Detection and surgical treatment of cervical lymph nodes in differentiated thyroid cancer

A combination of risk stratification systems for thyroid nodules and cervical lymph nodes may improve the diagnosis and management of thyroid nodules

Introduction

To assess the performance of the European Thyroid Association Thyroid Imaging and Reporting Data System (EU-TIRADS) and the Korean Thyroid Imaging Reporting and Data System (K-TIRADS), which combine risk stratification systems for thyroid nodules (TN-RSS) and cervical lymph nodes (LN-RSS) in diagnosing malignant and metastatic thyroid cancer in a single referral center.

Methods

We retrospectively analyzed 2,055 consecutive patients who underwent thyroidectomy or fine-needle aspiration (FNA) from January 2021 to December 2022. TNs and LNs were categorized according to the ultrasonography (US) features of EU-TIRADS and K-TIRADS, respectively. The diagnostic performance and postponed malignancy rate (PMR) were compared with those of EU-TIRADS and K-TIRADS. PMR was defined as the number of patients with malignant nodules not recommended for biopsy among patients with cervical LN metastasis.

Results

According to the EU-TIRADS and K-TIRADS, for TN-RSS alone, there were no significant differences in sensitivity, specificity, accuracy, unnecessary FNA rate (UFR), missed malignancy rate (MMR), and PMR between the two TIRADSs (29.0% vs. 28.8%, 50.5% vs. 51.1%, 32.3% vs. 32.2%, 23.6% vs. 23.5%, 88.6% vs. 88.5%, and 54.2% vs. 54.5%, P > 0.05 for all). Combining the LN-RSS increased the diagnostic accuracy (42.7% vs. 32.3% in EU-TIRADS; 38.8% vs. 32.2% in K-TIRADS) and decreased the PMR (54.2% vs. 33.9% in EU-TIRADS; 54.5% vs. 39.3% in K-TIRADS). EU-TIRADS had higher sensitivity and accuracy and lower PMR than K-TIRADS (41.3% vs. 36.7%, 42.7% vs. 38.8%,33.9% vs. 39.3%, P < 0.05 for all).

Conclusions

A combination of TN-RSS and LN-RSS for the management of thyroid nodules may be associated with a reduction in PMR, with enhanced sensitivity and accuracy for thyroid cancers in EU-TIRADS and K-TIRADS. These results may offer a new direction for the detection of aggressive thyroid cancers.

Theranostics of Thyroid Cancer

Molecular imaging is pivotal in evaluating and managing patients with different thyroid cancer histotypes. The existing, pathology-based, risk stratification systems can be usefully refined, by incorporating tumor-specific molecular and molecular imaging biomarkers with theranostic value, allowing patient-specific treatment decisions. Molecular imaging with different radioactive iodine isotopes (ie, I131, I123, I124) is a central component of differentiated carcinoma (DTC)'s risk stratification while [18F]F-fluorodeoxyglucose ([18F]FDG) PET/CT is interrogated about disease aggressiveness and presence of distant metastases. Moreover, it is particularly useful to assess and risk-stratify patients with radioiodine-refractory DTC, poorly differentiated, and anaplastic thyroid cancers. [18F]F-dihydroxyphenylalanine (6-[18F]FDOPA) PET/CT is the most specific and accurate molecular imaging procedure for patients with medullary thyroid cancer (MTC), a neuroendocrine tumor derived from thyroid C-cells. In addition, [18F]FDG PET/CT can be used in patients with more aggressive clinical or biochemical (ie, serum markers levels and kinetics) MTC phenotypes. In addition to conventional radioiodine therapy for DTC, new redifferentiation strategies are now available to restore uptake in radioiodine-refractory DTC. Moreover, peptide receptor theranostics showed promising results in patients with advanced and metastatic radioiodine-refractory DTC and MTC, respectively. The current appropriate role and future perspectives of molecular imaging and theranostics in thyroid cancer are discussed in our present review.

Sonographic Diagnosis of Cervical Lymph Node Metastasis in Patients with Thyroid Cancer and Comparison of European and Korean Guidelines for Stratifying the Risk of Malignant Lymph Node

OBJECTIVE

To evaluate the ultrasonography (US) features for diagnosing metastasis in cervical lymph nodes (LNs) in patients with thyroid cancer and compare the US classification of risk of LN metastasis between European and Korean guidelines.

MATERIALS AND METHODS

From January 2014 to December 2018, US-guided fine-needle aspiration was performed on 836 LNs from 714 patients for the preoperative nodal staging of thyroid cancer. The US features of LNs were retrospectively reviewed for the following features: size, presence of hilum, margin, orientation, cystic change, punctate echogenic foci (PEF), large echogenic foci, eccentric cortical thickening, abnormal vascularity, and cortical hyperechogenicity. A multiple logistic regression analysis was performed to identify the independent US features for the diagnosis of metastatic LNs. The diagnostic performance of independent US features was subsequently evaluated. LNs were categorized according to the Korean Thyroid Imaging Reporting and Data System (K-TIRADS) and European Thyroid Association (ETA) guidelines, and the correlation between the two sets of classifications was assessed.

RESULTS

Absence of the hilum, presence of cystic changes, PEF, abnormal vascularity, and cortical hyperechogenicity were independent US features of metastatic LNs. Cystic changes, PEF, abnormal vascularity, and cortical hyperechogenicity showed high specificity (86.8%-99.6%). The absence of the hilum had the highest sensitivity yet low specificity (66.4%). When LNs were classified according to the ETA guidelines and K-TIRADS, they yielded similar categorizations of malignancy risks and were strongly correlated (Spearman coefficient, 0.9766 [95% confidence interval, 0.973-0.979]). According to the ETA guidelines, 9.8% (82/836) of LNs were classified as "not specified."

