Q-elastography in the presurgical diagnosis of thyroid nodules with indeterminate cytology

[Elastography in thyroid nodules]

BACKGROUND

Elastography is an imaging method to examine the elasticity of tissue. In the meantime, various elastography methods have been developed, which are subdivided according to the type of stimulus applied. In principle, a distinction should be made between strain elastography (SE) and shear wave elastography (SWE). Both methods provide another means of assessing thyroid disease in addition to conventional B-mode sonography.

OBJECTIVE

The aim is to provide an overview of elastography techniques including physical basics and their importance in the clarification algorithm of thyroid nodules.

MATERIALS AND METHODS

International guidelines and recent publications on elastography were selectively assessed.

RESULTS

Elastography provides additional information compared to conventional B-mode sonography. The change in shear stiffness is the essential physical mechanism for tissue contrast in all elastograms. In addition to the qualitative assessment of elasticity in SE, quantification is possible with SWE. In the international literature, elastography was analyzed as a single method or in comparison or combination with conventional B-mode sonography and especially with standardization using a risk stratification system (RSS, TIRADS). The results are quite controversial. In nodules with unclear findings on fine-needle biopsy (Bethesda III/IV), the combination of morphologic criteria and elastography improved diagnostic accuracy. In particular, the high negative predictive value of soft nodules represents a relevant added value. This strength of the method can play an important role in the clarification of nodules with intermediate malignancy risk or of unclear FNB results. Elastography has previously only been incorporated into French-TIRADS. Although the procedure is mentioned in the EU-TIRADS as a complementary method, integration has not been described. Limitations of the method are idealized basic assumptions, dependence of manufacturer and examiner, and artifacts.

CONCLUSION

Elastography can be a useful adjunct to standard diagnostic procedures in the evaluation of thyroid nodules, especially in nodules with intermediate risk of malignancy and unclear results on fine needle aspiration.

Diagnostic performance of shear wave elastography in thyroid nodules with indeterminate cytology: A systematic review and meta-analysis

Purpose

Thyroid nodules classified as indeterminate in previous fine-needle aspiration cytology often necessitate additional evaluation to determine their histology, while shear wave elastography (SWE) offers an alternative option in this regard. The objective of this study was to assess the diagnostic effectiveness of SWE in evaluating indeterminate nodules.

Methods

The PubMed, EMBASE, and Web of Science databases were searched from 1st January 1970 to 1st March 2023. The studies were reviewed and the data was extracted by two separate reviewers. A Bayesian bivariate model was utilized to quantitatively synthesize the diagnostic accuracy and yield of the studies in R.

Results

A total of seven studies, involving indeterminate thyroid nodules undergoing SWE were included, and the overall malignancy rate was 34.1% (307/900). The summarized estimates of sensitivity and specificity were 0.792 (95% credible interval [CI], 0.727-0.850) and 0.845 (95% CI, 0.797-0.887), respectively. The summarized estimate for the diagnostic odds ratio (DOR) was 17.8 (95% CI, 14.0-22.6). Summarized receiver operating characteristic (SROC) plots indicated a trade-off between sensitivity and specificity, and the estimate of AUC was 0.866 (95% CI, 0.834-0.895). The summary estimates for positive and negative likelihood ratios were 4.67 (95% CI, 3.98-5.85) and 0.26 (95% CI, 0.23-0.28), respectively.

Conclusions

The overall accuracy of SWE remains satisfactory in indeterminate thyroid nodules. However, it should be noted that the available data are still extremely limited, and more studies or guidelines are required to provide further insights.

US-Elastography With Different Techniques for Thyroid Nodule Characterization: Systematic Review and Meta-analysis

Background

Thyroid nodules are frequent in adult population and thyroid cancer incidence has increased dramatically over the past three decades. The aim of this systematic review and meta-analysis was to evaluate the US-Elastosonography (USE) diagnostic performance in assessing the thyroid nodules malignancy risk.

Methods

PubMed and Embase databases were searched from January 2011 to July 2021. We extracted data from selected studies and calculated the overall diagnostic accuracy of qualitative USE, semi-quantitative USE and quantitative USE. Summary receiver operating characteristic (ROC) curve was elaborated to show the results. All statistical tests were performed using Metadisc and Medcal software package.

Results

Finally 72 studies with 13,505 patients and 14,015 thyroid nodules (33% malignant) undergoing elastography were included. The pooled sensitivity, specificity and AUC were 84%, 81%, and 0.89 respectively for qualitative USE; 83%, 80%, and 0.93 for semi-quantitative USE and 78%, 81% and 0.87, for quantitative USE. The qualitative and semiquantitative USE present very similar diagnostic accuracy values and both better than the quantitative USE.

Conclusions

USE is a useful imaging tool for thyroid nodule characterization. In accordance with recent guidelines and meta-analyses, the USE could be used daily in thyroid nodule malignancy risk stratification.

Systematic Review Registration

PROSPERO: CRD42021279257.

Ultrasound elastography

Physicians have used palpation as a diagnostic examination to understand the elastic properties of pathology for a long time since they realized that tissue stiffness is closely related to its biological characteristics. US elastography provided new diagnostic information about elasticity comparing with the morphological feathers of traditional US, and thus expanded the scope of the application in clinic. US elastography is now widely used in the field of diagnosis and differential diagnosis of abnormality, evaluating the degree of fibrosis and assessment of treatment response for a range of diseases. The World Federation of Ultrasound Medicine and Biology divided elastographic techniques into strain elastography (SE), transient elastography and acoustic radiation force impulse (ARFI). The ARFI techniques can be further classified into point shear wave elastography (SWE), 2D SWE, and 3D SWE techniques. The SE measures the strain, while the shear wave-based techniques (including TE and ARFI techniques) measure the speed of shear waves in tissues. In this review, we discuss the various techniques separately based on their basic principles, clinical applications in various organs, and advantages and limitations and which might be most appropriate given that the majority of doctors have access to only one kind of machine.

Assessment of diagnostic value of preoperative elastography in thyroid nodules having indeterminate cytology results

Background/aim

The management of nodules with indeterminate cytology [atypia of undetermined significance (AUS), follicular lesion of undetermined significance (FLUS), follicular neoplasm (FN), suspicious for a follicular neoplasm (SFN), and suspicious for malignancy (SM)] results is controversial. To assess the role of the elastography technique in the diagnosis of malignancy in the subtypes of indeterminate thyroid nodules.

Materials and methods

We included 132 patients with indeterminate cytology who underwent thyroid surgery. Sensitivity, specificity, area under the curve, and optimal cut-off points were calculated with receiver operating characteristic (ROC) analysis for elastography score (ES) and strain index (SI).

