Suspicious Ultrasound Features Research Articles

Sonographic risk stratification of FDG-avid thyroid nodules using the Thyroid Imaging Reporting and Data System.

The increasing usage of positron emission tomography/computed tomography (PET/CT) for detection and monitoring of malignancy has led to an increase in incidental detection of thyroid nodules. Nodules that demonstrate increased avidity for 2-[18F]-fluoro-2-deoxy-d-glucose (FDG) have been shown to carry a high incidence of malignancy and warrant further investigation. At present, there has been limited research on the risk stratification of FDG-avid thyroid incidentalomas. Thus, this study aims to evaluate the efficacy of the ACR TIRADS classification in the risk stratification of such nodules. Data were collected retrospectively for FDG-avid thyroid incidentalomas over a 10-year period. Nodules were characterised using the TIRADS classification and, subsequently, underwent fine-needle aspirate cytology. Cytological findings were classified using the Bethesda reporting system. Non-diagnostic samples (Bethesda class I) were excluded. The remaining samples were divided into two groups: benign (Bethesda class II) or suspicious for malignancy/malignant (Bethesda class III or above). Thirty-six percent of low-risk nodules and 45% of high-risk nodules were malignant, respectively (P = 0.516). The sensitivity and specificity of TIRADS for detection of malignant nodules were 56% and 54%, respectively. There were no malignant TIRADS 1 or 2 nodules. The absence of any suspicious sonographic features had a 1.0 negative predictive value. FDG-avid nodules classified as TIRADS 1 or 2 or have no suspicious ultrasound features have a 0% incidence of malignancy and thus may not require further assessment with fine-needle aspirate cytology (FNA) when detected incidentally. FDG-avid nodules that are TIRADS 3 or above should undergo FNA regardless of size due to the high risk of malignancy and poor sensitivity of the TIRADS classification system.

Integrated Diagnostics of Thyroid Nodules.

Thyroid nodules are common findings, particularly in iodine-deficient regions. Our paper aims to revise different diagnostic tools available in clinical thyroidology and propose their rational integration. We will elaborate on the pros and cons of thyroid ultrasound (US) and its scoring systems, thyroid scintigraphy, fine-needle aspiration cytology (FNAC), molecular imaging, and artificial intelligence (AI). Ultrasonographic scoring systems can help differentiate between benign and malignant nodules. Depending on the constellation or number of suspicious ultrasound features, a FNAC is recommended. However, hyperfunctioning thyroid nodules are presumed to exclude malignancy with a very high negative predictive value (NPV). Particularly in regions where iodine supply is low, most hyperfunctioning thyroid nodules are seen in patients with normal thyroid-stimulating hormone (TSH) levels. Thyroid scintigraphy is essential for the detection of these nodules. Among non-toxic thyroid nodules, a careful application of US risk stratification systems is pivotal to exclude inappropriate FNAC and guide the procedure on suspicious ones. However, almost one-third of cytology examinations are rendered as indeterminate, requiring "diagnostic surgery" to provide a definitive diagnosis. 99mTc-methoxy-isobutyl-isonitrile ([99mTc]Tc-MIBI) and [18F]fluoro-deoxy-glucose ([18F]FDG) molecular imaging can spare those patients from unnecessary surgeries. The clinical value of AI in the evaluation of thyroid nodules needs to be determined.

Benign thyroid nodules classified as ACR TI-RADS 4 or 5: Imaging and histological features

BackgroundAmerican College of Radiology Thyroid Imaging Reporting and Data System (ACR TI-RADS) being most widely applied in clinical practice, there is an overlap in US imaging manifestations between benign and malignant thyroid nodules. ObjectivesTo analyze the imaging and histological characteristics of pathological benign thyroid nodules categorized as American College of Radiology Thyroid Imaging Reporting and Data System (ACR TI-RADS) 4 or 5, and to explore the correlation between the suspicious sonographic signs resulting in the misdiagnoses and the histopathological features. Materials and methodsOverall, 227 benign thyroid nodules (215 patients) in ACR TI-RADS 4 or 5 sampled through surgical excision were analyzed between December 2020 and August 2022. We retrospectively reread the ultrasound (US) images of the pathological discordant cases, after which we performed a systematic analysis focusing on the histopathological characteristics of thyroid lesions and recorded the findings. Qualitative US features and pathological significance of the thyroid nodules were analyzed using the chi-square and Fisher’s exact tests. ResultsThe pathological type of 227 thyroid nodules (n = 103 in ACR TI-RADS 4 and n = 124 in ACR TI-RADS 5) was nodular goiter together with other histopathological features, namely, fibrosis (n = 103, 45.4 %), calcification (n = 70, 30.8 %), adenomatous hyperplasia (n = 31, 13.7 %), follicular epithelial hyperplasia (n = 23, 10.1 %), Hashimoto’s thyroiditis (n = 18, 7.9 %), and cystic degeneration (n = 16, 7.1 %). Fibrosis was the most common histopathological feature in both ACR TI-RADS 4 (n = 42, 40.8 %) and 5 (n = 61, 49.2 %) categories of benign thyroid nodules. Thyroid nodules with fibrosis demonstrated sonographic features of “taller than wide” (p < 0.05), while lesions with follicular epithelial hyperplasia were likely to be detected with irregular and/or lobulated margins and very hypoechoic on US (p < 0.05 for both). ConclusionBenign thyroid nodules with histopathological findings such as fibrosis are associated with suspicious US features, which may give inappropriately higher TIRADS stratification.

