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.

Objective: It is difficult to predict medical outcomes for acute pyelonephritis (APN) in women. A delay in diagnosis and treatment results in rapid progression to circulatory collapse, multiple organ failure, and death. We investigated the value of procalcitonin (PCT) and neutrophil-to-lymphocyte ratio (NLR) in APN patients hospitalized through the emergency room. Methods: We retrospectively evaluated women with APN presenting in the emergency room from January 2014 to May 2018. Inflammatory biomarkers, including PCT and NLR, were measured, and the severity of pyelonephritis was assessed using the Surviving Sepsis Campaign definitions (Sepsis-3). Multivariable logistic regression analysis was used to evaluate the risk factors associated with septic shock and the prediction for septic shock was compared using a receiver operating characteristic (ROC) curve. Results: A total of 357 female patients with APN were included. The median level of PCT and NLR was higher in the septic shock group compared with other groups. Multivariate logistic regression analysis showed that age and PCT were risk factors for septic shock. When the ROC curve of septic shock was compared, PCT showed a higher area under the curve than NLR (NLR 0.65 vs. PCT 0.80). Conclusion The initial NLR in the emergency room showed significant differences depending on the severity as classified by Sepsis-3 definitions. However, NLR was not found to be associated with septic shock in female patients with APN.

Objective: It is difficult to predict medical outcomes for acute pyelonephritis (APN) in women. A delay in diagnosis and treatment results in rapid progression to circulatory collapse, multiple organ failure, and death. We investigated the value of procalcitonin (PCT) and neutrophil-to-lymphocyte ratio (NLR) in APN patients hospitalized through the emergency room. Methods: We retrospectively evaluated women with APN presenting in the emergency room from January 2014 to May 2018. Inflammatory biomarkers, including PCT and NLR, were measured, and the severity of pyelonephritis was assessed using the Surviving Sepsis Campaign definitions (Sepsis-3). Multivariable logistic regression analysis was used to evaluate the risk factors associated with septic shock and the prediction for septic shock was compared using a receiver operating characteristic (ROC) curve. Results: A total of 357 female patients with APN were included. The median level of PCT and NLR was higher in the septic shock group compared with other groups. Multivariate logistic regression analysis showed that age and PCT were risk factors for septic shock. When the ROC curve of septic shock was compared, PCT showed a higher area under the curve than NLR (NLR 0.65 vs. PCT 0.80). Conclusion The initial NLR in the emergency room showed significant differences depending on the severity as classified by Sepsis-3 definitions. However, NLR was not found to be associated with septic shock in female patients with APN.

Pseudomonas stutzeri is a Gram-negative, rod-shaped, motile, single polar-flagellated, soil bacterium that was first isolated from human spinal fluid and is widely distributed in the environment. It was isolated as an uncommon opportunistic pathogen from humans, and a few cases of P. stutzeri-induced peritonitis have been reported in patients undergoing continuous ambulatory peritoneal dialysis (CAPD). Catheter removal with antibiotic treatment is generally recommended because peritonitis by Pseudomonas species is commonly associated with catheter-related infection. Here, we describe the first case of P. stutzeri-induced peritonitis in an 82-year-old woman in Korea. She had received two antipseudomonal antibiotics, an aminoglycoside (isepamicin, Yuhan corporation, Seoul, Korea) and a fluoroquinolone (ciprofloxacin), and was successfully treated without removal of the CAPD catheter.
Aged, 80 and over ; Anti-Bacterial Agents ; Catheter-Related Infections ; Catheters ; Female ; Humans ; Korea ; Peritoneal Dialysis ; Peritoneal Dialysis, Continuous Ambulatory ; Peritonitis ; Pseudomonas ; Pseudomonas stutzeri ; Soil

Selective IgA deficiency is one of the most common primary immunodeficiency. Some patients with IgA deficiency also have deficits in one or more immunoglobulin G subclasses. It has been estimated that up to 25% of patients with certain primary immunodeficiencies will develop tumors, primarily B-cell lymphomas during their lifetime. We hereby present 2 cases of malignant lymphomas, one diffuse large cell lymphoma and another mixed cellularity Hodgkin's disease, respectively, which developed in patients with selective IgA and IgG subclass deficiency.
Child* ; Hodgkin Disease ; Humans ; IgA Deficiency ; Immunoglobulin A* ; Immunoglobulin G* ; Lymphoma* ; Lymphoma, B-Cell ; Lymphoma, Large B-Cell, Diffuse ; Lymphoma, Non-Hodgkin