Isthmusectomy in selected patients with well-differentiated thyroid carcinoma

Characteristics and risk factors of cervical lymph node metastasis in cN0 papillary thyroid microcarcinoma of the isthmus

The surgical resection range of papillary thyroid microcarcinoma of the isthmus (PTMCI) is controversial, and the guidelines do not fully guide the central lymph node dissection (CLND).We retrospectively studied the comparison of PTMCI (Group A, n = 65 cases) and non-PTMCI (Group B, n = 80 cases). Based on whether central lymph node metastasis (CLNM) was further detected, they were further divided into the PTMCI with CLNM (group C, n = 42 cases), the PTMCI without CLNM (group D, n = 23 cases), the non-PTMCI with CLNM (group E, n = 45 cases), the non-PTMCI without CLNM (group F, n = 35 cases). All patients underwent total thyroidectomy and CLND. The CLNM pathological examination was divided into right recurrent laryngeal nerve superficial lymph nodes (Right VI a), right recurrent laryngeal nerve deep lymph nodes (Right VI b), left VI area lymph nodes (Left VI), prelaryngeal lymph node, and pretracheal lymph node. The extent of lymph node metastasis and risk factors of PTMCI were analyzed by univariate and multivariate analysis. The ROC curve was used to calculate the maximum diameter of the tumor and the Youden index was calculated to analyze the impact of diameter on the risk factors for CLNM in PTMCI. To construct a prediction model of transfer risk of high risk factors by Nomogram, there were significant differences in prelaryngeal lymph nodes (p = 0.034) and pretracheal lymph nodes ( n = 0.035) between group A and group B, and the risk factors of lymph node metastasis were tumor invasion (p = 0.003), multifocality (p = 0.001), and the maximum tumor diameter≧6.5 mm. PTMCI is more prone to metastasis of pretracheal lymph nodes and prelaryngeal lymph nodes, and the presence of tumor invasion, multifocality, and tumor diameter≧6.5 mm are high risk factors for metastasis in PTMCI. According to the prediction model, with all risk factors the risk of cervical lymph node metastasis is up to 90%.

The use of thyroid isthmusectomy for management of well differentiated thyroid carcinoma - A systematic review and meta-analysis

OBJECTIVE

With the growing global incidence of thyroid carcinomas, there is an increasing need for distinct guidelines for isthmus-confined carcinomas. Here, we performed the first systematic review on the topic to date, aiming to provide understanding to isthmusectomy as surgical management for well-differentiated thyroid carcinoma of the isthmus.

METHODS

We conducted a systematic review following the PRISMA guidelines, analyzing English-language studies from the past decade that report on thyroid isthmusectomy. Exclusion criteria included isthmusectomy performed alongside full thyroidectomy or partial thyroid lobectomy, lack of data on tumor characteristics or survival outcomes, and non-English publications where a translation was unavailable. Our review identified a total of 227 patients from seven studies.

RESULTS

The average 5-year overall survival and disease-free survival rates for patients with isthmus-confined PTC who underwent isthmusectomy were 100 % and 93.1 %, respectively. Similar to that of total thyroidectomy. 3.1 % of patients required completion thyroidectomy. Furthermore, isthmusectomy resulted in fewer surgical complications than total thyroidectomy.

CONCLUSIONS

The scarcity of studies providing detailed tumor characteristics and patient outcomes limits our ability to fully evaluate the safety and efficacy of isthmusectomy for isthmus-confined PTC. Additionally, the variable sample sizes and restricted geographic distribution of the included studies calls into questions the generalizability of their findings. Despite these limitations, the data suggest that isthmusectomy may be a viable surgical option for select patients with small, isthmus-confined PTC. In the absence of a randomized controlled trial on the noninferiority of isthmusectomy, significantly more publications are needed before strong conclusions can be drawn.

Isthmusectomy for papillarythyroid carcinoma in the isthmus: The less the better

BACKGROUND

Appropriate surgical treatments of papillary thyroid carcinoma (PTC) located in the isthmus (PTCI) remains controversial. This study evaluated the outcomes from isthmusectomy in single PTCI and compared it with those for patients who underwent total thyroidectomy.

