Diagnostic value of thyroglobulin assay in cervical lymph node fine-needle aspirations for metastatic differentiated thyroid cancer

[Diagnosis of lymph node metastases from papillary thyroid carcinoma by measuring thyroglobulin in the puncture needle. Calculation of optimal cut-off point in our series]

Fine-needle aspiration cytology (FNAC), used in suspicious cervical lymph nodes of unknown origin is frequently inconclusive and prone to false negatives. In order to evaluate the usefulness of measuring thyroglobulin in the washing with saline solution of the puncture needle for the diagnosis of metastasis of papillary carcinoma of the thyroid, an optimal thyroglobulin cutting point has to be calculated, being positive or negative depending on whether the thyroglobulin levels are higher or lower than the cutting point. We have retrospectively studied 33 patients (19 women and 14 men) with an average age of 49.3 years, with papillary carcinoma of the thyroid and suspected lymph node metastasis. Of them 16 (47.1%) had a positive FNAC. To determine thyroglobulin predictive capacity with regards to the metastasis of papillary carcinoma of the thyroid a ROC analysis was carried out with an under curve area UCA: 0.987 (CI 95%: 0.808-1.000) obtaining, using Youden's J statistic, 0.4 ng/ml as the thyroglobulin cutting point with best predictive capacity. The study of the relationship between thyroglobulin and the preservation/non-preservation of the thyroid showed statistically significant differences (P=.023). Our results validate 0.4 ng/ml of thyroglobulin as an optimal cutting point of the presence of metastasis of papillary carcinoma of the thyroid in lymph nodes. When reviewing the bibliography, a great diversity of cutting points may be found, which is explained mainly by the great inter-observer and inter-assay variability. That is why we recommend calculating each laboratory's own optimal cutting point; and determine in subsequent studies two cutting points depending on whether or not thyroid is preserved.

A Combination of Contrast-Enhanced Ultrasound and Thyroglobulin Level in Fine-Needle Aspirates Improves Diagnostic Accuracy for Metastatic Lymph Nodes of Papillary Thyroid Carcinoma

OBJECTIVE

To evaluate the diagnostic performance of contrast-enhanced ultrasound (CEUS) combined with thyroglobulin (Tg) levels in fine-needle aspirates (FNA) washout fluid (FNA-Tg) in diagnosing cervical lymph node (LN) metastasis in papillary thyroid cancer (PTC) patients.

METHODS

Data from 190 LNs in 167 patients suspected of metastasis from the US between November 2018 and September 2020 were included. All subjects underwent FNA, CEUS, and FNA-Tg examinations. The final outcomes were confirmed by histopathological or cytological examination or follow-up imaging. Data were analyzed using the Wilcoxon rank-sum or chi-squared test. The diagnostic efficacy of FNA, CEUS, and FNA-Tg in diagnosing LNs was compared.

RESULTS

A cutoff value of 6.15 ng/ml (AUC 0.925, 95% confidence interval (CI) 0.885-0.966) successfully identified metastatic LNs. FNA missed 58 LN metastases, of these, 94.8% (55/58) were correctly diagnosed using the combination of CEUS and FNA-Tg. FNA-Tg showed higher sensitivity (90.2%), NPV (86.1%) and accuracy (88.9%) than either FNA (48.2, 57.4 and 69.5%, respectively) or CEUS (82.1, 67.7 and 70.5%, respectively) alone. The combination of CEUS, FNA and FNA-Tg resulted in maximal sensitivity (100%) and NPV (100%) but reduced specificity (51.3%) and overall diagnostic accuracy (80.0%). After adding FNA-Tg to discordant samples between CEUS and FNA, 81.9% of LNs (77/94) were correctly diagnosed.

CONCLUSIONS

The combination of FNA, FNA-Tg and CEUS was found to be a promising imaging tool in detecting metastatic LNs in PTC patients.

Value of thyroglobulin combined with ultrasound-guided fine-needle aspiration cytology for diagnosis of lymph node metastasis of thyroid carcinoma

BACKGROUND

Surgery for thyroid carcinoma offers a good prognosis; however, cervical lymph node metastasis may occur in the early stage. An effective diagnostic method can accurately guide clinical surgical planning and the scope of lymph node dissection, ultimately improving patient prognosis.

AIM

To explore the diagnostic value of fine-needle aspiration of thyroglobulin (FNA-Tg) combined with ultrasound (US)-guided fine-needle aspiration cytology for cervical lymph node metastasis in thyroid carcinoma.

METHODS

We enrolled 209 pathologically confirmed thyroid carcinoma patients who visited our hospital between Jan 2017 and Dec 2020. Patients were tentatively diagnosed with cervical lymph node enlargement using preoperative US. They underwent US-guided fine-needle aspiration cytology and FNA-Tg. The value of single and combined application of the two methods for the diagnosis of cervical lymph node metastasis was calculated. The factors affecting FNA-Tg for diagnosis were analyzed using univariate and multivariate methods.

RESULTS

FNA-Tg values were significantly higher among patients with positive cervical lymph node metastasis. The sensitivity and specificity of US-guided fine-needle aspiration cytology, FNA-Tg, and US-guided fine-needle aspiration cytology + FNA-Tg were 85.48% and 90.59%, 83.06% and 87.06%, and 96.77% and 91.76%, respectively. The area under the receiver operating characteristic curve for US-guided fine-needle aspiration cytology, FNA-Tg, and the two combined, was 0.880, 0.851, and 0.943, respectively. A long diameter/short diameter ratio < 2, an insufficient number of acquired cells, a low serum thyroglobulin level, and an absence of typical metastatic US features increased the risk of cervical lymph node metastasis in thyroid carcinoma patients misdiagnosed using FNA-Tg.

