FACTORS INFLUENCING THE SUCCESSFUL MAINTENANCE OF EUTHYROIDISM AFTER LOBECTOMY IN PATIENTS WITH PAPILLARY THYROID MICROCARCINOMA: A SINGLE-CENTER STUDY.

Objective: This study aimed to evaluate factors influencing the successful maintenance of postoperative euthyroidism in patients who did not undergo immediate thyroid hormone replacement after lobectomy for papillary thyroid microcarcinoma (PTMC). Methods: From September 2015 to June 2017, 186 patients underwent lobectomy for PTMC in our hospital. Patients taking medications for hypothyroidism and hyperthyroidism before and after lobectomy were excluded. Multiple parameters, including sex, age, pre-operative free thyroxine (T4), thyroid-stimulating hormone (TSH), thyroglobulin (TG), and thyroid autoantibody levels, body mass index (BMI), postoperative histopathology of the thyroid gland, remnant thyroid gland volume, and session number of levothyroxine discontinuation were retrospectively evaluated. These factors were compared between groups based on the maintenance of postoperative euthyroidism. Results: In 88 of the 175 patients (50.3%), postoperative euthyroidism was successfully maintained without thyroid hormone replacement during the first year after lobectomy. There were significant differences in sex (P = .003), pre-operative TSH levels (P = .002), and histopathology of the thyroid gland (P = .035) between the groups showing maintenance success and failure. The group showing successful maintenance had a higher percentage of male patients, lower levels of pre-operative TSH, and normal parenchymal histology of the thyroid gland. However, there were no significant between-group differences in age, pre-operative free T4, TG, and thyroid autoantibody levels, BMI, remnant thyroid gland volume, and session number of levothyroxine discontinuation. Conclusion: Patient sex, pre-operative TSH levels, and histopathology of the thyroid gland may influence the maintenance of postoperative euthyroidism after lobectomy. Abbreviations: BMI = body mass index; PTMC = papillary thyroid microcarcinoma; RR = reference range; T4 = thyroxine; TFT = thyroid function test; TG = thyroglobulin; TSH = thyroid-stimulating hormone.

Utility of Preoperative Ultrasonography in Transferred Patients with Suspicious Malignancy on Ultrasonography-Guided Fine-Needle Aspiration Cytology of Thyroid Nodules: A Single-Center Retrospective Study.

BACKGROUND This study aimed to assess the utility and characteristics of preoperative ultrasonography (US) in patients transferred to referral hospitals from local clinics with a diagnosis of malignancy on US-guided fine-needle aspiration cytology of thyroid nodules. MATERIAL AND METHODS From January 2018 to June 2018, 109 transferred patients underwent preoperative US in our hospital for suspected thyroid malignancy on cytological analysis after US-guided fine-needle aspiration of thyroid nodules in local clinics. Preoperative US was performed by a single radiologist in all patients. Among them, 6 were excluded from the study because of refusal of thyroid surgery. Preoperative US and histopathological results were compared in all patients. RESULTS After thyroid surgery, pathological examination revealed papillary thyroid carcinoma (PTC) (n=98), follicular adenoma (n=1), and nodular hyperplasia (n=4). Of the 103 patients, 91 exhibited suspicious US findings on the preoperative US, whereas 12 did not. In the 91 patients with suspicious US findings, PTC (n=90) and follicular adenoma (n=1) were confirmed after thyroid surgery. In the 12 patients with no suspicious US findings, PTC (n=8) and nodular hyperplasia (n=4) were confirmed after thyroid surgery. On repeat analysis of the cytological slides of the 4 nodular hyperplasia cases from the local clinics, Bethesda category II (n=1) and III (n=3) were determined. CONCLUSIONS In the transferred patients with a malignant cytology, preoperative US might be helpful to detect false-positive cytology cases.

Comparison of Prevalence and Ultrasonography Features of Thyroglossal Duct Cyst in Adults According to Radioactive Iodine Ablation.