MATERIAL AND METHODS

This study enrolled 89 PTCI patients who underwent total thyroidectomy or isthmusectomy plus bilateral central lymph node dissection (BCLND). Patients were divided into Group A (n = 48) with total thyroidectomy plus BCLND and Group B (n = 41) with isthmusectomy plus BCLND. We compared the effects of different surgical modalities and clinicopathological characteristics on the prognosis of PTCI, and conducted a multivariate analysis to assess risk factors for bilateral central node metastasis for PTCI.

RESULTS

There was no significant difference in postoperative recurrence-free survival (RFS) between Group A and Group B (P = 0.574). Temporary hypocalcemia occurred more in Group A than Group B (χ2 = 4.608, P = 0.032). There was no significant difference in metastatic lymph nodes between the 2 groups. However, there are 8 patients occurred bilateral central node metastasis in group A, and 6 in Group B (16.7% vs. 14.6%, respectively, P = 0.793). Multiple logistic analysis suggested that tumor size greater than 1.0 cm (OR = 9.72, 95% CI: 2.06-56.59, P < 0.001), and tumor located in the center of isthmus (OR = 5.19, 95% CI: 1.04-2.58,P < 0.001) were risk factors for bilateral central node metastasis.

CONCLUSIONS

Our results reveal that isthmusectomy plus BCLND may be a simple but feasible approach for selected PTCI patients, resulting in a better quality of life than total thyroidectomy plus BCLND.

Total thyroidectomy versus less-than-total thyroidectomy for papillary thyroid carcinoma of isthmus: a systematic review and meta-analysis

Background

Papillary thyroid carcinoma of isthmus (PTCI) has a more aggressive nature, a higher rate of lymph node metastasis and tumor recurrence. Clinicians have different preferences for the surgical approach to PTCI, but there are no definitive guidelines. The purpose of this article is to compare the oncologic outcomes and complications of total thyroidectomy and less-than-total thyroidectomy for PTCI using meta-analysis.

Methods

We searched PubMed, Embase, Cochrane Library, and Web of Science databases for articles that met the inclusion criteria, with an unlimited start date and an end date of February 19, 2023. Exclusion criteria were applied to filter out articles for further analysis. Ultimately, seven articles were used for analysis, all of which were retrospective studies. The MINORS scale was adopted to evaluate the quality of the included literature, and Review Manager 5.4 was used for data analysis.

Results

A total of 814 patients were included in the seven articles, including 401 in the less-than-total thyroidectomy group (trial group) and 413 in the total thyroidectomy group (control group). The results of the meta-analysis showed that there was no significant difference in the tumor recurrence rate between the two groups after total thyroidectomy or less-than-thyroidectomy for PTCI (odds ratio, 1.51; 95% confidence interval: 0.49, 4.65; P=0.47), and there was no statistical difference in the incidence of all postoperative complications between the two groups.

Conclusions

There may be some limitations in this analysis, such as publication bias and the fact that the included articles were all retrospective studies with a certain degree of heterogeneity. PTCI patients with early staging and no significant lymph node metastases may be able to choose a more conservative surgical approach, which is less-than-total thyroidectomy. Patients with relatively late staging and significant preoperative lymph node metastases or extra thyroidal extension may opt for total thyroidectomy plus lymph node dissection in the central region and, if necessary, lymph node dissection in the lateral cervical region.

Radiofrequency ablation for papillary thyroid cancer located in isthmus: comparison with that originated in thyroid lobe

PURPOSE

To analyze the outcomes of radiofrequency ablation (RFA) for isthmus papillary thyroid cancer (PTC) versus PTC originating from the lobes.