CONCLUSION

The diagnostic value of FNA-Tg for detecting cervical lymph node metastasis is not high; however, combined with US-guided fine-needle aspiration cytology, it is significantly improved.

The diagnostic value of thyroglobulin in fine-needle aspiration of metastatic lymph nodes in patients with papillary thyroid cancer and its influential factors

Thyroglobulin (Tg) measurement in fine-needle aspiration (FNA-Tg) has proved to be an excellent tool to identify metastatic cervical lymph nodes (CLN) before or after surgery for papillary thyroid cancer (PTC). The diagnostic value of FNA-Tg for metastatic CLN in PTC patients is higher than that of ultrasound (US) and fine-needle aspiration cytology (FNAC), especially for small or cystic LN. The combination of FNAC and FNA-Tg can provide nearly 100% diagnostic sensitivity and specificity for CLN metastasis. However, the cutoff values of FNA-Tg for metastatic CLN have not been standardized, and the reported cutoff values of FNA-Tg range from 0.2 ng/ml to 77 ng/ml because of the differences in study samples, Tg measurement methods, Tg assays kits, etc. Serum anti-thyroglobulin antibody level, serum thyroglobulin level, the presence or absence of thyroid glands, and the characteristics of CLN may be factors affecting the accuracy of FNA-Tg. This review summarizes the recent research on the application of FNA-Tg in the diagnosis of metastatic LN in PTC and provides a reliable basis for the clinical diagnosis of cervical lymph node metastasis.

Image-guided lymph node fine-needle aspiration: the Johns Hopkins Hospital experience

INTRODUCTION

Although the diagnostic utility of lymph node fine-needle aspiration (FNA) is well established in the evaluation of metastatic malignancy, its value in the diagnosis of lymphoma is more controversial; yet, there is a growing trend among practitioners towards less-invasive procedures such as FNA and core needle biopsy (CNB). The guidelines recently published by the American Society for Clinical Pathology/College of American Pathology (CAP) regarding the workup of lymphoma include recommendations on the value and limitations of FNA.

MATERIALS AND METHODS

We reviewed 1237 image-guided lymph node aspirates from 695 procedures (410 nodes from 360 ultrasound [US]-guided cases, 799 from 309 endobronchial ultrasound [EBUS], 25 from 23 endoscopic ultrasound [EUS], and 3 from 3 computed tomography [CT]).

RESULTS

The majority (40 of 46, 87%) of lymph nodes suspected of lymphomatous involvement were aspirated under ultrasound. Core needle biopsy [CNB] was obtained for 41 (89%) lymph nodes, including all 40 US specimens. Flow cytometry (FC) was performed on 37 (80%) aspirates; aspirates without FC were from patients who had a history of Hodgkin lymphoma, or showed granulomata or non-hematologic malignancy onsite. Thirty-one (67%) lymph nodes were sent for review by hematopathology. Forty-two (91%) lymph node FNA/CNB yielded actionable diagnoses. Seventeen of 241(7%) cases aspirated for other indications (14 US, 3 EBUS) were involved by a lymphoproliferative process. All were reviewed by hematopathology. All 14 US cases had FC and CNB.

CONCLUSION

Our institutional approach towards lymph node cytopathology for lymphoma workup appears to be in accordance with the new CAP guidelines, and demonstrates a potential triage and workflow model for lymph node FNA specimens that allows for accurate diagnosis in cases where lymphoma is a consideration.

Diagnostic Algorithm for Metastatic Lymph Nodes of Differentiated Thyroid Carcinoma

Simple Summary

Fine-needle aspiration cytology (FNAC) with measurement of thyroglobulin concentrations obtained through aspiration (FNA-Tg) is routinely used for the diagnosis of metastatic lymph nodes (LNs) from differentiated thyroid carcinomas. However, some areas of uncertainty remain, including the optimal FNA-Tg cutoff and its interpretation based on ultrasound (US) features. In this study, we evaluated the appropriate strategies for interpreting FNAC and FNA-Tg results based on the sonographic features of LNs. We confirmed that the malignancy rate of LNs found to be malignant by FNAC or elevated FNA-Tg was sufficiently high to be diagnosed as metastasis, regardless of the sonographic features. The malignancy rate of LNs with indeterminate or benign FNAC findings and low FNA-Tg were stratified according to their sonographic features. We propose a diagnostic algorithm, based on combined FNAC, FNA-Tg, and US features of LNs, for diagnosing metastatic LNs of differentiated thyroid carcinomas.

Abstract

We aimed to evaluate appropriate strategies for interpreting fine-needle aspiration cytology (FNAC) and thyroglobulin concentrations obtained through aspiration (FNA-Tg) results based on the sonographic features of lymph nodes (LNs). Consecutive patients who underwent ultrasound-guided FNAC and FNA-Tg for metastatic LNs from differentiated thyroid carcinomas (DTCs) from January 2014 to December 2018 were reviewed retrospectively. LNs were categorized sonographically as suspicious, indeterminate, or benign. The optimal FNA-Tg cutoff for metastatic LNs was evaluated preoperatively, after lobectomy, and after total thyroidectomy. The diagnostic performances of FNA-Tg, FNAC, and their combination were analyzed based on the sonographic features of LNs. The malignancy rates of LNs were analyzed based on the sonographic features, FNAC, and FNA-Tg results. Of the 1543 LNs analyzed, 528 were benign, whereas 1015 were malignant. FNA-Tg increased the sensitivity and accuracy of FNAC for LNs. The malignancy rate of LNs found to be malignant by FNAC or elevated FNA-Tg ranged from 82% to 100%, regardless of the sonographic features. The malignancy rate of LNs with indeterminate or benign FNAC findings and low FNA-Tg were stratified according to their sonographic features. We propose a diagnostic algorithm, based on combined FNAC, FNA-Tg, and ultrasound features of LNs, for diagnosing metastatic LNs of DTCs.