BACKGROUND This study aimed to evaluate the prevalence of thyroglossal duct cysts (TGDCs) on ultrasonography (US) and US features of TGDCs in adults, and to assess whether the prevalence or size of TGDCs increases after radioactive iodine ablation (RIA). MATERIAL AND METHODS Between July and December 2018, 2820 patients underwent thyroid or neck US examination, performed by 2 radiologists, at our center. On the basis of real-time US, the presence or absence of TGDCs was prospectively investigated by 2 radiologists. Among the 2820 patients, 54 patients who were <19 years of age or had a radiation therapy history to the neck were excluded. Eventually, 2766 patients were included. RESULTS Of the 2766 patients, 160 (5.8%) showed a TGDC on US. The mean size of TGDCs in RIA history (+) (n=36) and RIA history (-) (n=124) groups was 0.92±0.41 cm and 0.86±0.45 cm, respectively. There was no significant difference in size of TGDCs between RIA history (+) and RIA history (-) groups (p=0.684). Between the TGDC (+) and TGDC (-) groups, there was no significant difference in patient age, gender, reason for thyroid/neck US, type of thyroid surgery, and session number and application/no application of RIA (p>0.05). The prevalence rate of TGDCs in radiologist A and B was 4.9% (70/1427) and 6.7% (90/1339), respectively. TGDCs were more common in the suprahyoid neck, and the common shapes of TGDCs were flat-to-ovoid and round. CONCLUSIONS RIA may not be associated with the prevalence or enlargement of TGDCs.

Utility of routine ultrasonography follow-up after total thyroidectomy in patients with papillary thyroid carcinoma: a single-center study.

BACKGROUND: This study aimed to assess the appropriate number of sessions and interval of routine follow-up ultrasonography (US) in patients who underwent total thyroidectomy for papillary thyroid carcinoma (PTC). METHODS: Between January 2008 and December 2009, 569 patients underwent total thyroidectomy for PTC. Of the 569 patients, 44 were excluded from the study because of no US follow-up data for the neck (n = 43) or owing to indeterminate tumor recurrence/persistence (n = 1). The follow-up US for all the patients was performed by a single radiologist. Based on the cytohistopathological results, tumor recurrence/persistence was determined. RESULTS: In the 525 patients, the mean interval to the last follow-up US was 54.7 months, and the mean number of follow-up US sessions was 4.4. Of the 525 patients, 31 (5.9%) showed nodal (n = 30) and non-nodal (n = 1) tumor recurrence/persistence. Patient age and N stage were independently associated with tumor recurrence/persistence. Among patients showing tumor recurrence/persistence after total thyroidectomy, the time at first detection of suspicious US findings on follow-up US was ≤8 months in 2 patients, between 10 and 23 months in 21, and ≥ 25 months in 8. In a receiver operating characteristic curve analysis, the number of sessions and interval of the provided follow-up US were inappropriate for the detection of tumor recurrence/persistence. CONCLUSIONS: For the detection of tumor recurrence/persistence after total thyroidectomy in PTC patients, routine US follow-up with a 1- or 2-year interval may be excessive.

Sonographically based diagnosis of contralateral malignancy in preoperative patients with papillary thyroid microcarcinoma.

OBJECTIVES: We aimed to assess the usefulness of sonographically based diagnosis to predict whether contralaterally located dominant thyroid nodules are malignant or benign in patients with known papillary thyroid microcarcinoma. METHODS: We studied 143 patients with primary papillary thyroid microcarcinoma who underwent preoperative thyroid sonography. Each dominant thyroid nodule was prospectively classified into 1 of 5 diagnostic categories by a single radiologist: benign, probably benign, borderline, possibly malignant, and malignant. We calculated the efficacy of sonographic diagnosis for contralateral malignancy by using histopathologic or long-term sonographic follow-up results as reference standards. RESULTS: Of the 143 primary papillary thyroid microcarcinomas, 17 showed satellite carcinomas; hence, the bilaterality rate in all patients was 11.9% (17 of 143). Real-time sonography of the contralateral thyroid yielded no thyroid nodules (n = 55) and benign (n = 52), probably benign (n = 10), borderline (n = 13), possibly malignant (n = 4), and malignant (n = 9) nodules. When the borderline sonographic class was excluded, the sensitivity, specificity, positive and negative predictive values, and accuracy of sonographic diagnosis for detecting contralateral malignancy were 86.7%, 100%, 100%, 98.3%, and 98.5%, respectively. Within individual sonographic classes for the dominant thyroid nodules, the diagnostic accuracy rates for classes IV and V (possibly malignant and malignant) were higher than those for other classes. CONCLUSIONS: Sonographically based diagnosis may be helpful for detection of contralateral malignancy in preoperative patients with papillary thyroid microcarcinoma.