METHODS

Patients with solitary low-risk PTC treated with RFA between July 2014 and December 2019 were retrospectively reviewed. This study was approved by our institutional review board. Of the 562 patients, 104 and 458 had PTCs located in the thyroid isthmus and thyroid lobes, respectively. Local tumor progression (LTP), LTP-free survival (LTPFS), changes in tumor volume, and complications were compared between the two groups using propensity-score matching (PSM).

RESULTS

The isthmic and lobar groups showed no significant differences in LTP (2.9% vs. 3.8%), new PTC (2.9% vs. 2.9%), persistent lesions (0.0% vs. 0.2%), or LTPFS after PSM. Before PSM, the two groups showed significant differences in the volume reduction ratio (VRR) of the ablated tumors at 1, 3, 24, 30, and 48 months after RFA, but no differences between the two groups were observed in tumor volume, VRR, or disappearance rate after PSM (p > .05). One patient in the isthmic group presented with coughing, while another complained of hoarseness. Complications did not differ significantly between the two groups (p > .05).

CONCLUSIONS

The outcomes of RFA for patients with low-risk PTC in the thyroid isthmus and thyroid lobes were similar. Therefore, RFA may serve as an alternative treatment option for patients with low-risk isthmic PTC.

Development and validation of nomograms for predicting the risk of central lymph node metastasis of solitary papillary thyroid carcinoma of the isthmus

BACKGROUND

This study was conducted to develop nomograms and validate them by assessing risk factors for the development of central lymph node metastasis (CLNM) in patients with solitary papillary thyroid carcinoma of the isthmus (PTCI) for predicting the probability of CLNM.

METHODS

Demographic and clinicopathological variables of patients with solitary papillary thyroid carcinoma (PTC) from May 2018 to May 2023 at the First Hospital of Shanxi Medical University were retrospectively analyzed, and the lobar group and the isthmus group were divided according to tumor location. Patients with the same sex, age difference of less than 3 years, and equal gross tumor diameter were selected from the lobar group and compared with the paraisthmic tumor group. Independent risk factors were determined using univariate and multivariate logistic regression analysis. On this basis, clinical predictive nomograms were developed and validated.

RESULTS

Clinical data from 326 patients with solitary PTCI and 660 cases of solitary lobar PTC were used for analysis in our study. The incidence of solitary tumors CLNM located in the median isthmus, paracentral isthmus, and lobes was 69.8%, 40.9%, and 33.6%, respectively. Statistical analysis revealed that gender, age, isthmus location, maximum nodal diameter, the presence of possible CLNM in advance on preoperative ultrasound, chronic lymphocytic thyroiditis, and the lymphocyte/monocyte ratio were independent risk factors for preoperative CLNM in patients with solitary PTCI. Age, isthmus location, chronic lymphocytic thyroiditis, gross tumor diameter, presence of intraoperative extrathyroidal extension, and presence of metastasis in the Delphian lymph node on frozen section were independent risk factors for intraoperative CLNM. The concordance indices of nomograms for preoperative and intraoperative are 0.871 and 0.894 in the training set and 0.796 and 0.851 in the validation set, calibration curve and decision curve analysis also demonstrated the strong reliability and clinical applicability of this clinical prediction model.

CONCLUSION

In this study, we concluded that solitary PTCI is more aggressive compared to solitary lobar PTC, and we constructed nomograms and risk stratification to accurately identify patients with solitary PTCI who are at high risk of developing CLNM, which will help clinicians in personalized decision making.

Implications of isthmic location as a risk factor in papillary thyroid carcinoma

Background

Papillary thyroid carcinoma (PTC) located in the isthmus generally has been known to have more extrathyroidal extension (ETE), lymph node involvement, and multifocality. The purpose of this study was to determine the clinical significance of an isthmic location of PTC.

Methods

The records of 160 patients who underwent a total thyroidectomy due to a single, dominant isthmic PTC were retrospectively reviewed. The characteristics of isthmic cancer were compared with those of unilateral-lobar cancer in a PTC cohort at Seoul St. Mary's hospital. After propensity score matching for age, sex, and tumor size, 160 isthmic PTCs and 800 unilateral-lobar PTCs were compared. The clinicopathologic characteristics were analyzed to evaluate the prognostic significance of an isthmic tumor location.

