Background: Active surveillance (AS) has emerged as a viable management strategy for low-risk papillary thyroid microcarcinoma (PTMC), following pioneering trials at Kuma Hospital and the Cancer Institute Hospital in Japan. Numerous prospective cohort studies have since validated AS as a management option for low-risk PTMC, leading to its inclusion in thyroid cancer guidelines across various countries. From 2016 to 2020, the Multicenter Prospective Cohort Study of Active Surveillance on Papillary Thyroid Microcarcinoma (MAeSTro) enrolled 1,177 patients, providing comprehensive data on PTMC progression, sonographic predictors of progression, quality of life, surgical outcomes, and cost-effectiveness when comparing AS to immediate surgery. The second phase of MAeSTro (MAeSTro-EXP) expands AS to low-risk papillary thyroid carcinoma (PTC) tumors larger than 1 cm, driven by the hypothesis that overall risk assessment outweighs absolute tumor size in surgical decision-making. Methods: This protocol aims to address whether limiting AS to tumors smaller than 1 cm may result in unnecessary surgeries for low-risk PTCs detected during their rapid initial growth phase. By expanding the AS criteria to include tumors up to 1.5 cm, while simultaneously refining and standardizing the criteria for risk assessment and disease progression, we aim to minimize overtreatment and maintain rigorous monitoring to improve patient outcomes. Conclusion This study will contribute to optimizing AS guidelines and enhance our understanding of the natural course and appropriate management of low-risk PTCs. Additionally, MAeSTro-EXP involves a multinational collaboration between South Korea and Australia. This cross-country study aims to identify cultural and racial differences in the management of low-risk PTC, thereby enriching the global understanding of AS practices and their applicability across diverse populations.

Background: Active surveillance (AS) has emerged as a viable management strategy for low-risk papillary thyroid microcarcinoma (PTMC), following pioneering trials at Kuma Hospital and the Cancer Institute Hospital in Japan. Numerous prospective cohort studies have since validated AS as a management option for low-risk PTMC, leading to its inclusion in thyroid cancer guidelines across various countries. From 2016 to 2020, the Multicenter Prospective Cohort Study of Active Surveillance on Papillary Thyroid Microcarcinoma (MAeSTro) enrolled 1,177 patients, providing comprehensive data on PTMC progression, sonographic predictors of progression, quality of life, surgical outcomes, and cost-effectiveness when comparing AS to immediate surgery. The second phase of MAeSTro (MAeSTro-EXP) expands AS to low-risk papillary thyroid carcinoma (PTC) tumors larger than 1 cm, driven by the hypothesis that overall risk assessment outweighs absolute tumor size in surgical decision-making. Methods: This protocol aims to address whether limiting AS to tumors smaller than 1 cm may result in unnecessary surgeries for low-risk PTCs detected during their rapid initial growth phase. By expanding the AS criteria to include tumors up to 1.5 cm, while simultaneously refining and standardizing the criteria for risk assessment and disease progression, we aim to minimize overtreatment and maintain rigorous monitoring to improve patient outcomes. Conclusion This study will contribute to optimizing AS guidelines and enhance our understanding of the natural course and appropriate management of low-risk PTCs. Additionally, MAeSTro-EXP involves a multinational collaboration between South Korea and Australia. This cross-country study aims to identify cultural and racial differences in the management of low-risk PTC, thereby enriching the global understanding of AS practices and their applicability across diverse populations.