Fine needle aspiration wash out for thyroglobulin determination in the differential diagnosis of lung lesions

PURPOSE

Distant metastasis from papillary thyroid cancer is rare, and the more frequent site is neck and bone. During follow-up after surgery new distant lesions could appear, while Tg levels remain normal. When suspicious lesions are superficial, fine needle aspiration is the first choice. In case of deeper localization, the diagnosis could need more invasive procedure, such as in case of lung nodules.

METHODS

We report a case of a patient with a lung lesion suspicious for metastasis from papillary thyroid cancer. The patient underwent thyroidectomy and radioiodine 10 years before and after 2 years of follow-up was submitted to right cervical lymphadenectomy for nodal recurrence. During the following 5 years Tg values on TSH suppressive treatment ranged 3.7-5.4, always with negative TgAb and negative neck US. CT scans showed the presence of a single nodule in the left lung with subpleuric localization, progressively increasing in size. A CT-guided fine needle aspiration was performed.

RESULTS

The Tg levels measured in the washout out of the Chiba's needle (386 ng/ml) provided an unequivocal demonstration of the thyroid origin of the nodule.

CONCLUSIONS

Thyroglobulin measurement in the specimen obtained from CT-guided fine needle aspiration is a useful and effective tool to diagnose lung metastasis from thyroid cancer. This procedure could avoid a surgical approach that is more invasive and potentially detrimental for the patient.

Unstimulated Serum Thyroglobulin Levels after Thyroidectomy and Radioiodine Therapy for Intermediate-Risk Thyroid Cancer Are Not Always a Reliable Marker of Lymph Node Recurrence: Case Report and a Lesson for Clinicians

Over 50% of patients with papillary thyroid carcinoma (PTC) have cervical lymph-node metastasis on diagnosis, and up to 30% show nodal recurrence after surgery plus radioactive iodine (131I) (RAI) therapy. The combination of ultrasonography (US) and fine-needle aspiration cytology (FNAC) and the measurement of thyroglobulin (Tg) in washout fluid are cornerstones in the diagnosis of nodal metastasis. In the absence of anti-Tg antibodies, unstimulated serum thyroglobulin (Tg) levels are generally a reliable marker of recurrent disease, and 18F-FDG positron emission tomography (PET)/computed tomography (CT) plays an important role in the imaging work-up. We report the case of a 65-year-old man evaluated for a large multinodular goitre which caused compressive symptoms; the dominant nodule in the left lobe presented suspicious features on US. Thyroid function showed subclinical hypothyroidism, calcitonin was normal, serum thyroglobulin levels were low, and anti-thyroid antibodies were absent. The prevalent left nodule showed an intense uptake on 18F-FDG PET/CT but proved benign at FNAC. On the basis of the suspicious clinical and imaging features, total thyroidectomy was performed. Histology revealed a tall-cell variant of PTC with scattered expression of Tg and diffuse high expression of cytokeratin (CK) 19; RAI therapy was performed. Within 6 years of surgery, left laterocervical lymph-node recurrence was twice detected (first at levels II and III, then at levels IV and VI) by US and 18F-FDG-PET/CT and was confirmed by FNAC. Tg levels in the washout fluid proved clearly diagnostic of metastasis only in the second, larger, recurrence, whereas serum Tg levels (in the absence of anti-Tg antibodies) always remained undetectable on L-thyroxine therapy. Surgery was performed on both recurrences, and histology confirmed lymph-node metastasis of PTC. Immunohistochemical expression of Tg and CK 19 was similar to that of the primary tumour. No further relapses have occurred to date. Posttherapy (surgery and RAI) unstimulated serum Tg levels may not be a reliable marker of nodal recurrence in patients with differentiated thyroid cancer (DTC) that produces low amounts of Tg.

Diagnostic values of thyroglobulin in lymph node fine-needle aspiration washout: a systematic review and meta-analysis diagnostic values of FNA-Tg

Thyroglobulin measurement in the needle washout after fine-needle aspiration (FNA-Tg) served as an important measurement for suspicious recurrent or metastatic lesions. We conducted a pooled analysis to evaluate the diagnostic accuracy of FNA-Tg and searched electronic databases for original articles in English from 1993 through 2017. Finally, a total of 22 studies containing 2,670 lymph nodes (LNs) that enrolled participants with suspicious neck LNs during thyroid nodule workup or papillary thyroid cancer (PTC) follow-up were included. In our analysis, the overall pooled sensitivity for FNA-Tg was 0.91 (95%CI: 0.87-0.93), specificity was 0.94 (95% CI: 0.91-0.96). Meta regression revealed that the cutoff value and status of serum Tg were sources of heterogeneity for sensitivity, and the cutoff value was source of heterogeneity for specificity. Additionally, the cutoff value and status of serum Tg were sources of heterogeneity in the joint model. Subgroup analysis about cut-off value showed that the choice of 1 ng/mL had highest sensitivity, 40 ng/mL had highest specificity. At last, we arrived at the conclusion that FNA-Tg measurement had high specificity and sensitivity in the early detection of LNs metastases from PTC by our meta-analysis. The technique was simple and could be recommended to apply in any FNA facility, especially when LN were small-sized. Significantly, a better standardization of criteria for FNA-Tg detection and cutoff value was required to provide useful data and to improve management of PTC patients in the future.

