Micronodulation: ultrasonographic sign of Hashimoto thyroiditis

Normal Parathyroid Glands Are Most Often Seen on Neck Ultrasound

RATIONALE AND OBJECTIVES

The dogma is that normal parathyroid glands (PTGs) are not visible on ultrasound (US). Recently, several studies have shown that PTGs present these US features: ovoid structure, homogeneous and hyperechoic. The primary objective was to assess the detection rate, standard size and locations of normal PTGs in a population of patients consulting for thyroid US exam. The secondary objective was to determine if the presence of a goiter or a thyroiditis could modify the visualization of normal PTGs.

METHOD

Single-center prospective study on 192 patients based on the typical US appearance previously described to identify one or more PTGs.

RESULTS

One or more PTGs were visualized in 75% of patients (144/192). They were visualized preferentially at the lower pole of the thyroid gland and in the infra-thyroid region (66%). The mean (± SD) size of normal PTGs was 5.68 mm (± 1,42 mm)×4.05 mm (± 1,03 mm)×2,68 mm (± 0,61 mm) and mean volume was 33.3 mm3 (± 17.75 mm3). The presence of a goiter made the search for PTGs more difficult whereas the presence of thyroiditis facilitated it.

CONCLUSION

The US detection rate of PTGs is high (75%). The identification of PTGs could be particularly useful in the preoperative assessment before total thyroidectomy or parathyroid surgery. It could reduce the risk of postoperative hypoparathyroidism and improve the accuracy of postoperative US surveillance of thyroid cancer. Better knowledge of the usual anatomical location of normal PTGs could also enable better detection of abnormal glands.

Clinical Value of Artificial Intelligence-Based Computer-Aided Diagnosis System Versus Contrast-Enhanced Ultrasound for Differentiation of Benign From Malignant Thyroid Nodules in Different Backgrounds

OBJECTIVES

The aim of this study was to compare the value of AI-SONIC ultrasound-assisted diagnosis system versus contrast-enhanced ultrasound (CEUS) for differential diagnosis of thyroid nodules in diffuse and non-diffuse backgrounds.

METHODS

A total of 555 thyroid nodules with pathologically confirmed diagnosis were included in this retrospective study. The diagnostic efficacies of AI-SONIC and CEUS for differentiating benign from malignant nodules in diffuse and non-diffuse backgrounds were evaluated, with pathological diagnosis as the gold standard.

RESULTS

The agreement between AI-SONIC diagnosis and pathological diagnosis was moderate in diffuse backgrounds (κ = 0.417) and almost perfect in non-diffuse backgrounds (κ = 0.81). The agreement between CEUS diagnosis and pathological diagnosis was substantial in diffuse backgrounds (κ = 0.684) and moderate in non-diffuse backgrounds (κ = 0.407). In diffuse backgrounds, AI-SONIC had slightly higher sensitivity (95.7 vs 89.4%, P = .375), but CEUS had significantly higher specificity (80.0 vs 40.0%, P = .008). In non-diffuse background, AI-SONIC had significantly higher sensitivity (96.2 vs 73.4%, P < .001), specificity (82.9 vs 71.2%, P = .007), and negative predictive value (90.3 vs 53.3%, P < .001).

CONCLUSION

In non-diffuse backgrounds, AI-SONIC is superior to CEUS for differentiating malignant from benign thyroid nodules. In diffuse backgrounds, AI-SONIC could be useful for screening of cases to detect suspicious nodules requiring further examination by CEUS.

Quantitative Diagnosis Progress of Ultrasound Imaging Technology in Thyroid Diffuse Diseases

High-frequency ultrasound (HFUS), the imaging modality of choice for thyroid screening, is most commonly used in the study of diffuse thyroid disease (DTD) with Hashimoto's thyroiditis (HT) and Graves' disease (GD). DTD can involve thyroid function and severely affect life quality, so early diagnosis is important for the development of timely clinical intervention strategies. Previously, the diagnosis of DTD relied on qualitative ultrasound imaging and related laboratory tests. In recent years, with the development of multimodal imaging and intelligent medicine, ultrasound and other diagnostic imaging techniques have gradually become more widely used for quantitative assessment of the structure and function of DTD. In this paper, we review the current status and progress of quantitative diagnostic ultrasound imaging techniques for DTD.

A prospective follow-up of thyroid volume and thyroiditis features on ultrasonography among survivors of predominantly mild to moderate COVID-19

Background

We previously showed that higher SARS-CoV-2 viral load correlated with smaller thyroid volumes among COVID-19 survivors at 2 months after acute COVID-19. Our current follow-up study evaluated the evolution of thyroid volumes and thyroiditis features within the same group of patients 6 months later.

Methods

Adult COVID-19 survivors who underwent thyroid ultrasonography 2 months after infection (USG1) were recruited for follow-up USG 6 months later (USG2). The primary outcome was the change in thyroid volume. We also reassessed thyroiditis features on USG, thyroid function and anti-thyroid antibodies.

Results

Fifty-four patients were recruited (mean age 48.1 years; 63% men). The mean thyroid volume increased from USG1 to USG2 (11.9 ± 4.8 to 14.5 ± 6.2 mL, p < 0.001). Thirty-two patients (59.3%) had significant increase in thyroid volume by ≥15%, and they had a median increase of +33.3% (IQR: +20.0% to +45.0%). Multivariable logistic regression analysis showed that only higher baseline SARS-CoV-2 viral load independently correlated with significant thyroid volume increase on USG2 (p = 0.022). Among the seven patients with thyroiditis features on USG1, six (85.7%) had the features resolved on USG2. None had new thyroiditis features on USG2. All abnormal thyroid function during acute COVID-19 resolved upon USG1 and USG2.

Conclusion

Most COVID-19 survivors had an increase in thyroid volume from early convalescent phase to later convalescent phase. This increase correlated with high initial SARS-CoV-2 viral load. Together with the resolution of thyroiditis features, these may suggest a transient direct atrophic effect of SARS-CoV-2 on the thyroid gland with subsequent recovery of thyroid volume and thyroiditis features.

Higher SARS-CoV-2 viral loads correlated with smaller thyroid volumes on ultrasound among male COVID-19 survivors

PURPOSE

Thyroid dysfunction, including thyroiditis, is well recognized in COVID-19 patients. We evaluated thyroid ultrasonographic features among COVID-19 survivors, which are less well known.

METHODS

Adult COVID-19 survivors without known thyroid disorders who attended dedicated COVID-19 clinic underwent thyroid ultrasonography and assessment of thyroid function and autoimmunity. Adults admitted for acute non-thyroidal surgical problems and negative for COVID-19 were recruited as control. SARS-CoV-2 viral load (VL) was presented as the inverse of cycle threshold values from the real-time reverse transcription-polymerase chain reaction of the respiratory specimen on admission.

RESULTS

In total, 79 COVID-19 patients and 44 non-COVID-19 controls were included. All abnormal thyroid function tests during acute COVID-19 recovered upon follow-up. Thyroid ultrasonography was performed at a median of 67 days after acute COVID-19. The median thyroid volume was 9.73 mL (IQR: 7.87-13.70). In multivariable linear regression, SARS-CoV-2 VL on presentation (standardized beta -0.206, p = 0.042) inversely correlated with thyroid volume, in addition to body mass index at the time of ultrasonography (p < 0.001). Sex-specific analysis revealed similar results among men but not women. Eleven COVID-19 patients (13.9%) had ultrasonographic changes suggestive of thyroiditis, comparable to non-COVID-19 patients (p = 0.375). None of these 11 patients had isolated low thyroid-stimulating hormone levels suggestive of thyroiditis at initial admission or the time of ultrasonography.

CONCLUSIONS

Higher SARS-CoV-2 VL on presentation were associated with smaller thyroid volumes, especially in men. Further research is suggested to investigate this possible direct viral effect of SARS-CoV-2 on the thyroid gland. There was no increased rate of ultrasonographic features suggestive of thyroiditis in COVID-19 survivors.