Background: Active surveillance (AS) has emerged as a viable management strategy for low-risk papillary thyroid microcarcinoma (PTMC), following pioneering trials at Kuma Hospital and the Cancer Institute Hospital in Japan. Numerous prospective cohort studies have since validated AS as a management option for low-risk PTMC, leading to its inclusion in thyroid cancer guidelines across various countries. From 2016 to 2020, the Multicenter Prospective Cohort Study of Active Surveillance on Papillary Thyroid Microcarcinoma (MAeSTro) enrolled 1,177 patients, providing comprehensive data on PTMC progression, sonographic predictors of progression, quality of life, surgical outcomes, and cost-effectiveness when comparing AS to immediate surgery. The second phase of MAeSTro (MAeSTro-EXP) expands AS to low-risk papillary thyroid carcinoma (PTC) tumors larger than 1 cm, driven by the hypothesis that overall risk assessment outweighs absolute tumor size in surgical decision-making. Methods: This protocol aims to address whether limiting AS to tumors smaller than 1 cm may result in unnecessary surgeries for low-risk PTCs detected during their rapid initial growth phase. By expanding the AS criteria to include tumors up to 1.5 cm, while simultaneously refining and standardizing the criteria for risk assessment and disease progression, we aim to minimize overtreatment and maintain rigorous monitoring to improve patient outcomes. Conclusion This study will contribute to optimizing AS guidelines and enhance our understanding of the natural course and appropriate management of low-risk PTCs. Additionally, MAeSTro-EXP involves a multinational collaboration between South Korea and Australia. This cross-country study aims to identify cultural and racial differences in the management of low-risk PTC, thereby enriching the global understanding of AS practices and their applicability across diverse populations.

Background: Active surveillance (AS) has emerged as a viable management strategy for low-risk papillary thyroid microcarcinoma (PTMC), following pioneering trials at Kuma Hospital and the Cancer Institute Hospital in Japan. Numerous prospective cohort studies have since validated AS as a management option for low-risk PTMC, leading to its inclusion in thyroid cancer guidelines across various countries. From 2016 to 2020, the Multicenter Prospective Cohort Study of Active Surveillance on Papillary Thyroid Microcarcinoma (MAeSTro) enrolled 1,177 patients, providing comprehensive data on PTMC progression, sonographic predictors of progression, quality of life, surgical outcomes, and cost-effectiveness when comparing AS to immediate surgery. The second phase of MAeSTro (MAeSTro-EXP) expands AS to low-risk papillary thyroid carcinoma (PTC) tumors larger than 1 cm, driven by the hypothesis that overall risk assessment outweighs absolute tumor size in surgical decision-making. Methods: This protocol aims to address whether limiting AS to tumors smaller than 1 cm may result in unnecessary surgeries for low-risk PTCs detected during their rapid initial growth phase. By expanding the AS criteria to include tumors up to 1.5 cm, while simultaneously refining and standardizing the criteria for risk assessment and disease progression, we aim to minimize overtreatment and maintain rigorous monitoring to improve patient outcomes. Conclusion This study will contribute to optimizing AS guidelines and enhance our understanding of the natural course and appropriate management of low-risk PTCs. Additionally, MAeSTro-EXP involves a multinational collaboration between South Korea and Australia. This cross-country study aims to identify cultural and racial differences in the management of low-risk PTC, thereby enriching the global understanding of AS practices and their applicability across diverse populations.

Background/Objectives: Pediatric parotid malignancies are rare but represent a critical subset of head and neck cancers. This study integrates nationwide incidence trends in Korea with detailed surgical outcomes from a single tertiary institution to better understand the characteristics and management of these tumors.Materials & Methods: Nationwide data from the Korea Central Cancer Registry (1999-2019) were analyzed to assess trends in pediatric parotid malignancy incidence. A retrospective review was conducted on 31 pediatric parotidectomy cases at a tertiary hospital from 2011 to 2024. Clinical data, surgical methods, pathology results, and follow-up outcomes were examined. Results: Nationwide analysis revealed an annual mean of 9.0 ± 4.0 cases of pediatric parotid malignancies, with a significant rise in incidence among patients aged 10-19 years (APC 5.4%, 95% CI 1.1-9.8, p=0.016). Institutional data showed that the median age of patients underwent parotidectomy was 15.0 years, with males comprising 67.7%. Among 31 cases, 19 (61.3%) were benign, primarily pleomorphic adenomas (68.4%), and 12 (38.7%) were malignant, predominantly mucoepidermoid carcinoma (87.5%). Superficial or partial parotidectomy was the most common surgical approach (71.0%), and no unexpected complications or recurrences were observed. Conclusion Pediatric parotid malignancies in Korea exhibit rising incidence rates, particularly among teenagers. Surgical outcomes confirm the predominance of pleomorphic adenomas and mucoepidermoid carcinomas. Pediatric parotid surgery is a procedure with minimized complications and a promising prognosis. Tailored treatment strategies adapted to the unique characteristics of pediatric patients are essential to optimize outcomes.