Superior detection of metastatic cystic lymphadenopathy in patients with papillary thyroid cancer by utilization of thyroglobulin washout

BACKGROUND

Fine-needle aspiration (FNA) cytology has been the standard of care in the workup of cervical lymph nodes (LNs) in patients with recurrent papillary thyroid cancer (PTC) and suspicious cervical LNs. Recently, FNA thyroglobulin (TG) washout measurement has been proposed as an adjunct in the management of these patients. We hypothesize that using FNA-TG washout for suspicious cervical LNs would increase the accuracy of diagnosing metastatic disease especially in cystic and highly vascular cervical LN in patients with recurrent PTC.

METHODS

This is a retrospective study of a prospectively collected database for patients with thyroid cancer who underwent preoperative FNA followed by selective neck dissection by one surgeon at an academic institution. FNA-cytology and FNA-TG washout were performed simultaneously. A total of 138 patients were included in our study, of which 92 (66.7%) had undergone surgical intervention. Results of both methods were then correlated with the final surgical pathology.

RESULTS

FNA-cytology alone showed a sensitivity of 80.0%, specificity of 100.0% with a negative predictive value (NPV) of 60.0%. By contrast, FNA-TG washout had a sensitivity of 95.8%, specificity of 90.5% with a NPV of 86.4%. Combination of the FNA-cytology with FNA-TG washout of cystic/highly vascular LN increased the accuracy of diagnosis with a sensitivity of 98.2%, specificity of 100.00% with a NPV of 95.0%. All 14 malignant cervical LNs with false-negative FNA-cytology showed elevated FNA-TG washout, 10 (71.4%) of which were cystic in nature and 4 were highly vascular on ultrasonography.

CONCLUSION

FNA-TG washout increases the diagnostic accuracy in detecting metastatic disease in patients with recurrent thyroid cancer. FNA-TG washout may be of special diagnostic importance in cystic or highly vascular LNs, which might have falsely negative cytology.

LEVEL OF EVIDENCE

2B.

Identification of metastatic papillary thyroid carcinoma in FNA specimens using thyroid peroxidase immunohistochemistry

INTRODUCTION

We evaluated immunohistochemical staining for thyroid peroxidase (TPO), a glycoprotein found in the apical plasma membrane of thyroid follicular cells, as a marker for metastatic PTC in FNA samples and compared results with thyroglobulin (Tg) and thyroid transcription factor 1 (TTF1) staining.

METHODS

Cell block sections prepared from 100 FNA specimens were stained with a rabbit monoclonal antibody to TPO (EP159). The FNAs included 64 metastatic malignancies from non-thyroid primary sites, including 18 lung, and 36 cases of thyroid tumours (29 PTC, six cases of medullary thyroid carcinoma and one thyroid anaplastic carcinoma). Thyroid tumours were stained with TTF1 and Tg in addition to TPO. All cases of metastatic lung carcinoma also had TTF-1 staining results.

RESULTS

TPO staining was negative in all non-thyroid malignancies. Ninety percent (26/29) of PTC were positive. All positive cases showed strong cytoplasmic staining, although 54% (14/26) showed positivity in less than half of the cells. By comparison, Tg staining of TPC cases was present in 62% and TTF-1 in 100%. In addition to showing higher sensitivity, interpretation of staining results with TPO was generally easier with than Tg. All metastatic lung adenocarcinomas were positive for TTF-1 and TPO negative. The six medullary cancers showed positivity in 17%, 0% and 83% with TPO, Tg and TTF-1, respectively.

CONCLUSIONS

TPO (mAb EP159) may be a useful addition to immunohistochemical panels for FNA specimens where metastatic PTC is a consideration, particularly in cases where metastatic lung carcinoma features in the differential diagnosis.

Measurement of thyroglobulin, calcitonin, and PTH in FNA washout fluids

Different imaging tools, circulating endocrine markers, and fine-needle aspiration (FNA) cytology are of great importance in the diagnosis and follow-up of different thyroid and parathyroid diseases. Sometimes, however, they are conflicting or inconclusive: interestingly, measuring endocrine markers (i.e. thyroglobulin, calcitonin, parathyroid hormone) in fluids from FNA proved to be a very useful complementary diagnostic tool in such cases. The determination of endocrine markers in fluids other than serum/plasma has been developed in the last years. Although studies have reported overall satisfactory results, a good standardization of procedures has not yet been reached, and further efforts should be made in order to better define pre-analytical, analytical, and post-analytical aspects. Here we reviewed critically the literature on the measurement of FNA endocrine markers, focusing on laboratory issues, such as preparation of the sample, choice of solution, and technical features of determination of these markers. Indeed, information for use of FNA-Tg, FNA-CT, and FNA-PTH in clinical practice was also provided.

Effects of sample storage and diluents in the reliability of thyroglobulin measurement in the washout of fine needle aspirates

OBJECTIVE

To evaluate two variables affecting Thyroglobulin stability in the washout of fine needle aspiration biopsies of thyroid nodules and metastatic lymph nodes.