Results

Malignancy was observed in 27/95 (28.4%) of the AUS-FLUS cytology and 12/24 (50%) of FN, SFN cytology. All of the 13 patients (100 %) with SM are found to be malignant on histology. In the FLUS group, nodules with ES greater or equal to 3, the presence of malignancy was higher 17/41 (41.5%) when compared with nodules with ES smaller than 39/46 (19.6 %) (p = 0.023). In the SFN group, 2 of 2 nodules with an ES score of 4 and 1 of 1 nodule with an ES score of 5 were malignant. In the FLUS group, 4 of 10 nodules with an ES score of 4 and 2 of 2 nodules with an ES score of 5 were malignant.

Conclusion

Thyroid elastography may reduce unnecessary surgery for both patients with AUS/FLUS and selected SFN cytology. Elastography appears to be helpful in follicular variants and other types of papillary thyroid cancer, however, not in follicular thyroid cancer.

Diagnostic accuracy of B-mode ultrasound, ultrasound elastography and diffusion weighted MRI in differentiation of thyroid nodules (prospective study)

Background

The incidence of the thyroid nodules and its detection is increasing rapidly. The most precise method for diagnosis of the nodules of the thyroid is FNAC. But, about 10–20% of specimens of FNAC are indeterminate and non-diagnostic. Therefore, there is a demand for another diagnostic method for evaluating thyroid nodules. Thyroid ultrasound elastography may improve the ability to differentiate malignant from benign thyroid nodules. Few articles were published about the results of DW MRI in thyroid nodules, with its results confirmed that malignant nodules have lower mean ADC values than benign nodules. This study aims to investigate and compare the accuracy of B-mode ultrasound, ultrasound elastography and diffusion-weighted MRI in characterization of the nodules of the thyroid.

Results

The study included 56 patients with thyroid nodules (36 benign and 20 malignant). Thyroid ultrasound, ultrasound elastography and DWI were done for all patients. Ultrasound-guided FNA Cytological examination (as the gold standard) was done for 48 patients and surgical histopathology was done to 8 patients with non-diagnostic FNAC. The results showed: TIRADS score had sensitivity 90%, specificity 77.8% and accuracy of 82.14%. The elastography score had sensitivity 80%, specificity 88.9% and accuracy 85.7%. The use of the strain ratio had 80% sensitivity, 94.4% specificity and 89.3% accuracy. DWI and ADC value had 100% sensitivity and 94.4% specificity and the accuracy was 96.4% for differentiating malignant from benign thyroid nodules. Multi-parametric analysis by TIRADS and ADC had 100% accuracy.

Conclusion

Ultrasound elastography add valuable data over ultrasound TIRADS. But, diffusion weighted MRI and ADC value has more accuracy in differentiating malignant from benign thyroid nodules. The best performance was achieved by the combination of ACR-TIRADS and ADC value.

Thyroid Nodule Characterization: How to Assess the Malignancy Risk. Update of the Literature

Ultrasound (US) is the first imaging modality for thyroid parenchyma evaluation. In the last decades, the role of ultrasound has been improved with the introduction of new US software, such as contrast-enhanced ultrasound (CEUS) and US-elastography (USE). USE is nowadays recognized as an essential part of the multiparametric ultrasound (MPUS) examination, in particular for the indeterminate thyroid nodule with possible fine-needle aspiration cytology (FNAC) number reduction; even if further and larger studies are needed to validate it. More controversial is the role of CEUS in thyroid evaluation, due to its high variability in sensitivity and specificity. Semi-automatic US systems based on the computer-aided diagnosis (CAD) system are producing interesting results, especially as an aid to less experienced operators. New knowledge on the molecular mechanisms involved in thyroid cancer is allowing practitioners to identify new genomic thyroid markers that could reduce the number of "diagnostic" thyroidectomies. We have therefore drawn up an updated representation of the current evidence in the literature for thyroid nodule multiparametric ultrasound (MPUS) evaluation with particular regard to USE, the US CAD system and CEUS.

TIRADS, SRE and SWE in INDETERMINATE thyroid nodule characterization: Which has better diagnostic performance?

Purpose

To assess Strain Ratio (SRE) and Shear Wave Elastography (SWE) accuracy alone and with TIRADS classification, for the risk stratification of indeterminate thyroid nodules.

Materials and methods

128 Patients with 128 indeterminate nodules candidates for thyroidectomy underwent preoperative staging neck ultrasound and were classified according to K-TIRADS score. After TIRADS evaluation, semi-quantitative (SRE) and quantitative (SWE expressed in kPa) elastosonography were performed and relative diagnostic performances, alone and in combination, were compared through ROC curves analysis. In order to maximize the SRE and SWE sensitivity and specificity, their cut-off values were calculated using the Liu test. Bonferroni test was used to evaluate statistically significant differences with a p value < 0.05.

Results

Sensitivity, specificity, PPV and NPV were, respectively, 71.4%, 82.4%, 62.5%, 87.5% for K-TIRADS baseline US, 85.7%, 94.1%, 85.7%, 94.1% for SRE and 57.1%, 79.4%, 53.3%, 81.8% for SWE (kPa expressed). SRE evaluation showed the best diagnostic accuracy compared to the SWE (kPa expressed) (p < 0.05) and to the K-TIRADS (p > 0.05). The association of SRE with conventional ultrasound with K-TIRADS score increased sensitivity (92.9% vs 71.4%) but decreased the specificity than conventional US alone (76.5% vs 82.4%).

Conclusion

Strain Elastosonography can be associated with K-TIRADS US examination in the thyroid nodule characterization with indeterminate cytology; in fact, adding the SRE to K-TIRADS assessment significantly increases its sensitivity and negative predictive value. However, further multicenter studies on larger population are warranted.

Which Is the Best Reference Tissue for Strain Elastography in Predicting Malignancy in Thyroid Nodules, the Sternocleidomastoid Muscle or the Thyroid Parenchyma?

OBJECTIVES

This study aimed to compare 2 types of strain ratios (SRs) in thyroid nodules. Two reference points were used: the sternocleidomastoid (SCM) muscle and the thyroid parenchyma.

METHODS

A total of 101 nodules in 83 patients were prospectively enrolled in the study. For the semiquantitative analysis, 2 types of SRs were used: SR1, the ratio of the SCM muscle strain to the thyroid nodule strain; and SR2, the ratio of the surrounding normal thyroid tissue strain to the thyroid nodule strain. For each nodule, the SR1 and SR2 elastographic values were calculated, and their averages were compared.