Factors associated with postoperative hypothyroidism after lobectomy in papillary thyroid microcarcinoma patients.

PURPOSE: No previous study regarding the correlation between post-operative thyroid function and underlying thyroid histopathology has been published. This study assessed the relationship between postoperative thyroid function after lobectomy and multiple factors in papillary thyroid microcarcinoma (PTMC) patients. MATERIALS AND METHODS: From January 2010 to December 2010, 338 patients who had undergone thyroid lobectomy for PTMC were enrolled. Patients with pre-operative hyperthyroidism or those with hypothyroidism but no pre-operative serological data were excluded, leaving a cohort of 285 patients. The relationships between post-operative thyroid function (based on successful cessation of thyroxine replacement therapy) and multiple factors (patient age and sex, serological data, the Pre-operative anteroposterior diameter of the thyroid gland, underlying histopathology of the thyroid gland, and number of attempts to stop thyroxine replacement therapy) were analyzed. RESULTS: Out of 285 patients, 157 attempted to stop thyroxine replacement therapy once or twice after lobectomy; 91 successfully stopped thyroxine replacement therapy during the study period. The final histopathologic diagnoses after surgery included Hashimoto's thyroiditis (n = 5), non-Hashimoto type of lymphocytic thyroiditis (n = 17), and normal thyroid parenchyma (n = 135). Pre-operative thyroid-stimulating hormone (TSH) levels differed significantly between patients with postoperative hypothyroidism and those with postoperative euthyroidism (univariate logistic regression analysis, p = 0.0028; multivariate logistic regression analysis, p = 0.0029). No statistically significant differences were found for any other factors. CONCLUSIONS: The study results demonstrated that the Pre-operative TSH level was the only predictor for the development of post-operative hypothyroidism after thyroid lobectomy in PTMC patients.

Ultrasound assessment of degrees of extrathyroidal extension in papillary thyroid microcarcinoma.

OBJECTIVE: This study aimed to assess the diagnostic accuracy of ultrasound (US)-based T staging of papillary thyroid microcarcinoma (PTMC). METHODS: From January to June 2013, a total of 185 patients underwent preoperative thyroid US for the treatment of thyroid malignancy. A single radiologist immediately determined sonographic T staging for PTMC during real-time US examination. Based on histopathologic results, the diagnostic accuracy of sonographic T staging for PTMC and the difference in the frequency of level VI node metastasis according to the T stage of PTMC were evaluated. RESULTS: Of 105 PTMC cases, the preoperative sonographic diagnoses included intraglandular location (n = 35), subcapsular location (n = 30), mild capsule abutment (n = 7), moderate capsule abutment (n = 19), and perithyroidal invasion without adjacent strap muscle invasion (n = 14). When the sonographic T stages were compared with histopathologic results, all the sonographic categories showed high specificity and low sensitivity. The intraglandular and subcapsular location cases in preoperative US diagnosis showed a low rate of extrathyroidal tumor invasion (6.2%, 4/65). The extrathyroidal tumor invasion cases in preoperative US diagnosis only included 26 extrathyroidal fat invasion cases, and 12 (46.2%, 12/26) true positives. There was a significant correlation between multifocality and histopathologic T stage, but no significant relationship between level VI node metastasis and histopathologic T stage was found. CONCLUSION: The sonographic T staging categorization described here may be helpful for the preoperative evaluation of PTMC patients.