Imaging of the Thyroid: Practical Approach

Imaging evaluation of the thyroid gland spans a plethora of modalities, including ultrasound imaging, cross-sectional studies, and nuclear medicine techniques. The overlapping of clinical and imaging findings of benign and malignant thyroid disease can make interpretation a complex undertaking. We aim to review and simplify the vast current literature and provide a practical approach to the imaging of thyroid disease for application in daily practice. Our approach highlights the keys to differentiating and diagnosing common benign and malignant disease affecting the thyroid gland.

Validation of Diagnostic Performance and Interobserver Agreement of DTD-TIRADS for Diffuse Thyroid Disease on Ultrasound: A Single-Center Study

OBJECTIVE. This retrospective study aimed to investigate the capability of the already-proposed thyroid imaging reporting and data system for detecting diffuse thyroid disease (DTD-TIRADS) on ultrasound (US) by assessing interobserver agreement and diagnostic performance. MATERIALS AND METHODS. A total of 180 patients who underwent thyroid US before thyroid surgery were included. Three radiologists blinded to the pathologic and serologic data independently categorized the US features according to a four-category DTD-TIRADS classification system. On the basis of the pathologic results of thyroid parenchyma, diagnostic performance values were calculated using ROC curve analyses. Interobserver agreements of each US feature and DTD-TIRADS category among the three radiologists were also assessed. RESULTS. Of the 180 patients, 143 (79.4%) had normal thyroid parenchyma and 37 (20.6%) had diffuse thyroid disease (DTD). The areas under the ROC curve for DTD were not significantly different among the three radiologists: 0.876 (95% CI, 0.819-0.920) for radiologist 1, 0.883 (95% CI, 0.827-0.926) for radiologist 2, and 0.861 (95% CI, 0.801-0.908) for radiologist 3 (p > .05). The cutoff for the diagnosis of DTD was category III DTD-TIRADS. The sensitivity, specificity, and accuracy of DTD-TIRADS for detecting DTD were 86.5%, 81.1%, and 82.2% for radiologist 1; 86.5%, 83.2%, and 83.9% for radiologist 2; and 83.8%, 82.5%, and 82.8% for radiologist 3, respectively. Interobserver agreement of DTD-TIRADS categorization was almost perfect (κ = 0.81). CONCLUSION. DTD-TIRADS has high diagnostic performance and almost-perfect interobserver agreement. Thus, DTD-TIRADS can be considered to be an effective classification system for diagnosing DTD.

The Presence of Hypoechoic Micronodules in Patients with Hashimoto's Thyroiditis Increases the Risk of an Alarming Cytological Outcome

The aim of the study was to identify a possible relation between various ultrasonographic (US) appearances of Hashimoto's thyroiditis (HT) and the risk of obtaining an alarming cytology of coexisting nodules. The study included 557 patients with HT, who had been referred for fine needle aspiration biopsy (FNA). We divided US patterns of HT (UP-HT) into eight groups: (a) Hypoechoic (compared to submandibular glands), homogeneous/fine echotexture; (b) hypoechoic, heterogeneous/coarse echotexture; (c) marked hypoechoic (darker than strap muscles), heterogeneous/coarse echotexture; (d) heterogeneous echotexture with hyperechoic, fibrous septa; (e) multiple, discrete marked hypoechoic areas (sized as 1 to 6 mm); (f) normoechoic pseudo-nodular areas; (g) echostructure similar to connective tissue; (h) thyroid parenchyma with no signs of HT. Indications for a surgical treatment resulting from the FNA outcome (categories IV-VI of Bethesda System for Reporting Thyroid Cytopathology) were identified only in patients with variants b, c, and e of UP-HT, but merely the "multiple, discrete marked hypoechoic areas" variant significantly increased the odds of obtaining such cytology (OR:5.7). The presence of the "normoechoic pseudo-nodular areas" variant significantly increased the odds for the benign cytology (OR:1.7). There are significant differences in the frequency of obtaining an alarming cytology in relation to the UP-HT variant.

Clinical applications of Doppler ultrasonography for thyroid disease: consensus statement by the Korean Society of Thyroid Radiology

Doppler ultrasonography (US) is widely used for the differential diagnosis of thyroid nodules, metastatic cervical lymph nodes in patients with thyroid cancer, and diffuse parenchymal disease, as well as for guidance in various US-guided procedures, including biopsy and ablation. However, controversies remain regarding the appropriate use and interpretation of Doppler US. Therefore, the Korean Society of Thyroid Radiology organized a taskforce to develop a consensus statement on the clinical use of Doppler US for thyroid disease. The review and recommendations in this article are based on a comprehensive analysis of the current literature and the consensus of experts.

A challenging case of Mesenchymal Chondrosarcoma involving the thyroid and special considerations for diagnosis

Background

Thyroid ultrasound is usually used to risk-stratify incidental thyroid nodules. Nodules with high risk sonographic features for malignancy are evaluated by fine-needle aspiration. The role of core needle biopsy for thyroid nodules is limited to cases where the fine needle aspiration is inconclusive.

Case presentation

We describe a rare case of mesenchymal chondrosarcoma of the thyroid gland with uncertain primary origin. Thyroid ultrasound showed right sided large, solid, hypoechoic nodule with calcifications and peripheral vascularity and unremarkable isthmus and left thyroid lobe. Fine needle aspiration of the right nodule suggested lymphocytic thyroiditis. The sonographic findings contradicted the typical bilateral clinical and sonographic picture of lymphocytic thyroiditis. A core needle biopsy showed mesenchymal chondrosarcoma.

Conclusion

This case highlights the importance of correlating pathologic diagnosis with sonographic findings, the appropriate utilization of fine needle aspiration and core needle biopsy to evaluate thyroid nodules and the rare incidence of mesenchymal chondrosarcoma involving the thyroid.

Comparison of Real-Time and Static Ultrasonography Diagnoses for Detecting Incidental Diffuse Thyroid Disease: A Multicenter Study

This study aimed to compare diagnostic accuracy of real-time and static ultrasonography (US) for differentiating diffuse thyroid disease (DTD) from normal thyroid parenchyma (NTP). At 4 participating institutions, 203 patients underwent real-time thyroid US before thyroid surgery. For static US, the same radiologists retrospectively evaluated US findings on a picture archive and communication system after 4 weeks. In real-time and static US diagnoses, US category included no DTD, indeterminate, suspicious for DTD, and DTD. We investigated the diagnostic accuracy of real-time and static US with a receiver operating characteristic curve analysis using histopathologic results as the reference standard. Histopathologic results exhibited NTP (n = 139), Hashimoto thyroiditis (n = 24), non-Hashimoto lymphocytic thyroiditis (n = 33), and diffuse hyperplasia (n = 7). Of 203 patients, there were significant differences in echogenicity, echotexture, glandular margin, and vascularity of the thyroid gland and US category between NTP and DTD groups in both real-time and static US diagnoses (P < 0.001). The diagnostic indices of real-time and static US were highest when the cutoff criterion was chosen as 1 or more abnormal US features. In addition, US category was the only feature with a significant difference between DTD and NTP groups regardless of the practical experience. The receiver operating characteristic curve analysis showed that real-time US was superior to static US in the diagnostic accuracy; however, there was no significant difference (P = 0.09). In conclusion, real-time and static US can be helpful for detecting incidental DTD by using US classification based on abnormal US features.

Risk factors for hypothyroidism in euthyroid thyroid nodule patients with lymphocytic thyroiditis on fine needle aspiration cytology

BACKGROUND/AIMS

Lymphocytic thyroiditis as cytology diagnosis from fine needle aspiration (FNA) is frequently detected in patients with thyroid nodules. However, the clinical outcome for upcoming hypothyroid events has been rarely clarified in euthyroid patients.

METHODS

We retrospectively reviewed the data of patient who had lymphocytic thyroitidis on FNA cytology of thyroid nodule from January 2005 to December 2010 at a tertiary referral hospital. In total, 109 patients with follow-up thyroid function tests (TFT) were enrolled. Final outcomes included overt and subclinical hypothyroidism with thyroid stimulating hormone (TSH) levels ≥ 10 mIU/L. Potential parameters predicting clinical hypothyroidism were analyzed by multivariate analysis.