Predictive factors of lymph node metastasis in papillary thyroid cancer.

This study aimed to evaluate factors that predict lymph node metastasis (LNM) in papillary thyroid cancer (PTC). This retrospective cross-sectional study compared the demographic, clinical, and ultrasonographic findings of patients with PTC with and without LNM. Subgroup analysis was conducted for micro-PTCs (<1 cm). Among total (n = 512; mean age, 47.3 ± 12.7 years) and micro-PTC patients (n = 312), 35.7% and 19.6% had LNM, respectively. Younger age, male sex, tumor size, bilaterality, and suspicious ultrasound features of the tumor were associated with LNM. In multiple logistic regression analysis, among all patients, age, tumor size, and extrathyroidal extension were independent risk factors for LNM (all p<0.05). In the micro-PTC subgroup, age, extrathyroidal extension, bilaterality of tumor, and presence of autoimmune thyroid disease were independent risk and protective factors for LNM (all p<0.05). In the receiver operating characteristic analysis, the accuracy of the multivariable logistic regression model for predicting LNM among all patients and micro-PTC was acceptable (area under the curve = 0.729 and 0.733, respectively). Age, sex, tumor size, and extrathyroidal extension can assist in predicting LNM in PTC patients. Additionally, the bilaterality of tumors and presence of autoimmune thyroid disease can assist in predicting LNM in micro-PTCs.

A single-center study on the oncological outcomes of active surveillance of thyroid nodules measuring≤1 cm with highly suspicious ultrasound features

Objective: To investigate the oncological outcomes of active surveillance (AS) in patients showing thyroid nodules measuring≤1 cm with highly suspicious ultrasound features. Methods: A prospective single-center cohort study. A total of 534 patients with highly suspicious thyroid nodules (2015 American Thyroid Association Nodule Sonographic Patterns and Risk of Malignancy: High Suspicion) were enrolled in this study, the patients received AS at Peking Union Medical College Hospital between January 2017 and November 2022 to assess oncological outcomes (disease progression, recurrence/metastasis rate, etc). The patients were followed up every 6 months for physical examination and neck ultrasound examination. And the value of tumor volume changes in evaluating tumor enlargement was explored too. Results: There were 413 females and 121 males in this cohort, with a mean age of (42.6±11.8) years. During a median follow-up period of 45.6 months (ranged from 3.5 to 176.0 months), disease progression occurred in 26 patients (4.9%) with highly suspicious thyroid nodules, characterized by a minimum 3-mm increase in tumor diameter in 19 patients (3.6%) and lymph node metastases in 7 patients (1.3%). Forty-seven (8.8%) patients opted for delayed surgery, with 29 patients due to a change in preference. There was no significant differences in pathologic and follow-up outcomes between patients with disease progression and preference change. Patients aged≤40 years had a higher cumulative incidence of 5-year disease progression than those aged>40 years (4.9% vs 1.9%, P=0.060). No patients experienced distant metastases or deaths. Among the 595 high-risk thyroid nodules with continuous volume assessment results and an increase in nodule diameter of less than 3 mm (including all high-risk nodules in patients with single or multiple nodules), 184 (30.9%) and 79 (13.3%) nodules exhibited volume increases of more than 50% and 100%, respectively, in multiple measurements. Among the nodules with volume changes exceeding 50% and 100%, the proportion of nodules with a baseline tumor diameter of≤0.5 cm was significantly higher than those with a diameter of>0.5 cm, at 69.0% vs 31.0% (P<0.001) and 77.2% vs 22.8% (P<0.001), respectively. Conclusions: Active surveillance in patients with highly suspicious subcentimeter thyroid nodules has good short-term oncological outcomes and can be considered a safe alternative to surgery. Due to the large variability in the measurement results of tumor volume, it is not suitable as an indicator for evaluating tumor enlargement.