RESULTS

Eighty-one (80.2%) of 101 thyroid nodules were benign, and 20 (19.8%) were malignant. In both benign and malignant histopathologic types, the SR1 averages were significantly higher than the SR2 averages (P = .001; P < .001, respectively). Both the SR1 and SR2 values were found to be significantly successful in differentiating benign from malignant histopathologic types (P < .001 for both). The areas under the curve were then compared for the methods, and the difference was found to be statistically significant (P = .046). The diagnostic accuracy of the SR1 was superior to that of the SR2.

CONCLUSIONS

The SR1 and SR2 are effective adjunctive diagnostic tools for identifying malignant thyroid nodules. Using the SCM muscle as a reference point instead of thyroid tissue may be a more valuable way to measure SRs.

Ultrasound elastography of the thyroid: principles and current status

Ultrasound (US) elastography has been introduced as a non-invasive technique for evaluating thyroid diseases. This paper presents a detailed description of the technical principles, peculiarities, and limitations of US elastography techniques, including strain elastography and shear-wave elastography. This review was conducted from a clinical perspective, and aimed to assess the usefulness of US elastography for thyroid diseases in specific clinical scenarios. Although its main focus is on thyroid nodules, the applications of US elastography for other thyroid diseases, such as diffuse thyroid diseases and thyroiditis, are also presented. Furthermore, unresolved questions and directions for future research are also discussed.

Diagnostic Utility of Molecular and Imaging Biomarkers in Cytological Indeterminate Thyroid Nodules

Indeterminate thyroid cytology (Bethesda III and IV) corresponds to follicular-patterned benign and malignant lesions, which are particularly difficult to differentiate on cytology alone. As ~25% of these nodules harbor malignancy, diagnostic hemithyroidectomy is still custom. However, advanced preoperative diagnostics are rapidly evolving.This review provides an overview of additional molecular and imaging diagnostics for indeterminate thyroid nodules in a preoperative clinical setting, including considerations regarding cost-effectiveness, availability, and feasibility of combining techniques. Addressed diagnostics include gene mutation analysis, microRNA, immunocytochemistry, ultrasonography, elastosonography, computed tomography, sestamibi scintigraphy, [18F]-2-fluoro-2-deoxy-d-glucose positron emission tomography (FDG-PET), and diffusion-weighted magnetic resonance imaging.The best rule-out tests for malignancy were the Afirma® gene expression classifier and FDG-PET. The most accurate rule-in test was sole BRAF mutation analysis. No diagnostic had both near-perfect sensitivity and specificity, and estimated cost-effectiveness. Molecular techniques are rapidly advancing. However, given the currently available techniques, a multimodality stepwise approach likely offers the most accurate diagnosis, sequentially applying one sensitive rule-out test and one specific rule-in test. Geographical variations in cytology (e.g., Hürthle cell neoplasms) and tumor genetics strongly influence local test performance and clinical utility. Multidisciplinary collaboration and implementation studies can aid the local decision for one or more eligible diagnostics.

New perspectives in the diagnosis of thyroid follicular lesions

Thyroid nodules are very common, affecting 19%-67% of the adult population. However, about 10% of them harbor a malignant lesion. Consequently, the first aim in their clinical evaluation is to exclude malignancy. Fine-needle aspiration cytology (FNAC) represents the main diagnostic tool for the evaluation of thyroid nodules. However, FNAC has a main diagnostic limit, namely cellular atypias of indeterminate significance, which require surgical excision and histological examination to differentiate benign from malignant lesions. Histology reports show that approximately 80% of these patients harbor a benign lesion. Therefore, in order to reduce unnecessary thyroidectomy, over the last years, the cytological classification of thyroid nodules has been revised and a number of new instrumental and molecular approaches have been proposed. In the present article, we will attempt to summarize the most recent cytological, molecular and echographic strategies to enhance the diagnostic accuracy of preoperative thyroid follicular lesions. In particular, we will discuss the new cytological classifications from the Bethesda System for Reporting Thyroid Cytopathology (BSRTC), the British Thyroid Association-Royal College of Pathologists (PTA-RCPath) and the new Italian Society for Anatomic Pathology and Cytology (SIAPEC 2014. We will review molecular tests evaluated to ameliorate follicular lesion diagnosis as well as the clinical utility of the new echographic Thyroid Imaging Reporting and Data System (TI-RADS) score.

Head and neck ultrasound: technical advances, novel applications and the role of elastography

High-resolution ultrasound (US) provides superb anatomical detail in the superficial anatomy of the neck and has become the first-line imaging investigation for neck lumps and a crucial component of clinical pathways. In this article, a wide range of advances in neck US are described with a focus on the emerging role of ultrasound elastography. Selected examples of clinical utility are presented across a spectrum of scenarios with discussion of newer applications, service delivery, and training issues. The changing role of the neck ultrasound practitioner and the future of the technique in the head and neck are considered.

Thyroid Imaging Reporting and Data System Score Combined with the New Italian Classification for Thyroid Cytology Improves the Clinical Management of Indeterminate Nodules

The new Italian cytological classification (2014) of thyroid nodules replaced the TIR3 category of the old classification (2007) with two subclasses, TIR3A and TIR3B, with the aim of reducing the rate of surgery for benign diseases. Moreover, thyroid imaging reporting and data system (TI-RADS) score appears to ameliorate the stratification of the malignancy risk. We evaluated whether the new Italian classification has improved diagnostic accuracy and whether its association with TI-RADS score could improve malignancy prediction. We retrospectively analyzed 70 nodules from 70 patients classified as TIR3 according to the old Italian classification who underwent surgery for histological diagnosis. Of these, 51 were available for cytological revision according to the new Italian cytological classification. Risk of malignancy was determined for TIR3A and TIR3B, TI-RADS score, and their combination. A different rate of malignancy (p = 0.0286) between TIR3A (13.04%) and TIR3B (44.44%) was observed. Also TI-RADS score is significantly (p = 0.003) associated with malignancy. By combining cytology and TI-RADS score, patients could be divided into three groups with low (8.3%), intermediate (21.4%), and high (80%) risk of malignancy. In conclusion, the new Italian cytological classification has an improved diagnostic accuracy. Interestingly, the combination of cytology and TI-RADS score offers a better stratification of the malignancy risk.

