Carcinoma Showing Thymus-like Differentiation (CASTLE) with Synchronous Papillary Thyroid Carcinoma: A Case Report and Review

Carcinoma showing thymus-like differentiation (CASTLE) is a rare malignant tumor that accounts for 0.1%–0.15% of all thyroid cancers. More than half of the patients have tumor extension to adjacent organs, including the recurrent laryngeal nerve, trachea, and esophagus. The diagnosis of CASTLE is based on histology and immunohistochemistry. A 58-year-old female patient complained of hoarseness for one and half years. Right side vocal cord palsy was diagnosed by fiberscopy. Thyroid sonography revealed right thyroid tumors, which were reported to be papillary thyroid carcinoma through FNAC. Total thyroidectomy with central lymph node dissection was performed. Pathologist found 2 isolated malignancy tumors. One patient in the right thyroid lobe had papillary thyroid carcinoma features. The other extrathyroid tumor seemed to be separated from the first tumor and invaded the thyroid capsule. After multiple immunohistochemical studies, PTC synchronous CASTLE was the final diagnosis. Coexisting PTC and CASTLE is very rare. This is the first report to describe a case showing PTC at first, while subsequent pathologic examination revealed the presence of CASTLE in addition to PTC. Since the prognosis of CASTLE is favorable, the treatment is different from other aggressive thyroid cancers, such as poorly differentiated or anaplastic thyroid carcinoma.

Effect of Prophylactic Central Lymph Node Dissection on Locoregional Recurrence in Patients with Papillary Thyroid Microcarcinoma

There is a consensus that central compartment lymph node dissection or modified radical lateral neck dissection should be performed in papillary thyroid microcarcinoma (PTMC) patients with lymph node metastases. Prophylactic central lymph node dissection (PCLND) in patients with clinically node-negative (cN0) PTMC to reduce locoregional recurrence (LRR) rate and improve prognosis remains controversial. The present study aimed to analyze the effect of PCLND on LRR and postoperative complications of PTMC in cN0 patients. We reviewed a cohort of patients with cN0 PTMC who underwent surgery between January 1997 and October 2019. The patients were divided into the PCLND and no lymph node dissection (NLND) groups. Kaplan–Meier curves were constructed to estimate 15-year locoregional recurrence-free survival rate of the two groups, and the difference was compared by the log-rank test. Three Cox regression models were performed to evaluate the correlation between PCLND and LRR. All patients underwent thyroidectomy, and 25 patients developed LRR; of whom, 23 underwent PCLND at initial surgery and 2 went without lymph node dissection. Cox regression analysis showed that PCLND had no effect on LRR. Postoperative hematoma and permanent recurrent laryngeal nerve injury did not occur in the NLND group, and their incidences were 0.5% and 0.3% in the PCLND group, respectively. PCLND had no significant correlation with LRR in patients with cN0 PTMC, and the absolute benefit for PTMC was small.

Prediction Model of Pathologic Central Lymph Node Negativity in cN0 Papillary Thyroid Carcinoma

BackgroundMost patients with papillary thyroid carcinoma (PTC) have an excellent prognosis. Although central lymph node invasion is frequent, management via central lymph node dissection (CLND) remains controversial. The present study retrospectively investigated independent predictors of pathologic central lymph node negativity (pCLN-) and established a prediction model for pCLN- in clinical lymph node negativity (cN0) PTC.MethodsA total of 2,687 patients underwent thyroid surgery for cN0 PTC from 2013 to 2018 at the First Affiliated Hospital of Chongqing Medical University, and lobectomy plus ipsilateral CLND was the basic surgical extent. Clinicopathological characteristics were reviewed and analyzed. Univariate and multivariate analyses were performed to identify factors related to pCLN-. A prediction model was established based on the results of multivariate analyses.ResultsThe pCLN- rate was 51.5% (1,383/2,687). Multivariate analysis revealed that sex, age, thyroid stimulating hormone (TSH), size, location, laterality, unifocality and extrathyroidal extension negativity (ETE-) were independent predictors of pCLN-. The nomogram showed good discriminative ability (C-index: 0.784 and 0.787 in derivation and validation groups, respectively) and was well calibrated. We quantified the clinical usefulness of the nomogram by decision curve analysis. The median length of follow-up was 30 (range 12– 83) months, and 190 cases were lost, with a follow-up rate of 92.9% (2,497/2,687). Of the 2,687 patients included, 21 (0.8%) experienced recurrence.ConclusionThis nomogram, which integrates available preoperative clinicopathological features and intraoperative frozen biopsy outcomes, is a reliable tool with high accuracy to predict pCLN- in cN0 PTC.

