In patients with differentiated thyroid cancer (DTC), initial recurrence risk stratification based on clinical, histopathological, and perioperative data remains the key determinant for guiding management strategies during the first 1-2 years post-treatment. However, the adoption of ongoing risk stratification (ORS), which dynamically reassesses risk by integrating longitudinal clinical data and treatment response, enables more precise long-term prognostic assessment and facilitates highly individualized management. Building upon recent guidelines, the 2026 KTA guideline has been further refined by incorporating robust evidence from large-scale national cohorts and comprehensive systematic reviews. These updated recommendations outline contemporary concepts of ORS, risk-adapted TSH suppression targets, optimized surveillance modalities for recurrence detection, and disease-specific long-term follow-up strategies. Reflecting the paradigm shift toward de-escalated treatment, this revision integrates evolved perspectives on TSH suppression intensity, the clinical interpretation of thyroglobulin levels, and tailored follow-up intervals. These evidence-based recommendations aim to minimize unnecessary treatment and excessive surveillance in the large proportion of patients with excellent prognosis after initial therapy, while ensuring that each patient receives appropriately tailored and effective long-term management.

The increasing detection of papillary thyroid microcarcinoma (PTMC) has raised concerns about overtreatment.For low-risk PTMC, either immediate surgery or active surveillance (AS) can be considered. To support AS implementation, the Korean Thyroid Association convened a multidisciplinary panel and developed the first Korean guideline. AS is recommended to adults with pathologically proven Bethesda V-VI PTMC without clinical evidence of lymph node or distant metastasis, gross extrathyroidal extension, tracheal or recurrent laryngeal nerve invasion, or aggressive histology. Baseline assessment requires high‑resolution cervical ultrasound by experienced operators to rule out extrathyroidal extension, tracheal or recurrent laryngeal nerve invasion, and lymph node metastasis;contrast‑enhanced neck computed tomography is optional. Patient characteristics such as age, comorbidities, and capacity for long-term follow-up should be assessed. Shared decision-making should weigh the benefits and risks of surgery and AS, expected oncologic outcomes, complications, quality of life, anxiety, medical cost, and patient preference. Follow-up includes cervical ultrasound and thyroid function test every six months for two years, then annually. Disease progression, defined as significant tumor growth or newly detected nodal or distant metastasis, warrants surgery. Despite remaining uncertainties, this guideline offers a framework to ensure oncologic safety and support patient-centered active surveillance.

These guidelines aim to establish the standard practice for diagnosing and treating patients with differentiated thyroid cancer (DTC). Based on the Korean Thyroid Association (KTA) Guidelines on DTC management, the “Treatment of Advanced DTC” section was revised in 2024 and has been provided through this chapter. Especially, this chapter covers surgical and nonsurgical treatments for the local (previous surgery site) or regional (cervical lymph node metastasis) recurrences. After drafting the guidelines, it was finalized by collecting opinions from KTA members and related societies. Surgical resection is the preferred treatment for local or regional recurrence of advanced DTC. If surgical resection is not possible, nonsurgical resection treatment under ultrasonography guidance may be considered as an alternative treatment for local or regional recurrence of DTC. Furthermore, if residual lesions are suspected even after surgical resection or respiratory-digestive organ invasion, additional radioactive iodine and external radiation treatments are considered.

Pediatric differentiated thyroid cancers (DTCs), mostly papillary thyroid cancer (PTC, 80-90%), are diagnosed at more advanced stages with larger tumor sizes and higher rates of locoregional and/or lung metastasis. Despite the higher recurrence rates of pediatric cancers than of adult thyroid cancers, pediatric patients demonstrate a lower mortality rate and more favorable prognosis. Considering the more advanced stage at diagnosis in pediatric patients, preoperative evaluation is crucial to determine the extent of surgery required. Furthermore, if hereditary tumor syndrome is suspected, genetic testing is required. Recommendations for pediatric DTCs focus on the surgical principles, radioiodine therapy according to the postoperative risk level, treatment and follow-up of recurrent or persistent diseases, and treatment of patients with radioiodine-refractory PTCs on the basis of genetic drivers that are unique to pediatric patients.