RESULTS

Over the mean follow-up duration of 51.6 months, 14 out of 109 patients (12.8%) developed clinical hypothyroidism that required thyroid hormone replacement. The median onset time to hypothyroidism was 16 months (range, 3 to 88) and ≥ 60% of patients experienced clinical hypothyroidism within 1 year. By multivariate analysis, background thyroiditis (relative risk [RR], 9.78; p = 0.004), thyroid peroxidase antibody positivity (RR, 9.90; p = 0.003), nodule size (RR, 1.24; p < 0.001), and initial TSH (RR, 1.47; p = 0.009) were the independent risk factors for predicting hypothyroidism in euthyroid patients.

CONCLUSION

Hypothyroidism frequently occurs during the follow-up in euthyroid patients with thyroid nodules which show lymphocytic thyroiditis on FNA cytology. Close surveillance and regular TFT are needed in high-risk patients for upcoming clinical hypothyroidism.

Thyroid Imaging Reporting and Data System for Detecting Diffuse Thyroid Disease on Ultrasonography: A Single-Center Study

Objective: This study aimed to compare the ultrasonography (US) features of diffuse thyroid disease (DTD) and normal thyroid parenchyma (NTP), and to propose a structured imaging reporting system for detecting DTD. Methods: This retrospective study assessed the findings for 270 consecutive patients who underwent thyroid US before thyroid surgery. The following US data were analyzed: DTD-specific features, parenchymal echotexture and echogenicity, anteroposterior diameter, glandular margin, and parenchymal vascularity. Univariate and multivariate analyses with generalized estimating equations were performed to investigate the relationship between US features and DTD. The fitted probability of DTD was analyzed by using a regression equation. Results: Of the 270 patients, there were NTP (n = 193), Hashimoto thyroiditis (n = 24), non-Hashimoto lymphocytic thyroiditis (n = 51), Graves' disease (n = 1), and diffuse hyperplasia (n = 1). The following US features were significantly associated with DTD: decreased or increased parenchymal echogenicity, coarse parenchymal echotexture, increased anteroposterior diameter, lobulated glandular margin, and increased parenchymal vascularity. Of these, coarse parenchymal echotexture was the most significant independent predictor of DTD. The numbers of abnormal US features were positively correlated with the fitted probability and risk of DTD. The diagnostic indices were highest when the chosen cut-off criterion was category III with the largest Az value (0.867, 95% confidence interval: 0.820-0.905), yielding a sensitivity of 68.8%, specificity of 92.2%, positive predictive value of 77.9%, negative predictive value of 88.1%, and accuracy of 85.6% (p < 0.001). Conclusions: Our sonographic reporting and data system may be useful for detecting DTD.

Diagnostic Accuracy of Real-Time Sonography in Differentiating Diffuse Thyroid Disease From Normal Thyroid Parenchyma: A Multicenter Study

OBJECTIVE

The purpose of this multicenter study was to assess the diagnostic accuracy of real-time sonography (US) for differentiating diffuse thyroid disease (DTD) from normal thyroid parenchyma among radiologists blinded to patients' clinical, serologic, and imaging history and to determine the differences in diagnostic accuracy among radiologists from different institutions.

MATERIALS AND METHODS

From January to March 2017, 214 patients underwent preoperative thyroid US and subsequent thyroid surgery at four participating institutions. Real-time US was performed at each institution by an attending radiologist, who classified US diagnoses into one of the following four categories based on US findings: no DTD, indeterminate, suspicious for DTD, and DTD. The outcomes of US diagnoses were compared with histopathologic results to determine the diagnostic accuracy of real-time US at each institution.

RESULTS

Histopathologic results included normal thyroid parenchyma (n = 143), Hashimoto thyroiditis (n = 29), non-Hashimoto lymphocytic thyroiditis (n = 37), and diffuse hyperplasia (n = 5). Normal thyroid parenchyma and DTD exhibited statistically significant differences in echogenicity, echotexture, size, glandular margin, vascularity of thyroid, and US classification. There was positive correlation between US classification and histopathologic results at all institutions for detecting DTD. The highest diagnostic indexes were obtained when the cutoff criterion was suspicious for DTD. There was favorable diagnostic accuracy, with statistically significant differences, at all institutions for the diagnosis of DTD.

CONCLUSION

Real-time US can be helpful for differentiating DTD from normal thyroid parenchyma.

Role of Virtual Touch Tissue Quantification in Hashimoto's Thyroiditis

We investigated the role of the virtual touch tissue quantification (VTQ) technique in diagnosing Hashimoto's thyroiditis (HT) and in distinguishing various HT-related thyroid dysfunctions. Two hundred HT patients and 100 healthy volunteers (the control group) were enrolled. The diagnostic performance of VTQ in predicting HT was calculated as the area under the receiver operating characteristic curve (A_Z). The HT patients were further classified into three subgroups on the basis of serologic tests of thyroid function: hyperthyroidism, euthyroidism and hypothyroidism. Comparisons of shear wave velocity (SWV) between three subgroups were evaluated by analysis of variance. The mean SWV of the control group was significantly lower than that of the HT group (1.93 ± 0.33 m/s vs. 2.32 ± 0.49 m/s, p <0.001). A_z was 0.734 with a cut-off value of 1.86 m/s for performance of SWV in distinguishing between HT and a healthy thyroid; the sensitivity and specificity were 82.5% and 50.0%, respectively. Mean SWV values in the three HT subgroups (hyperthyroidism [2.07 ± 0.37 cm/s] vs. euthyroidism [2.20 ± 0.40 cm/s] vs. hypothyroidism [2.49 ± 0.46 cm/s]) were significantly different (p <0.05). Our results suggest that VTQ is a promising technique for assessing HT and HT-related thyroid dysfunction.

Sonographic Features of Nodular Hashimoto Thyroiditis

OBJECTIVE

The aim of the study was to analyze the sonographic features of nodular Hashimoto thyroiditis (HT) in patients with diffuse background thyroiditis and normal background thyroid parenchyma.

SUBJECTS AND METHODS

Eighty-six patients who had fine-needle aspiration biopsy of 100 thyroid nodules confirmed to be HT and a thyroid ultrasound within 1 year of the biopsy were included in the study. Retrospective analysis of several sonographic features of each nodule was then performed.

RESULTS

The mean age of patients with nodular HT was 53 years, 84% of which were female. Nodular HT occurred in a background of diffuse thyroiditis in 85% and in a homogeneous normal background in 15%. Ninety-three percent of nodules were completely solid and 7% of nodules were cystic and solid. Although the sonographic appearance of nodular HT was variable, the most common appearance was a solid (93/100) and hypoechoic nodule (44/100) with a thin hypoechoic halo (42/100) without calcifications (96/100). On color Doppler, 17% of nodules showed peripheral hypervascularity, 14% of nodules were diffusely hypervascular, 34% were iso vascular, 32% were hypovascular, and 3% were avascular. The sonographic appearance of nodular HT was not significantly different in patients with diffuse background thyroiditis compared with those without background thyroiditis.

CONCLUSIONS

The sonographic appearance of nodular HT is variable, but the most common appearance is a solid sharply circumscribed hypoechoic nodule with thin hypoechoic halo without calcification. There was no significant difference in the appearance of nodular HT in patients with diffuse background thyroiditis compared with patients with normal background thyroid parenchyma.

18F-PET/CT imaging of metastasis to the thyroid gland: Imaging findings and effect on patient management

Purpose

While metastasis to the thyroid from a primary cancer remote to the thyroid is uncommon, current imaging techniques have improved detection of these intrathyroid metastases. The purpose of this study was to evaluate the ¹⁸F-PET/CT appearance of intrathyroid metastases and assess the impact of detection on patient management.