Sonographic detection of thyroid pyramidal lobes before thyroid surgery: a prospective single-center study.

OBJECTIVES: This study aimed to assess the rate of preoperative sonographic detection of thyroid pyramidal lobes with subsequent surgical findings as the reference standard. METHODS: From January 2013 to March 2013, a single radiologist prospectively performed thyroid sonography to detect thyroid pyramidal lobes in consecutive patients who were scheduled for thyroid surgery on the same day. The location, anteroposterior and transverse diameters, length, and location of the upper end of each thyroid pyramidal lobe and its separation or contiguity with the main thyroid gland were investigated by thyroid sonography and surgery. RESULTS: The types of thyroid surgery included total thyroidectomy (n = 85), subtotal thyroidectomy (n = 4), and hemithyroidectomy (n = 43). The surgical incidence of thyroid pyramidal lobes was 59.8% (79 of 132), and the sensitivity, specificity, positive and negative predictive values, and accuracy of sonography for detection of thyroid pyramidal lobes were 81.0%, 79.2%, 85.3%, 73.7%, and 80.3%, respectively. The mean values for the anteroposterior diameter, transverse diameter, and length of the 79 thyroid pyramidal lobes at surgery were 2.2, 6.2, and 26.5 mm, respectively, but these measurements did not show statistically significant correlations with the sonographic detection rate of thyroid pyramidal lobes. CONCLUSIONS: Our study indicates that thyroid sonography may be helpful for identifying the presence and location of thyroid pyramidal lobes.

A Multicenter, Randomized, Controlled Trial for Assessing the Usefulness of Suppressing Thyroid Stimulating Hormone Target Levels after Thyroid Lobectomy in Low to Intermediate Risk Thyroid Cancer Patients (MASTER): A Study Protocol.

BACKGROUND: Postoperative thyroid stimulating hormone (TSH) suppression therapy is recommended for patients with intermediate- and high-risk differentiated thyroid cancer to prevent the recurrence of thyroid cancer. With the recent increase in small thyroid cancer cases, the extent of resection during surgery has generally decreased. Therefore, questions have been raised about the efficacy and long-term side effects of TSH suppression therapy in patients who have undergone a lobectomy. METHODS: This is a multicenter, prospective, randomized, controlled clinical trial in which 2,986 patients with papillary thyroid cancer are randomized into a high-TSH group (intervention) and a low-TSH group (control) after having undergone a lobectomy. The principle of treatment includes a TSH-lowering regimen aimed at TSH levels between 0.3 and 1.99 µIU/mL in the low-TSH group. The high-TSH group targets TSH levels between 2.0 and 7.99 µIU/mL. The dose of levothyroxine will be adjusted at each visit to maintain the target TSH level. The primary outcome is recurrence-free survival, as assessed by neck ultrasound every 6 to 12 months. Secondary endpoints include disease-free survival, overall survival, success rate in reaching the TSH target range, the proportion of patients with major cardiovascular diseases or bone metabolic disease, the quality of life, and medical costs. The follow-up period is 5 years. CONCLUSION: The results of this trial will contribute to establishing the optimal indication for TSH suppression therapy in low-risk papillary thyroid cancer patients by evaluating the benefit and harm of lowering TSH levels in terms of recurrence, metabolic complications, costs, and quality of life.

Comparison of Ultrasonography Features and K-TIRADS for Isthmic and Lobar Papillary Thyroid Carcinomas: A Single-Center Study.

