and 3.6±1.9 vs. 0.4±0.7, respectively; p<0.001). No side effects occurred. CONCLUSIONS: RFA was effective in reducing the volume of BTN. The outcome was similar in centers with different experience in the moving-shot technique.

Diagnostic performance of elastography in cytologically indeterminate thyroid nodules.

Cytological examination of material from fine-needle aspiration biopsy is the mainstay of diagnosis of thyroid nodules, thanks to its remarkable accuracy and scarcity of complications. However, follicular lesions (also called indeterminate lesions or Thy3 in the current classification), a heterogeneous group of lesions in which cytology is unable to give a definitive diagnosis to, represent its main limit. Elastography has been proposed as a potential diagnostic tool to define the risk of malignancy in the aforementioned nodules, but at present there is no conclusive data due to the small number of specifically addressed studies and the lack of concordance among them. The objective of our study was to evaluate the role of real-time elastography (RTE) for refining diagnosis of Thy3 nodules, by integrating diagnostic information provided by traditional ultrasound (US). The study included 108 patients with Thy3 nodules awaiting for surgery, which were evaluated by US (considering hypoecogenicity, irregular margins, microcalcifications, halo sign, and intranodular vascularization) and RTE. Nodules were classified at RTE using a four-class color scale. At histologic examination, 75 nodules were benign and 33 malignant. As expected, none of the ultrasound parameters alone was adequate in predicting malignancy or benignity of the nodules; in the presence of at least two US risk factors, we obtained 61 % sensitivity, 83 % specificity, and 77 % accuracy with 6.8 OR (95 % CI 2.4-20.4). RTE scores 3 and 4 showed 76 % sensitivity, 88 % specificity, 74 % PPV, and 89 % NPV with diagnostic accuracy of 84 %; the data are statistically significant (p < 0.0001) with a OR of 21.9 (95 % CI 7.1-76). By combining RTE with US parameters, the presence of at least 2 characters of suspicion had 88 % sensitivity and 94 % NPV with 23.8 OR (95 % CI 7-106.3). The use of combined RTE and US leads to the identification of two patients subpopulations which have a significantly different malignancy risk (6 vs. 63 %); further studies are needed to verify if it is possible to send only the first group to thyroidectomy and the other to follow-up.

High diagnostic accuracy and interobserver reliability of real-time elastography in the evaluation of thyroid nodules.

Elastography is a new diagnostic tool in the evaluation of thyroid nodules. Aim of the study was to evaluate the accuracy and reliability of elastography in discriminating thyroid lesions and the interobserver variability. One hundred thirty-two nodules in 115 patients selected for thyroid surgery underwent conventional ultrasound and elastographic evaluation. Elastography score was divided in four categories (totally elastic nodule, mainly elastic, mainly rigid and totally rigid) according to signal distribution. Three independent operators conducted the study. Final histology showed 92 benign nodules and 40 malignant. On elastography, 77/92 benign nodules were classified as score 1 or 2 and 34/40 malignant nodules as score 3 or 4 (sensitivity 85%, specificity 83.7%, positive predictive value [PPV] 69.3%, negative predictive value [NPV] 92.7%). Rate of concordance between operators was good (K test: 0.64, p < 0.0001). Simple to use, with good interobserver agreement, elastography has all the requisites to become an important complement of conventional US examination in the near future.

Diagnostic value of a cytomorphological subclassification of follicular patterned thyroid lesions: a study of 927 consecutive cases with histological correlation.

BACKGROUND: Fine-needle aspiration cytology (FNAC) has proved to be an effective diagnostic tool in patients with thyroid nodules. Several reporting schemes have been suggested to define the risk of malignancy and consequent clinical management. To date, however, among lesions showing a follicular pattern, FNAC is still unable to differentiate between benign and malignant ones. The aim of our study was to evaluate whether a subclassification of follicular cytologic specimens, based on cytoarchitectural patterns, could differentiate categories with a different risk of malignancy, thus improving the clinical management of patients harboring follicular nodules. METHODS: We report a cohort of 927 consecutive cases who underwent thyroid surgery in our hospital between 2000 and 2008. Each patient underwent FNAC before surgery. All the cytologic specimens were divided into five categories (Thy 1: inadequate material, Thy 2: benign, Thy 3: indeterminate, Thy 4: suspicious for malignancy, Thy 5: malignant). Thy3 specimens were further divided into three subcategories (Thy 3a, or "follicular lesions of indeterminate significance": scant colloid, microfollicular pattern, or small clusters of thyrocytes with round nuclei usually without, but sometimes with, minimal cellular pleomorphism; Thy 3b, or "follicular neoplasm": absence of colloid, small clusters, or microfollicles of medium-large sized cell populations arranged in cohesive groups with nuclear overlapping, crowding, and pleomorphisms; and Thy 3c or "Hurthle-cell neoplasm": scant colloid, sheets or clusters of oxyphilic cells). RESULTS: Thy 1 specimens (51 cases on the whole) proved to be malignant in 5.88% (3 cases), Thy 2 specimens (319) in 3.45% (11 cases), Thy 4 specimens (91) in 84.62% (77 cases), and Thy 5 specimens (172) in 98.84% (170 cases). Thy 3 specimens (294 cases) proved to be malignant in 17.35% as a whole, but when divided into the three subcategories, the percentage of malignant cases was significantly different between the Thy 3a group (4.95%) and the Thy 3b and Thy 3c groups (25.0% and 22.77% respectively). CONCLUSIONS: This study supports the National Cancer Institute consensus showing a different risk of malignancy for "follicular lesions of undetermined significance" compared with "follicular neoplasms" and "Hurthle cells neoplasms," which are more suspect for malignancy. This subclassification could improve clinical management of thyroid nodules, helping to better select patients for surgery or follow up.