Methods

The ¹⁸F-PET/CT appearance of intrathyroid metastasis, including standardized uptake value (SUV), disease extent, and the effect on patient management following diagnosis were retrospectively reviewed. Inclusion criteria included ¹⁸F-PET/CT imaging and diagnosis of the intrathyroid metastasis matching the remote primary tumor.

Results

Intrathyroid metastasis were detected in 24 patients. The intrathyroid metastases presented on ¹⁸F-PET/CT as focal nodular uptake (n = 21), multiple nodular uptake (n = 2), or diffuse uptake/infiltration of the thyroid gland (n = 1). The SUV ranged between 3.9 and 42 (median 12.5 ± 7.5); in 2 patients, the FDG-avidity was minimal. On ¹⁸F-PET/CT, distant metastases were present outside the neck (n = 18), or limited to the neck (n = 6). In 2 of these 6 patients, the thyroid was the only site of metastatic disease. Due to the metastatic disease, the therapy was changed in 23 of 24 patients; 1 patient was lost to follow-up.

Conclusion

In any patient with a previous or current history of an extrathyroid malignancy, an ¹⁸FDG-avid thyroid mass or diffuse infiltration of the thyroid on ¹⁸F-PET/CT should be considered a potential intrathyoid metastasis until proven otherwise. Knowledge of an intrathyroid metastasis may impact patient management, especially if the thyroid or neck are the only sites of metastatic disease.

A Modified Thyroid Imaging Reporting and Data System (mTI-RADS) For Thyroid Nodules in Coexisting Hashimoto's Thyroiditis

To develop a conventional ultrasound (US) modified Thyroid Imaging Reporting and Data System (mTI-RADS) to stratify the malignancy risk of thyroid nodule in coexisting Hashimoto’s thyroiditis (HT). The study included 138 malignant and 292 benign thyroid nodules confirmed by cytological or histopathological results. The risk score (RS) for each significant US feature was estimated by multiplying corresponding regression coefficient and the total score for each nodule was defined as the sum of these individual scores. The mTI-RADS was established according to the total RS and divided into category 3, 4a, 4b, 4c and 5. Marked hypoechogenicity, taller-than-wide shape, poorly-defined margin, microcalcification or macrocalcification and halo sign absence were statistically significant US features in prediction of thyroid malignancy (all p < 0.05). The total RS for each nodule was defined as following: RS = 2.1× (if marked hypoechogenicity) + 1.2× (if taller-than-wide shape) + 1.7× (if no halo sign) + 0.6× (if poorly-defined margin) + 1.2× (if microcalcification or macrocalcification). The malignancy rates in mTI-RADS category 3, 4a, 4b, 4c and 5 nodules were 3.7%, 19.3%, 38.1%, 62.7% and 94.1%, respectively, with significant differences among different categories (P < 0.001). The mTI-RADS category may facilitate subsequent treatment management in HT patients.

Importance of Delphian Lymph Node Evaluation in Autoimmune Thyroiditis: Fact or Fiction?

Background

Our main objective was to evaluate the association between autoimmune thyroiditis and the Delphian lymph node during different stages of thyroiditis.

Material/Methods

The relationships between the ultrasonography (US) results of thyroiditis and characteristics of the Delphian lymph node in different stages of AT were evaluated. Thyroid hormone and antibody levels were assessed. A total of 126 patients were divided into four groups according to the thyroid US findings: Group 1: control cases; Group 2: indeterminate cases; Group 3: established thyroiditis cases; Group 4: advanced-late stage thyroiditis cases.

Indeterminate cases attended a 1-year follow-up, and the cases with a sonographic finding matching thyroiditis formed Group 2.

Results

The rate of Delphian lymph node presence in Group 4 was significantly higher than in Groups 1 and 2 (p<0.01). In addition, its presence was significantly higher in Group 3 than in Group 1 (p<0.05). Although there was a difference in Delphian lymph node presence between Groups 2 and 3, it was not significant (p=0.052), nor was there a significant difference between Groups 1 and 2 (p>0.05). Both the long and short axis measurements were significantly higher in Groups 2, 3, and 4 compared to those in the control group. However, the same increase was not observed in the long/short axis ratio.

Conclusions

Both the presence and dimensions of the Delphian lymph node were highly correlated with the progress of autoimmune thyroiditis. Evaluating the Delphian lymph nodes might prevent missing a diagnosis of autoimmune thyroiditis.

The Diffuse Sclerosing Variant of Papillary Thyroid Cancer Presenting as Innumerable Diffuse Microcalcifications in Underlying Adolescent Hashimoto's Thyroiditis: A Case Report

Hashimoto's thyroiditis is the most common diffuse thyroid disease and is characterized by diffuse lymphocytic infiltration. However, the ultrasonographic findings of papillary thyroid carcinomas that arise from Hashimoto's thyroiditis in the pediatric and adolescent population are not well known.We report a rare ultrasonographic finding in a 22-year-old woman diagnosed with the diffuse sclerosing variant of papillary thyroid carcinoma that arose from underlying Hashimoto's thyroiditis: innumerable diffuse microcalcifications instead of a typical malignant-appearing nodule.

Evaluation of Underlying Lymphocytic Thyroiditis With Histogram Analysis Using Grayscale Ultrasound Images

OBJECTIVES

The purpose of this study was to evaluate diagnostic performance of histogram analysis using grayscale ultrasound (US) images in the diagnosis of lymphocytic thyroiditis.

METHODS

Three radiologists reviewed a total of 505 US images and classified the images according to the presence/existence of lymphocytic thyroiditis. After 2 months, each reviewer repeated the process with the same 505 images in a randomly mixed order. The intraobserver and interobserver variability was analyzed with a generalized κ value. Four histogram parameters (mean value, standard deviation, skewness, and kurtosis) were obtained, and an index was calculated from principal component analysis. Diagnostic performances were compared.

RESULTS

Of 505 patients, 125 (24.8%) had lymphocytic thyroiditis, and 380 (75.2%) had normal thyroid parenchyma on pathologic analysis. The κ value for intraobserver variance ranged from -0.002 to 0.781, and the overall κ values for interobserver variance were 0.570 and 0.214 in the first and second tests, respectively. The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value for the 3 reviewers versus the principal component analysis index were 28.0% to 83.2%, 43.7% to 82.6%, 53.5% to 79.0%, 24.6% to 56.2%, and 75.2% to 88.9% versus 58.4%, 72.4%, 68.9%, 41.0%, and 84.1%.

CONCLUSIONS

Histogram analysis of grayscale US images provided confirmable and quantitative information about lymphocytic thyroiditis and was comparable with performers' assessments in diagnostic performance.

The Clinical and Pathological Presentation of Thyroid Nodules in Children and the Comparison with Adult Population: Experience of a Single Institution

The clinical and pathological presentation of thyroid nodules among younger and adult patients was compared in an iodine-deficient (ID) region. Data of 3,010 consecutive patients younger than 20 years and 3,010 patients older than 20 years were compared. The proportion of nodular goiters (22.8% versus 39.3%), the ratio of surgically treated nodules (33.2% versus 15.2%), and the proportion of malignant nodules (4.3% versus 2.1%) among diseased patients differed significantly between the two groups (younger versus adult). Nine papillary and 1 medullary carcinoma were found among children, while 15 papillary, 2 follicular, 1 insular, 1 anaplastic, and 1 medullary carcinomas occurred among adults. The ratio of follicular adenoma to hyperplastic nodules (3 : 1 to 1 : 1.67), the proportion of follicular variant (77.8% versus 26.7%), T4 tumors (77.8% versus 33.3%), and tumors with lymph node metastasis (88.9% versus 66.7%) were significantly higher among younger papillary carcinoma patients. No malignancies occurred among spongiform and central type cysts. Similarly to iodine-sufficient regions, more nodules are malignant and carcinomas have a clinically more aggressive presentation in children in comparison with adult patients in ID. Taking the significantly greater proportion of adenomas and the lack of follicular carcinoma into account, a conservative approach has to be considered in follicular tumors among children.