Clinico-cytopathological subcategorization in thyroid nodules of atypia of undetermined significance/follicular lesion of undetermined significance using the TIRADS and Bethesda classifications.

Bethesda category III - atypia of undetermined significance/follicular lesion of undetermined significance (AUS/FLUS) is a heterogeneous class of the Bethesda system for thyroid nodules. In order to clarify the therapeutic road for clinicians, this category was subclassified based on the cytopathological features. In this study, we evaluated the risk of malignancy, surgical outcome, demographic characteristics, and correlation of ultrasound features with the final outcome in patients with thyroid nodules based on AUS/FLUS subclassification. After evaluating 867 thyroid nodules from three different centers, 70 (8.07%) were initially diagnosed as AUS/FLUS. The cytopathologists re-interpreted the FNA samples and subclassified them into five subcategories: architectural atypia, cytologic atypia, cytologic and architectural atypia, and Hürthle cell AUS/FLUS, and atypia, which was not specified. Based on the suspicious ultrasound features, an appropriate ACR TI-RADS score was allocated to each nodule. Finally, the malignancy rate, surgical outcomes, and ACR TI-RADS scores were evaluated among Bethesda category III nodules. Among the 70 evaluated nodules, 28 (40%) were subclassified as Hürthle cell AUS/FLUS, 22 (31.42%) as cytologic and architectural atypia, 8 (11.42%) as architectural atypia, 7 (10%) as cytologic atypia, and 5 (7.14%) as atypia which was not specified. The overall malignancy rate was 34.28%, and the architectural atypia and Hürthle cell nodules displayed lower malignancy compared to other groups (P-Value<0.05). Utilizing ACR TI-RADS scores showed no statistical significance between Bethesda III subcategorization and ACR TI-RADS scores. However, ACR TI-RADS can be a reliable predictor for Hürthle cell AUS/FLU nodules. ACR TI-RADS helps evaluate malignancy only in the Hürthle cell AUS/FLUS subcategory of AUS/FLUS. Besides, cytopathological reporting based on the suggested AUS/FLUS subclassification could help clinicians take appropriate measures to manage thyroid nodules.

Reliable neck sonography of nodal thyroglobulin to diagnose recurrent/persistent disease from papillary thyroid carcinoma.

This study evaluates the correlation between the sonographic features and the nodal fine-needle aspiration thyroglobulin (FNA-Tg) in papillary thyroid carcinoma (PTC) patients with the recurrent/persistent lymph node for the purpose of the reasonable selection of lymph nodes. This study prospectively contained PTC patients with the suspicious cervical lymph nodes in one medical center from April 2018 to January 2019. Each suspected lymph node was aspirated with a 22-gauge needle and the value of FNA-Tg was measured as well. There were 136 lymph nodes related to the disease involved. The FNA-Tg levels of 89 (65.44%) metastatic lymph nodes were significantly higher than those of the benign. The median value of the former was 631.550 ng/mL while the latter was 0.056 ng/mL (p = 0.000). The cut-off value of the metastatic lymph nodes diagnosed by FNA-Tg was 2.71 ng/mL, and 6.5 by FNA-Tg/sTg. The suspicious ultrasonographic features including cystic, hyperechoic content, and lack of hilum were closely related to the high level of FNA-Tg value (p < 0.05). However, the round shape (Solbiati index <2) and calcification were not significantly correlated with the positive FNA-Tg (p > 0.05). FNA-Tg is an effective supplement to fine-needle aspiration (FNA) cytology in the nodal metastasis diagnosis. The FNA-Tg level was much higher in the metastatic lymph nodes. The reliable sonographic features of lymph nodes suggested the positive FNA-Tg were cystic content, hyperechoic content and lack hilum. Solbiati index <2 and calcification did not show an exact correlation with the result of FNA-Tg.

Transrectal ultrasound examination of prostate cancer guided by fusion imaging of multiparametric MRI and TRUS: avoiding unnecessary mpMRI-guided targeted biopsy.