Results

The isthmic group was significantly older (49.6 vs. 46.8 years, P=0.007) and had a smaller mean tumor size (0.8±0.4 vs. 1.0±0.7 cm, P<0.001) than the unilateral-lobar group. After propensity score matching, tumor size categories, ETE, multifocality, nodal metastasis and proportion of patients with more than five metastatic lymph nodes were similar in both groups. However, N1b cases were more frequent in the unilateral-lobar group both before and after propensity score matching. In multivariate analysis, isthmic location was not correlated with gross ETE, multifocality, and higher-risk N1 disease. Younger age and more than five metastatic nodes increased the risk of PTC recurrence. However, isthmic tumor location was not significantly correlated with recurrence-free survival.

Conclusions

Isthmic location is not an independent risk factor for aggressive clinicopathologic features and is not related to PTC recurrence.

Isthmectomy is effective and sufficient for selected patients with solitary papillary thyroid carcinoma confined to the isthmus

BACKGROUND

To retrospectively analyze the outcomes of patients treated with isthmusectomy for a solitary papillary thyroid carcinoma (PTC) confined to the isthmus, and re-assess the role of isthmusectomy in these patients.

METHODS

The medical records of 65 patients who underwent isthmusectomy for a solitary PTC confined to the isthmus at the National Cancer Center/Cancer Hospital, Chinese Academy of Medical Sciences, Peking Union Medical College between 1985 and 2015 were retrospectively reviewed. Demographic data, surgical procedures, pathological characteristics, stages, and outcomes were analyzed.

RESULTS

Patients' median age was 39 years (range, 19-63), and the majority were female (86.2% female, 13.8% male). All patients had a solitary PTC confined to the isthmus and were treated with isthmusectomy. Pretracheal lymph node dissection was performed in 34 patients, in which unilateral central neck dissection was performed in 4 patients and bilateral central neck dissection in 2 patients. Microscopic extrathyroidal extension (ETE) was observed in 23 (35.4%) patients, and macroscopic ETE was observed in 3 (4.6%) patients. Thirty-eight (58.5%) patients were stage pT1a, 19 (29.2%) patients were stage pT1b, 5 (7.7%) patients were stage pT2, and 3 (4.6%) patients were stage p3b. Fifteen (23.1%) patients were stage pN1a. Median follow-up time was 78 months (range, 12-274). Two patients experienced a recurrence and both achieved remission after re-operation. The 10-year recurrence-free survival was 92.1%. The 10-year overall survival and disease specific survival were 98.3% and 100%, respectively.

CONCLUSIONS

Isthmusectomy is effective and sufficient for select patients with a solitary PTC confined to the isthmus.

Risk prediction for central lymph node metastasis in isolated isthmic papillary thyroid carcinoma by nomogram: A retrospective study from 2010 to 2021

BACKGROUND

Isthmic papillary thyroid carcinoma (IPTC) is an aggressive thyroid cancer associated with a poor prognosis. Guidelines elaborating on the extent of surgery for IPTC are yet to be developed. This study aims to construct and validate a model to predict central lymph node metastasis (CLNM) in patients with IPTC, which could be used as a risk stratification tool to determine the best surgical approach for patients.

METHODS

Electronic medical records for patients diagnosed with isolated papillary thyroid carcinoma who underwent surgery at Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, from January 2010 to December 2021 were reviewed. All patients who underwent thyroidectomy with central neck dissection (CND) for isolated IPTC were included. We conducted univariate and multivariate logistic regression analyses to assess risk factors for ipsilateral and contralateral CLNM and the number of CLNM in IPTC patients. Based on the analysis, the nomogram construction and internal validations were performed.