Papillary Thyroid Carcinoma Arising in Children and Adolescent Hashimoto's Thyroiditis: Ultrasonographic and Pathologic Findings

Objectives. We compared the ultrasonography and pathology features of papillary thyroid carcinoma (PTC) in pediatric and adolescents with Hashimoto's thyroiditis (HT) with those of non-HT patients. Materials and Methods. Eleven patients who were surgically confirmed to have pediatric or adolescent PTC from 2006 to 2014 were included in this study. We retrospectively analyzed the preoperative ultrasonography and pathology features of PTC arising in HT and non-HT patients. Results. On ultrasonography, thyroid gland was lobulated and enlarged, with many scattered microcalcifications in four of five HT patients. Four of six non-HT patients had suspicious masses with calcifications. The diffuse sclerosing variant of PTC (DSVPTC) was found in three of five HT patients, but none in non-HT patients. Macroscopic or microscopic extrathyroidal extension was evident in all of the HT patients and four of the non-HT patients. Neck lymph node metastases were in all HT patients and five of non-HT patients. Conclusions. Three of five PTCs in pediatric and adolescent HT patients were DSVPTC, whereas all PTCs of the non-HT patients were classic type. On ultrasonography, thyroid gland was diffusely enlarged with scattered microcalcifications in four of five HT patients. All five HT cases had aggressive disease, including extrathyroidal extension and cervical lymph node metastases.

Diagnostic performance of thyroid ultrasonography screening in pediatric patients with a hypothyroid, hyperthyroid or euthyroid goiter

BACKGROUND

Goiter is frequently the first indicator of thyroid disease in children.

OBJECTIVE

To evaluate the usefulness of ultrasonography (US) in the identification of potential malignant nodules and autoimmune thyroiditis in children with diffuse goiter.

MATERIALS AND METHODS

This study consisted of 113 patients <20 years with a diffuse goiter who underwent thyroid US. Parenchymal echogenicity and the presence of nodules and abnormal lymph nodes were evaluated on US; if a thyroid nodule was detected, its characteristics were analyzed. The diagnostic accuracy of the US findings in the diagnosis of autoimmune thyroid disease was assessed.

RESULTS

Thyroid nodules were detected on US in 72 of the 113 (63.7%) patients. Of these, 65 (90.3%) had probably benign nodules and 4 (5.6%) patients had nodules suspicious of malignancy. The remaining had indeterminate nodules only. In one child with suspected malignant nodules, papillary thyroid cancer with coexisting autoimmune thyroiditis was confirmed. Hypoechogenicity was visualized in 23 (88.5%) patients with autoimmune thyroiditis and 12 (85.7%) with Graves disease. The sensitivity and specificity of micronodulation for autoimmune thyroiditis were 53.9% and 98.3%, respectively.

CONCLUSION

Although the potential for malignant nodules is relatively low in children with diffuse goiter, US can detect focal thyroid disease and characterize the nodules. US thus plays a useful role in excluding autoimmune thyroiditis in this population.

Hashimoto's Thyroiditis Does Not Affect Ultrasonographical, Cytological, and Histopathological Features in Patients with Papillary Thyroid Carcinoma

The association between papillary thyroid carcinoma (PTC) and Hashimoto's thyroiditis (HT) is controversial. In this study, we aimed to compare preoperative thyroid functions, ultrasonography (US) features, fine-needle aspiration biopsy (FNAB) results, and histopathological characteristics of PTC in patients with and without HT. Data of 919 PTC patients were reviewed retrospectively. The diagnosis of HT was based on histopathological examination and patients were grouped as HT and non-HT. There were 1321 PTC lesions in 919 patients among which 317 (34.5 %) had coexistent HT. There were no significant differences in nodule volume, longitudinal diameter, texture, echogenicity, marginal regularity, presence of microcalcification and hypoechoic halo, and peripheral vascularization in patients with and without HT (p > 0.05, for all parameters). Macrocalcification was observed more frequently in the non-HT group (p = 0.021). FNAB results were similar in the two groups (p = 0.105). Distribution of variants, capsule invasion, vascular invasion, and extrathyroidal extension were observed with similar rates in the HT and non-HT groups. Lymph node metastasis was significantly higher in patients without HT (p = 0.012). Of the carcinomas, 66.1 % (n = 874) were papillary thyroid microcarcinoma (PTMC). Tumor size was lower in PTMC lesions coexistent with HT (p = 0.026). We observed lower rates of capsule invasion, extrathyroidal extension, and lymph node metastases in PTMC with HT compared to without HT (p = 0.007, p = 0.003, and p = 0.015, respectively). This study showed that US features, FNAB results, and histopathological findings of PTC lesions are not influenced by the presence of HT. However, PTMC seems to be related with less aggressive histopathological behavior in HT.

Using Acoustic Structure Quantification During B-Mode Sonography for Evaluation of Hashimoto Thyroiditis

OBJECTIVES

This study aimed to evaluate the usefulness of Acoustic Structure Quantification (ASQ; Toshiba Medical Systems Corporation, Nasushiobara, Japan) values in the diagnosis of Hashimoto thyroiditis using B-mode sonography and to identify a cutoff ASQ level that differentiates Hashimoto thyroiditis from normal thyroid tissue.

METHODS

A total of 186 thyroid lobes with Hashimoto thyroiditis and normal thyroid glands underwent sonography with ASQ imaging. The quantitative results were reported in an echo amplitude analysis (Cm(2)) histogram with average, mode, ratio, standard deviation, blue mode, and blue average values. Receiver operating characteristic curve analysis was performed to assess the diagnostic ability of the ASQ values in differentiating Hashimoto thyroiditis from normal thyroid tissue. Intraclass correlation coefficients of the ASQ values were obtained between 2 observers.

RESULTS

Of the 186 thyroid lobes, 103 (55%) had Hashimoto thyroiditis, and 83 (45%) were normal. There was a significant difference between the ASQ values of Hashimoto thyroiditis glands and those of normal glands (P < .001). The ASQ values in patients with Hashimoto thyroiditis were significantly greater than those in patients with normal thyroid glands. The areas under the receiver operating characteristic curves for the ratio, blue average, average, blue mode, mode, and standard deviation were: 0.936, 0.902, 0.893, 0.855, 0.846, and 0.842, respectively. The ratio cutoff value of 0.27 offered the best diagnostic performance, with sensitivity of 87.38% and specificity of 95.18%. The intraclass correlation coefficients ranged from 0.86 to 0.94, which indicated substantial agreement between the observers.

CONCLUSIONS

Acoustic Structure Quantification is a useful and promising sonographic method for diagnosing Hashimoto thyroiditis. Not only could it be a helpful tool for quantifying thyroid echogenicity, but it also would be useful for diagnosis of Hashimoto thyroiditis.

Focal Lymphocytic Thyroiditis Nodules Share the Features of Papillary Thyroid Cancer on Ultrasound

PURPOSE

It is often difficult to discriminate focal lymphocytic thyroiditis (FLT) or adenomatous hyperplasia (AH) from thyroid cancer if they both have suspicious ultrasound (US) findings. We aimed to make a predictive model of FLT from papillary thyroid cancer (PTC) in suspicious nodules with benign cytologic results.

MATERIALS AND METHODS

We evaluated 214 patients who had undergone fine-needle aspiration biopsy (FNAB) and had shown thyroid nodules with suspicious US features. PTC was confirmed by surgical pathology. FLT and AH were confirmed through more than two separate FNABs. Clinical and biochemical findings, as well as US features, were evaluated.

RESULTS

Of 214 patients, 100 patients were diagnosed with PTC, 55 patients with FLT, and 59 patients with AH. The proportion of elevated thyrotropin (TSH) levels (p=0.014) and thyroglobulin antibody (Tg-Ab) or thyroid peroxidase antibody (TPO-Ab) positivity (p<0.001) in the FLT group was significantly higher than that in the PTC group. Regarding US features, absence of calcification (p=0.006) and "diffuse thyroid disease" (DTD) pattern on US (p<0.001) were frequently seen in the FLT group. On multivariate analysis, Tg-Ab positivity, presence of a DTD pattern on US, and absence of calcification in nodules were associated with FLT with the best specificity of 99% and positive predictive value of 96%. In contrast, a taller than wide shape of nodules was the only variable significant for differentiating AH from PTC.