The purpose of this study was to explore transrectal ultrasound (TRUS) findings of prostate cancer (PCa) guided by multiparametric magnetic resonance imaging (mpMRI) and to improve the Prostate Imaging Reporting and Data System (PI-RADS) system for avoiding unnecessary mpMRI-guided targeted biopsy (TB). From January 2018 to October 2019, fusion mpMRI and TRUS-guided biopsies were performed in 162 consecutive patients. The study included 188 suspicious lesions on mpMRI in 156 patients, all of whom underwent mpMRI-TRUS fusion imaging-guided TB and 12-core transperineal systematic biopsy (SB). Univariate analyses were performed to investigate the relationship between TRUS features and PCa. Then, logistic regression analysis with generalized estimating equations was performed to determine the independent predictors of PCa and obtain the fitted probability of PCa. The detection rates of PCa based on TB alone, SB alone, and combined SB and TB were 55.9% (105 of 188), 52.6% (82 of 156), and 62.8% (98 of 156), respectively. The significant predictors of PCa on TRUS were hypoechogenicity (odds ratio [OR]: 9.595, P = 0.002), taller-than-wide shape (OR: 3.539, P = 0.022), asymmetric vascular structures (OR: 3.728, P = 0.031), close proximity to capsule (OR: 3.473, P = 0.040), and irregular margins (OR: 3.843, P = 0.041). We propose subgrouping PI-RADS score 3 into categories 3a, 3b, 3c, and 3d based on different numbers of TRUS predictors, as the creation of PI-RADS 3a (no suspicious ultrasound features) could avoid 16.7% of mpMRI-guided TBs. Risk stratification of PCa with mpMRI-TRUS fusion imaging-directed ultrasound features could avoid unnecessary mpMRI-TBs.

Efficacy and safety of ultrasound-guided microwave ablation versus surgical resection for Bethesda category IV thyroid nodules: A retrospective comparative study.

ObjectiveThe objective of this study was to assess the efficacy and safety of ultrasound-guided microwave ablation (MWA) for Bethesda IV thyroid nodules and to compare the outcomes, complications, and costs of MWA and thyroidectomy.MethodsA total of 130 patients with Bethesda IV nodules were retrospectively reviewed, involving 46 in the MWA group and 84 in the surgery group. The local institutional review board approved this study. Patients in the MWA group were followed up at 1, 3, 6, and 12 months after the intervention. Postoperative complications, treatment time, and cost in the two groups were compared.ResultsAmong 84 patients with 85 Bethesda IV nodules in the surgery group, postoperative pathology was benign lesions, borderline tumors, papillary thyroid carcinoma, follicular variant papillary thyroid carcinoma, follicular thyroid carcinoma, and medullary carcinoma in 44, 4, 27, 6, 3, and 1 cases, respectively. Malignant thyroid nodules were more prone to solid echostructure (86.11% vs. 72.72%), hypoechogenicity (55.56% vs. 13.63%), and irregular margin (47.22% vs. 13.63%) than benign lesions. The nodule volume reduction rate of patients at 12 months after MWA was 85.01% ± 10.86%. Recurrence and lymphatic and distant metastases were not reported during the follow-up period. The incidence of complications, treatment time, hospitalization time, incision length, and cost were significantly lower in the MWA group than in the surgery group (all p < 0.001).ConclusionsMWA significantly reduces the volume of Bethesda IV nodules with high safety and is recommended for those with surgical contraindications or those who refuse surgical resection. Patients with suspicious ultrasound features for malignancy should be actively treated with surgery.

US features of normal parathyroid glands: a comparison with metastatic lymph nodes in thyroid cancer.

This study aimed to determine the ultrasound (US) features of normal parathyroid glands (PTGs) and to evaluate whether normal PTGs can be differentiated from metastatic lymph nodes (LNs) in thyroid cancer. This retrospective study included 10 normal PTGs and 95 metastatic LNs from thyroid cancer showing suspicious US features. The echogenicity, echotexture, echogenic foci (calcifications), cystic change, abnormal vascularity, size, shape, and location were retrospectively assessed and compared between normal PTGs and metastatic LNs. The echogenicity of normal PTGs was significantly different from that of metastatic LNs (P<0.001). Normal PTGs exhibited marked hyperechogenicity (100%), homogeneous echotexture (80%), focal intraglandular hypoechogenicity (20%), ovoid shape (90%), and focal cystic change in one case (10%). The echogenicity of metastatic LNs was markedly hyperechoic (0%), moderately hyperechoic (15.8%), mildly hyperechoic (53.7%), and hypoechoic (28.4%). The size and long axis/short axis ratios of normal PTGs were significantly smaller and larger than those of metastatic LNs (P<0.01 and P=0.022, respectively). Marked hyperechogenicity was found only in normal PTGs, and small, ovoid, markedly hyperechoic structures in the paramedian central neck characterized normal PTGs. Normal PTGs may be differentiated from metastatic LNs in thyroid cancer.

Features of breast cancer initially assessed as probably benign on ultrasound: A retrospective study.