Objective: This study aimed to compare ultrasonography (US) features and the Korean-Thyroid Imaging Reporting and Data System (K-TIRADS) categories for diagnosing isthmic and lobar papillary thyroid carcinomas (PTC). Methods: From January 2009 to December 2012, 163 patients who underwent thyroid surgery and were confirmed with a post-operative histopathological diagnosis of isthmic PTC were retrospectively included. Fifty-nine patients were excluded because their tumor size was <0.5 cm or because of other reasons. The control group comprised of 145 patients who underwent thyroid surgery from January to April 2013 for a classic type of PTC, with the largest diameter being ≥ 0.5 cm and located in the thyroid lobe. A single radiologist retrospectively reviewed the US features and K-TIRADS categories of each nodule using a picture archiving and communication system. Results: Among 104 patients with isthmic PTC, 95 and 9 had primary and secondary cancers, respectively. On the other hand, all 145 patients with lobar PTC had primary cancers. Isthmic PTC showed a lower prevalence of non-parallel orientation than lobar PTC (23.1 and 71%). Nodule orientation was the only US feature statistically different between the two groups (p < 0.0001). However, there was no significant difference in patient age, sex, nodule size, composition, echogenicity, microcalcification, spiculated/microlobulated margin, and K-TIRADS category between the two groups (p > 0.05). Conclusions: K-TIRADS may be useful in the diagnosis of both isthmic and lobar PTC.

Prevalence and Features of Thyroglossal Duct Cyst on Ultrasonography, According to Radioactive Iodine Therapy: A Single-Center Study.

Objective: The relationship between radioactive iodine therapy (RIT) and prevalence of thyroglossal duct cysts (TGDC) on ultrasonography (US) has not been reported. We assessed the prevalence and US features of TGDC according to RIT. Methods: From July 2017 to June 2018, 3,146 subjects underwent thyroid or neck US at our center. The presence or absence of TGDCs was prospectively investigated based on real-time US examination. Among the 3,146 subjects, 261 subjects were excluded because of <18 years of age, unclear information of RIT, or the presence of a radiation therapy history to the neck. Eventually, 2,885 subjects were included in this study. Results: Of the 2,885 subjects finally included, 126 (4.4%) showed a TGDC on US. Those with RIT history showed a higher prevalence of TGDCs than those without (no statistical difference, p = 0.062). In 697 male subjects, there were statistical differences in type of surgery, RIT history, and session number of RIT between those with or without TGDCs (p < 0.0001). In 126 subjects with TGDCs, only sex showed a significant difference between those with or without RIT history (p = 0.015). However, there were no significant differences in the location, size, and shape of TGDCs (p > 0.05). The common US features of TGDC were suprahyoid location, ~1 centimeter, and flat-to-ovoid or round shape. Conclusions: RIT may increase the prevalence of TGDCs, particularly in men.

Ultrasonography, Cytology, and Thyroglobulin Measurement Results of Cervical Nodal Metastasis in Patients With Unclear Papillary Thyroid Carcinoma.

Objective: This study aimed to evaluate the ultrasonography (US), cytology, and thyroglobulin (Tg) measurement results of nodal metastasis in patients showing unclear US or cytology results of primary papillary thyroid carcinoma (PTC). Methods: From January 2016 to December 2018, 179 patients underwent US-guided fine-needle aspiration (FNA) to diagnose lymphadenopathy in the neck. Among them, 36 patients underwent subsequent total thyroidectomy and nodal dissection, and cervical lymph node (LN) metastasis from PTC was confirmed. However, two patients were excluded because of mismatch between the US and pathological findings of LNs. US images and cytological slides for metastatic LNs were retrospectively analyzed, and serum and FNA Tg levels for metastatic LNs were investigated using data from the electric medical records. Primary PTC patients with suspicious results on both US and cytology were classified as the clear group, and the remaining patients were classified as the unclear group. Results: Of the 34 patients, 24 had clear results of primary PTC on both US and cytology (clear group), whereas 10 had unclear results of primary PTC on US or cytology (unclear group). Of the 10 patients in the unclear group, seven had suspicious nodal metastasis from PTC on cytology after US-guided FNA of the cervical LN, and the remaining three had negative cytology but a positive Tg measurement. Metastatic LNs with cystic change tended to show a positive Tg measurement but negative cytology. Conclusions: The combination of US, cytology, and Tg measurement is necessary for diagnosing nodal metastasis from PTC. In cases with unclear primary PTC on US or cytology, the detection of nodal metastasis may be helpful for assessing primary PTC.