Differentiated thyroid cancer demonstrates a wide range of clinical presentations, from very indolent cases to those with an aggressive prognosis. Therefore, diagnosing and treating each cancer appropriately based on its risk status is important. The Korean Thyroid Association (KTA) has provided and amended the clinical guidelines for thyroid cancer management since 2007. The main changes in this revised 2024 guideline include 1) individualization of surgical extent according to pathological tests and clinical findings, 2) application of active surveillance in low-risk papillary thyroid microcarcinoma, 3) indications for minimally invasive surgery, 4) adoption of World Health Organization pathological diagnostic criteria and definition of terminology in Korean, 5) update on literature evidence of recurrence risk for initial risk stratification, 6) addition of the role of molecular testing, 7) addition of definition of initial risk stratification and targeting thyroid stimulating hormone (TSH) concentrations according to ongoing risk stratification (ORS), 8) addition of treatment of perioperative hypoparathyroidism, 9) update on systemic chemotherapy, and 10) addition of treatment for pediatric patients with thyroid cancer.

The primary objective of initial treatment for thyroid cancer is minimizing treatment-related side effects and unnecessary interventions while improving patients’ overall and disease-specific survival rates, reducing the risk of disease persistence or recurrence, and conducting accurate staging and recurrence risk analysis. Appropriate surgical treatment is the most important requirement for this purpose, and additional treatments including radioactive iodine therapy and thyroid-stimulating hormone suppression therapy are performed depending on the patients’ staging and recurrence risk. Diagnostic surgery may be considered when repeated pathologic tests yield nondiagnostic results (Bethesda category 1) or atypia of unknown significance (Bethesda category 3), depending on clinical risk factors, nodule size, ultrasound findings, and patient preference. If a follicular neoplasm (Bethesda category 4) is diagnosed pathologically, surgery is the preferred option. For suspicious papillary carcinoma (suspicious for malignancy, Bethesda category 5), surgery is considered similar to a diagnosis of malignancy (Bethesda category 6). As for the extent of surgery, if the cancer is ≤1 cm in size and clinically free of extrathyroidal extension (ETE) (cT1a), without evidence of cervical lymph node (LN) metastasis (cN0), and without obvious reason to resect the contralateral lobe, a lobectomy can be performed. If the cancer is 1-2 cm in size, clinically free of ETE (cT1b), and without evidence of cervical LN metastasis (cN0), lobectomy is the preferred option. For patients with clinically evident ETE to major organs (cT4) or with cervical LN metastasis (cN1) or distant metastasis (M1), regardless of the cancer size, total thyroidectomy and complete cancer removal should be performed at the time of initial surgery. Active surveillance may be considered for adult patients diagnosed with low-risk thyroid papillary microcarcinoma. Endoscopic and robotic thyroidectomy may be performed for low-risk differentiated thyroid cancer when indicated, based on patient preference.

Background/Aims: We aimed to assess the validity of the Korean translated version of the Clinical Frailty Scale (CFS) in determining the frailty status in geriatric outpatients. Methods: The records of 123 ambulatory outpatients who had undergone CFS and comprehensive geriatric assessments (CGAs) including measurements for the Cardiovascular Health Study (CHS) frailty scale and the frailty index (CGA-FI) were analyzed. Correlations between CFS, CHS frailty scale, and CGA-FI were assessed. The ability of CFS to classify frailty status was calculated using the CHS frailty scale and CGA-FI as references. Results: The mean CFS score was 3.2 in the study population, with a mean age of 77.49 years (45.5% men). Individuals with higher CFS scores were older, had a greater burden of chronic diseases, and worse daily functions and cognitive performance. CFS scores positively correlated with CGA-FI (B = 0.78, p < 0.001) and CHS frailty scale (B = 0.67, p < 0.001) scores. For CFS, C-statistics to classify frailty by CGA-FI and CHS scale were 0.905 and 0.826, respectively. The cut-off value of CFS ≥ 4 maximized Youden’s J to classify frailty by both the CHS scale and CGAFI. Conclusions The CFS is a valid screening tool to assess the frailty status in outpatients of a geriatric clinic in Korea. As a simple and quick measure, the CFS may facilitate frailty assessments in real-world clinical practice.