We evaluated the features of breast cancers initially assessed as probably benign at ultrasound (US).Of the 7098 patients who underwent breast cancer surgery at our institution between 2014 and 2016, 179 lesions in 178 patients who had both a prior US with Breast Imaging Reporting and Data System (BI-RADS) category 3 assessment and a recent US with a diagnosis of breast cancer were enrolled. Prior and recent US findings and category were retrospectively reassessed in line with the BI-RADS Atlas and analyzed.Of the 179 BI-RADS 3 lesions, 105 (59%) were retrospectively reassessed to category 4 and 74 (41%) retained category 3. Noncircumscribed margin, irregular shape, posterior enhancement, and nonparallel orientation were more frequently observed in the reassessment category 4 group than in the reassessment category 3 group (94% vs 43%, 81% vs 19%, 16% vs 4%, 14% vs 0%, respectively). The recent US revealed that 150 of the 179 lesions (84%) had > 20% size increase, and 121 (68%) showed morphologic changes. Margin was the most frequently observed morphologic feature to change (41%, 73/179).Care should be taken to look for subtle but suspicious US features and changes in mass, especially of margin, for early diagnosis of breast cancer.

Outcomes of nonsuspicious contralateral nodules with active surveillance after lobectomy in patients with papillary thyroid carcinoma.

ObjectiveTo observe the outcomes of nonsuspicious contralateral nodules with active surveillance in patients with papillary thyroid carcinoma (PTC).Methods4pt?>Consecutive patients who underwent lobectomy for PTC were retrospectively reviewed. Patients with one or more nodules with nonsuspicious ultrasonography (US) features in the contralateral lobe were included.ResultsTwo hundred and eighty-three patients were included. All patients underwent thyroid lobectomy with ipsilateral prophylactic central neck dissection. A total of 123 patients (43.5%) were classified as ATA low-risk, and 160 patients (56.5%) were classified as intermediate-risk. The median size of the contralateral nodules was 3 mm (range, 2 to 16 mm). After a period of follow-up, the median size change of contralateral nodules was 0 mm (range, -7 to 8 mm). Eight patients (2.8%) had nodule growth >3 mm, 223 patients (78.8%) had stable or decreased nodules, and 52 patients (18.4%) had no detectable nodules. Nodules in 24 patients had suspicious US features, 16 of which were diagnosed with PTMC by either cytology after FNA (in 7 patients) or histopathology after completion thyroidectomy (in 9 patients). Another four patients received completion thyroidectomy for ipsilateral cervical lymph node metastasis. The 5-year residual lobe recurrence (RLR) rate and recurrence-free survival (RFS) rate were 7.4% and 89.8%, respectively. Multivariate analysis showed that multifocality and ATA intermediate-risk were independent predictors for RLR (HR4.083, 95%CI 1.480-11.261, P = 0.007; HR 6.045, 95%CI 1.370-26.662, P = 0.017, respectively) and RFS (HR 5.240, 95%CI 2.114-12.991, P < 0.001; HR 5.223, 95%CI 1.353-17.765, P = 0.008, respectively).ConclusionsActive surveillance for nonsuspicious contralateral nodules in patients with low-risk and selected intermediate-risk PTC is safe. Multifocality and ATA intermediate-risk are predicters for recurrence. Early detection and salvage surgery are effective.

Malignancy risk of thyroid nodules with minimal cystic changes: a multicenter retrospective study.

PurposeThe aim of this multicenter study was to investigate the malignancy risk of minimally cystic thyroid nodules (MCTNs) using cyto-histopathologic diagnoses as the reference standard.MethodsFrom June 2015 to September 2015, 5,601 thyroid nodules (≥1 cm) from 4,989 consecutive patients who underwent thyroid ultrasonography (US) at 26 institutions were retrospectively analyzed. Each thyroid nodule was categorized according to its cystic proportion: purely solid, minimally cystic (≤10%), and partially cystic (>10%). The malignancy risk of MCTNs was compared with those of purely solid nodules and partially cystic thyroid nodules (PCTNs). The malignancy risk of MCTNs was assessed according to echogenicity and the presence of suspicious US features.ResultsThe prevalence of MCTNs was 22.5%. The overall malignancy risk of MCTNs was 8.8%, which was significantly lower than that of purely solid nodules (29.5%) (P<0.001), and slightly higher than that of PCTNs (6.2%) (P=0.013). The risk of malignancy associated with MCTNs was similar to that of PCTNs regardless of echogenicity or the presence of suspicious US features (all P>0.05). MCTNs were associated with a higher risk of malignancy in hypoechoic nodules than in isohyperechoic nodules and in nodules with suspicious US features than in those without suspicious US features (all P<0.001).ConclusionThe malignancy risk of MCTNs was significantly lower than that of purely solid nodules. MCTNs could be categorized as PCTNs rather than as solid nodules to increase the accuracy of the risk stratification system for thyroid nodules.