Thyroid Imaging Reporting and Data System for Detecting Diffuse Thyroid Disease on Ultrasonography: A Single-Center Study.

Objective: This study aimed to compare the ultrasonography (US) features of diffuse thyroid disease (DTD) and normal thyroid parenchyma (NTP), and to propose a structured imaging reporting system for detecting DTD. Methods: This retrospective study assessed the findings for 270 consecutive patients who underwent thyroid US before thyroid surgery. The following US data were analyzed: DTD-specific features, parenchymal echotexture and echogenicity, anteroposterior diameter, glandular margin, and parenchymal vascularity. Univariate and multivariate analyses with generalized estimating equations were performed to investigate the relationship between US features and DTD. The fitted probability of DTD was analyzed by using a regression equation. Results: Of the 270 patients, there were NTP (n = 193), Hashimoto thyroiditis (n = 24), non-Hashimoto lymphocytic thyroiditis (n = 51), Graves' disease (n = 1), and diffuse hyperplasia (n = 1). The following US features were significantly associated with DTD: decreased or increased parenchymal echogenicity, coarse parenchymal echotexture, increased anteroposterior diameter, lobulated glandular margin, and increased parenchymal vascularity. Of these, coarse parenchymal echotexture was the most significant independent predictor of DTD. The numbers of abnormal US features were positively correlated with the fitted probability and risk of DTD. The diagnostic indices were highest when the chosen cut-off criterion was category III with the largest Az value (0.867, 95% confidence interval: 0.820-0.905), yielding a sensitivity of 68.8%, specificity of 92.2%, positive predictive value of 77.9%, negative predictive value of 88.1%, and accuracy of 85.6% (p < 0.001). Conclusions: Our sonographic reporting and data system may be useful for detecting DTD.

Unexpected Lung and Brain Metastases 9 Years After Thyroid Lobectomy for Follicular Adenoma: A Case Report.

Background: Benign thyroid follicular tumors without histological evidence of carcinoma can metastasize. However, the pathogenesis of metastasis remains unclear. Here, the new proposed terminology, "non-invasive follicular thyroid neoplasm with papillary-like nuclear features" should be considered. We present a case of an encapsulated type of follicular variant of papillary thyroid carcinoma (FVPTC) that exhibited distant lung and brain metastases and was initially diagnosed as follicular adenoma. Case Report: In December 2006, a 64-year-old woman underwent ultrasonography-guided fine-needle aspiration of the right thyroid nodule at our hospital because of a palpable right neck mass. Right lobectomy was performed, and a follicular adenoma was diagnosed. In October 2015, she visited our hospital owing to dry cough and mild dyspnea and underwent computed tomography-guided transthoracic core needle biopsy for the lung nodule owing to probably multiple lung metastasis on chest X-ray and computed tomography. Based on retrospective analysis of the primary thyroid tumor and lung nodule specimen, an encapsulated follicular variant of papillary thyroid carcinoma with lung metastasis was confirmed. Conclusion: We report a case of an encapsulated follicular variant of papillary thyroid carcinoma with unexpected metastasis to the lung 9 years after thyroid surgery in a patient who was initially diagnosed as follicular adenoma. A careful close follow-up with re-examination of the histopathology specimen may be needed in patients who were diagnosed with benign thyroid follicular tumors.

Nodular hyperplasia presenting as a mediastinal mass: Three case reports.

RATIONALE: Based on imaging and biopsy results, surgical removal of mediastinal nodular hyperplasia (MNH) may be unnecessary, and mediastomy may be avoidable. PATIENT CONCERNS: We report three cases of nodular hyperplasia presenting as a mediastinal mass on imaging studies during a health check-up or for the evaluation of known abscess in the right masticator and submandibular spaces. INTERVENTIONS: In the first two cases, surgical excision was performed, and in the third case, US-guided core needle biopsy was performed. DIAGNOSES: Histopathological examination revealed MNH in the first two cases, and histologic examination suggested MNH. OUTCOMES: In the first two cases, there were no associated complications after successful surgical removal. In the third case, surgery was not performed because of old age and no associated symptoms. LESSONS: MNH may mimic mediastinal tumors on imaging studies. Accordingly, awareness of imaging features, interval changes, associated symptoms, and biopsy results may be necessary for the appropriate management of MNH.