MATERIALS AND METHODS

Thyroglobulin stability after storage at -20 °C up to 14 days was studied in washout performed with normal saline solution and further dilutions with normal saline solution from five metastatic thyroid nodes and six benign thyroid nodules. We also studied thyroglobulin stability in diluents compared with normal saline solution: 4% bovine serum albumin in normal saline solution and diluents free from thyroglobulin or Calcitonin or parathyroid hormone in paired and simultaneous thyroglobulin measurements of washout dilutions from 5/6 benign thyroid nodules and 2/5 metastatic lymph nodes. Thyroglobulin and Thyroglobulin antibodies were measured by a chemiluminescent assay. Positive samples with thyroglobulin antibodies in serum and/or washout were excluded.

RESULTS

Thyroglobulin decreased with storage in washout or dilutions of washout performed in normal saline solution (p < 0.05). Lower thyroglobulin concentrations, close to the commonly used cut-off (1.1 ng/mL), showed the highest decrease as soon as after 1 day of storage. Diluents other than normal saline solution stabilized thyroglobulin in dilutions of all washout.

CONCLUSIONS

The results suggest that the reliability of thyroglobulin measurements in washout of fine needle aspirates could be preserved by immediate measure of thyroglobulin or the use of stabilizing diluents to perform washout.

Influence of presence/absence of thyroid gland on the cutoff value for thyroglobulin in lymph-node aspiration to detect metastatic papillary thyroid carcinoma

Background

Thyroglobulin measurement with fine-needle aspiration (Tg-FNA) is a sensitive method for detecting metastatic papillary thyroid carcinoma (PTC). However, the diagnostic threshold is not well established and the influence of the thyroid gland on the cutoff value is also controversial. In this study, patients were classified into two groups according to the presence or absence of thyroid tissue, to determine an appropriate cutoff value for clinical practice.

Methods

Patients with a history of thyroid nodules or surgery for PTC and with enlarged cervical lymph nodes on an FNA examination were enrolled for Tg-FNA detection.

Results

One hundred ninety-six lymph nodes (189 patients) were included: 100 from preoperative patients, 49 from patients treated with partial thyroid ablation, and 47 from patients with total thyroid ablation. In 149 lymph nodes from patient with thyroids, the cutoff value for Tg-FNA was 55.99 ng/mL (sensitivity, 95.1%; specificity, 100%), whereas in 47 lymph nodes from patients without a thyroid, it was 9.71 ng/mL (sensitivity, 96.7%; specificity, 100%). Thus, the cutoff value for Tg-FNA was higher in patients with thyroids than in patients without thyroids.

Conclusions

The cutoff value for Tg-FNA is influenced by residual thyroid tissue, and a higher cutoff value is recommended for patients with thyroids than for patients without thyroids.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-017-3296-3) contains supplementary material, which is available to authorized users.

AMERICAN ASSOCIATION OF CLINICAL ENDOCRINOLOGISTS, AMERICAN COLLEGE OF ENDOCRINOLOGY, AND ASSOCIAZIONE MEDICI ENDOCRINOLOGI MEDICAL GUIDELINES FOR CLINICAL PRACTICE FOR THE DIAGNOSIS AND MANAGEMENT OF THYROID NODULES--2016 UPDATE

Thyroid nodules are detected in up to 50 to 60% of healthy subjects. Most nodules do not cause clinically significant symptoms, and as a result, the main challenge in their management is to rule out malignancy, with ultrasonography (US) and fine-needle aspiration (FNA) biopsy serving as diagnostic cornerstones. The key issues discussed in these guidelines are as follows: (1) US-based categorization of the malignancy risk and indications for US-guided FNA (henceforth, FNA), (2) cytologic classification of FNA samples, (3) the roles of immunocytochemistry and molecular testing applied to thyroid FNA, (4) therapeutic options, and (5) follow-up strategy. Thyroid nodule management during pregnancy and in children are also addressed. On the basis of US features, thyroid nodules may be categorized into 3 groups: low-, intermediate-and high-malignancy risk. FNA should be considered for nodules ≤10 mm diameter only when suspicious US signs are present, while nodules ≤5 mm should be monitored rather than biopsied. A classification scheme of 5 categories (nondiagnostic, benign, indeterminate, suspicious for malignancy, or malignant) is recommended for the cytologic report. Indeterminate lesions are further subdivided into 2 subclasses to more accurately stratify the risk of malignancy. At present, no single cytochemical or genetic marker can definitely rule out malignancy in indeterminate nodules. Nevertheless, these tools should be considered together with clinical data, US signs, elastographic pattern, or results of other imaging techniques to improve the management of these lesions. Most thyroid nodules do not require any treatment, and levothyroxine (LT4) suppressive therapy is not recommended. Percutaneous ethanol injection (PEI) should be the first-line treatment option for relapsing, benign cystic lesions, while US-guided thermal ablation treatments may be considered for solid or mixed symptomatic benign thyroid nodules. Surgery remains the treatment of choice for malignant or suspicious nodules. The present document updates previous guidelines released in 2006 and 2010 by the American Association of Clinical Endocrinologists (AACE), American College of Endocrinology (ACE) and Associazione Medici Endocrinologi (AME).