CONCLUSION

Suspicious thyroid nodules with cytologic benign results could be followed up with US rather than repeat FNAB, if patients exhibit Tg-Ab positivity, no calcifications in nodules, and a DTD pattern on US.

The presentation of lymph nodes in Hashimoto's thyroiditis on ultrasound

BACKGROUND

Comprehensive neck ultrasound (US) examination has become an essential component of preoperative workup for patients with thyroid cancer. Regional cervical lymph nodes may be involved in cases of Hashimoto's thyroiditis (HT). This study seeks to examine the sonographic pattern of lymph nodes in patients with HT.

METHODS

This is a retrospective study looking at patients with confirmed diagnoses of HT on final surgical pathology who underwent preoperative comprehensive neck US. We compared preoperative ultrasound for patients with HT to euthyroid patients with goiter. Data collected included number, size and ultrasonographic features of cervical lymph nodes.

RESULTS

We included a total of 417 patients: 202 patients with HT in the study group, and 215 patients with goiter and euthyroid status in the control group. Patients with HT had a higher number of total cervical lymph nodes than the control group (2.00±2.35 vs. 0.76±1.36 mm; P<0.0001), most notably in cervical levels III and IV (P<0.05 for both).

CONCLUSIONS

HT seems to be associated with an ultrasonographic pattern of increased number of enlarged cervical lymph nodes, particularly in levels III, and IV.

Sonographic appearance of thyroid cancer in patients with Hashimoto thyroiditis

OBJECTIVES

To determine whether the sonographic appearance of thyroid cancer differs in patients with and without Hashimoto thyroiditis.

METHODS

Patients with histologically proven thyroid cancer who had thyroid peroxidase (TPO) antibodies measured and sonography performed preoperatively were included. We evaluated each nodule for size, echogenicity, composition, margins, halo, and vascularity and evaluated the background heterogeneity of the gland.

RESULTS

There were 162 thyroid cancers in 145 patients. Forty-two patients (29.0%) had Hashimoto thyroiditis with positive TPO antibodies, and 103 patients (71.0%) had negative TPO antibodies. The background echogenicity was more often heterogeneous in TPO antibody-positive patients compared to those who had negative TPO antibodies (57.1% versus 26.2%; P= .0005). Comparing cancers in TPO antibody-positive to TPO antibody-negative patients, there was no significant difference in the size, echogenicity, composition, margins, halo presence, calcification presence and type, or vascularity of the cancerous nodule (P > .05). Among TPO antibody-positive patients, comparing thyroid cancerous nodules in patients with heterogeneous glands to those with homogeneous glands, there was no significant difference in any sonographic characteristic except the margin of the nodule, which was more often irregular or poorly defined in heterogeneous glands and more often smooth in homogeneous glands (P< .05).

CONCLUSIONS

Sonographic features of thyroid cancer are similar in patients with and without Hashimoto thyroiditis. Among patients with Hashimoto thyroiditis and thyroid cancer, the sonographic appearance of the cancerous nodule is similar, except that cancerous nodule margins are more likely to be irregular or poorly defined when the gland is heterogeneous.

Ultrasonography of various thyroid diseases in children and adolescents: a pictorial essay

Thyroid imaging is indicated to evaluate congenital hypothyroidism during newborn screening or in cases of a palpable thyroid mass in children and adolescents. This pictorial essay reviews the ultrasonography (US) of thyroid diseases in children and adolescents, including normal thyroid gland development, imaging features of congenital thyroid disorders (dysgenesis, [aplasia, ectopy, hypoplasia], dyshormonogenesis, transient hypothyroidism, thyroglossal duct cyst), diffuse thyroid disease (Grave's disease, Hashimoto's thyroiditis, and suppurative thyroiditis), and thyroid nodules. The primary imaging modalities for evaluating thyroid diseases are US and radionuclide scintigraphy. Additionally, US can be used to guide aspiration of detected nodules.

Ultrasound characteristics of the thyroid in children and adolescents with goiter: a single center experience

INTRODUCTION

Autoimmune thyroiditis (AIT) is a common cause of goiter in children, and sonographic changes have been reported in more than one-third at presentation. The aim of this study was to evaluate the ultrasound (US) characteristics of the thyroid and the prevalence of thyroid nodules in children and adolescents presenting with goiter in the presence or absence of AIT.

METHODS

A retrospective review was conducted of the US characteristics of 154 children and adolescents aged <18 years of age with goiter from July 2008 to December 2010. US characteristics were analyzed according to each patient's age, sex, thyrotropin (TSH) levels, and thyroid peroxidase antibody titer (TPOAb). Heterogeneity and nodule prevalence were compared between antibody-positive and -negative goiter.

RESULTS

Heterogeneity was more common in TPOAb-positive (59/71, 83%) compared to TPOAb-negative goiter (24/46, 52%; p<0.001), but there was no correlation between the presence of heterogeneity and TPOAb titer within the antibody-positive group. Nodules were equally prevalent in children with (17%) and without (17.4%) TPOAb, and there was no correlation between the serum TSH level or TPOAb titer and the presence of nodules. Papillary thyroid cancer (PTC) was diagnosed in 3/71 with positive TPOAb compared to 1/46 with negative antibodies. Pseudonodules were identified in 11/71 antibody-positive and none of the antibody-negative patients. However, during follow-up, two of these were later identified as nodules and one was PTC.

CONCLUSION

The majority of children and adolescents with goiter had positive TPOAb (71/117). Sonographic heterogeneity was more common among TPOAb-positive patients. However, thyroid nodules and PTC were equally common in both groups. Only 15% of the nodules and none of the PTC were palpable. These data support the utility of thyroid US to detect unsuspected thyroid nodules and PTC in children with goiter. Prospective follow-up studies of children with goiter are needed to formulate recommendations for evaluation with US and fine-needle aspiration.

Elastography Evaluation of Benign Thyroid Nodules in Patients Affected by Hashimoto's Thyroiditis

The aim of the present prospective study was to evaluate the predictive value of elastography in benign thyroid nodules of patients affected by Hashimoto's thyroiditis (HT). From January 2011 to January 2012, 242 nodules in patients affected by HT were submitted to fine needle aspiration cytology (FNAC). All of the patients underwent sonography and elastography performed before FNAC. 230 (95%) nodules were benign, 8 papillary cancers, and 4 follicular lesions. Score 1 was found in 79.1% of benign lesions (sensitivity 79.1%; specificity 66.7%; PPV 97.8%; NPV 14.3%; accuracy 78.5%; p < 0.05). In order to evaluate the outcome of thyroid ultrasound echogenicity in relation to elastography features of nodule(s), all the patients with benign nodules were stratified according to their hypoechoic pattern of thyroid (mild-moderate and severe). Following stratification score 1 was found in 84.2% of benign nodules (sensitivity 75.0%; specificity 88.9%; PPV 27.3%; NPV 98.4%; accuracy 88.2%; p < 0.0001) of patients with a mild-moderate ultrasound thyroid hypoechogenicity, whereas it was found in 60% of benign nodules (p = 0.715) of patients with a marked thyroid hypoechogenicity. Elastography appears to have limited value in detecting thyroid cancer in patients affected by Hashimoto's thyroiditis with severe hypoechoic thyroid tissue.

A comparison of lymphocytic thyroiditis with papillary thyroid carcinoma showing suspicious ultrasonographic findings in a background of heterogeneous parenchyma

Purpose:

The aim of this study was to compare ultrasonographic features in patients with lymphocytic thyroiditis (LT) and papillary thyroid carcinoma (PTC) having suspicious thyroid nodule(s) in a background of heterogeneous parenchyma and to determine the clinical and radiological predictors of malignancy.