Magnetic Resonance Imaging Features of Normal Thyroid Parenchyma and Incidental Diffuse Thyroid Disease: A Single-Center Study.

Background: No previous studies have investigated the feasibility of magnetic resonance imaging (MRI) diagnosis for detecting incidental diffuse thyroid disease (DTD). This study investigated MRI features of normal thyroid parenchyma and incidental DTD. Methods: From January 2008 to December 2017, 387 patients underwent neck MRI in our hospital due to tumor/nodal staging (n = 137), lymphadenopathy (n = 122), inflammatory neck lesion (n = 85), congenital neck lesion (n = 12), and patient request (n = 31). Among them, 375 patients were excluded because of a lack of appropriate histopathological data on the thyroid parenchyma. Results: Among the patients included, 10 had normal thyroid parenchyma, 1 had Hashimoto thyroiditis, and 1 had diffuse hyperplasia. The common MRI features of normal thyroid parenchyma include iso-/slightly high and homogeneous signal intensity on T1/T2-weighted images, normal anteroposterior diameter of the thyroid gland, smooth margin, and homogeneously increased enhancement as compared to adjacent muscle. Hashimoto thyroiditis exhibited high and inhomogeneous signal intensity on T2-weighted images, while diffuse hyperplasia revealed an increased anteroposterior diameter and lobulated margin of the thyroid gland, and inhomogeneous enhancement. Conclusions: MRI may be helpful for detection of incidental DTD.

Ultrasonographic Features of Papillary Thyroid Carcinomas According to Their Subtypes.

BACKGROUND: The ultrasonographic characteristics and difference for various subtypes of papillary thyroid carcinoma (PTC) are still unclear. The aim of this study was to compare the ultrasonographic features of PTC according to its subtype in patients undergoing thyroid surgery. METHODS: In total, 140 patients who underwent preoperative thyroid ultrasonography (US) and thyroid surgery between January 2016 and December 2016 were included. The ultrasonographic features and the Korean Thyroid Imaging Reporting and Data System (K-TIRADS) category of each thyroid nodule were retrospectively evaluated by a single radiologist, and differences in ultrasonographic features according to the PTC subtype were assessed. RESULTS: According to histopathological analyses, there were 97 classic PTCs (62.2%), 34 follicular variants (21.8%), 5 tall cell variants (3.2%), 2 oncocytic variants (1.3%), 1 Warthin-like variant (0.6%), and 1 diffuse sclerosing variant (0.6%). Most PTCs were classified under K-TIRADS category 5. Among the ultrasonographic features, the nodule margin and the presence of calcification were significantly different among the PTC subtypes. A spiculated/microlobulated margin was the most common type of margin, regardless of the PTC subtype. In particular, all tall cell variants exhibited a spiculated/microlobulated margin. The classic PTC group exhibited the highest prevalence of intranodular calcification, with microcalcification being the most common. The prevalence of multiplicity and nodal metastasis was high in the tall cell variant group. CONCLUSION: The majority of PTCs in the present study belonged to K-TIRADS category 5, regardless of the subtype. Our findings suggest that ultrasonographic features are not useful for distinguishing PTC subtypes.

Utility of including BRAF mutation analysis with ultrasonographic and cytological diagnoses in ultrasonography-guided fine-needle aspiration of thyroid nodules.