RESULTS

A total of 147 patients with isolated IPTC were included. The occurrence of CLNM was 53.7% in the patients. We identified three predictors of ipsilateral CLNM, including age, gender, and size. For contralateral CLNM, three identified predictors were age, gender, and capsular invasion. Predictors for the number of CLNM included age, gender, capsular invasion, tumor size, and chronic lymphocytic thyroiditis (CLT). The concordance index(C-index) of the models predicting ipsilateral CLNM, contralateral CLNM, 1-4 CLNM, and ≥5 CLNM was 0.779 (95%CI, 0.704, to 0.854), 0.779 (95%CI, 0.703 to 0.855), 0.724 (95%CI, 0.629 to 0.818), and 0.932 (95%CI, 0.884 to 0.980), respectively. The corresponding indices for the internal validation were 0.756 (95%CI, 0.753 to 0.758), 0.753 (95%CI, 0.750 to 0.756), 0.706 (95%CI, 0.702 to 0.708), and 0.920 (95%CI, 0.918 to 0.922). Receiver operating characteristic (ROC) curves, calibration, and decision curve analysis (DCA) results confirmed that the three nomograms could precisely predict CLNM in patients with isolated IPTC.

CONCLUSION

We constructed predictive nomograms for CLNM in IPTC patients. A risk stratification scheme and corresponding surgical treatment recommendations were provided accordingly. Our predictive models can be used as a risk stratification tool to help clinicians make individualized surgical plans for their patients.

Nomograms to predict ipsilateral and contralateral central lymph node metastasis in clinically lymph node-negative patients with solitary isthmic classic papillary thyroid carcinoma

BACKGROUND

Isthmus-originating papillary thyroid carcinoma has unique clinicopathological characteristics. There are no specific guidelines regarding the extent of surgery for isthmic papillary thyroid carcinoma. We aimed to evaluate the characteristics of clinically lymph node-negative patients with solitary isthmic papillary thyroid carcinoma and to determine the best surgical protocol for these patients.

METHODS

A total of 904 patients diagnosed with solitary papillary thyroid carcinoma who underwent surgery were retrospectively reviewed. These patients were divided into the isthmic group (246 patients) or lobar group (658 patients). We compared the 2 groups and conducted a multivariate analysis to assess risk factors for ipsilateral and contralateral central lymph node metastasis in isthmic papillary thyroid carcinoma patients. Nomograms for predicting central lymph node metastasis in isthmic papillary thyroid carcinoma patients were developed and internal calibration was performed for these models.

RESULTS

Isthmic papillary thyroid carcinoma patients have a significantly higher incidence of extrathyroidal extension and central lymph node metastasis than do lobar papillary thyroid carcinoma patients. For isthmic papillary thyroid carcinoma patients, sex, BRAF V600E mutation, chronic lymphocytic thyroiditis, tumor size, margin, and extrathyroidal extension were independent risk factors of ipsilateral central lymph node metastasis. Body mass index, BRAF V600E mutation, tumor size, location, and extrathyroidal extension were independent risk factors of contralateral central lymph node metastasis. All the above factors were incorporated into nomograms, which showed the perfect discriminative ability.

CONCLUSION

Based on the predictive nomograms, we proposed a risk stratification scheme and corresponding individualized surgical treatment based on different nomogram scores. In the debate about prophylactic central neck dissection among clinically lymph node-negative patients with solitary isthmic papillary thyroid carcinoma, our nomograms provide the balance to avoid overtreatment and undertreatment through personal risk assessment.

[The Therapy of Malignant Thyroid Disease from ENT-Perspective]

INTRODUCTION

 Malignant tumours of the thyroid gland show a rising incidence. As in the ENT-department Bad Hersfeld the management of thyroid disorders has been in focus for a longer period, we want to share our experiences in this field.