Background/Objectives: Pediatric parotid malignancies are rare but represent a critical subset of head and neck cancers. This study integrates nationwide incidence trends in Korea with detailed surgical outcomes from a single tertiary institution to better understand the characteristics and management of these tumors.Materials & Methods: Nationwide data from the Korea Central Cancer Registry (1999-2019) were analyzed to assess trends in pediatric parotid malignancy incidence. A retrospective review was conducted on 31 pediatric parotidectomy cases at a tertiary hospital from 2011 to 2024. Clinical data, surgical methods, pathology results, and follow-up outcomes were examined. Results: Nationwide analysis revealed an annual mean of 9.0 ± 4.0 cases of pediatric parotid malignancies, with a significant rise in incidence among patients aged 10-19 years (APC 5.4%, 95% CI 1.1-9.8, p=0.016). Institutional data showed that the median age of patients underwent parotidectomy was 15.0 years, with males comprising 67.7%. Among 31 cases, 19 (61.3%) were benign, primarily pleomorphic adenomas (68.4%), and 12 (38.7%) were malignant, predominantly mucoepidermoid carcinoma (87.5%). Superficial or partial parotidectomy was the most common surgical approach (71.0%), and no unexpected complications or recurrences were observed. Conclusion Pediatric parotid malignancies in Korea exhibit rising incidence rates, particularly among teenagers. Surgical outcomes confirm the predominance of pleomorphic adenomas and mucoepidermoid carcinomas. Pediatric parotid surgery is a procedure with minimized complications and a promising prognosis. Tailored treatment strategies adapted to the unique characteristics of pediatric patients are essential to optimize outcomes.

Background/Objectives: Pediatric parotid malignancies are rare but represent a critical subset of head and neck cancers. This study integrates nationwide incidence trends in Korea with detailed surgical outcomes from a single tertiary institution to better understand the characteristics and management of these tumors.Materials & Methods: Nationwide data from the Korea Central Cancer Registry (1999-2019) were analyzed to assess trends in pediatric parotid malignancy incidence. A retrospective review was conducted on 31 pediatric parotidectomy cases at a tertiary hospital from 2011 to 2024. Clinical data, surgical methods, pathology results, and follow-up outcomes were examined. Results: Nationwide analysis revealed an annual mean of 9.0 ± 4.0 cases of pediatric parotid malignancies, with a significant rise in incidence among patients aged 10-19 years (APC 5.4%, 95% CI 1.1-9.8, p=0.016). Institutional data showed that the median age of patients underwent parotidectomy was 15.0 years, with males comprising 67.7%. Among 31 cases, 19 (61.3%) were benign, primarily pleomorphic adenomas (68.4%), and 12 (38.7%) were malignant, predominantly mucoepidermoid carcinoma (87.5%). Superficial or partial parotidectomy was the most common surgical approach (71.0%), and no unexpected complications or recurrences were observed. Conclusion Pediatric parotid malignancies in Korea exhibit rising incidence rates, particularly among teenagers. Surgical outcomes confirm the predominance of pleomorphic adenomas and mucoepidermoid carcinomas. Pediatric parotid surgery is a procedure with minimized complications and a promising prognosis. Tailored treatment strategies adapted to the unique characteristics of pediatric patients are essential to optimize outcomes.