Methods:

We reviewed the cases of 100 patients who underwent ultrasonography between April 2011 and October 2012, and showed suspicious thyroid nodule(s) in a background of heterogeneous parenchyma. Eight patients who did not undergo ultrasonography-guided fineneedle aspiration cytology (FNAC) and 34 cases of follow-up ultrasonography after initial FNAC were excluded. We compared the benign and malignant nodules in terms of their clinical and radiological factors.

Results:

For the 58 nodules including 31 LTs (53.4%) and 27 PTCs (46.6%), the mean tumor sizes of the two groups were 0.96 cm for LT and 0.97 cm for PTC. A univariate analysis revealed that PTCs were more frequent in patients younger than 45 years and having microcalcifications than was LT. An independent predictor of PTC after adjustment was an age of <45 years.

Conclusion:

LT mimics malignancy in a background of heterogeneous parenchyma on ultrasonography. A young age of <45 years is the most important predictor of malignancy in this condition.

Roles of ultrasound and power Doppler ultrasound for diagnosis of Hashimoto thyroiditis in anti-thyroid marker-positive euthyroid subjects

PURPOSE

The present study was performed to investigate the contribution of ultrasonographic (US) findings to diagnosis in anti-thyroid marker-positive patients with normal hormone levels among euthyroid subjects with Hashimoto's thyroiditis (HT).

METHODS

Forty premenopausal euthyroid patients with a median age of 32 years (range, 20-44 years) with normal levels of free triiodothyronine (FT3) and free thyroxine (FT4), and elevated anti-thyroid peroxidase (TPO) antibodies were enrolled in this study. A control group of 46 healthy individuals with a median age of 29 years (range, 18-43 years) was composed of randomly selected volunteers. The examinations included basic morphometric (measurement of thyroid gland dimensions in three axes, the volume of each thyroid lobe, and the total thyroid volume), morphological grayscale imaging (echogenicity, nodularity, septations, undulation of the margins, and reactive lymph nodes), and thyroid gland vascularity.

RESULTS

There were no statistically significant differences in morphometric parameters of the thyroid gland between the study and control groups. There were significant differences in the presence of nodularity, undulation of the gland margins, septations inside the glands, infrathyroidal and/or pretracheal reactive lymph nodes, and increased vascularity on power Doppler imaging between the groups. The use of all parameters together yielded a sensitivity of 90%, specificity of 84.8%, positive predictive value (PPV) of 83.7%, negative predictive value (NPV) of 90.7%, and accuracy of 87.2% for diagnosis of HT.

CONCLUSIONS

US and power Doppler US are helpful for the diagnosis of HT in anti-thyroid marker-positive patients with normal thyroid hormone levels.

Comparative study of ultrasound and computed tomography for incidentally detecting diffuse thyroid disease

The aim of this study was to compare the diagnostic values of thyroid ultrasound (US) and neck computed tomography (CT) in incidentally detecting diffuse thyroid disease (DTD). A single radiologist made US and CT diagnoses of incidentally detected DTD in 130 consecutive patients before thyroidectomy for various malignancies. Histopathologic examinations confirmed normal thyroid (n = 80), Hashimoto thyroiditis (n = 20), non-Hashimoto lymphocytic thyroiditis (n = 28) and diffuse hyperplasia (n = 2). Receiver operating characteristic curves revealed that the best diagnostic indices of both imaging methods were achieved on the basis of two or more abnormal imaging findings. The sensitivity, specificity and accuracy of US and CT in incidentally detecting DTD by this classification were 72% and 72%, 87.5% and 91.3% and 81.5% and 83.8%, respectively. Thyroid US and neck CT have similar diagnostic values for differentiating incidental DTD from normal thyroid.

Papillary Thyroid Cancer and Hashimoto's Thyroiditis: An Association Less Understood

Hashimoto's thyroiditis (HT), part of the spectrum of autoimmune thyroid diseases is a major cause of thyroid hypofunction worldwide. Papillary thyroid carcinoma (PTC), the most prevalent of all thyroid carcinomas has been associated with HT. Literature on this association are based on preoperative FNA or post thyroidectomy histopathology reports, which are subject to potential biases. Molecular, hormonal and histopathalogical basis of this association has been hypothesized, however a definite causal association has not been proved till date. This review aims to study the basis of this association and clinical features and management of HT concurrent with PTC. There are no distinctive clinical or radiological features that categorically differentiates HT concurrent with PTC from PTC or which can pick up a nodule harboring PTC in setting of HT. Smaller nodule size and radiological features like hypoechogenecity; hyper vascularity and calcification in a clinical setting of hypothyroidism have a higher odds ratio for malignancy and merit further investigations. PTC associated with HT has been seen to be less aggressive with earlier presentation with lesser chances of extra thyroidal extension and lymph nodal metastasis. The management and follow up of PTC in HT is no different from that of PTC alone. The prognosis of PTC concurrent with HT is better compared to age and stage matched PTC in terms of lower recurrence and disease free and overall survival.

Diffuse metastasis to the thyroid: unique ultrasonographic finding and clinical correlation

Cases of metastases to the thyroid gland seem to be increasing in recent years. The clinical and ultrasonographic findings of diffuse metastases have been sparsely reported. Thirteen cases of diffuse metastases to the thyroid gland were documented by thyroid ultrasonography-guided fine needle aspiration cytology between 2004 and 2013. We retrospectively reviewed the patients with diffuse thyroid metastases. The most common primary site was the lung (n=9), followed by unknown origin cancers (n=2), cholangiocarcinoma (n=1), and penile cancer (n=1). Eleven patients were incidentally found to have thyroid metastases via surveillance or staging FDG-PET. Other 2 patients were diagnosed during work-up for hypothyroidism and palpable cervical lymph nodes. On ultrasonography, the echogenicity of the enlarged thyroid gland was heterogeneously hypoechoic or isoechoic, and reticular pattern internal hypoechoic lines were observed without increased vascularity found by power Doppler ultrasonography (3 right lobe, 2 left lobe, and 8 both lobes). In the 8 patients who had involvement of both lobes, 3 had hypothyroidism. In conclusion, ultrasonographic finding of diffuse metastasis is a diffusely enlarged heterogeneous thyroid with reticular pattern internal hypoechoic lines. Thyroid function testing should be performed in all patients with diffuse thyroid metastases, especially those with bilateral lobe involvement.

Heterogeneous echogenicity of the thyroid parenchyma does not influence the detection of multi-focality in papillary thyroid carcinoma on preoperative ultrasound staging

Heterogeneous echogenicity and micro-nodulations of diffuse thyroid disease on ultrasonography (US) might influence the diagnostic performance of pre-operative US staging, especially the detection of multi-focality. This study was designed to determine whether heterogeneous echogenicity of the thyroid parenchyma influences the diagnostic performance of US in the detection of multi-focality in papillary thyroid carcinoma. Between December 2010 and April 2011, 811 patients underwent pre-operative staging US for papillary thyroid carcinoma and surgery. Twelve radiologists performed the pre-operative US for T and N staging. Underlying parenchymal echogenicity and unilateral and bilateral multi-focality of the thyroid nodules were also evaluated. Patients were divided into two groups on the basis of the underlying echogenicity of the thyroid gland. To evaluate the diagnostic accuracy of US with respect to underlying echogenicity, the sensitivity, specificity, positive predictive value, negative predictive value and accuracy were calculated and compared between the two groups. Among the 811 patients included, US revealed underlying heterogeneous echogenicity of the thyroid parenchyma in 204 (25.2%) and underlying homogeneous echogenicity of the thyroid parenchyma in 607 (74.8%). There were no significant differences between the two groups in the diagnostic performance of pre-operative staging US in predicting unilateral multi-focality and bilaterality. Underlying heterogeneous echogenicity in a thyroid gland with Hashimoto's thyroiditis does not significantly influence the detection of multi-focality in papillary thyroid cancer on pre-operative US staging.