CONCLUSION

Absence of hilum, cystic changes, PEF, abnormal vascularity, and cortical hyperechogenicity were independent US features suggestive of metastatic LNs in thyroid cancer. Both K-TIRADS and the ETA guidelines provided similar risk stratification for metastatic LNs with a high correlation; however, the ETA guidelines failed to classify 9.8% of LNs into a specific risk stratum. These results may provide a basis for revising LN classification in future guidelines.

Pattern and Predictive Factors of Metastasis in Lymph Nodes Posterior to the Right Recurrent Laryngeal Nerve in Papillary Thyroid Carcinoma

OBJECTIVE

The right cervical central lymph nodes include lymph nodes anterior to the right recurrent laryngeal nerve (LN-arRLN) and lymph nodes posterior to the right recurrent laryngeal nerve (LN-prRLN), and are separated by the right recurrent laryngeal nerve (RLN). LN-prRLN is a common site of nodal recurrence after the resection of papillary thyroid carcinoma (PTC). However, the complexity in anatomical structure brings difficulties in determining the surgical scope, so it is necessary to assess the pattern and predictive factors of right cervical central lymph nodes, especially LN-prRLN metastasis in papillary thyroid carcinoma.

METHODS

A total of 562 diagnosed PTC patients who underwent right or total thyroidectomy were enrolled in this retrospective study. The clinicopathological features were collected, univariate and multivariate analyses were performed to determine predictive factors of the right central lymph node metastasis.

RESULTS

In this study, the metastatic rates of the right CLN, the LN-arRLN and the LN-prRLN were 59.6% (335/562), 51.8% (291/562) and 30.4% (171/562), respectively. And 22.6% (127/562) of patients had both LN-arRLN and LN-prRLN metastasis. Among patients without LN-arRLN metastasis, the rate of LN-prRLN metastasis was 16.2% (44/271), accounting for 25.7% of the LN-prRLN metastasis group. Factors associated with an increased risk of LN-arRLN metastasis include male, age below 55 years, tumor size > 1cm, extrathyroidal extension (ETE), clinical lymph nodes metastasis(cN1), lateral lymph node metastasis, and left CLN metastasis. In addition, ETE, lateral lymph node metastasis, and LN-arRLN metastasis were independent factors of LN-prRLN metastasis. The predictive factors of LN-prRLN in cN0 PTC were further explored, revealing that tumor size ≥1.5cm, ETE, and LN-arRLN metastasis were independent predictors of LN-prRLN metastasis in cN0 PTC.

CONCLUSION

The LN-prRLN should not be ignored in surgery because of its high rate of metastasis. Our findings indicate that thorough dissection of central lymph nodes, especially LN-prRLN is crucial in clinical work.

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.

Occult contralateral central neck metastasis in papillary thyroid carcinoma with preoperatively documented ipsilateral lateral neck metastasis

BACKGROUND

This study was conducted to evaluate risk factors and long-term prognosis of contralateral central neck metastasis (CCNM) in papillary thyroid cancer (PTC) patients with ipsilateral lateral neck metastasis. We present clinical evidence to aid in surgical decision-making regarding the extent of central neck dissection (CND), focusing on separation between ipsilateral and contralateral sides.

METHODS

A total of 379 PTC patients who underwent total thyroidectomy and concomitant bilateral central neck dissection with ipsilateral lateral neck dissection (LND) at a single institution was retrospectively included between January 1997 and December 2015.

RESULTS

The median follow-up time was 83.2 months, the mean age was 44.3 years, and the mean tumor size was 1.5 cm. Among the study sample, 266 patients were female (70.2%) and 113 (29.8%) were male. Of 379 patients, CCNM was present in 34.6%. In multivariate analysis, male sex (adjusted OR = 2.46, p = 0.002), bilaterality (adjusted OR = 2.58, p = 0.004), number of metastatic ipsilateral central lymph nodes (adjusted OR = 1.15, p = 0.002), number of metastatic lateral lymph nodes (adjusted OR = 1.48, p < 0.001), and three-level metastasis (adjusted OR = 2.46, p = 0.012) were identified as risk factors of CCNM. Overall recurrence occurred in 6.0% and 11.5% of patients in the CCNM (-) group and CCNM (+) group, respectively. In addition, contralateral recurrence was observed in 1.2% patients and 0.8% patients in the CCNM (-) group and CCNM (+) group, respectively. However, CCNM did not significantly increase risk of recurrence (adjusted HR = 1.01, p = 0.981).

CONCLUSIONS

Although the probability of pathological CCNM is not negligible, CCNM was not associated with higher risk of recurrence. This study suggest that central neck dissection may be limited to the ipsilateral side, and the result regarding prognosis of CCNM may help to avoid bilateral CND so that it could have potential to minimize unnecessary surgery-related complications such as recurrent laryngeal nerve(RLN) injury or hypoparathyroidism.

Risk factors of metastasis to the lymph nodes posterior to the right recurrent laryngeal nerve in papillary thyroid carcinoma

PURPOSE

To investigate the risk factors of lymph node posterior to the right recurrent laryngeal nerve (LN-prRLN) metastasis in papillary thyroid carcinoma.

METHODS

Clinicopathologic feature data of 427 patients with right or double lobes who underwent surgery between January 2014 to August 2019 in the Department of General Surgery, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, were retrospectively analyzed. The risk factors of LN-prRLN metastasis were analyzed by the Chi-squared test and multivariate logistic regression.

RESULTS

LN-prRLN metastasis was detected in 96 patients. Univariate analysis showed that age, right-side tumor diameter, capsular invasion, comorbid adenoma, and VIa compartment LN metastasis were significantly associated with LN-prRLN metastasis (all P < 0.05). Multivariate logistic regression analysis showed that right-side tumor diameter, capsular invasion, and VIa compartment LN metastasis were independent risk factors of LN-prRLN metastasis (all P ≤ 0.001). The receiver operating characteristic curve showed that the cutoff value of the right tumor diameter for predicting LN-prRLN metastasis was 1.25 cm (sensitivity = 0.5, specificity = 0.819, area under the curve = 0.720, P < 0.001).