Quantitative analysis of vascularity for thyroid nodules on ultrasound using superb microvascular imaging: Can nodular vascularity differentiate between malignant and benign thyroid nodules?

This study aimed to investigate the utility of adding superb microvascular imaging (SMI) to B-mode ultrasound (US) for distinguishing between benign and malignant thyroid nodules and evaluate the usefulness of SMI quantification of nodular vascularity for diagnosing thyroid cancer.The malignancy likelihood was scored for 3 datasets before versus after additional color Doppler imaging or SMI using 4-scale visual analysis (i.e., B-mode US alone, B-mode US + color Doppler image, and B-mode US + SMI). Further, the SMI pixel count was measured in the region of interest, including the whole nodule, on the longitudinal view. It was compared between benign and malignant nodules and analyzed according to the US patterns of thyroid nodules based on the Korean thyroid imaging reporting and data system. We calculated the area under the receiver operating characteristic curve values, sensitivities, and specificities.There was no significant difference in the area under the receiver operating characteristic curve values among B-mode, B-mode + color Doppler, and B-mode + SMI. However, the SMI pixel count was significantly higher in malignant thyroid nodules than in benign ones. The optimal cut-off value for the SMI pixel count for predicting malignant thyroid nodules obtained using a receiver operating characteristic curve was 17 (40.54% in sensitivity, 91.3% in specificity). Analysis based on the US pattern of thyroid nodules revealed significant differences in the nodules with low-to-intermediate suspicious US features between malignant and benign nodules.Quantification analysis of vascularity using SMI can differentiate malignant thyroid nodules from benign ones.

Diagnostic Performance of Core Needle Biopsy for Characterizing Thyroidectomy Bed Lesions.

ObjectiveThyroidectomy bed lesions frequently show suspicious ultrasound (US) features after thyroid surgery. Fine-needle aspiration (FNA) may not provide definitive pathological information about the lesions. Although core-needle biopsy (CNB) has excellent diagnostic performance in characterizing suspicious thyroid nodules, no published studies have evaluated the performance of CNB specifically for thyroidectomy bed lesions. Therefore, we aimed to evaluate the diagnostic performance and safety of CNB for characterizing thyroidectomy bed lesions.Materials and MethodsA total of 124 thyroidectomy bed lesions in 113 patients (79 female and 34 male; age, 23–85 years) who underwent US-guided CNB between December 2008 and December 2020 were included. We reviewed the US imaging features of the target lesions and the histories of previous biopsies. The pathologic results, diagnostic performance for malignancy, and complications of CNB were analyzed.ResultsAll samples (100%) obtained by CNB were adequate for pathological analysis. Pathological analysis revealed inconclusive results in two lesions (1.6%). According to the reference standard, 50 lesions were ultimately malignant (40.3%), and 72 were benign (58.1%), excluding the two inconclusive lesions. The performance of CNB for diagnosing malignant thyroidectomy bed lesions in the 122 lesions had a sensitivity of 98.0% (49/50), a specificity of 100% (72/72), positive predictive value of 100% (49/49), and negative predictive value of 98.6% (72/73). Eleven lesions were referred for CNB after prior inconclusive FNA results in thyroidectomy bed lesions, for all of which CNB yielded correct conclusive pathologic diagnoses. According to the pathological analysis of CNB, there were various benign lesions (58.9%, 73/124) besides recurrence, including benign postoperative lesions other than suture granuloma (32.3%, 40/124), suture granuloma (15.3%, 19/124), remnant thyroid tissue (5.6%, 7/124), parathyroid lesions (4%, 5/124), and abscesses (1.6%, 2/124). No major or minor complications were associated with the CNB procedure.ConclusionUS-guided CNB is accurate and safe for characterizing thyroidectomy bed lesions.

EU-TIRADS-Based Omission of Fine-Needle Aspiration and Cytology from Thyroid Nodules Overlooks a Substantial Number of Follicular Thyroid Cancers.