Background/Aims: We aimed to assess the validity of the Korean translated version of the Clinical Frailty Scale (CFS) in determining the frailty status in geriatric outpatients. Methods: The records of 123 ambulatory outpatients who had undergone CFS and comprehensive geriatric assessments (CGAs) including measurements for the Cardiovascular Health Study (CHS) frailty scale and the frailty index (CGA-FI) were analyzed. Correlations between CFS, CHS frailty scale, and CGA-FI were assessed. The ability of CFS to classify frailty status was calculated using the CHS frailty scale and CGA-FI as references. Results: The mean CFS score was 3.2 in the study population, with a mean age of 77.49 years (45.5% men). Individuals with higher CFS scores were older, had a greater burden of chronic diseases, and worse daily functions and cognitive performance. CFS scores positively correlated with CGA-FI (B = 0.78, p < 0.001) and CHS frailty scale (B = 0.67, p < 0.001) scores. For CFS, C-statistics to classify frailty by CGA-FI and CHS scale were 0.905 and 0.826, respectively. The cut-off value of CFS ≥ 4 maximized Youden’s J to classify frailty by both the CHS scale and CGAFI. Conclusions The CFS is a valid screening tool to assess the frailty status in outpatients of a geriatric clinic in Korea. As a simple and quick measure, the CFS may facilitate frailty assessments in real-world clinical practice.

Cholangiocarcinoma is a malignant disease originating from the epithelium of the biliary tract, and its prognosis is dismal due to distant metastasis in its early stages. The most common metastatic sites are the intra-abdominal organs, lymph nodes, and lungs. A patient was diagnosed with intrahepatic cholangiocarcinoma and underwent surgical resection. During the follow-up period, metastases were detected at the remnant liver and both lung fields. Eleven months after resection, the patient complained of severe headache. An approximately 5-cm cystic mass was found at the left occipital lobe of the cerebrum, and metastatic malignant cells were present on cerebrospinal fluid cytology. The patient underwent whole-brain radiotherapy. We herein report a rare case of cholangiocarcinoma with cystic brain metastasis together with a review of the relevant literature.
Biliary Tract ; Brain ; Cerebrum ; Cholangiocarcinoma ; Epithelium ; Follow-Up Studies ; Headache ; Humans ; Liver ; Liver Neoplasms ; Lung ; Lymph Nodes ; Meningeal Carcinomatosis ; Neoplasm Metastasis ; Occipital Lobe ; Prognosis

BACKGROUND: Diamond Blackfan anemia (DBA), characterized by impaired red cell production, is a rare condition that is usually symptomatic in early infancy. The purpose of this study was to assess nationwide experiences of DBA encountered over a period of 20 years. METHODS: The medical records of 56 patients diagnosed with DBA were retrospectively reviewed from November 1984 to July 2010. Fifteen institutions, including 13 university hospitals, participated in this study. RESULTS: The male-to-female ratio of patients with DBA was 1.67:1. The median age of diagnosis was 4 months, and 74.1% were diagnosed before 1 year of age. From 2000 to 2009, annual incidence was 6.6 cases per million. Excluding growth retardation, 38.2% showed congenital defects: thumb deformities, ptosis, coarctation of aorta, ventricular septal defect, strabismus, etc. The mean hemoglobin concentration was 5.1+/-1.9 g/dL, mean corpuscular volume was 93.4+/-11.6 fL, and mean number of reticulocytes was 19,700/mm3. The mean cellularity of bone marrow was 75%, with myeloid:erythroid ratio of 20.4:1. After remission, 48.9% of patients did not need further steroids. Five patients with DBA who received hematopoietic transplantation have survived. Cancer developed in 2 cases (3.6%). CONCLUSION: The incidence of DBA is similar to data already published, but our study had a male predilection. Although all patients responded to initial treatment with steroids, about half needed further steroids after remission. It is necessary to collect further data, including information regarding management pathways, from nationwide DBA registries, along with data on molecular analyses.
Anemia ; Anemia, Diamond-Blackfan ; Aortic Coarctation ; Bone Marrow ; Congenital Abnormalities ; Diamond ; Erythrocyte Indices ; Heart Septal Defects, Ventricular ; Hemoglobins ; Hospitals, University ; Humans ; Incidence ; Korea ; Male ; Medical Records ; Registries ; Reticulocytes ; Retrospective Studies ; Steroids ; Strabismus ; Thumb ; Transplants