CONCLUSION

The incidence of LN-prRLN metastasis cannot be ignored, and our findings indicate that prophylactic LN-prRLN dissection should be performed in patients with right-side tumor diameter ≥ 1.25 cm, capsular invasion, and VIa compartment LN metastasis.

Predictive gene signatures of nodal metastasis in papillary thyroid carcinoma

BACKGROUND

Cervical lymph node metastases (LNM) in papillary thyroid carcinomas (PTCs) are common and develop in approximately 30-80% of PTCs. The presence of cervical LNM significantly increases the rate of locoregional recurrence in PTCs.

OBJECTIVE

To search for predictive gene signatures for nodal metastasis in PTCs.

METHODS

We used unsupervised clustering with unbiased manner to compare molecular profiles between PTCs with nodal metastasis and PTCs without nodal metastasis using mRNA-seq of TCGA data. Using gene ontology (GO) and logistic regression test, we generated 12-predictive genes for nodal metastasis in PTCs.

RESULTS

Unsupervised clustering of mRNA-seq (training set, N = 158) revealed that PTCs with nodal metastasis showed different gene expression patterns compared to PTCs without nodal metastasis. We generated 12 predictive genes and these gene signatures showed consistency for predicting nodal metastasis when we applied them to a validation set (N = 80). Based on multivariate analysis, these 12 predictive gene signatures showed more significant odds ratio compared to other variables.

CONCLUSIONS

These 12 gene signatures could be used to predict the chance of nodal metastasis in PTCs in preoperative evaluation using fine needle aspiration biopsy (FNAB) so that appropriate plan such as central neck dissection could be made.

Using a nomogram based on preoperative serum fibrinogen levels to predict recurrence of papillary thyroid carcinoma

Background

Hyperfibrinogenemia is increasingly being recognized as an important risk factor related to cancer stage, development and outcomes. We evaluated whether preoperative serum fibrinogen levels predict recurrence of papillary thyroid carcinoma (PTC).

Methods

We retrospectively collected data for 1023 PTC patients who underwent surgery at our institution from Aug 2014 to Aug 2016. In total, 414 patients (from Aug 2014 to Dec 2015) were used as the training set to build the model, and 609 patients (from Jan 2016 to Aug 2016) were used as the testing set to validate the model.

Results

In the training set, PTC cases with high serum fibrinogen levels were more likely to have multiple PTCs (P = 0.001) and to exhibit surrounding tissue or organ invasion (both P < 0.01). Moreover, PTC patients with higher serum fibrinogen levels were also more likely to have an advanced tumor stage (T, P = 0.001) and distance metastasis (P < 0.001), and these patients had a significantly higher rate of postoperative PTC recurrence (P = 0.002). All of these findings were validated in the testing set. The results of univariate and multivariate analyses indicated that hyperfibrinogenemia was a risk factor for PTC recurrence. The identified risk factors were incorporated into a nomogram and validated using the testing set (C-index = 0.811, 95% CI: 0.762–0.871).

Conclusion

PTC cases with hyperfibrinogenemia are more likely to have an advanced TNM stage and have a higher rate of PTC recurrence. Our nomogram could be used to objectively and accurately predict PTC recurrence in a clinical setting.

Accuracy of preoperative MRI to assess lateral neck metastases in papillary thyroid carcinoma

Primary treatment of papillary thyroid carcinoma (PTC) with lateral lymph node metastasis is surgery, but the extent of lateral neck dissection remains undefined. Preoperative imaging is used to guide the extent of surgery, although its sensitivity and specificity for defining the number and level of affected lymph nodes on the lateral neck is relatively modest. Our aim was to assess the role of preoperative magnetic resonance imaging (MRI) in predicting the requisite levels of neck dissection in patients with regionally metastatic PTC, with a focus on Levels II and V. All patients with PTC and lateral neck metastasis who had undergone neck dissection at the Department of Otorhinolaryngology—Head and Neck Surgery, Helsinki University Hospital, Helsinki, Finland from 2013 to 2016 and had a preoperative MRI available were retrospectively reviewed. A head and neck radiologist re-evaluated all MRIs, and the imaging findings were compared with histopathology after neck dissection. In the cohort of 39 patients, preoperative MRI showed concordance with histopathology for Levels II and V as follows: sensitivity of 94 and 67%, specificity of 20 and 91%, positive predictive value of 56 and 75%, and negative predictive value of 75 and 87%, respectively. In PTC, MRI demonstrated fairly high specificity and negative predictive value for Level V metastasis, and future studies are needed to verify our results to omit prophylactic dissection of this level. Routine dissection of Level II in patients with regionally metastatic PTC needs to be considered, as MRI showed low specificity.

Central compartment management in patients with papillary thyroid cancer presenting with metastatic disease to the lateral neck: Anatomic pathways of lymphatic spread

BACKGROUND

Papillary thyroid cancer (PTC) occasionally presents with metastases to the lateral neck, without clinically evident disease in the central neck. These cases may ultimately manifest as either skip metastases to the lateral compartment or as occult metastases in the central compartment.

METHODS

This is a retrospective review of 80 patients with PTC with metastases to the lateral cervical lymph nodes treated from 2006 to 2015. Photographs of the cadaveric dissections were used with permission from the author. Schematic illustrations were created to highlight lymphatic drainage pathways.

RESULTS

The rate of skip metastasis in this cohort was 5%. Clinical evidence of central neck disease did not predict the pathologic status of the compartment.

CONCLUSION

PTC rarely spreads to the lateral neck without depositing metastases within the central neck. This finding is supported by the anatomic pathways for lymphatic spread, not previously highlighted in the English literature. © 2017 Wiley Periodicals, Inc. Head Neck 39: 853-859, 2017.