US-guided percutaneous radiofrequency thermal ablation for the treatment of solid benign hyperfunctioning or compressive thyroid nodules.

The aim of the study was to define the effectiveness and safety of ultrasound-guided percutaneous radiofrequency (RF) thermal ablation in the treatment of compressive solid benign thyroid nodules. Thirty-one patients not eligible for surgery or radioiodine (131I) treatment underwent RF ablation for benign nodules; a total of 33 nodules were treated (2 patients had 2 nodules treated in the same session): 10 cold nodules and 23 hyperfunctioning. Fourteen patients complained of compressive symptoms. Nodule volume, thyroid function and compressive symptoms were evaluated before treatment and at 1, 3 and 6 mo. Ultrasound-guided RF ablation was performed using a Starbust RITA needle, with nine expandable prongs; total exposure time was 6 to 10 min at 95 degrees C in one area or more of the nodule. Baseline volume (measured at the time of RF ablation) was 27.7 +/- 21.5 mL (mean +/- SD), but significantly decreased during follow-up: 19.2 +/- 16.2 at 1 mo (-32.7%; p < 0.001), 15.9 +/- 14.1 mL at 3 mo (-46.4 %; p < 0.001) and 14.6 +/- 12.6 mL at 6 mo (-50.7%; p < 0.001). After treatment, all patients with cold nodules remained euthyroid: five patients with hot nodules normalized thyroid function, and the remaining sixteen showed a partial remission of hyperthyroidism. Besides a sensation of heat and mild swelling of the neck, no major complications were observed. Improvement in compressive symptoms was reported by 13 patients, with a reduction on severity scale from 6.1 +/- 1.4 to 2.2 +/- 1.9 (p < 0.0001). Radiofrequency was effective and safe in reducing volume by about 50% and compressive symptoms in large benign nodules. Hyperfunction was fully controlled in 24% of patients and partially reduced in the others.

Thyroid cytology and risk of thyroid cancer: differences among indeterminate specimens.

OBJECTIVE: To assess the potential for stratification of indeterminate cytologic findings on fine-needle aspiration (FNA) of thyroid nodules in an effort to improve therapeutic strategies. METHODS: We attempted to determine the malignant risk associated with various indeterminate FNA cytologic patterns by correlation of specimens with the final histologic diagnosis. For this analysis, we identified 294 computerized medical records of surgically treated thyroid nodules during a 5-year period at our institution with the corresponding FNA cytology reports available. RESULTS: Of the 294 surgical cases, 162 with a positive or indeterminate cytologic report were selected, reviewed, and classified. Of 52 patients with positive cytologic findings on FNA, 51 (98%) had a final histologic report of a malignant thyroid nodule. Of 110 patients with indeterminate specimens, 30 (27%) had a final histologic diagnosis of thyroid carcinoma. The presence of nuclear atypia was predictive of thyroid carcinoma in 75% of patients, a Hürthle cell cytologic pattern was associated with a malignant thyroid nodule in 33%, and a hypercellular smear was suggestive of malignant involvement in 26% of cases. The lowest rate of malignant potential was associated with cytologic microfollicular and scant colloid alone subtype (6%). CONCLUSION: The results of this study show that indeterminate thyroid cytologic specimens can be subdivided into groups with different malignant risks. A microfollicular cytologic pattern in the absence of a hypercellular smear or nuclear atypia does not support a recommendation of surgical treatment. A malignant cytologic diagnosis has a high positive predictive value for detection of thyroid cancer.

Fine-needle aspiration biopsy of the thyroid: comparison between thyroid palpation and ultrasonography.

OBJECTIVE: To describe our experience with fine-needle aspiration biopsy (FNAB) of the thyroid and compare our results with direct palpation versus ultrasound scanning (USS) in an area of endemic goiter in Italy. METHODS: We considered all patients submitted to ultrasound-guided FNAB of thyroid nodules during a 10-month period at our outpatient clinic and analyzed the following: (1) clinical data (number of nodules and identification of the nodule for FNAB); (2) USS data (number of nodules and identification of the nodule for FNAB on the basis of hypoechoic pattern + blurred perinodal halo + microcalcifications or intranodal color Doppler signal indicative of blood flow); (3) cytologic specimens, categorized as suspicious, malignant, negative, or nondiagnostic; and (4) histologic final report of the cytologically positive nodules. RESULTS: The study group consisted of 348 female and 72 male patients who underwent FNAB of the thyroid at our institution. Among the 140 patients with no palpable thyroid nodules, USS showed that 106 had a single nodule and 34 had multinodular goiters. Among the 182 patients with a single palpable thyroid nodule, USS revealed that 138 had a single nodule, 42 had a multinodular goiter, and 2 had lobe enlargement without detectable nodules. All 98 patients with multinodular palpable goiter had a similar pattern on USS. Of the 420 cytologic specimens, 46(11.0%) were positive for thyroid cancer, 313 (74.5%)were negative, and 61 (14.5%) were nondiagnostic. Histologic malignant growth was confirmed in 27 cytologically positive nodules. Of these histologically malignant nodules, 12 (45%) were nonpalpable, 9 (33%) were single palpable nodules, and 6 (22%) were from a nodule with a suspicious ultrasound pattern within a multinodular goiter. CONCLUSION: Manually guided FNAB is not feasible in nonpalpable nodules and not accurate in a multinodular goiter. Both situations are clinical challenges, and USS should be performed for accurate FNAB under these circumstances. Because 52% of histologically malignant nodules in our study were found only with the aid of ultrasound-guided FNAB, this procedure should be used where multinodular goiter is endemic. Our overall rate of nondiagnostic specimens was comparable to that reported in the literature.