Surgical treatment of thyroid follicular neoplasms: results of a retrospective analysis of a large clinical series

The most appropriate surgical management of "follicular neoplasm/suspicious for follicular neoplasm" lesions (FN), considering their low definitive malignancy rate and the limited predictive power of preoperative clinic-diagnostic factors, is still controversial. On behalf of the Italian Association of Endocrine Surgery Units (U.E.C. CLUB), we collected and analyzed the experience of 26 endocrine centers by computerized questionnaire. 1379 patients, surgically treated after a FN diagnosis from January 2012 and December 2103, were evaluated. Histological features, surgical complications, and medium-term outcomes were reported. Total thyroidectomy (TT) was performed in 1055/1379 patients (76.5 %), while hemithyroidectomy (HT) was carried out in 324/1379 cases (23.5 %). Malignancy rate was higher in TT than in HT groups (36.4 vs. 26.2 %), whereas the rates of transient and definitive hypoparathyroidism following TT were higher than after HT. Consensual thyroiditis (16.8 vs. 9.9 %) and patient age (50.9 vs. 47.9 %) also differed between groups. A cytological FN diagnosis was associated to a not negligible malignancy rate (469/1379 patients; 34 %), that was higher in TT than in HT groups. However, a lower morbidity rate was observed in HT, which should be considered the standard of care in solitary lesions in absence of specific risk factors. Malignancy could not be preoperatively assessed and clinical decision-making is still controversial. Further efforts should be spent to more accurately preoperatively classify FN thyroid nodules.

WFUMB Guidelines and Recommendations on the Clinical Use of Ultrasound Elastography: Part 4. Thyroid

The World Federation for Ultrasound in Medicine and Biology (WFUMB) has produced guidelines for the use of elastography techniques including basic science, breast and liver. Here we present elastography in thyroid diseases. For each available technique, procedure, reproducibility, results and limitations are analyzed and recommendations are given. Finally, recommendations are given based on the level of evidence of the published literature and on the WFUMB expert group's consensus. The document has a clinical perspective and is aimed at assessing the usefulness of elastography in the management of thyroid diseases.

Ultrasound Strain Elastography for Circumscribed Solid Thyroid Nodules without Malignant Features Categorized as Indeterminate by B-Mode Ultrasound

The aim of this study was to evaluate the diagnostic performance of ultrasound strain elastography (USE) for circumscribed solid thyroid nodules without malignant or benign features seen on US. This retrospective study included 197 thyroid nodules in 196 patients who underwent USE with color mapping and strain ratio measurement between 2010 and 2014. Of the 197 nodules, 24 (12.2%) were malignant. No significant differences in color mapping or strain ratio were observed between benign and malignant nodules. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy were 29.2% (95% confidence interval [CI]: 13.8%-49.4%), 77.5% (95% CI: 75.3%-80.3%), 15.2% (95% CI: 7.2%-25.8%), 88.7% (95% CI: 86.3%-92.0%), and 71.6% (95% CI: 67.8%-76.5%) for color mapping and 50.0% (95% CI: 30.%-69.5%), 57.2% (95% CI: 54.5%-59.9%), 14.0% (95% CI: 8.5%-18.4%), 89.2% (95% CI: 85.0%-93.4%) and 56.3% (95% CI: 51.6%-61.1%) for strain ratio measurement, respectively. USE with color mapping and strain ratio measurement has a limited ability to differentiate benign from malignant nodules for circumscribed solid thyroid nodules without definite malignant features categorized as indeterminate by B-mode US.

The role of elastography in thyroid ultrasonography

PURPOSE OF REVIEW

Elastography is a novel noninvasive diagnostic tool that is helpful in the evaluation of thyroid nodules. The purpose of this review is to provide a comprehensive summary of the use of elastography in the clinical thyroid setting.

RECENT FINDINGS

Initial and subsequent studies show that elastography has both a sensitivity and specificity that approaches 100% for the determination of thyroid cancer within a thyroid nodule. In addition, the technique also has a very high negative predictive value and thus, may also be helpful in identification of thyroid nodules that do not need further diagnostic evaluation, including fine-needle aspiration biopsy. These characteristics also apply to both strain and shear wave elastography. However, as both the extent of tissue compression and the operator's classification of a nodule using a qualitative color code are subjective, intra and interobserver variability is an important reason for some conflicting findings.

SUMMARY

Elasticity within a thyroid nodule, as evaluated by elastography, offers diagnostic results that are equal to or sometimes even greater than that of conventional ultrasonography for the determination of thyroid malignancy. The integration of both techniques in the clinical work-up of thyroid nodules can thus significantly improve the accuracy of the diagnosis of thyroid nodules.

Can New Ultrasound Signs Help in Identifying Follicular Variant of Papillary Carcinoma of Thyroid? - A Pilot Study

AIM

To describe two new ultrasound signs for thyroid nodules - "nodule in nodule" and "hypoechoic internal septae" and assess their usefulness in differentiating follicular variant of papillary thyroid carcinoma (FVPTC) from benign thyroid nodules (BTN).

METHODOLOGY

Ultrasound findings of 210 patients with histopathologically proven FVPTC (68 nodules, M:F=13:47 with mean age of 39.5±11.9 years) and BTN (165 nodules, (M:F=41:109 with mean age of 44±11.3 years) were retrospectively reviewed from PACS by a single radiologist blinded to the final diagnosis. Logistic regression analysis was performed to identify the best predictors of FVPTC and their diagnostic performance was assessed.

RESULTS

The "nodule in nodule" sign was seen in 80.9% of FVPTC and only 12.1% of BTN. The "hypoechoic internal septae" sign was seen in 44.1% of FVPTC and 17% of BTN. Younger patients, heterogeneous echotexture, nodule in nodule sign, thick incomplete non-uniform halo and presence of significant nodes were the best predictors of FVPTC (p<0.05). The sensitivity, specificity, positive predictive value, negative predictive value, accuracy and relative risk for FVPTC given as odds ratio (95% CI) for heterogeneous echotexture and nodule in nodule sign which were the best 2 predictors of FVPTC were 91.2%, 81.8%, 67.3%, 95.7%, 84.5%, 46.5 (18.5-117.4) and 80.9%, 87.7%, 74.3%, 91.2%, 86.2%, 32.5 (15.04-70.2), respectively. There was improvement in the specificity (91.5%) and accuracy (86.6%) when a combined criterion of heterogeneous echotexture and nodule in nodule sign was applied to predict FVPTC.

CONCLUSION

The "nodule in nodule" sign is common in FVPTC and when combined with heterogeneous echotexture can differentiate FVPTC and BTN with high specificity.