Preoperative predictors of lateral neck lymph node metastasis in papillary thyroid microcarcinoma

Lateral lymph node metastasis (LNM) is not uncommon in papillary thyroid microcarcinoma (PTMC). Our present study aimed to investigate the risk factors associated with lateral LNM in PTMC.We retrospectively collected data pertaining to 366 patients with PTMC who underwent surgery at our center from 2010 to 2015. These patients were divided into the following 2 groups: a lateral LNM-positive group and a lateral LNM-negative group. Clinical and ultrasound data were compared between the 2 groups to determine the risk factors associated with lateral LNM.Univariate and multivariate analyses indicated that capsule invasion (OR = 3.995, 95% CI, 2.148-7.430) and upper portion location (OR = 4.541, 95% CI, 2.444-8.438) were significant risk factors for lateral LNM of PTMC and that capsule invasion (AUC = 0.666) and upper portion location (AUC = 0.678) could be used to predict lateral LNM of PTMC. Moreover, the patients in lateral LNM positive group exhibited significantly higher rates of tumor recurrence or metastasis than the patients in lateral LNM negative group (P = 0.027).Patients with PTMC located in the upper portion or exhibiting capsule invasion should receive meticulous preoperative evaluations for lateral LNM, prophylactic lateral LND may be considered.

A novel thyroid cancer nodal map classification system to facilitate nodal localization and surgical management: The A to D map

OBJECTIVES/HYPOTHESIS

To evaluate the effectiveness, reproducibility, and usability of our proposed nodal nomenclature and classification system employed for several years in our high-volume thyroid cancer unit, for the adequate localization and mapping of lymph nodes in thyroid cancer patients with extensive nodal disease.

STUDY DESIGN

Retrospective review.

METHODS

Thirty-three thyroid cancer patients with extensive nodal disease treated from January 2004 to May 2013 were included in our study. Preoperative ultrasound and computed tomography scans of these patients were reanalyzed by blinded radiologists to investigate the feasibility for the assignment of abnormal lymph nodes to compartments defined in our proposed nodal classification system and to identify areas of difficulty in the assignment.

RESULTS

Analysis of nodal localization revealed a discrepancy in compartment agreement between the two radiologists in the assignment of abnormal nodes in nine patients (9/33, 27%). In six patients (6/33, 18%), discrepancy existed in labeling paratracheal and pretracheal nodes. In three patients (3/33, 9%), disagreement arose in the classification of retrocarotid nodes into lateral versus central compartment. A further refinement of the definition of key borderline regions of the pretracheal versus paratracheal and retrocarotid regions of our classification improved the agreement and demonstrated a complete concordance (100%) amongst the reviewing radiologists.

CONCLUSIONS

The proposed nodal classification system, derived specifically for differentiated thyroid carcinoma, with readily identifiable anatomic boundaries on imaging and at surgery, facilitates communication among multidisciplinary physicians and aids in creating a uniform and reproducible radiographic nodal map to guide surgical therapy.

LEVEL OF EVIDENCE

4 Laryngoscope, 127:2429-2436, 2017.

Posterosuperior lesion has a high risk of lateral and central nodal metastasis in solitary papillary thyroid cancer

BACKGROUND

Preoperative nodal assessment of papillary thyroid cancer (PTC) is very important because 60 to 70 % of all disease recurrence in the neck can occur in the lymph nodes. This study explored the association between ultrasonographic intrathyroidal location and the nodal metastasis pattern in solitary PTC.

METHODS

Data from 218 patients who underwent total thyroidectomy with or without neck dissection for previously untreated PTC between 2006 and 2010 were retrospectively analyzed. Only patient data for which both preoperative ultrasound findings and postoperative pathologic reports were available were included. Multifocal cases, cases with extrathyroidal extension, and distant metastasis were excluded. The association between nodal metastasis pattern and clinical or pathologic features of solitary PTCs was analyzed, as was the association between ultrasonographic intrathyroidal location and central or lateral nodal metastasis in solitary PTC.

RESULTS

Mass size larger than 2 cm (p < 0.001, Odds ratio (OR) 4.117) and central nodal metastasis (p < 0.001, OR 3.984) were related with lateral neck metastasis in multivariate analysis. Male sex (p = 0.001, OR 3.012) and capsular invasion (p < 0.001, OR 4.720) were related with central neck metastasis in multivariate analysis. When analyzing ultrasonographic location of intrathyroidal solitary lesion, posterosuperiorly located lesion was strongly associated with both lateral and central neck metastasis. (p < 0.001 and p = 0.002, respectively).

CONCLUSIONS

Posterosuperior location of intrathyroidal solitary PTC has a high risk of lateral and central nodal metastasis when compared to other locations. For such patients, careful preoperative evaluation of nodal status should be done.

Clinicopathological features of recurrent papillary thyroid cancer

Background

To investigate the clinicopathological features of recurrent papillary thyroid carcinoma (PTC).

Methods

A retrospective analysis on clinical and pathological data of 34 patients with recurrent PTC was carried out. A total of 281 patients with non-recurrent PTC during the same time period were chosen as the control group.

Results

Patients were divided into three groups according to the pathological subtype. The number of patients belonging to Groups 1, 2, and 3 were 28, 154, and 133, respectively. 78 patients underwent partial or whole thyroidectomy, 151 cases underwent thyroidectomy combining neck regional lymph node dissection, and 86 patients underwent thyroidectomy combining modified or radical neck dissection. Univariate analysis showed that PTC recurrence was associated with tumor size, extrathyroid invasion, initial surgery approach, lymph node metastasis, and pathological subtype (P < 0.05). Patient age, gender, complication with Hashimoto's thyroiditis, and multifocality were unrelated to PTC recurrence (P > 0.05). Multivariate analysis showed that initial surgery approach and pathological subtype perform important functions in PTC recurrence (P < 0.001). Initial surgery approach presented a negative correlation with PTC recurrence (β = −0.320, OR = 0.726). The pathological subtype was also related to PTC recurrence (β = 0.923, OR = 2.517).