Thyroid Cancer in Pediatrics

Well differentiated thyroid cancer (DTC) in children is characterized by a high rate of response to treatment and low disease-specific mortality. Treatment of children with DTC has evolved toward a greater reliance on evaluation and monitoring with serial serum thyroglobulin measurements and ultrasound examinations. Radioiodine therapy is recommended for thyroid remnant ablation in high-risk patients, treatment of demonstrated radioiodine-avid local-regional disease not amenable to surgical resection, or distant radioiodine-avid metastatic disease. Sufficient time should be given for benefits of radioiodine therapy to be realized, with follow-up monitoring. Re-treatment with radioiodine can be deferred until progression of significant disease manifests.

2015 American Thyroid Association Management Guidelines for Adult Patients with Thyroid Nodules and Differentiated Thyroid Cancer: The American Thyroid Association Guidelines Task Force on Thyroid Nodules and Differentiated Thyroid Cancer

BACKGROUND

Thyroid nodules are a common clinical problem, and differentiated thyroid cancer is becoming increasingly prevalent. Since the American Thyroid Association's (ATA's) guidelines for the management of these disorders were revised in 2009, significant scientific advances have occurred in the field. The aim of these guidelines is to inform clinicians, patients, researchers, and health policy makers on published evidence relating to the diagnosis and management of thyroid nodules and differentiated thyroid cancer.

METHODS

The specific clinical questions addressed in these guidelines were based on prior versions of the guidelines, stakeholder input, and input of task force members. Task force panel members were educated on knowledge synthesis methods, including electronic database searching, review and selection of relevant citations, and critical appraisal of selected studies. Published English language articles on adults were eligible for inclusion. The American College of Physicians Guideline Grading System was used for critical appraisal of evidence and grading strength of recommendations for therapeutic interventions. We developed a similarly formatted system to appraise the quality of such studies and resultant recommendations. The guideline panel had complete editorial independence from the ATA. Competing interests of guideline task force members were regularly updated, managed, and communicated to the ATA and task force members.

RESULTS

The revised guidelines for the management of thyroid nodules include recommendations regarding initial evaluation, clinical and ultrasound criteria for fine-needle aspiration biopsy, interpretation of fine-needle aspiration biopsy results, use of molecular markers, and management of benign thyroid nodules. Recommendations regarding the initial management of thyroid cancer include those relating to screening for thyroid cancer, staging and risk assessment, surgical management, radioiodine remnant ablation and therapy, and thyrotropin suppression therapy using levothyroxine. Recommendations related to long-term management of differentiated thyroid cancer include those related to surveillance for recurrent disease using imaging and serum thyroglobulin, thyroid hormone therapy, management of recurrent and metastatic disease, consideration for clinical trials and targeted therapy, as well as directions for future research.

CONCLUSIONS

We have developed evidence-based recommendations to inform clinical decision-making in the management of thyroid nodules and differentiated thyroid cancer. They represent, in our opinion, contemporary optimal care for patients with these disorders.

The value of combined application of ultrasound-guided fine needle aspiration cytology and thyroglobulin measurement for the diagnosis of cervical lymph node metastases from thyroid cancer

Objective:

The aim of this study was to explore the diagnostic value of ultrasound-guided (US-guided) fine-needle aspiration cytology (FNAC), thyroglobulin measurement on fine-needle aspiration (FNA-Tg), combined US-guided FNAC, and the ratio between FNA-Tg and serum Tg (FNA-Tg/serum Tg) for patients with cervical lymph node (CLN) metastases from thyroid carcinoma.

Methods:

We selected 148 patients with thyroid cancer with suspicious CLN metastases who met the inclusion criteria. FNAC findings, FNA-Tg levels, and serum Tg levels were evaluated before surgical treatment. The results of FNAC and FNA-Tg from CLNs were analyzed retrospectively.

Results:

Ninety-four of 148 cases were metastatic and 54 were benign. The sensitivity, specificity, and accuracy of FNAC were 68.1%, 100.0%, and 79.7%, respectively. The sensitivity, specificity, and accuracy of FNA-Tg/serum Tg were 91.5%, 88.9%, and 90.5%, respectively. The sensitivity, specificity, and accuracy of FNA-Tg [10 ng/mL] were 98.9%, 68.5%, and 87.8%, respectively. The sensitivity, specificity, and accuracy of combined US-guided FNAC and FNA-Tg/serum Tg were 95.7%, 96.3%, and 95.9%, respectively. There was a statistically significant difference between FNAC and combined US-guided FNAC and FNA-Tg/serum Tg for sensitivity, specificity, and accuracy (P < 0.05).

Conclusion:

The method of FNA-Tg/serum Tg is sensitive enough for diagnosing CLN metastases from thyroid cancer. The combined application of US-guided FNAC and FNA-Tg/serum Tg contributes to improving the accuracy of diagnosing CLN metastases in patients with thyroid cancer.

Glycan-Dependent Mutual and Reversible Sequestration of Two Thyroid Cancer Biomarkers

BACKGROUND

Thyroglobulin (Tg), the major thyroidal protein, plays important roles in thyroid hormone biosynthesis and in autoimmune thyroid diseases (AITD). Tg also serves as a pre- and postoperative biomarker of differentiated thyroid cancer (DTC). The endogenous β-galactoside binding lectin galectin-3 (Gal-3), secreted by transformed thyroid cells, has been shown to be another useful biomarker of DTC. Tg contains covalently linked complex-type glycans that can serve as binding epitopes of Gal-3. The objective of the study is to investigate the interaction between Tg and Gal-3 and discuss its potential consequences.