Comparison of Diagnostic Accuracy of Real-Time Elastography and Shear Wave Elastography in Differentiation Malignant From Benign Thyroid Nodules

Thyroid nodules are relatively more prevalent in iodine-deficiency area, and the incidence increased sharply in the past decade in these areas. Workup of malignant from benign nodules in clinic was the main problem for managing thyroid nodules.An overall search for the articles about the diagnostic performance of real-time elastography (RTE) and shear wave elastography (SWE) before April 2015 in the databases of PubMed, Embase, and Google scholar. The pooled sensitivity, specificity, and summary receiver operating characteristic (SROC) curve were obtained from individual studies with a random-effects model. Subgroup and meta-regression analysis were also performed.Fifty-six studies involved in 2621 malignant nodules and 7380 benign nodules were contained in our meta-analysis. The pooled sensitivity and specificity of RTE was 83.0% and 81.2%, which is higher than SWE (sensitivity: 78.7%, specificity: 80.5%). The areas under the SROC curve of RTE and SWE were 0.885 and 0.842 respectively. RTE had higher diagnostic value for Caucasians than Asians. Stran ratio (SR) assessment had higher diagnostic performance than elasticity score (ES) system. Similarly, it had higher diagnostic value when malignant nodules were more than 50.In summary, the results revealed that RTE had higher diagnostic performance than SWE in differentiating malignant from benign nodules. However, future international multicenter studies in the region of thyroid risk need to further assess the diagnostic performance of RTE.

Assessment of Diffuse Thyroid Disease by Strain Ratio in Ultrasound Elastography

The goal of this study was to explore the value of strain ratio from real-time elastography in the semi-quantitative assessment of diffuse thyroid disease. Fifty-one patients with primary hyperthyroidism, 70 with Hashimoto's thyroiditis, 8 with subacute thyroiditis and 43 with normal healthy thyroids were recruited to measure the strain ratio (SR) of thyroid tissue and sternocleidomastoid muscle (on the same side of the thyroid). SR values of all groups were subjected to statistical analysis. The SRs (mean ± standard deviation) of patients with hyperthyroidism, Hashimoto's thyroiditis and subacute thyroiditis were 2.30 ± 1.08, 7.04 ± 7.74 and 24.09 ± 13.56, respectively. The SR of the control group was 1.76 ± 0.54. SR values ranked in ascending order were control group < hyperthyroidism group < Hashimoto's thyroiditis group < subacute thyroiditis group. There were statistically significant (p < 0.05) differences in thyroid hardness between groups with different diffuse thyroid diseases. SR values of the hyperthyroidism and control groups did not statistically differ (p > 0.05). It is feasible to assess diffuse thyroid disease with strain ratios obtained with ultrasound elastography.

Reliability of real-time elastography to diagnose thyroid nodules previously read at FNAC as indeterminate: a meta-analysis

The main limit of thyroid fine-needle aspiration cytology (FNAC) is represented by indeterminate report. Recently, real-time elastography (RTE) has been described in the management of these cases. Here, we performed a meta-analysis of published studies specifically focused on the use of RTE in indeterminate thyroid nodules. A comprehensive literature search of PubMed/MEDLINE and Google Scholar databases was conducted by using the combination of the terms "thyroid" and "indeterminate" and "elastography." Pooled sensitivity, specificity, accuracy, PPV and NPV of RTE as predictor of malignancy in thyroid nodules with indeterminate FNAC were calculated, including 95% confidence intervals (95% CI). The area under the summary ROC curve (AUC) was also assessed. Databases found 572 papers, and eight were included in the meta-analysis. Of these, six studies had prospective design and two were retrospective. Pooled malignancy rate was 31%. As common denominator, all studies set the prevalence of hardness within the nodule as risk factor for malignancy of the lesion. Sensitivity of RTE ranged from 11 to 89% (pooled estimate of 69%; 95% CI 55-82%), specificity varied from 6 to 100% (pooled estimate of 75%; 95% CI 42-96%), and accuracy was comprised between 35 and 94% (pooled estimate of 73%; 95% CI 54-89%). The AUC was 0.77. RTE has suboptimal diagnostic accuracy to diagnose thyroid nodules previously classified as indeterminate. Then, RTE alone should not be used for selecting these patients for surgery or not. We advice for further studies using other elastographic approaches and combined RTE and B-mode ultrasonography.

Strain ratio ultrasound elastography increases the accuracy of colour-Doppler ultrasound in the evaluation of Thy-3 nodules. A bi-centre university experience

OBJECTIVES

To assess whether ultrasound elastography (USE) with strain ratio increases diagnostic accuracy of Doppler ultrasound in further characterisation of cytologically Thy3 thyroid nodules.

METHODS

In two different university diagnostic centres, 315 patients with indeterminate cytology (Thy3) in thyroid nodules aspirates were prospectively evaluated with Doppler ultrasound and strain ratio USE before surgery. Ultrasonographic features were analysed separately and together as ultrasound score, to assess sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV). Receiver operating characteristic (ROC) curves to identify optimal cut-off value of the strain ratio were also provided. Diagnosis on a surgical specimen was considered the standard of reference.

RESULTS

Higher strain ratio values were found in malignant nodules, with an optimum strain ratio cut-off of 2.09 at ROC analysis. USE with strain ratio showed 90.6% sensitivity, 93% specificity, 82.8% PPV, 96.4% NPV, while US score yielded a sensitivity of 52.9%, specificity of 84.3%, PPV 55.6% and NPV 82.9%. The diagnostic gain with strain ratio was statistically significant as proved by ROC areas, which was 0.9182 for strain ratio and 0.6864 for US score.

CONCLUSIONS

USE with strain ratio should be considered a useful additional tool to colour-Doppler US, since it improves characterisation of thyroid nodules with indeterminate cytology.

KEY POINTS

• Strain ratio measurements improve differentiation of thyroid nodules with indeterminate cytology • Elastography with strain ratio is more reliable than ultrasound features and ultrasound score • Strain ratio may help to better select patients with Thy 3 nodules candidate for surgery.

Risk stratification of thyroid nodules on ultrasonography with the French TI-RADS: description and reflections

The widespread use of ultrasonography places it in a key position for use in the risk stratification of thyroid nodules. The French proposal is a five-tier system, our version of a thyroid imaging reporting and database system (TI-RADS), which includes a standardized vocabulary and report and a quantified risk assessment. It allows the selection of the nodules that should be referred for fine-needle aspiration biopsies. Effort should be directed towards merging the different risk stratification systems utilized around the world and testing this unified system with multi-center studies.

Diagnostic performance of elastography in cytologically indeterminate thyroid nodules

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

Thyroid nodule ultrasound: technical advances and future horizons

Thyroid nodules are extremely common and the vast majority are non-malignant; therefore the accurate discrimination of a benign lesion from malignancy is challenging. Ultrasound (US) characterisation has become the key component of many thyroid nodule guidelines and is primarily based on the detection of key features by high-resolution US. The thyroid imager should be familiar with the strengths and limitations of this modality and understand the technical factors that create and alter the imaging characteristics. Specific advances in high-resolution US are discussed with reference to individual features of thyroid cancer and benign disease. Potential roles for three-dimensional thyroid ultrasound and computer-aided diagnosis are also considered. The second section provides an overview of current evidence regarding thyroid ultrasound elastography (USE). USE is a novel imaging technique that quantifies tissue elasticity (stiffness) non-invasively and has potential utility because cancers cause tissue stiffening. In recent years, there has been much research into the value of thyroid USE for distinguishing benign and malignant nodules. Preliminary findings from multiple pilot studies and meta-analyses are promising and suggest that USE can augment the anatomical detail provided by high-resolution US. However, a definite role remains controversial and is discussed.