Conclusion

PTC patients without neck dissection showed greater likelihood of postoperative recurrence. Patients with the tall cell, columnar cell, diffuse sclerosing, and oncocytic variants showed a higher propensity for PTC recurrence after operation compared with those who did not. Tumor volume, extrathyroid invasion, and multiple lymph node metastases at the time of initial operation were also significantly related to postoperative recurrence. Follow-up supervision must be enhanced after initial treatment to mitigate PTC recurrence in susceptible patients. Effective and standard treatments must be adopted immediately after the discovery of recurrence.

Intraoperative ultrasonography is useful in surgical management of neck metastases in differentiated thyroid cancers

Differentiated thyroid carcinomas are the most common malignancies of endocrine organs. Metastases to cervical lymph nodes occur in 20-50% of cases. Recurrence and survival rates are closely related to the type of surgery performed. High-resolution ultrasonography (USG) is a sensitive imaging method used to detect occult lymph node metastases in patients with thyroid cancer. We evaluated how intraoperative USG affected surgical success. This was a retrospective study comparing two groups of patients with thyroid carcinoma who underwent cervical lymph node dissection. A total of 101 patients (33 males and 68 females) were included. Group 1 included 53 patients who underwent surgery with intraoperative USG guidance. Group 2 included 48 patients who underwent surgery without the use of USG. All patients were followed up (mean 23 months; range 5-44 months) with thyroglobulin measurements and USG evaluations. Group 1 (intraoperative USG) had a residual/recurrent tumor rate of 1.9% (1/53 patients). Group 2 had a residual/recurrent tumor rate of 12.5% (6/48 patients). A statistically significant difference appeared between the residual/recurrent tumor rates in Groups 1 and 2 (p<0.05). In addition to its classical use in diagnosis and follow-up, intraoperative use of high-resolution USG can improve surgical success and may decrease the number of residual/recurrent tumors encountered during follow-up.

Involvement of level IIb lymph node metastasis and dissection in thyroid cancer

Thyroid neoplasms are the most frequent neoplasm in the head and neck region. Most thyroid carcinomas are well-differentiated tumors of follicular cell origin. Thyroid papillary carcinoma (TPC) is the most common thyroid malignancy. It constitutes 60% to 90% of all the thyroid carcinomas and cervical lymph node metastases are commonly seen in these patients. Although cervical lymph node metastases are common in this cancer, the management and the prognostic role of lymph nodes in TPC remains controversial. In this paper we reviewed the currently available literature regarding the extent of lateral neck dissection in papillary thyroid carcinoma patients with lateral neck metastasis.

Therapeutic impact of (18)F-FDG PET/CT in recurrent differentiated thyroid carcinoma

PURPOSE

(18)F-fluorodeoxyglucose-positron emission tomography/computed tomography (PET/CT) has proved effective in detecting recurrent or metastatic differentiated thyroid carcinoma (DTC) in the follow-up of operated DTC patients with high thyroglobulin (Tg) levels and negative findings on radioiodine whole-body scan. The aim of this retrospective study was to assess the impact of PET/CT on the planning of appropriate treatment for known recurrent disease in operated DTC patients.

MATERIALS AND METHODS

The study concerned 44 consecutive DTC patients (36 papillary, 8 follicular), who underwent total thyroidectomy and thyroid remnant ablation with (131)I and PET/CT. All patients had proven or strongly suspected recurrent disease judging from neck ultrasound (US) and fine-needle aspiration cytology, and detectable basal Tg levels.

RESULTS

PET/CT findings were positive in 25/44 patients (56.81 %) and negative in 19. A positive PET/CT result predicted resectable tumour recurrences in 19/25 patients, but also detected additional tumour sites that prompted changes to the treatment plan in 6/25 patients (24 %). A negative PET/CT result led to clinical monitoring for 11/19 patients (57.89 %).

CONCLUSIONS

PET/CT can help select patients, who might benefit from a tailored therapy by improving the detection of local recurrences not apparent on neck US or metastases.

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.

Pitfalls in the staging of cancer of thyroid

Thyroid cancer includes several neoplasms originating from the thyroid gland-from indolent and curable histologies of differentiated thyroid carcinoma to aggressive anaplastic thyroid carcinoma. Differentiation of thyroid nodules is problematic on CT and MR imaging unless there is evidence of extrathyroidal extension. Evaluation of regional lymph nodes is often performed clinically or with ultrasound. The retropharyngeal and mediastinal lymph nodes are better evaluated by CT and MR imaging. Nuclear scintigraphy is useful for staging and treatment of distant metastasis in differentiated thyroid carcinoma. PET may have a role in aggressive cancers. Accurate staging affects surgical management and subsequent therapy.

Management of lateral cervical metastases in papillary thyroid cancer: patterns of lymph node distribution

In this article we discuss the management of lateral cervical lymph node metastases in papillary thyroid cancer (PTC). We conducted a retrospective analysis of cases of PTC at our tertiary academic medical center involving 32 patients who underwent 39 neck dissections for the management of lateral cervical metastases from 2000 to 2007. Of these patients, 18 underwent primary neck dissections at the time of thyroidectomy after fine-needle aspiration biopsy confirmed the PTC. Secondary neck dissections for delayed metastases were performed in 14 patients who had previously undergone thyroidectomy for confirmed PTC. All 32 patients had positive nodes in at least one level. Our results highlight the high incidence of multilevel cervical metastasis associated with PTC and suggest the importance of including level II-B (submuscular recess) when performing a neck dissection; the upper posterior triangle (level V-A) is less likely to harbor occult tumor. Lateral neck metastasis from PTC is common and predictable; locoregional control is improved with a formal, comprehensive neck dissection at the time of thyroidectomy.