Background The classification of nodules by Thyroid Imaging Reporting and Data Systems (TIRADS) is important in guiding management. Whether sensitivity in identifying thyroid cancers varies with thyroid cancer phenotype remains unclarified. Methods The ultrasound (US) characteristics of nodules of 26,908 nodular goiter patients were recorded. Fine-needle aspiration cytology (FNA) was performed in all nodules >1 cm irrespective of US findings (n = 25,025) and in nodules between 5 mm and 10 mm with suspicious US characteristics (n = 1,883). Of the 3281 operated cases, 221, 30, and 23 were papillary (PTC), follicular (FTC), and medullary (MTC) cancers, respectively. The US-based indication of FNA, as defined by EU-TIRADS scores, combined with lesion size, was calculated. This study design is unique in avoiding the common selection bias when TIRADS' sensitivity is tested in a cohort selected for FNA and surgery based on the same US characteristics on which TIRADS is based. Results The EU-TIRADS score influences decision of FNA in the 10–20 mm range. In such nodules (n = 118), the number of suspicious features (marked hypoechogenicity, microcalcifications, irregular shape, and irregular border) per lesion was lower in FTC (0.7 ± 0.6) than in PTC (1.7 ± 1.0) or MTC (1.8 ± 0.7; p < 0.02), resulting in EU-TIRADS scores of 4.1 ± 0.6, 4.8 ± 0.3, and 4.9 ± 0.2, respectively (p < 0.01). The EU-TIRADS-based FNA indication rate was lower in FTC (55.5%) compared to PTC (85.0%) and MTC (88.9%) (p=0.02). Conclusions EU-TIRADS-defined suspicious US features are less common in FTC than in PTC and MTC. Therefore, a substantial number of FTCs in the 10–20 mm range escape surgery.

The Prediction of Malignancy Risk in Thyroid Nodules Classified as Bethesda System Category III (AUS/FLUS) and the Role of Ultrasound Finding for Prediction of Malignancy Risk

ObjectiveTo predict the risk of malignancy in category III of the Bethesda System for Reporting Thyroid Cytopathology "Atypia of Undetermined Significance/Follicular Lesion of Undetermined Significance (AUS/FLUS)" at King Abdulaziz Medical City, Riyadh, Saudi Arabia. It also intends to determine other possible contributing predictors of malignancy in thyroid nodules such as age, sex, and ultrasound (US) findings.MethodThis retrospectively designed study included 187 patients (mean age, 43.9 ± 14.1 years) with thyroid nodules, which were diagnosed as AUS/FLUS and all patients included had total thyroidectomy or lobectomy between January 2013 and December 2018 at King Abdulaziz Medical City in Riyadh, Saudi Arabia. The electronic medical records, US images, and final cytopathology and histopathology reports were reviewed and analyzed.ResultThe overall incidence of AUS/FLUS was (46.5%). Multivariate analysis of US features revealed that malignancy was significantly associated with nodules with irregular margins, microcalcification, multiple numbers (P < 0.001), and hypoechogenicity (P 0.04).ConclusionDespite the high rate of malignancy of nodules AUS/FLUS, it is still consistent with previously reported studies. The highly suspicious ultrasound features (irregular margins, microcalcification, multiple nodules, and hypoechogenicity) could be helpful in the diagnosis of thyroid cancer.

A practical approach for the management of small thyroid nodules referred for biopsy.

Current guidelines recommend against routine ultrasound (US) guided fine-needle aspiration biopsy (FNAB) of small (<1cm) thyroid nodules and suggest follow-up of ≥5mm small nodules only if they are TI-RADS-5. This study aims to determine the best suspicious ultrasound features related to cytology results in patients referred for FNAB of small thyroid nodules and construct an algorithm for declining unnecessary biopsies and selection of patients to be followed up. This prospective observational study enrolled patients referred for US-guided biopsy of ≤1cm thyroid nodules. Ultrasound features including composition, echogenicity, shape, margin, echogenic focus, hypoechoic rim, vascularity were assessed. The cytology results were dichotomised as either benign or malignant/high risk. The features with excellent interobserver reliability and more than 90% sensitivity were selected. Overall, 95 patients [82 (86.3%) females, mean age 48.5±11.9years] with 95 small (≤1cm) thyroid nodules were biopsied. Cytology revealed 15 (15.8%) malignant nodules. Pure solid composition, hypoechogenicity, taller than wide shape and irregular margin of the nodules were significantly associated with malignancy. Hypoechogenicity (100%) and pure solid composition (93%) had very high sensitivity and excellent interobserver agreement (Cohen's Kappa 0.83, P=.003 for both) for predicting high risk/malignant nodule. In the absence of these two features, 48 (50.5%) nodules either would not require FNAB or follow-up. The presence of cyst or iso/hyperechogenicity within a small thyroid nodule in patients already referred for invasive sampling safely allows for declining a decision of FNAB or follow-up without the concern of missing malignancy.