TEACHING POINTS

• High-resolution US characterises thyroid nodules by demonstration of specific anatomical features • Technical advances heavily influence the key US features of thyroid nodules • Most papillary carcinomas appear stiffer than benign thyroid nodules on US elastography (USE) • Thyroid USE is controversial because of variation in the reported accuracies for malignancy • Combined grey-scale US/USE may lower the FNAC rate in benign nodules.

Dependence of thyroid sonographic markers of malignancy and its influence on the diagnostic value of sonographic findings

Introduction. Thyroid nodules constitute frequent medical condition. Ultrasonographic (US) examination remains the basis in the diagnostics of nodular goiter and selection of the suspected ones requiring fine-needle aspiration biopsy (FNAB). The aim of this study was to evaluate if the features so far considered to be US malignancy markers are dependent or independent variables and to check if these data are clinically relevant. Materials and Methods. Patients with diagnosed thyroid nodular goiter admitted for thyroidectomy, irrespectively of the indications for surgery, were involved. The following parameters were assessed: echogenicity, the presence of calcifications, presence of halo, shape, margins, structure (solid, partially or pure cystic), and elasticity of the nodules (assessed quantitatively). Results. 122 consecutive patients with 393 thyroid nodules were included. There were significant associations between halo absence and irregular borders, micro- and macrocalcifications, taller-than-wide feature and macrocalcifications, irregular margins and macrocalcifications, and also decreased elasticity of nodules and several attributes (partially cystic character, micro- and macrocalcifications). Conclusions. Not only diagnostic value of particular sonographic features but also data about cooccurrence and associations between them are clinically relevant. Although most of these features turned out to be independent, omitting significant association can lead to incorrect assessment of the risk of malignancy.

Strain US Elastography for the Characterization of Thyroid Nodules: Advantages and Limitation

Thyroid nodules, with their high prevalence in the general population, represent a diagnostic challenge for clinicians. Ultrasound (US), although absolutely reliable in detecting thyroid nodules, is still not accurate enough to differentiate them into benign and malignant. A promising novel modality, US elastography, has been introduced in order to further increase US accuracy. The purpose of this review article is to assess the thyroid application of US strain elastography, also known as real-time elastography or quasistatic elastography. We provide a presentation of the technique, and of up-to-date literature, analyzing the most prominent results reported for thyroid nodules differentiation. The practical advantages and limitations of strain elastography are extensively discussed herein.

Biochemical and ultrasonographic parameters influencing thyroid nodules elasticity

Elastography is a method of tissue stiffness assessment. It has already been demonstrated that thyroid cancers are less elastic than benign lesions. However, little is known about other factors, which might influence the stiffness of thyroid nodules and disrupt the prediction of malignancy using this technique. The aim of this study was to conduct the first systematic assessment of factors potentially affecting the elasticity of thyroid lesions. One hundred and twenty-two patients with thyroid nodular disease admitted for thyroidectomy underwent preoperative ultrasonography and sonoelastography. The definite diagnosis of thyroid lesions was based on histological examination. What was evaluated in the study was the influence of composition, size, localization, nodularity, and selected laboratory parameters on thyroid nodule elasticity. Firstly, association between the above-mentioned factors and elasticity was assessed in benign lesions. Secondly, all nodules (benign and malignant) were divided into subgroups according to the presence or absence of particular features, which turned out to be an important disturbing factor increasing the stiffness of the lesion in the first step of analysis. There were 22 malignant and 371 benign lesions. The analysis of benign lesions revealed that the presence calcifications (p < 0.0001) significantly increased nodule stiffness. Partially, cystic nodules were significantly less elastic than solid ones (p = 0.03). There was also positive correlation between nodule size and stiffness (p < 0.0001). Lesions localized in the isthmus were significantly less elastic than nodules in other localizations. (p = 0.0001). Solitary nodules were less elastic than lesions in multinodular goiter (p = 0.006). Correlation between Tg concentration and stiffness was significant (p < 0.0001, r = 0.24). The concentration of anti-thyroid autoantibodies was associated with stiffness at the border of significance. However, there was no significant difference between benign lesions in patients with diagnosed chronic autoimmune thyroiditis and patients without the disease. The analysis of the entire group of nodules revealed that shear wave elastography is a valuable modality of thyroid nodule assessment, with sensitivity of over 95 % and specificity of about 70 %. However, the stiffness value of the lesion might be increased in the case of nodules containing calcifications, cystic component, and those of size above 20 mm. Certain clinical conditions or attributes of the lesions influence the stiffness values of thyroid nodules. Identifying these variables is the basis for a credible interpretation of the results of a sonoelastographic examination and makes it possible to estimate the risk of thyroid nodule malignancy adequately.

Follicular nodules (Thy3) of the thyroid: is total thyroidectomy the best option?

Background

Identification of the best management strategy for nodules with Thy3 cytology presents particular problems for clinicians. This study investigates the ability of clinical, cytological and sonographic data to predict malignancy in indeterminate nodules with the scope of determining the need for total thyroidectomy in these patients.

Methods

The study population consisted of 249 cases presenting indeterminate nodules (Thy3): 198 females (79.5%) and 51 males (20.5%) with a mean age of 52.43 ± 13.68 years. All patients underwent total thyroidectomy.

Results

Malignancy was diagnosed in 87/249 patients (34.9%); thyroiditis co-existed in 119/249 cases (47.79%) and was associated with cancer in 40 cases (40/87; 45.98%). Of the sonographic characteristics, only echogenicity and the presence of irregular margins were identified as being statistically significant predictors of malignancy. 52/162 benign lesions (32.1%) and 54/87 malignant were hypoechoic (62.07%); irregular margins were present in 13/162 benign lesions (8.02%), and in 60/87 malignant lesions (68.97%). None of the clinical or cytological features, on the other hand, including age, gender, nodule size, the presence of microcalcifications or type 3 vascularization, were significantly associated with malignancy.

Conclusions

The rate of malignancy in cytologically indeterminate lesions was high in the present study sample compared to other reported rates, and in a significant number of cases Hashimoto’s thyroiditis was also detected. Thus, considering the fact that clinical and cytological features were found to be inaccurate predictors of malignancy, it is our opinion that surgery should always be recommended. Moreover, total thyroidectomy is advisable, being the most suitable procedure in cases of multiple lesions, hyperplastic nodular goiter, or thyroiditis; the high incidence of malignancy and the unreliability of intraoperative frozen section examination also support this preference for total over hemi-thyroidectomy.