Outcome of radical resection and postoperative radiotherapy for thyroid carcinoma showing thymus-like differentiation

BACKGROUND

Carcinoma showing thymus-like differentiation (CASTLE) is a rare disease that is difficult to diagnose. The aim of this study was to assess the effects of combined-modality treatment in CASTLE patients.

METHODS

We retrospectively studied patients identified between January 1, 2000 and December 31, 2009 as having CASTLE and who subsequently underwent surgery and radiotherapy or chemotherapy. Preoperative laboratory findings, ultrasonographic (US) and computed tomographic (CT) features, and fine-needle aspiration biopsy (FNAB) specimens were evaluated.

RESULTS

Seven patients with CASTLE were identified (four men, three women). The median age at initial diagnosis was 48 years (range 25-56 years). The five newly diagnosed patients were treated with curative surgery and postoperative radiotherapy, whereas two patients with recurrent disease were treated with salvage surgery plus radiotherapy or chemotherapy. All patients were disease-free at a median follow-up period of 34 months (range 12-61 months). The pattern of immunohistochemical staining was similar to that of thymic carcinoma. Specimens from all seven patients stained positively for CD5, CD117, and cytokeratin but were uniformly negative for thyroglobulin, thyroid transcription factor 1 (TTF-1), and calcitonin.

CONCLUSIONS

Patients with CASTLE have excellent outcomes after curative resection and postoperative radiotherapy compared with patients with anaplastic thyroid carcinoma. Even patients with local recurrent disease benefited from salvage surgery with subsequent operation and/or radiotherapy. CD5 immunohistochemical staining on FNAB samples may help identify the possible entities that are part of the differential diagnosis.

The role of prophylactic central neck dissection in differentiated thyroid carcinoma: issues and controversies

Prophylactic central neck dissection (pCND) in differentiated thyroid carcinoma (DTC) is one of the most controversial surgical subjects in recent times. To date, there is little evidence to support the practice of pCND in patients with DTC undergoing total thyroidectomy. Although the recently revised American Thyroid Association (ATA) guideline has clarified many inconsistencies regarding pCND and has recommended pCND in “high-risk” patients, many issues and controversies surrounding the subject of pCND in DTC remain. The recent literature has revealed an insignificant trend toward lower recurrence rate in patients with DTC who undergo total thyroidectomy and pCND than those who undergo total thyroidectomy alone. However, this was subjected to biases, and there are concerns whether pCND should be performed by all surgeons who manage DTC because of increased surgical morbodity. Performing a unilateral pCND may be better than a bilateral pCND given its lower surgical morbidity. Further studies in this controversial subject are much needed.

Clinicopathologic and molecular disease prognostication for papillary thyroid cancer

Despite its increasing incidence over the last 30 years, the mortality rate of papillary thyroid cancer (PTC) has decreased significantly. Nevertheless, a minority of patients still present with an aggressive form of PTC that can lead to death, even after a prolonged period of survival. Many classifications exist that allow one to stratify the clinical risk of recurrence and death in patients with PTC; however, the parameters upon which they are established are pathological and molecular and, therefore, are revealed only after surgery. The preoperative identification of these aggressive variants of PTC would allow one to schedule a more aggressive operation (e.g., total thyroidectomy together with central and/or mono- or bi-lateral node dissections) in patients with high-risk PTC. This article reviews the parameters used most commonly to differentiate low-risk PTCs from their more aggressive variants and describes some of the newest molecular therapies for this latter group of tumors.

Routine bilateral central lymph node clearance for papillary thyroid cancer

BACKGROUND

Controversy exists regarding the extent of surgical treatment for paratracheal (level VI) lymph nodes in patients with papillary thyroid cancer (PTC). Local recurrence within lymph nodes in the central neck compartment after total thyroidectomy can be difficult to detect and more hazardous to treat surgically. An initial bilateral central lymph node dissection (CLND) can best minimize this risk of local recurrence, if CLND is established as reasonably safe and oncologically justified.

METHODS

This study is based on a retrospective review of the institutional tumor registry of all patients treated for PTC between January 2000 and May 2008 at a 636-bed tertiary referral center and university-affiliated hospital. The following data were analyzed: the operative procedures, tumor characteristics (size, lymph node metastasis), injury to the recurrent laryngeal nerve (RLN), tumor recurrence, and need for further operative procedures.

RESULTS

Of 310 patients identified as treated surgically for PTC, 281 received total thyroidectomy and 29 received a lesser operation. Bilateral CLND was performed in 169 patients, unilateral CLND in 11, and no CLND in 130. The central lymph nodes were positive in 84 (46.7%) of 180 patients with CLND. Excluding isthmus tumors and those with bilateral same-size PTC, 41 (25.5%) of 161 patients with bilateral CLND had positive contralateral lymph nodes. Of the 603 RLNs at risk, 13 temporary injuries occurred, and 8 (1.3%) permanent injuries resulted. The risk of RLN injury was not greater with bilateral CLND compared to unilateral or no CLND (P = .18), and those patients with bilateral CLND had statistically larger tumors (1.60 cm vs 0.84 cm; P < .0001). Of the 10 documented cancer recurrences requiring reoperation, 4 were in the central neck, and all of these occurred in patients who did not have CLND.

CONCLUSION

Lymph node metastases are present in both the ipsilateral and contralateral central lymph node basins in a significant percentage of patients with PTC. Routine bilateral CLND in patients with PTC has the potential to clear metastatic disease without significantly increasing the risk of RLN injury.

Diagnostic accuracy of CT and ultrasonography for evaluating metastatic cervical lymph nodes in patients with thyroid cancer

BACKGROUND

The present study was designed to investigate the diagnostic ability of computed tomography (CT) and ultrasonography (USG) in the preoperative evaluation of the cervical nodal status of patients with thyroid cancer.