METHODS

Binding interaction between Tg and Gal-3 was first studied by hemagglutination inhibition assays. Subsequently, a detailed analysis of binding thermodynamics was carried out by isothermal titration calorimetry. Quantitative precipitation was performed to study the complex formation between Tg and Gal-3 and to determine the binding stoichiometry. The concentration-dependent rate and amount of complex formation between Tg and Gal-3 was examined spectrophotometrically. A similar approach was taken to study the effect of free Tg and Gal-3 on preformed Tg-Gal-3 complex.

RESULTS

Quantitative biochemical and biophysical data show that these two biomarkers produced by thyroid cancer cells interact with each other with submicromolar affinity and form an insoluble complex at their stoichiometric concentration. One Tg molecule could bind up to 14 molecules of Gal-3. Such complex formation mutually sequestered both Tg and Gal-3, decreasing the concentration of their freely available forms. Formation of the Tg-Gal-3 complex was reversible as the preformed complex was dissolved by free Tg as well as free Gal-3. While free Tg rapidly dissolved preformed Tg-Gal-3 complex in a concentration-dependent manner, Gal-3 was found to be much less efficient and slowly dissolved only a fraction of the preformed complex at a relatively higher Gal-3 concentration.

CONCLUSIONS

Complex formation between Tg and Gal-3 through high affinity binding and the sensitivity of the complex to free Tg and Gal-3 can potentially influence their biological functions. Interactions between Tg and Gal-3 might also interfere with their clinical detection, the same way Tg autoantibody (TgAb) is reported to interfere with Tg assays. The data support a model of Gal-3-mediated homeostatic process of Tg.

Neck schwannoma diagnosed by core needle biopsy: a case report

Here we present a case of a 58 year old man referred to our hospital to undergo neck and thyroid ultrasonography (US) following palpable neck mass. US revealed a solid hypoechoic nodule in right thyroid lobe, and a solid lesion on the right laterocervical neck region with ultrasound suspicious features of neoplastic lymph node. In order to achieve a diagnosis of the neck mass and to get a proper evaluation of the thyroid nodule, we decided to perform a fine-needle aspiration (FNA) of both lesions. At cytopathologic examination the thyroid nodule appeared as benign, while cytologic sampling of the neck lesion was inadequate for a proper evaluation. Thus, we performed core needle biopsy (CNB) of the neck lesion like recently proposed for thyroid lesions; also, to definitively exclude malignancy of thyroid nodule, this also underwent CNB. Histologic report of CNB confirmed benign thyroid nodule, while the neck lesion revealed a proliferation of neuronal type consistent with schwannoma. The patient has been addressed to clinical and ultrasonographic follow-up. CNB appears as a safe and minimally-invasive approach to diagnose indeterminate neck masses and avoid unnecessary diagnostic surgery.

Management Guidelines for Children with Thyroid Nodules and Differentiated Thyroid Cancer

BACKGROUND

Previous guidelines for the management of thyroid nodules and cancers were geared toward adults. Compared with thyroid neoplasms in adults, however, those in the pediatric population exhibit differences in pathophysiology, clinical presentation, and long-term outcomes. Furthermore, therapy that may be recommended for an adult may not be appropriate for a child who is at low risk for death but at higher risk for long-term harm from overly aggressive treatment. For these reasons, unique guidelines for children and adolescents with thyroid tumors are needed.

METHODS

A task force commissioned by the American Thyroid Association (ATA) developed a series of clinically relevant questions pertaining to the management of children with thyroid nodules and differentiated thyroid cancer (DTC). Using an extensive literature search, primarily focused on studies that included subjects ≤18 years of age, the task force identified and reviewed relevant articles through April 2014. Recommendations were made based upon scientific evidence and expert opinion and were graded using a modified schema from the United States Preventive Services Task Force.

RESULTS

These inaugural guidelines provide recommendations for the evaluation and management of thyroid nodules in children and adolescents, including the role and interpretation of ultrasound, fine-needle aspiration cytology, and the management of benign nodules. Recommendations for the evaluation, treatment, and follow-up of children and adolescents with DTC are outlined and include preoperative staging, surgical management, postoperative staging, the role of radioactive iodine therapy, and goals for thyrotropin suppression. Management algorithms are proposed and separate recommendations for papillary and follicular thyroid cancers are provided.

CONCLUSIONS

In response to our charge as an independent task force appointed by the ATA, we developed recommendations based on scientific evidence and expert opinion for the management of thyroid nodules and DTC in children and adolescents. In our opinion, these represent the current optimal care for children and adolescents with these conditions.

Diagnostic values of thyroglobulin measurement in fine-needle aspiration of lymph nodes in patients with thyroid cancer

We aimed to evaluate the diagnostic performance of measuring the concentration of thyroglobulin (Tg) in the washout fluid of the needle aspiration (FNA-Tg). We performed a systematic search of MEDLINE (inception to October 2013) and EMBASE (inception to October 2013) for English publications using keywords "thyroid", "aspiration", "washout", and "thyroglobulin". All searches were limited to human studies. We included studies of FNA-Tg measurement in the washout fluid rinsed with 1 ml of normal saline. Eight studies including 843 lymph nodes (LNs) were eligible for this study. The pooled sensitivity and specificity of preoperative studies are 0.89 [95 % CI 0.82-0.95], 0.60 [0.49-0.70], and those of postoperative studies are 1.0 [0.83-1.0], 1.0 [0.92-1.0]. To determine best cutoffs from each preoperative and postoperative study, the distance between the point (0, 1) and each observed cutoff values (1-specificity, sensitivity) was calculated, and the distance is minimal when the cutoff value of 32.04 for preoperative studies and of 0.9 for postoperative one are selected. FNA-Tg can be used for both preoperative and postoperative evaluation of LN metastasis. Although the cutoff values for the FNA-Tg has not been standardized, preoperative values of 32.04 ng/ml and postoperative values of 0.9 ng/ml are recommended for identifying neck LN metastasis.