This study investigated the role of BRAF mutation analysis in thyroid fine-needle aspiration (FNA) samples compared to ultrasonographic and cytological diagnoses. A total 316 patients underwent ultrasonography (US)-guided FNA with BRAFV600E mutation analysis to diagnose thyroid nodules. One hundred sixteen patients with insufficient US images (n = 6), follow-up loss (n = 43), or unknown final diagnosis (n = 67) were excluded from the study. Comparisons between US diagnoses, cytological diagnoses, and BRAF mutation analysis were performed. Of 200 thyroid nodules, there was US diagnosis with 1 false negative and 11 false positive cases, cytological diagnosis with 10 false negative and 2 false positive cases, and BRAFV600E mutation analysis with 19 false negative and 2 false positive cases. The sensitivity, specificity, positive and negative predictive values, and accuracy of BRAFV600E mutation analysis were 83.2%, 98.1%, 97.5%, 86.6%, and 91%, respectively. Of the 18 nodules with Bethesda category III, 9 were true positive, 6 were true negative, 3 was a false negative, and none were false positive on BRAF mutation analysis. In conclusion, we recommend that BRAFV600E mutation analysis only be performed for evaluating thyroid nodules with Bethesda category III, regardless of US diagnosis.

Comparison of Postoperative Neck Pain and Discomfort, Swallowing Difficulty, and Voice Change After Conventional Open, Endoscopic, and Robotic Thyroidectomy: A Single-Center Cohort Study.

Background: The objective of this study was to compare the postoperative neck pain and discomfort, swallowing difficulty, and voice change after conventional open thyroidectomy (COT), endoscopic thyroidectomy (ET), or robotic thyroidectomy (RT) performed by a single surgeon. Methods: From January 2013 to December 2017, 254 patients underwent COT, ET, or RT performed by a single surgeon and completed a postoperative symptom survey conducted in the outpatient clinic by three nurses. The survey collected information on postoperative neck pain and discomfort, swallowing difficulty, and voice change. Results: Of the 254 patients, 169 underwent COT, 32 underwent ET, and 53 underwent RT. The mean age in the COT, ET, and RT groups was 50.1, 44.5, and 41.6 years, respectively. The mean interval between thyroidectomy and survey in the COT, ET, and RT groups was 42.7, 50.2, and 9.2 months, respectively. Postoperative neck pain was significantly higher in the ET and RT groups than in the COT group (p = 0.026). The average neck impairment index score in the RT group was significantly higher than that in the COT group (p < 0.001). There were no significant differences in pain scale scores, swallowing difficulty, swallowing impairment index, voice change, and voice hand index among the three groups. Conclusions: There were no significant differences in postoperative voice change or swallowing difficulty among the COT, ET, and RT groups, whereas neck pain and discomfort were more common after ET and RT than COT.

Appropriate Frequency and Interval of Neck Ultrasonography Surveillance during the First 10 Years after Total Thyroidectomy in Patients with Papillary Thyroid Carcinoma.

BACKGROUND: No previous study has employed the frequency and interval of follow-up ultrasonography (US) during the first 10 years after total thyroidectomy in patients with papillary thyroid carcinoma (PTC). The aim of this study was to determine the appropriate frequency and interval of follow-up US during the first 10 years in patients who have undergone total thyroidectomy for PTC. METHODS: Two hundred seventy-two patients underwent total thyroidectomy for PTC at our institution from January 2006 to December 2007. Nineteen patients were excluded because of lack of US follow-up data for the neck. Follow-up US was performed by one of two radiologists in all patients. Tumor recurrence/persistence was confirmed by histopathology. RESULTS: The mean interval between surgery and the final follow-up US examination was 79.0 months, and the mean number of follow-up US sessions was 5.9 in the 253 evaluable patients. Eleven patients (4.3%) developed tumor recurrence/persistence, which was detected on follow-up US within 5 years after total thyroidectomy in all cases. T and N stages were independently associated with tumor recurrence/persistence. The interval between surgery and first suspicion of tumor recurrence/persistence on follow-up US was ≤12 months in six patients and 20, 35, 41, 53, and 60 months in the remaining five patients. CONCLUSION: For detection of tumor recurrence/persistence after total thyroidectomy in patients with PTC, one or two sessions of follow-up US during the first 2 years, depending on T and N stages and one session of follow-up US in every second year during the following 8 years may be appropriate.