METHODS

The study population consisted of 37 consecutive patients (female:male = 30:7, age range: 20-68 years) who subsequently underwent total thyroidectomy and neck dissection for thyroid cancer. The results of the review of the preoperative CT and those of the original USG reports were compared with the histopathologic results. The accuracy was evaluated by "per level" and "per patient" analyses of whether the CT or USG results had or had not altered the choice of surgical method.

RESULTS

By "per level" analysis, the sensitivities, specificities, and diagnostic accuracies were 77%, 70%, 74% for CT and 62%, 79%, 68% for USG, respectively, with a significant difference in the sensitivities (p = 0.002). When the lymph node levels were grouped into central and lateral compartments, all of the values for the lateral compartment tended to be higher than those for the central compartment for both CT (78%, 78%, 78% versus 74%, 44%, 64%) and USG (65%, 82%, 71 versus 55%, 69%, 60%). By per patient analysis, the sensitivities, specificities, and diagnostic accuracies of CT and USG were 100%, 90%, 97% and 100%, 80%, 95%, respectively.

CONCLUSION

Despite of very high accuracy of USG by per patient analysis, the superior sensitivity of CT on the per level analysis may enable CT to play a complementary role for determining the surgical extent in selected patients with thyroid cancer.

Surgical management of recurrent thyroid cancer

While well-differentiated thyroid cancer is generally thought to be a treatable cancer with excellent outcomes, some patients suffer from recurrent disease. Risk factors for recurrent disease include primary disease greater than 4 cm, incomplete resection, multiple positive lymph nodes in the central compartment, and lateral neck disease with multiple positive lymph nodes in multiple levels or pathologic extracapsular extension. These factors can help stratify the thyroid cancer population in to low-, medium-, and high-risk patients. Low-risk patients can generally be followed with thyroglogulin levels and routine ultrasounds to the head and neck. High-risk patients are best monitored with stimulated thyroglobulin, ultrasound of the head and neck, and low-dose iodine 131 uptake scans at the 6- to 12-month mark. The treatment of locoregional recurrent thyroid cancer is surgical resection with the overall goal of complete tumor removal while maintaining function and decreasing risks. The use of adjuvant therapy is dependent on the presence / absence of high risk pathologic features.

Elective paratracheal neck dissection for lateral metastases from papillary carcinoma of the thyroid: is it indicated?

BACKGROUND

Therapeutic paratracheal neck dissection for patients with papillary carcinoma of the thyroid is standard treatment. Its use as an elective procedure is controversial.

METHODS

Thirty-seven patients with papillary carcinoma of the thyroid and evidence of positive adenopathy at levels II-V underwent selective neck dissection and elective/therapeutic paratracheal neck dissection. Results of preoperative ultrasonography of the neck were compared with the dissection specimens.

RESULTS

Morbidity of the surgical procedure was minimal (1 permanent hypocalcemia). All specimens showed metastases from papillary thyroid carcinoma: 100% (37/37) in the jugular chain of lymphatics and 83.7% (31/37) in the paratracheal region. The rate of occult (negative physical examination and ultrasonography) metastases in the paratracheal region in the presence of metastases in the ipsilateral jugular chain was 83.3% (20/24).

CONCLUSION

The high rate of occult metastases in the paratracheal region and the low rate of surgical morbidity speak in favor of elective paratracheal neck dissection in patients with metastatic papillary carcinoma of the thyroid.

Preoperative diagnosis of cervical metastatic lymph nodes in papillary thyroid carcinoma: comparison of ultrasound, computed tomography, and combined ultrasound with computed tomography

BACKGROUND

Although ultrasound (US) is routinely used for the preoperative evaluation of neck nodes in patients with papillary thyroid carcinoma (PTC), the diagnostic role of computed tomography (CT) has not been established. The purpose of our study is to determine the diagnostic accuracies of US, CT, and combined US and CT (US/CT) for detecting metastatic neck nodes in patients with PTC.

METHODS

165 consecutive patients (140 females and 25 males, mean age 47.9 years) with surgically proven PTC underwent US and CT for preoperative evaluation. CT was performed 2 or 3 months before radioiodine therapy. We assessed the diagnostic accuracies of US, CT, and US/CT using level-by-level analysis.

RESULTS

In terms of predicting node metastases, overall sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of US were 51%, 92%, 77%, 81%, and 76%, respectively. Those of CT were 62%, 93%, 81%, 84%, and 80%, respectively, and those of US/CT were 66%, 88%, 79%, 77%, and 81%, respectively, at all neck levels. US/CT significantly increased sensitivity and demonstrated similar specificity compared with US alone in lateral neck levels (p = 0.02 and p = 1.0, respectively). US/CT increased sensitivity (p = 0.01), but decreased specificity compared with US alone in the central neck levels (p = 0.02). CT provided additional benefit for detecting metastatic nodes at more than one level in 8% of all patients, in 14% of patients with suspected nodal metastasis on US, and in 25% of patients with metastatic lymph nodes.

CONCLUSIONS

The US/CT combination was found to be superior to US alone for the detection of metastatic lymph nodes in the lateral neck levels in PTC patients by level-by-level analysis.

Imaging for staging and management of thyroid cancer

The management of thyroid cancer has been controversial and, as a result, the routine use of imaging in this disease, especially for pre-operative staging, has lagged behind other head and neck cancers. However, as more is known about the natural history of thyroid cancer, the role of imaging is becoming more established. This review focuses on how imaging now influences the staging and management of the primary cancer, nodal metastases and distant metastases. This is followed by a brief review of the role of imaging in planning post-operative radiotherapy and post-treatment surveillance.

Increased P2X7 receptor expression and function in thyroid papillary cancer: a new potential marker of the disease?