The role of fine-needle aspiration biopsy and post-operative histology in the evaluation of thyroid nodules

Thyroid nodules present a serious problem, and mostly they do not carry neoplastic characteristics. Thus, they do not need to be surgically treated. The risk of malignancy varies from 5 to 15 %. Steps to diagnose malignancy should include a careful clinical evaluation, laboratory tests, a thyroid ultrasound exam and a fine-needle aspiration biopsy. Fine-needle aspiration biopsy (FNAB) is the most important diagnostic tool in the assessment of thyroid nodules. Today it is considered the gold standard for malignancy diagnosis in thyroid cancer. In this review we evaluate the role of FNAB and post-operative cytology in the evaluation of thyroid nodules. FNA results are classified as diagnostic (satisfactory) or nondiagnostic (unsatisfactory). Unsatisfactory smears (5–10 %) result from hypocellular specimens usually caused by cystic fluid, bloody smears, or suboptimal preparation. Diagnostic smears are conventionally subclassified into benign, indeterminate, or malignant categories. Benign cytology (60–70 %) is negative for malignancy, and includes cysts, colloid nodule, or Hashimoto thyroiditis. Malignant cytology (5 %) is almost always positive for malignancy, and includes primary thyroid tumors or nonthyroid metastatic cancers. Indeterminate or suspicious specimens (10–20 %) include atypical changes, Hurthle cells or follicular neoplasms. The new Bethesda Cytologic Classification has a 6-category classification, subdividing indeterminate further by risk factors. Considering the increasing worldwide incidence of thyroid microadenomas, recently it is recommended to undergo FNAB under ultrasound guidance even in small (&lt; 1cm) nodules if they are correlated with suspicious ultrasonographic features or suspicious neck lymph nodes. FNAB is a cheap and reliable diagnostic tool that can be used in the selection candidates for surgery and pre-operative diagnosis of thyroid carcinomas. It was concluded that FNAB is the gold standard in the evaluation of thyroid nodules and can prevent many unnecessary surgeries. False-negative FNA cytology remains a concern for clinicians treating patients with thyroid nodules. Post-operative histology give the definitive diagnosis and studies confirm that it has a significant discordance between pre-operative cytology and post-operative histology in patients with thyroid nodule. Cytopathologists should strengthen their criteria for the identification of adenomatous hyperplasia, thyroiditis, cystic lesions or suspicious thyroid nodules to avoid misdiagnoses.

Toxic Thyroid Nodule: To FNA or Not?

Background: ATA guidelines recommend evaluation of hyperthyroidism with radioiodine scan and consideration of FNA for non-toxic nodules with suspicious sonographic features. However, there is no standard evidence-based approach to performing ultrasound in patients with toxic nodules. Recent studies have shown increased rates of thyroid cancer in patients with hyperthyroidism and has been shown to demonstrate aggressive histologic features. Clinical Case: A 41-year-old female presented to primary care provider for annual physical exam, found to have intermittent bigeminy and enlarged thyroid on exam. EKG notable for multiple premature ventricular complexes. Evaluation revealed suppressed TSH <0.01 µIU/mL (0.27-4.20), normal free T4 1.27 ng/dL (0.80-1.80), slightly elevated free T3 4.84 pg/mL (2.57-4.43) and elevated TSI 238% (<122). Methimazole was started for treatment of hyperthyroidism. Thyroid sonogram was ordered for abnormal exam, that showed 2.7 cm TIRADS 4 left thyroid nodule with microcalcifications. I-131 uptake values were 20% and 49% at 4-hours and 24-hours, respectively. Technetium-99M scan showed toxic autonomous nodule in the left thyroid lobe corresponding to the one seen on sonogram. The remainder of the thyroid gland showed heterogeneously suppressed uptake. FNA of the thyroid nodule was done due to the presence of microcalcifications and the cytopathology was suspicious for papillary carcinoma. She underwent total thyroidectomy with central neck dissection involving pre-tracheal and paratracheal lymph nodes (level VI). Pathology showed 1.4 cm papillary carcinoma with lymphovascular space invasion and multifocal papillary microcarcinomas in the left thyroid lobe, 0.2 cm papillary microcarcinoma in right thyroid lobe, metastatic papillary carcinoma in 2 out of 5 lymph nodes, largest metastatic deposit 0.1 cm in the largest dimension with no extra nodal extension. There was also follicular hyperplasia noted consistent with Graves’ disease. Post-operatively, she had thyrogen-stimulated adjuvant RAI treatment, dose 107.4 mCi. Post therapy scan did not show evidence of distant metastases. Conclusion: This case demonstrates the identification of a metastatic papillary thyroid carcinoma based on suspicious ultrasound features requiring total thyroidectomy, central neck dissection and adjunct radioactive iodine in a patient with hyperthyroidism from co-existent toxic thyroid nodule and Graves’ disease.