Background/Objectives: Pediatric parotid malignancies are rare but represent a critical subset of head and neck cancers. This study integrates nationwide incidence trends in Korea with detailed surgical outcomes from a single tertiary institution to better understand the characteristics and management of these tumors.Materials & Methods: Nationwide data from the Korea Central Cancer Registry (1999-2019) were analyzed to assess trends in pediatric parotid malignancy incidence. A retrospective review was conducted on 31 pediatric parotidectomy cases at a tertiary hospital from 2011 to 2024. Clinical data, surgical methods, pathology results, and follow-up outcomes were examined. Results: Nationwide analysis revealed an annual mean of 9.0 ± 4.0 cases of pediatric parotid malignancies, with a significant rise in incidence among patients aged 10-19 years (APC 5.4%, 95% CI 1.1-9.8, p=0.016). Institutional data showed that the median age of patients underwent parotidectomy was 15.0 years, with males comprising 67.7%. Among 31 cases, 19 (61.3%) were benign, primarily pleomorphic adenomas (68.4%), and 12 (38.7%) were malignant, predominantly mucoepidermoid carcinoma (87.5%). Superficial or partial parotidectomy was the most common surgical approach (71.0%), and no unexpected complications or recurrences were observed. Conclusion Pediatric parotid malignancies in Korea exhibit rising incidence rates, particularly among teenagers. Surgical outcomes confirm the predominance of pleomorphic adenomas and mucoepidermoid carcinomas. Pediatric parotid surgery is a procedure with minimized complications and a promising prognosis. Tailored treatment strategies adapted to the unique characteristics of pediatric patients are essential to optimize outcomes.

Thyroid nodules represent a prevalent condition that is detectable via palpation or ultrasound. In recent years, there has been a paradigm shift toward enhanced diagnostic precision and less aggressive therapeutic approaches, highlighting the growing necessity for tailored clinical recommendations to optimize patient outcomes. The Korean Thyroid Association (KTA) has developed guidelines for managing patients with thyroid nodules, following a comprehensive review by task force members of the relevant literature identified via electronic database searches. The recommendations are provided with a level of recommendation for each section. The guidelines encompass thyroid cancer screening in high-risk groups, appropriate diagnostic methods for thyroid nodules, role of pathologic and molecular marker testing in making a diagnosis, long-term follow-up and treatment of benign thyroid nodules, and special considerations for pregnant women. The major revisions that were made in the 2023 guidelines were the definition of high-risk groups for thyroid cancer screening, application of the revised Korean Thyroid Imaging Reporting and Data System (K-TIRADS), addition of the role of core needle biopsy and molecular marker tests, application of active surveillance in patients with low-risk papillary thyroid microcarcinoma, and updated indications for nonsurgical treatment of benign thyroid nodules. In the 2024 revision of the KTA guidelines for thyroid cancer, the evidence for some recommendations has been updated to address the tumor size in the context of active surveillance in patients with low-risk thyroid cancer and the surgical size cutoff. These evidence-based recommendations serve to inform clinical decision-making in the management of thyroid nodules, thereby facilitating the delivery of optimal and efficacious treatments to patients.

Thyroid nodules are a prevalent condition that can be detected through palpation or ultrasound. However, a small fraction of these nodules can be cancerous, and even benign nodules can cause symptoms if they grow and compress surrounding tissue. As such, it is important to monitor thyroid nodules and determine appropriate treatment options. In recent years, there has been a shift towards enhancing diagnostic accuracy and less aggressive treatment options. As a result, there is a growing need for the development of appropriate recommendations for their clinical application to ensure optimal patient outcomes. The present clinical practice guideline was developed by extracting the nodule section from the prior version of guidelines and updating it to fit the Korean circumstances. Task force members reviewed relevant studies selected after electronic database searching, and the recommendations are provided with a level of recommendation for each section. The revised guideline includes recommendations for thyroid cancer screening in high-risk groups, appropriate diagnostic methods for thyroid nodules, the role of pathological and molecular marker tests in diagnosis, long-term follow-up and treatment of benign thyroid nodules, and special considerations for pregnant women. The major changes in this revision are the definition of high-risk groups for thyroid cancer screening, the application of the revised Korean Thyroid Imaging Reporting and Data System (K-TIRADS), the addition of the role of core needle biopsy and molecular marker tests, the application of active surveillance in low-risk papillary thyroid microcarcinoma, and updated indications for non-surgical treatment of benign thyroid nodules. These evidence-based recommendations are expected to assist in clinical decision-making for thyroid nodule management, ensuring that patients receive the most appropriate and effective treatment options.