MATERIAL AND METHODS

 The investigation started in the year of 2014 till July 2020. All patients who underwent thyroid surgery were evaluated concerning important demographic and medical parameters such as age, sex, histology, calcium, recurrent nerve palsy, etc. RESULTS:  So far 63 patients with a malignant thyroid disease were enrolled in this study. The sex ratio showed a preponderance of the female patients with 42 and 21 males. Age had a wide range from 11 to 95 years. Patients with a differentiated cancer were in average younger than those with anaplastic disease. Histologically the papillary variant dominated with 65 % (n = 41) the other tumours as the follicular (n = 6), the medullary (n = 5) and the anaplastic carcinoma (n = 6). In two female patients with primary hyperparathyroidism a carcinoma of the parathyroid was found surprisingly. All patients underwent surgery; those with an advanced differentiated carcinoma were treated with radioiodine additionally. To our knowledge there was just one tumour related death in case of a differentiated carcinoma, whereas all patients with an anaplastic disease died of their malignancy.

CONCLUSIONS

 The otorhinolaryngologist is involved in the management of thyroid malignancies. As well as in the benign diseases of the endocrine neck organs the interdisciplinary collaboration is mandatory for a high medical standard.

Thyroid Isthmusectomy with Prophylactic Central Compartment Neck Dissection is a Feasible Approach for Papillary Thyroid Cancer on the Isthmus

BACKGROUND

The treatment for papillary thyroid cancer (PTC) has become more conservative, but still no specific guidelines exist for managing isthmic PTC. This study analyzed the outcomes from isthmusectomy in single isthmic PTC and compared it with those for patients who previously had undergone a total thyroidectomy.

METHODS

An isthmusectomy with prophylactic central compartment neck dissection (pCCND) was planned for a single isthmic PTC between 2014 and 2018 (isthmusectomy group). For cases with gross extrathyroidal extension (ETE) or multiple nodal metastasis, the procedure was converted to a total thyroidectomy. The study analyzed the characteristics and outcomes of the isthmusectomy group. Additionally, the results were compared with those of the isthmusectomy-feasible group who met the eligibility criteria for isthmusectomy among total thyroidectomies performed between 2009 and 2013.

RESULTS

Of the 90 patients in the isthmusectomy group, 81 received isthmusectomy and 9 had conversion to a total thyroidectomy. Microcarcinoma occurred in 72 cases and gross ETE in 3 cases. One patient showed occult satellite cancer, and seven patients showed more than five metastatic nodes. Transient hypocalcemia developed in five and patients and permanent hypocalcemia in one patient with total thyroidectomy. Of 46 patients who began hormone replacement postoperatively, 13 completely stopped taking medication during the follow-up period. Metachronous PTC was diagnosed for one patient 12 months after isthmusectomy. The isthmusectomy group and the isthmusectomy-feasible group showed similar clinicopathologic properties including multifocality, ETE, and nodal metastasis. However, the isthmusectomy group showed significantly less transient or permanent hypocalcemia and thyroid hormone dependency.

CONCLUSIONS

Isthmusectomy with pCCND may be a feasible alternative for properly selected isthmic PTC, resulting in a better quality of life than total thyroidectomy.

Microwave ablation for papillary thyroid cancer located in the thyroid isthmus: a preliminary study

PURPOSE

To assess the feasibility, efficacy, and safety of ultrasound (US)-guided microwave ablation (MWA) for the treatment of papillary thyroid cancer (PTC) located in the thyroid isthmus.

MATERIALS AND METHODS

Thirty-four patients (mean age, 43 ± 11 years; 26 women) with isthmic PTC treated with MWA between June 2014 and September 2020 were included in this retrospective study. The follow-up time after MWA was 17 ± 9 months (range, 8-50 months). Changes in thyroid function, parathyroid function, and tumor size were evaluated, along with the rates of tumor disappearance and complications.

RESULTS

The treatment was technically feasible and successfully completed in all 34 patients (100%). Measures of thyroid function (i.e. serum triiodothyronine, free thyroxine, and thyrotropin) and parathyroid function (i.e. serum calcium and intact parathyroid hormone) showed no changes from pretreatment levels at 1, 3, and 6 months after MWA (p > 0.05 for all). Tumor size was found to be increased at 1 and 3 months after MWA compared with before MWA (p < 0.05). However, the tumor sizes measured at 6, 9, 12, and 18 months after MWA were smaller than the pretreatment sizes (p < 0.05 for all). In 24 cases (70.6%), the tumors completely disappeared on US examination. Five cases (2.9%) experienced side effects from MWA treatment, but no major or minor complications were recorded.