Thyroglobulin measurement by highly sensitive assays: focus on laboratory challenges

Differentiated thyroid cancer (DTC) is the most common endocrine cancer and its incidence has increased in recent decades. The initial treatment consists of total thyroidectomy followed by ablation of thyroid remnants by radioiodine in most cases. As thyroid cells are the only source of thyroglobulin (Tg), circulating Tg serves as a biochemical marker of persistent or recurrent disease in the follow-up of DTC. Due to the suboptimal clinical detection rate of older Tg assays endogenous or exogenous thyrotropin (TSH) stimulations are recommended for unmasking occult disease. However, the development of new Tg assays with improved analytical sensitivity and precision at low concentrations now allows detection of very low Tg concentrations, reflecting minimal amounts of thyroid tissue, even without the need for TSH stimulation. Even if the use of these assays still has not found its way in current clinical guidelines, such assays are now increasingly used in clinical practice. As serum Tg measurement is a technically challenging assay and criteria to define a ‘highly sensitive’ assay may be different, a good knowledge of the technical difficulties and interpretation criteria is of paramount importance for both clinical thyroidologists, laboratory physicians and scientists involved in the care of DTC patients.

Any detectable thyroglobulin in lymph node biopsy washouts suggests local recurrence in differentiated thyroid cancer

The sensitivity of local recurrence detection in differentiated thyroid cancer (DTC) is increased by measuring thyroglobulin in needle washouts from lymph node fine-needle aspiration biopsies (FNA-Tg). Recent studies have proposed minimum diagnostic threshold values for FNA-Tg and have reported interference from Tg antibodies (Tg Ab), leading to low or false-negative results. The aim of this study was to assess the utility of FNA-Tg in the diagnosis of local DTC recurrence in patients referred to a single pathology service used by our tertiary teaching hospital, the first such study in an Australian cohort. Data were collected from the pathology service database for FNA-Tg over an 18-month period, and the results of 69 FNA-Tg samples from 57 patients were obtained. FNA-Tg findings were compared with cytology and histology when patients proceeded to surgery. Using the functional sensitivity as the cut-off, detectable FNA-Tg (≥0.9 μg/l) had a sensitivity of 95.7%, specificity of 50% and positive predictive value of 95.7%. Our results suggest that detectable FNA-Tg leads to histological confirmation of local nodal DTC recurrence and would support a decision to proceed to surgery. Serum Tg Ab can, however, interfere with FNA-Tg measurements. Thus, we now recommend routine use of FNA-Tg washouts in all lymph node FNA biopsies for the detection of DTC recurrence.

Detectable thyroglobulin with negative imaging in differentiated thyroid cancer patients

In the absence of autoantibodies against thyroglobulin (Tg), Tg measurement nowadays is the cornerstone of clinical management of differentiated thyroid cancer patients. DTC patients presenting with a positive Tg measurement without an anatomical correlate on anatomic imaging provide a management challenge to the attending physician.

Based on the literature we will provide an overview of the most important steps to undertake in such patients and their potential clinical consequences.

Superior mediastinal dissection for papillary thyroid carcinoma: approaches and outcomes

BACKGROUND

Superior mediastinal surgery for thyroid carcinoma is not a standardized procedure like the neck dissection. The objective of this study was to evaluate the effectiveness of superior mediastinal dissection for mediastinal metastasis of papillary thyroid carcinoma (PTC).

METHODS

We conducted a retrospective review of 119 patients who underwent superior mediastinal dissection for the treatment of PTC. The postoperative characteristics and follow-up data were analyzed. Cox regression was performed to identify the factors related to the mediastinal control.

RESULTS

No severe complications occurred in this series. The five-year local (mediastinum) disease-free survival rates of comprehensive (n = 29) and partial (n = 90) superior mediastinal dissection were 86.3 and 84.0%, respectively (log-rank = 0.562; p = 0.452). Different patterns of superior mediastinal dissection did not turn out to be related to mediastinal recurrence in the cox regression. Bilateral paratracheal metastasis was identified as an individual risk factor of mediastinal recurrence with a relative risk value of 4.635 (95% CI: 1.399-15.355; p = 0.012).

CONCLUSIONS

Both partial and comprehensive superior mediastinal dissections are effective and safe for the treatment of mediastinal metastasis of PTC if appropriately designed.

Detection and management of cervical lymph nodes in papillary thyroid cancer

Lymph node metastases in papillary thyroid cancer are a common occurrence; however, the management of clinically negative cervical lymph nodes remains controversial. Preoperative neck ultrasound mapping is crucial, and complete dissection of a nodal compartment is recommended for any metastatic lymph nodes. The role of prophylactic central neck dissection remains controversial. The BRAF V600E mutation is a common mutation in papillary thyroid cancer, and has been associated with more aggressive tumor behavior. Evaluating the BRAF status of tumors may have implications for treatment and surveillance. New areas of research continue to focus on risk stratification and identifying which patients benefit from a more aggressive treatment, such as prophylactic central lymphadenectomy and radioiodine ablation and more intense surveillance strategies.