Cytomorphologic spectrum of Hashimoto's thyroiditis and its clinical correlation: A retrospective study of 52 patients

BACKGROUND

Hashimoto's thyroiditis (HT) is an autoimmune disease and it is more prevalent in Asians. The incidence of HT seems to be increasing in the recent times. It is one of the most common cause of hypothyroidism. The purpose of this study is to review the cytomorphologic spectrum of HT and correlate it with clinical findings including thyroid function and antibody profile.

MATERIALS AND METHODS

We retrospectively analyzed the fine-needle aspiration (FNA) features of 52 HT patients. Based on cytomorphologic features patients were categorized into three groups. Clinical findings including thyroid function and thyroid peroxidase (TPO) antibody profile were correlated with cytomorphologic features in all three groups.

RESULTS

Majority of the patients were females and in 2(nd), 3(rd) and 4(th) decades. Diffuse goiter and thyroid hypofunction were the common findings. Significant number of patients had thyroid hyperfunction. Increased lymphocytes on the background and lymphocytic infiltration of thyroid follicular cell clusters in cytology smears were diagnostic of HT. The 32 patients showed elevated titers of TPO antibodies. In the early stages and mild form of the disease, results of thyroid function and anti TPO antibodies are quite variable.

CONCLUSIONS

HT is a disease of young and middle age and mostly occur in females. Clinical findings alone may not be adequate for definitive diagnosis. FNA is the gold standard for diagnosis. In the presence of abundant colloid, follicular hyperplasia or co-existing neoplasm, careful interpretation of cytology smears should be done. Aspiration from more than one site minimizes the diagnostic pitfalls.

Diagnostic role of conventional ultrasonography and shearwave elastography in asymptomatic patients with diffuse thyroid disease: initial experience with 57 patients

PURPOSE

Thyroid ultrasonography (US) is a useful diagnostic tool in the evaluation of diffuse thyroid disease (DTD), whereas shearwave elastography is a dynamic technique that can provide information about tissue hardness by using acoustic shearwaves remotely induced by a focused ultrasonic beam. This study aims at investigating the role of conventional US and shearwave elastography in the diagnosis of asymptomatic patients with DTD.

MATERIALS AND METHODS

Fifty-seven patients who underwent both conventional US and shearwave elastography were included in this study. Interobserver variability of the three radiologists in assessment of underlying thyroid echogenicity on conventional US was analyzed. Diagnostic performances for diagnosing DTD on conventional US and shearwave elastography were calculated and compared.

RESULTS

Fair agreement was observed in the identification of DTD with conventional US (kappa value= 0.27). The area under the receiver operating characteristic curve (Az) were 0.52-0.585 on conventional US by three radiologists. The Az values when using the mean and maximum elasticity values as a diagnostic criteria for DTD were 0.619 and 0.59 on shearwave elastography. Patients with DTD showed higher mean [24.1±10 kilo-Pascals (kPa)] and maximum (36.4±13.3 kPa) elasticity values on shearwave elastography when compared to the normal group (23.4±10.8 kPa and 33.7±12.4 kPa, respectively), although without statistical significance (p=0.802 and p=0.452, respectively).

CONCLUSION

Conventional US did not show reliable interobserver agreement in the diagnosis of DTD. Although not statistically significant, shearwave elastography may provide additional information in the diagnosis of DTD. Therefore, larger prospective studies are needed to define the values of shearwave elastography for diagnosing DTD.

Computed tomography features of incidentally detected diffuse thyroid disease

Objective. This study aimed to evaluate the CT features of incidentally detected DTD in the patients who underwent thyroidectomy and to assess the diagnostic accuracy of CT diagnosis. Methods. We enrolled 209 consecutive patients who received preoperative neck CT and subsequent thyroid surgery. Neck CT in each case was retrospectively investigated by a single radiologist. We evaluated the diagnostic accuracy of individual CT features and the cut-off CT criteria for detecting DTD by comparing the CT features with histopathological results. Results. Histopathological examination of the 209 cases revealed normal thyroid (n = 157), Hashimoto thyroiditis (n = 17), non-Hashimoto lymphocytic thyroiditis (n = 34), and diffuse hyperplasia (n = 1). The CT features suggestive of DTD included low attenuation, inhomogeneous attenuation, increased glandular size, lobulated margin, and inhomogeneous enhancement. ROC curve analysis revealed that CT diagnosis of DTD based on the CT classification of "3 or more" abnormal CT features was superior. When the "3 or more" CT classification was selected, the sensitivity, specificity, positive and negative predictive values, and accuracy of CT diagnosis for DTD were 55.8%, 95.5%, 80.6%, 86.7%, and 85.6%, respectively. Conclusion. Neck CT may be helpful for the detection of incidental DTD.

Heterogeneous echogenicity of the underlying thyroid parenchyma: how does this affect the analysis of a thyroid nodule?

Background

Heterogeneous echogenicity of the thyroid gland has been associated with diffuse thyroid disease and benign and malignant nodules can coexist with diffuse thyroid disease. Underlying heterogeneous echogenicity might make it difficult to differentiate between benign and malignant nodules on US. Thus, the aim of this study was to evaluate the influence of underlying thyroid echogenicity on diagnosis of thyroid malignancies using US.

Methods

A total of 1,373 patients who underwent US-guided fine needle aspiration of 1,449 thyroid nodules from June 2009 to August 2009 were included. The diagnostic performance of US assessment for thyroid nodules was calculated and compared according to underlying thyroid echogenicity. The diagnostic performance of US assessments in the diagnosis of thyroid malignancy according to the underlying parenchymal echogenicity was compared using a logistic regression with the GEE (generalized estimating equation) method. Each US feature of malignant and benign thyroid nodules was analyzed according to underlying echogenicity to evaluate which feature affected the final diagnosis.

Results

Among the 1,449 nodules, 325 (22.4%) were malignant and 1,124 (77.6%) were benign. Thyroid glands with heterogeneous echogenicity showed significantly lower specificity, PPV, and accuracy compared to thyroid glands with homogeneous echogenicity, 76.3% to 83.7%, 48.7% to 60.9%, and 77.6% to 84.4%, respectively (P = 0.009, 0.02 and 0.005, respectively). In benign thyroid nodules, microlobulated or irregular margins were more frequently seen in thyroid glands with heterogeneous echogenicity than in those with homogenous echogenicity (P < 0.001).

Conclusion

Heterogeneous echogenicity of the thyroid gland significantly lowers the specificity, PPV, and accuracy of US in the differentiation of thyroid nodules. Therefore, caution is required during evaluation of thyroid nodules detected in thyroid parenchyma showing heterogeneous echogenicity.

Increased serum type I interferon activity in organ-specific autoimmune disorders: clinical, imaging, and serological associations

Background: Activation of the type I interferon (IFN) pathway has been implicated in the pathogenesis of systemic autoimmune disorders but its role in the pathogenesis of organ-specific autoimmunity is limited. We tested the hypothesis that endogenous expression of type I IFN functional activity contributes to the pathogenesis of autoimmune thyroid disease (ATD) and type I diabetes (T1DM).

Methods: We studied 39 patients with ATD and 39 age and sex matched controls along with 88 T1DM patients and 46 healthy matched controls respectively. Available clinical and serological parameters were recorded by chart review, and thyroid ultrasound was performed in 17 ATD patients. Type I IFN serum activity was determined in all subjects using a reporter cell assay. The rs1990760 SNP of the interferon-induced helicase 1 gene was genotyped in ATD patients.

Results: Serum type I IFN activity was increased in patients with ATD and T1DM compared to controls (p-values: 0.002 and 0.04, respectively). ATD patients with high type I IFN serum activity had increased prevalence of antibodies against thyroglobulin (anti-Tg) and cardiopulmonary manifestations compared to those with low IFN activity. Additionally, the presence of micronodules on thyroid ultrasound was associated with higher type I IFN levels. In patients with T1DM, high IFN levels were associated with increased apolipoprotein-B levels.

Conclusion: Serum type I IFN activity is increased in ATD and T1DM and is associated with specific clinical, serological, and imaging features. These findings may implicate type I IFN pathway in the pathogenesis of specific features of organ-specific autoimmunity.