CONCLUSION

The results of this study demonstrate that US-guided MWA is a feasible, effective, and safe treatment option for selected patients with PTC located in the thyroid isthmus.

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

INTRODUCTION

To 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 METHODS

A 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.

RESULTS

Among 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.

CONCLUSIONS

The 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.

Comparison of Outcomes Following Thyroid Isthmusectomy, Unilateral Thyroid Lobectomy, and Total Thyroidectomy in Patients with Papillary Thyroid Microcarcinoma of the Thyroid Isthmus: A Retrospective Study at a Single Center

Background

Papillary thyroid microcarcinoma (PTMC) measures less than 10 mm in diameter, is more common in the thyroid lobes, but rarely presents in the thyroid isthmus. This retrospective study aimed to compare patient outcomes following various types of surgery in patients with PTMC of the thyroid isthmus, at a single center in China.

Material/Methods

We analyzed the clinical data of patients with isthmus thyroid cancer treated at the First Hospital of China Medical University. Patients were divided into 2 groups according to the tumor diameter-PTMC of the thyroid isthmus and papillary thyroid carcinoma >10 mm. The clinicopathological features between the 2 groups were compared, and the effects of various surgical methods on the prognosis of patients were analyzed.

Results

A total of 70 patients were included in this study: 29 with PTMC of the thyroid isthmus (41.4%) and 41 with papillary thyroid carcinoma >10 mm (58.6%). The rates of lymph node metastasis (10.3% vs. 34.1%) and extrathyroid extension (0% vs. 14.6%) in the PTMC of the thyroid isthmus were significantly lower than those in the papillary thyroid carcinoma >10 mm. The recurrence-free survival (RFS) rate was 97.1%. Survival analysis showed that there was no significant difference in RFS among patients with PTMC of the thyroid isthmus undergoing isthmusectomy, unilateral lobectomy, and total thyroidectomy.

Conclusions

These findings from a single center showed that for patients with PTMC of the thyroid isthmus, who had no comorbidities, there was no significant difference in outcome between the 3 types of thyroid surgery.

Surgical Outcomes and Efficacy of Isthmusectomy in Single Isthmic Papillary Thyroid Carcinoma: A Preliminary Retrospective Study

BACKGROUND AND OBJECTIVES

The optimal extent of surgery needed for isthmic papillary thyroid carcinoma (PTC) is not well-defined, although total thyroidectomy is usually recommended. This study aimed to evaluate the efficacy of isthmusectomy in the surgical treatment of isthmic PTC. Materials and Methods: We retrospectively studied 121 patients who underwent thyroidectomy with or without central neck dissection (CND) for single isthmic PTC from January 2003 to June 2019. We excluded patients who were clinically suspected to have clinically positive cervical lymph node metastasis and gross extrathyroidal extension or to have cancers at sites other than the thyroid isthmus. Patients were divided into three groups according to the extent of thyroidectomy-total thyroidectomy, lobectomy with isthmusectomy (the lobectomy group), and isthmusectomy. Clinical and pathologic characteristics, surgical outcomes, recurrence rate, and survival were analyzed. Results: Of 121 isthmic PTC patients, 28 were men and 93 were women. Total thyroidectomy, lobectomy with isthmusectomy, and isthmusectomy were performed in 70 (57.8%), 40 (33.1%), and 11 (9.1%) patients, respectively. Prophylactic CND was performed in 104 (86%) patients. In a subgroup analysis, patients who underwent total thyroidectomy showed higher postoperative hypoparathyroidism (p < 0.001) than those who underwent lobectomy and isthmusectomy. However, there were no differences in the recurrence rate or survival between the three groups. Conclusion: Thyroid isthmusectomy may be effective in the surgical treatment of small single isthmic PTC. Further studies are necessary to verify this result.