Real-time ultrasound elastography for differentiation of benign and malignant thyroid nodules: a meta-analysis

OBJECTIVES

The clinical challenge of managing thyroid nodules nowadays is to diagnose the minority of malignant disease. Real-time ultrasound elastography, which can measure tissue elasticity, is used as a complement to conventional sonography for improving the diagnosis of thyroid tumors. There are 2 common criteria for evaluating an elastogram: the elasticity score and strain ratio. This meta-analysis was performed to expand on a previous meta-analysis to assess the diagnostic power of ultrasound elastography in differentiating benign and malignant thyroid nodules for elasticity score and strain ratio assessment.

METHODS

The MEDLINE, EMBASE, PubMed, and Cochrane Library databases up to January 31, 2013, were searched. The pooled sensitivity, specificity, and summary receiver operating characteristic curve were obtained from individual studies with a random-effects model. The extent and sources of heterogeneity were explored.

RESULTS

A total of 5481 nodules in 4468 patients for elasticity score studies and 1063 nodules in 983 patients for strain ratio studies were analyzed. The overall mean sensitivity and specificity of ultrasound elastography for differentiation of thyroid nodules were 0.79 (95% confidence interval [CI], 0.77-0.81) and 0.77 (95% CI, 0.76-0.79) for elasticity score assessment and 0.85 (95% CI, 0.81-0.89) and 0.80 (95% CI, 0.77-0.83) for strain ratio assessment, respectively. The areas under the curve for the elasticity score and strain ratio were 0.8941 and 0.9285.

CONCLUSIONS

These results confirmed those obtained in the previous meta-analysis. Ultrasound elastography has high sensitivity and specificity for identification of thyroid nodules. It is a promising tool for reducing unnecessary fine-needle-aspiration biopsy.

Prospective evaluation of acoustic radiation force impulse technology in the differentiation of thyroid nodules: accuracy and interobserver variability assessment

PURPOSE

The aim of this study is to assess the diagnostic efficacy and interobserver agreement of acoustic radiation force impulse (ARFI) elasticity imaging in differentiating thyroid nodules.

METHODS

In our study, 74 consecutive patients (52 females, 22 males; age range 27-77 years, mean: 41 years) with 82 thyroid nodules (60 benign nodules, and 22 malignant) were examined by two radiologists with different experience. Patients underwent either cytology using fine needle aspiration cytology or thyroid surgery. The diagnostic performance of the two operators at ARFI with sensitivity, specificity, positive predictive and negative predictive value, and ROC curves was estimated. Inter-reader variability between the two operators was defined using Cohen's k.

RESULTS

According to receiver operating characteristics ROC curves (AUROC = 0.86 for observer 1; 0.81 for observer 2) sensitivity, specificity, PPV and NPV of reader 1 and 2 were respectively: 90, 75, 90.91 and 96.55 %; (cut-off value of shear wave: 2.455 m/s); 90, 72, 90 and 96.90 % (cut-off value shear wave: 2.365 m/s). Concordance between the two operators was good (k = 0.755).

CONCLUSIONS

This work is a feasibility study evaluating ARFI imaging. Its results suggest that ARFI imaging is a reproducible method which can be utilized with good diagnostic performance in the thyroid for discriminating benign and malignant nodules using the cut-off value of 2.455 m/s. However, larger studies are needed to validate this method.

Ultrasound elastography for thyroid nodules: recent advances

Ultrasonography (US)-based elastography has been introduced as a noninvasive technique for evaluating thyroid nodules that encompasses a variety of approaches such as supersonic shear imaging and acoustic radiation force impulse imaging as well as real-time tissue elastography. However, the diagnostic performances for differentiating malignant thyroid nodules from benign ones with elastography as an adjunctive tool of gray-scale US is still under debate. In this review article, diagnostic performances of conventional US and a combination of conventional US and elastography are compared according to the type of elastography. Further, the interobserver variability of elastography is presented according to the type of elastography.

Impact of prophylactic central compartment neck dissection on locoregional recurrence of differentiated thyroid cancer in clinically node-negative patients: a retrospective study of a large clinical series

BACKGROUND

In clinically node-negative patients with differentiated thyroid cancer (DTC), indications for routine central lymph node dissection (RCLD) are the subject of intensive research, and surgeons are divided between the pros and cons of this surgery. To better define the role of neck dissection in the treatment of DTC, we analyzed retrospectively the results in three centers in Italy.

METHODS

The clinical records of 752 clinically node-negative patients with DTC who underwent operative treatment between January 1998 and December 2005 in three endocrine surgery referral units were evaluated retrospectively. The complications and medium- and long-term outcomes of total thyroidectomy (TT) alone (performed in 390 patients: group A) and TT combined with bilateral RCLD (362 patients: group B) were analyzed and compared.

RESULTS

The incidence of permanent hypoparathyroidism and permanent unilateral vocal folds was 1% and 0.8% in group A and 3.6% and 1.7% in the group B, respectively. Bilateral temporary recurrent nerve palsy was observed in one of the 362 patients in group B. After a follow-up of 9.5 ± 3.5 years (mean ± SD), the locoregional recurrence rate with positive cervical lymph nodes was not substantially significantly different between the two groups.

CONCLUSION

In our series, TT combined with bilateral RCLD was associated with a greater rate of transient and permanent complications. Similar incidences of locoregional recurrence were reported in the two groups of patients. Considering the recent trend toward routine central lymphadenectomy, further studies are needed to evaluate the benefits of these different approaches.

The frequency of malignancy and the relationship between malignancy and ultrasonographic features of thyroid nodules with indeterminate cytology

Various approaches are available for the management of nodules that are evaluated to be indeterminate according to the results of thyroid fine needle aspiration biopsy. The present study aimed to determine the rate of malignancy and the ultrasonographic features that could be used as predictor of malignant pathologies at the nodules with indeterminate cytology. A total of 201 patients who underwent total thyroidectomy and whose fine needle aspiration biopsy results were evaluated to be Hurthle cell lesion (n = 99), follicular neoplasm (n = 61) and [corrected] suspicious for malignancy (n = 41) were enrolled in this study. Of these patients, 178 were females (88.6 %) and 23 were males (11.4 %). The rates of malignancy were found to be 33.3 % in the Hurthle cell lesion group, 23.0 % in the follicular neoplasm group and 53.7 % in the suspicious for malignancy group (p = 0.006). The comparison of the ultrasonographic characteristics of the malignant and benign nodules revealed hypoechogenicity and microcalcification to be more common in malignant nodules (34.3 vs. 16.9 %, p = 0.005; 27.1 vs. 13.1 %, p = 0.014; respectively). While 92.3 % of the malignant nodules were ≥1 cm, 82.9 % of the benign nodules were ≥1 cm (p = 0.042). We believe that as the patients at Hurthle cell lesion group have higher risk of malignancy than the patients with Follicular Neoplasia so total thyroidectomy will be suitable for these patients. [corrected]. In addition, microcalcification and hypoechoic nodules at patients with indeterminate cytology can be related with increased risk of malignancy. [corrected].