The Differences Between Multifocal and Unifocal Papillary Thyroid Carcinoma in Unilateral Lobe: A Meta-Analysis

BackgroundAs many inconsistent reports on the clinical manifestations and prognosis between unilateral unifocal PTC (UUPTC) and unilateral multifocal PTC (UMPTC), identifying the difference should guide management. The purpose of this study was to investigate other additional differences between UUPTC and UMPTC in addition to their difference in the number of cancer foci.Data SourcesA systematic literature search was conducted in the PubMed and Web of Science databases for relevant studies published before December 31, 2020. Their reference lists were also reviewed.Review MethodsTwo reviewers independently extracted data and assessed the quality of eligible studies. Studies on patients who underwent an open thyroidectomy with or without neck dissection were included. Data were analyzed using the RevMan 5.3 software.ResultsFifteen studies comprising 9,665 patients were selected for the meta-analysis. UMPTC occurred in 10% to 36% of all PTC cases. There were no significant differences between UMPTC and UUPTC patients in age, gender, tumor size, and extrathyroidal extension (ETE). However, significant differences (P < 0.05) between UMPTC and UUPTC patients were observed in central lymph node metastasis (CLNM), lateral lymph node metastasis (LLNM), tumor-node-metastasis (TNM) stage I+II, TNM stage III+IV, the recurrence/persistence of the UMPTC group after total thyroidectomy and overall recurrence/persistence.ConclusionUMPTC patients are more likely to have CLNM, LLNM, more advanced TNM stage, and recurrence/persistence than UUPTC patients. Compared with UUPTC, UMPTC patients should undergo central lymph node dissection, and pay more attention to LLNM, TNM stage and recurrence/persistence during the follow-up.

Novel Trocars and Suspension System Application in Gasless Transoral Endoscopic Thyroidectomy Vestibular Approach Oral Endoscopic Surgery

In the current study, we reported our initial experience of gasless transoral endoscopic thyroidectomy vestibular approach (TOETVA) by novel trocars and a suspension system. Between February 2019 to September 2020, thyroid cancer patients with indicated central lymph node metastasis by imaging examination who had received gasless TOETVA by our designed trocars and suspension system in The First Affiliated Hospital of University of Science and Technology of China were reviewed. A total of 95 thyroid cancer patients that received gasless TOETVA were included in this analysis. Of note, 73 cases underwent one-sided lobectomy and the remaining 22 cases underwent total thyroidectomy. All thyroid cancer patients underwent central lymph node dissection (CND). The average total examined lymph nodes number was 8.55 ± 5.67 per individual. No serious complications occurred during or after the operation besides one patient who had a short-term recurrent laryngeal nerve (RLN) deficit and one patient who had delayed postoperative bleeding. In conclusion, the use of novel trocars and a suspension system can effectively improve the safety and efficacy of TOETVA.

Prophylactic Bilateral Central Neck Dissection Should Be Evaluated Based on Prospective Study of 581 PTC Patients

Background: Prophylactic central lymph node dissection (PCND) had been a basic consensus for patients with papillary thyroid carcinoma in China. However, unilateral or bilateral central lymph node dissection (CND)was still controversial. This study aimed at investigating the safety and long-term benefit for the patients with bilateral central lymph node dissection (BCCD). Methods: 581 patients were enrolled and divided randomly into the test and control groups according to a different range of CND. 285 patients were prospectively assigned to undergo lobe thyroidectomy plus BCND in the test group, in comparison 296 patients were assigned to undergo lobe thyroidectomy plus ipsilateral central lymph node dissection (ICND) in the control group. Results: We found that the numbers of total LN and N1a in the test group were higher than that of the control group (p=0.002), but there was no difference in the number of metastasized lymph nodes (p=0.857) and tumor recurrence (p=0.308). Additionally, in the aspect of postoperative complication (1 day after surgery), the serum levels of parathyroid hormone in the BCND group were lower than that in the ICND group (P =0.010), and the numbers of transient laryngeal nerve palsy were higher than that(p=0.033). meanwhile we further found that tumors size larger than 1cm and tumor side lymph node metastasis were related to the contralateral lymph node metastasis. Conclusion: BCND resulted in more positive lymph nodes and complications while did not change the patient's long-term prognosis. It may be an alternative for patients with tumor sizes larger than 1cm in large medical centers.