Nucleotides are increasingly recognized as nonredundant extracellular signals for chemotaxis, cell growth, and cytokine release. Effects of extracellular nucleotides are mediated by P2 receptors, among which the P2X(7) subtype is attracting increasing attention for its involvement in apoptosis, cell growth, and cytokine release. Recent studies showed that P2X(7) is overexpressed in chronic lymphocytic leukemia and breast and prostate cancer. The aim of the present study was to better understand the clinical significance of P2X(7) receptor expression in normal and cancer human thyroid tissues. P2X(7) receptor message and protein expression and functional activity were tested in two cell lines (FB1 and FB2) established from either anaplastic or papillary primary thyroid cancer and in several histological samples of human papillary cancer. We show here that human thyroid papillary carcinoma, whether of the classical or follicular variant, expresses the P2X(7) receptor (P2X(7)R) to a much higher level than normal thyroid tissue. The P2X(7)R was similarly up-regulated in FB1 and FB2 cell lines. In contrast to normal thyroid cells, both cell lines responded to extracellular nucleotide stimulation with a large increase in intracellular Ca(2+) and secretion of IL-6. Ca(2+) increase was attenuated and release of IL-6 was fully blocked by P2X(7)R inhibitors. Finally, the thyroid carcinoma cell lines had at least a 3-fold higher intracellular ATP concentration and maintained at least a 3-fold higher extracellular ATP level, compared with control cells. These data suggest that an enhanced P2X(7)R function might be a feature of human thyroid cancer.

Thyroglobulin and human thyroid cancer

Thyroglobulin (Tg) is a large molecule containing 2750 amino acids with a molecular weight of 330 kD and twenty putative N-linked glycosylation sites. Tg gene expression is regulated by thyroid transcription factor 1 (TTF-1) and human paired box 8 (Pax-8). Iodinated Tg is stored in the lumen of the thyroid follicles and is released in response to specific hormonal stimulation by thyroid stimulating hormone (TSH). Following Tg reabsorption by thyrocytes and subsequent degradation, thyroid hormones triiodothryronine (T(3)) and thyroxine (T(4)) are secreted in the bloodstream. Mutations within the Tg gene cause defective thyroid hormone synthesis, resulting in congenital hypothyroidism. Thyroid carcinoma may develop from dyshormonogenic goiters due to Tg mutation. Post-thyroidectomy Tg levels are apparently associated with prognosis of papillary and follicular thyroid carcinomas and may predict tumor recurrence and metastastic potential. The detection of Tg by biochemical and molecular means has important diagnostic significance due to its pleiotropic roles in identification of tissue of thyroid origin, differentiation, and post-operative follow-up.

High frequency of level II-V lymph node involvement in RET/PTC positive papillary thyroid carcinoma

AIMS

To investigate the frequency and clinical significance of RET rearrangement in Chinese patients with papillary thyroid carcinoma (PTC) and discuss the role of RET rearrangement in therapeutic decision-making after the performance of level VI lymph node dissection and the 2002 AJCC staging system.

METHODS

RET/PTC-1 and RET/PTC-3 were detected in 126 PTCs using reverse transcription-polymerase chain reaction (RT-PCR) and direct sequencing.

RESULTS

RET rearrangement was detected in 18 cases of PTC. The patient group aged < 20 years had the highest frequency (3/6) of RET rearrangement among the age groups (< 20 years, 20-40 years and > or = 40 years; P=0.03). RET/PTC-1 positive patients were more likely to suffer from Hashimoto's thyroiditis simultaneously (P=0.02) while RET/PTC-3 positive patients had a higher frequency of extrathyroidal extension (P<0.01) and advanced T classification (P<0.01). RET rearrangement (OR=8.70, 95% CI 1.69-44.81), male (OR=3.88, 95% CI 1.41-10.69), age (OR=0.96, 95% CI 0.93-0.99), multifocality (OR=3.54, 95% CI 1.33-9.41) and advanced T classification (OR=7.32, 95% CI 2.91-18.40) were all identified as risk factors of level II-V lymph node involvement in the multivariate analysis.

CONCLUSIONS

The frequency of RET rearrangement in Chinese patients is low and age related. RET/PTC-1 and RET/PTC-3 are associated with different clinical pathological characteristics but not with lymph node involvement. The RET/PTC positive patients should receive more attention to lateral neck in the management of PTC.

Routine level VI lymph node dissection for papillary thyroid cancer: surgical technique

Total thyroidectomy is the treatment of choice for clinically significant papillary thyroid cancer (PTC); however, 10-15% develop palpable local recurrence in the cervical lymph nodes. Metastases in the cervical lymph nodes account for 75% of loco-regional recurrence and up to 50% of these patients eventually die of their disease. It is generally accepted that surgical excision of grossly involved lymph node disease should be carried out. The role of routine lymph node dissection, however, is greeted with far more controversy. Regional lymph node metastases have been shown to be associated with more frequent tumour recurrence. Not only is recurrence associated with increased disease-related mortality, but recent data have shown that the presence of involved lymph nodes is associated with adverse survival. Additionally, there have been significant changes to the way patients are managed after treatment for PTC in recent years. Surveillance previously relied on clinical assessment and radioiodine scans whereas now the use of serum thyroglobulin and high-resolution ultrasound are the standard as evidenced by recommendations by the American Thyroid Association. These techniques have greater sensitivity and subsequently lymph node metastases are being detected earlier and more frequently. This has led to a paradigm shift in the aims of treatment of PTC, from a focus on survival data to a focus on disease-free status. Routine central neck lymph node dissection can be carried out with no increased morbidity and can achieve lower 6-month stimulated thyroglobulin levels when compared with total thyroidectomy alone. Routine ipsilateral level VI lymph node dissection in addition to total thyroidectomy should be carried out for the management of clinically significant PTC.