Elastosonographic strain index in thyroid nodules with atypia of undetermined significance

AIM

In this study, we aimed to evaluate the diagnostic accuracy of elastosonography (ESG) scoring and strain ratio in patients who had atypia of undetermined significance (AUS) cytology and underwent surgery for thyroid nodules.

MATERIALS AND METHODS

250 patients were included in this study. They had at least one nodule in thyroid USG, underwent USG-guided FNAC according to the current guidelines and had AUS cytology according to the Bethesda system. Both elastosonographic color scoring and strain index were evaluated.

RESULTS

A total of 270 nodules in 250 patients were evaluated. Histopathologically, 81 (30 %) nodules were malignant and 189 (70 %) were benign. According to the ESG, 10 (3.7 %) nodules were assigned a score of 1, while 13 (4.8 %) nodules were assigned a score of 5. All of the nodules with an ESG score of 1 were histopathologically benign and 92.3 % of the patients with ESG score 5 were in the malignant group. Median SI in the benign histopathologic group was significantly lower compared to malignant group [(2.58 (IQR = 2.35) vs. 14.54 (IQR = 10.71)]. The optimal SI cut-off value to distinguish between the benign and malignant nodules was 6.66, with a sensitivity of 98.77 % and specificity of 96.30 %.

CONCLUSION

Our study is one of the first studies evaluating the role of SI for discriminating malignant and benign nodules with AUS cytology. Malignant nodules had a significantly higher stiffness compared to benign ones and SI had high sensitivity, specificity, positive predictive value, negative predictive value and accuracy for these nodules. We think SI may be helpful for the presurgical selection of nodules with AUS cytology.

Association between Pituitary Langerhans Cell Histiocytosis and Papillary Thyroid Carcinoma

Here we report a case of panhypopituitarism caused by pituitary Langerhans cell hystocitosis (LCH) in a 22-year-old woman affected by papillary thyroid carcinoma (PTC). Although several cases of the coexistence of PTC and LCH within thyroid tissue have been described in relative literature, in this case, the patient presented a unique suprasellar retrochiasmatic histocytosis localization which, to the best of our knowledge, had never been described before in association with PTC. Even if this aspect is not addressed in the present case report, it is worth noting that about 50% of the patients affected either by LCH or PTC are characterized by activating mutations of the proto-oncogene BRAF. This, along with other clinical studies, may warrant further biomolecular large-scale case study investigations in order to evaluate a possible connection between the 2 conditions and shed light on the etiology of these diseases, which are still largely unknown.

Predictive value of nodal metastases on local recurrence in the management of differentiated thyroid cancer. Retrospective clinical study

Background

The significance of nodal metastases, very common in papillary thyroid cancer, and the role of lymph node dissection in the neoplasm management, are still controversial. The impact of lymph node involvement on local recurrence and long-term survival remains subject of active research. With the aim to better analyze the predictive value of lymph node involvement on recurrence and survival, we investigated the clinico-pathological patterns of local relapse following total thyroidectomy associated with lymph node dissection, for clinical nodal metastases papillary thyroid cancer, in order to identify the preferred surgical treatment.

Methods

Clinical records, between January 2000 and December 2006, of 69 patients undergoing total thyroidectomy associated with selective lymph node dissection for clinical nodal metastases papillary thyroid cancer, were retrospectively evaluated. Radioiodine ablation, followed by Thyroid Stimulating Hormone suppression therapy was recommended in every case. In patients with loco regional lymph nodal recurrence, a repeated lymph node dissection was carried out. The data were compared with those following total thyroidectomy not associated with lymph node dissection in 210 papillary thyroid cancer patients without lymph node involvement, at preoperative ultrasonography and intra operative inspection.

Results

Incidence of permanent hypoparathyroidism (iPTH < 10 pg/ml) and permanent monolateral vocal fold paralysis were respectively 1.4 % (1/69) and 1.4% (1/69), similar to those reported after total thyroidectomy "alone". The rate of loco regional recurrence, with positive cervical lymph nodes, following 8 year follow-up, was 34.7% (24/69), higher than that reported in patients without nodal metastases (4.2%). A repeated lymph node dissection was carried out without significant complications.

Conclusions

Nodal metastases are a predictor of local recurrence, and a higher rate of lymph node involvement is expected after therapeutic lymph node dissection associated with total thyroidectomy. The prognostic significance of nodal metastases on long-term survival remains unclear, and more prospective randomized trials are requested to better evaluate the benefits of different therapeutic approaches.

Ultrasound elastography in the head and neck. Part II. Accuracy for malignancy

Ultrasound elastography (USE) describes a variety of ultrasound-based imaging techniques that measure tissue stiffness properties, and is currently under intense investigation for tissue characterization in several anatomic sites. This article summarizes the evidence regarding the accuracy of USE for malignancy in the head and neck. Currently, most published data pertains to small pilot studies with varied methodologies. Encouragingly, most studies have documented promising results for USE in terms of high accuracy for malignancy in thyroid nodules and cervical lymph nodes, which have surpassed conventional sonographic criteria. However, a minority of studies have documented opposite findings. USE seems to be suboptimal for salivary malignancies, and some evidence suggests that USE does not provide useful diagnostic information compared with conventional ultrasonography for miscellaneous neck masses. Further larger studies are required to validate these findings although, in view of the predominance of highly optimistic results for thyroid nodules and cervical lymph nodes, USE may become a useful ancillary technique in the routine diagnostic work-up of lesions in these tissues in the near future.

Elastographic and contrast-enhanced ultrasound features of a benign schwannoma of the common fibular nerve

Differential diagnosis of a mass in the popliteal fossa includes a number of pathologies, such as Baker's cyst, extra-articular ganglia cyst, hematoma, proliferation of adipose tissue, aneurysm of the popliteal artery, thrombosed varicose vein, gouty tophi and benign or malignant soft tissue tumors. Schwannoma is the most common benign peripheral nerve tumor. However, only a few authors have so far reported on schwannomas located on the common fibular nerve. The aim of this paper is to present contrast-enhanced ultrasound and ultrasound elastographic features of a rare case of schwannoma of the common fibular nerve as well as imaging features of a schwannoma of the peripheral nerve.