A Prediction Model for Contralateral Central Neck Lymph Node Metastases in Unilateral Papillary Thyroid Cancer

The health problems caused by the frequent relapse of papillary thyroid carcinoma (PTC) remain a worldwide concern since the morbidity rate of PTC ranks the highest among thyroid cancers. Residues from contralateral central lymph node metastases (con-CLNM) are the key reason for persistence or recurrence of unilateral papillary thyroid carcinoma (uni-PTC); however, the ability to assess the status of con-CLNM in uni-PTC patients is limited. To clarify the risk factors of con-CLNM, a total of 250 patients with uni-PTC who underwent total thyroidectomy and bilateral central lymph node dissection were recruited in this study. We compared the clinical, sonographic, and pathological characteristics of patients with con-CLNM to those without con-CLNM and established a nomogram for con-CLNM in uni-PTC. We found that male sex, without Hashimoto’s thyroiditis, present capsular invasion, with ipsilateral lateral lymph node metastases, and the ratio of ipsilateral central lymph node metastases ≥0.16 were independent con-CLNM predictors of uni-PTC (ORs: 2.797, 0.430, 2.538, 2.202, and 26.588; 95% CIs: 1.182–6.617, 0.211–0.876, 1.223–5.267, 1.064–4.557, and 7.596–93.069, respectively). Additionally, a preoperative nomogram for the prediction of con-CLNM based on these risk factors showed good discrimination (C-index 0.881; 95% CI: 0.840–0.923; sensitivity 85.3%; specificity 76.0%) and good agreement via the calibration plot. Our study provided a way to quantitatively and accurately predict whether con-CLNM occurred in patients with uni-PTC, which may guide surgeons to evaluate the nodal status and perform tailored therapeutic central lymph node dissection.

Surgical Extent of Central Lymph Node Dissection for Papillary Thyroid Carcinoma Located in the Isthmus: A Propensity Scoring Matched Study

IntroductionTo assess the risk factor for the central lymph node (CLN) metastasis and investigated the surgery extent of lymph node dissection for patients with isthmic PTC (papillary thyroid carcinoma).Materials and MethodsA total of 669 patients with a single nodule of isthmic PTC were retrospectively reviewed. The propensity score matching was performed twice separately. 176 patients respectively from patients who underwent thyroidectomy plus bilateral central lymph node dissection (BCLND) and who underwent thyroidectomy plus unilateral central lymph node dissection (UCLND) were matched. 77 patients were respectively selected from patients who underwent thyroidectomy plus BCLND and who underwent thyroidectomy with no central lymph node dissection (NCLND) were matched.ResultsAmong all the patients who underwent BCLND, 81/177 (45.76%) was confirmed with histologically positive CLN metastasis, and the occult lymph node metastasis is 25.42%. A tumor size of 1.05 cm was calculated as the cutoff point for predicting CLN metastasis by ROC curve analysis with 177 patients who underwent BCLND. The 5-year recurrence-free survival (RFS) rates were 92.9% in the NCLND group and 100% in the BCLND group with P<0.05, while there was no statistical difference in 5-year RFS between the BCLND group and UCLND group (P=0.11). The multivariate logistic regression analysis identified that age<55, tumor size>1cm, capsule invasion and lymphovascular invasion were significantly associated with CLN metastasis, while only age and lymphovascular invasion were proved to be independent risk factors related to contralateral CLN metastasis.ConclusionsThe thyroidectomy with NCLND could be insufficient for patients with isthmic PTC especially for those patients with high risk of central lymph node metastasis, considering that the rate of occult lymph node metastasis could not be ignored.

Identification of risk factors of regional metastasis of differentiated thyroid cancer

Diagnostic difficulties of regional metastases, especially lesion of the central neck, is the main problem with choosing the type of surgical intervention for patients with differentiated thyroid cancer diagnosis. The frequency of differentiated thyroid cancer regional metastasis to the neck lymph nodes is about 60 %. This article includes the search and identification of risk factors of differentiated thyroid cancer regional metastases, as well as a review of the literature on this problem. We have analyzed the results of surgical treatment of patients with papillary thyroid cancer of Stage I–III (T1–4aN0–1bM0) who underwent surgical treatment at the St. Petersburg State Healthcare Institution «City Clinical Oncology Center» in 2018–2019. As a result of the study, the data revealed a relationship between regional metastases and intrathyroid vascular invasion of the primary tumor (p < 0.05), while multifocality, extrathyroid extension and the incidence of BRAF mutation have not demonstrated this correlation (p > 0.05). After the surgical treatment we should focus on the presence of vascular invasion and, if it is detected, perform final thyroidectomy and central lymph node dissection with subsequent radioiodine therapy.