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.

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.

Coinfection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) with other respiratory pathogens may complicate diagnosis and treatment. Since the risk of coinfection with SARS-CoV-2 is expected to increase during the influenza epidemic period, it is necessary to study the clinical course of coinfection. To our knowledge, there have been a few cases of coinfection between SARS-CoV-2 and influenza virus in neonates. Here, we report the clinical course of a neonate who was coinfected with the influenza virus and SARS-CoV-2. A 20-day-old boy born with low birth weight presented with a fever. The patient was confirmed as positive with coronavirus disease 2019 (COVID-19) and influenza B by real-time polymerase chain reaction at admission, whereas his mother was only COVID-19 positive at that time. Initial chest x-ray revealed hyperinflation and increased peribronchial markings at the right lower lung bronchus, but slightly decreased lung sounds without crackle or wheezing at admission. We administered empirical antibiotics for neonatal sepsis and oseltamivir for influenza B. On the chest x-ray follow-up, the findings showed improvement. After discharge, the patient showed a stable general condition. Children ineligible for COVID-19 vaccination who are coinfected with SARS-CoV-2 and the influenza virus are more likely to develop severe symptoms. It is necessary to detect coinfections as some can be treated with antibiotics and antivirals in young infants.

Objectives: This study used the Korean National Health and Nutrition Examination Survey (KNHANES) to determine the association between fractures and low muscle mass. Methods: This cross-sectional study used the 2010–2011 KNHANES data. Low muscle mass was defined as (appendicular skeletal muscle mass [kg]/Height2 [m2 ]) < 5.45 kg/m2 , which is < 2 SD below the sex-specific mean of a young reference group. Patients with T-scores between –1.0 and –2.5 indicated osteopenia, whereas those with T-scores lower than –2.5 indicated osteoporosis. Results: Out of 1,306 women enrolled in the study, 330 were diagnosed with low muscle mass according to the abovementioned diagnostic criterion. The prevalence of fractures at various sites was significantly higher in postmenopausal women with low muscle mass than in those without low muscle mass (relative risk [RR], 1.64; odds ratio [OR], 1.62; 95% confidence interval [CI], 1.06–2.48; P = 0.027). Furthermore, the prevalence of fractures was increased by the presence of osteopenia or osteoporosis in addition to low muscle mass (RR, 1.59; OR, 1.60; 95% CI, 1.02–2.49; P = 0.039) and by osteoporosis only (RR, 2.12; OR, 2.29; 95% CI, 1.11–4.70; P = 0.025). Conclusions Fracture was more prevalent in postmenopausal women with low muscle mass than in those without low muscle mass.This finding is consistent in a subgroup analysis that included women who had osteoporosis or osteopenia. Moreover, the risk of fractures increased as low muscle mass worsened.

Objective: : Owing to advances in critical care treatment, the overall survival rate of preterm infants born at a gestational age (GA) <32 weeks has consistently improved. However, the incidence of severe intraventricular hemorrhage (IVH) has persisted, and there are few reports on in-hospital morbidity and mortality. Therefore, the aim of the present study was to investigate trends surrounding in-hospital morbidity and mortality of preterm infants with severe IVH over a 14-year period. Methods: : This single-center retrospective study included 620 infants born at a GA <32 weeks, admitted between January 2007 and December 2020. After applying exclusion criteria, 596 patients were included in this study. Infants were grouped based on the most severe IVH grade documented on brain ultrasonography during their admission, with grades 3 and 4 defined as severe. We compared in-hospital mortality and clinical outcomes of preterm infants with severe IVH for two time periods : 2007–2013 (phase I) and 2014–2020 (phase II). Baseline characteristics of infants who died and survived during hospitalization were analyzed. Results: : A total of 54 infants (9.0%) were diagnosed with severe IVH over a 14-year period; overall in-hospital mortality rate was 29.6%. Late in-hospital mortality rate (>7 days after birth) for infants with severe IVH significantly improved over time, decreasing from 39.1% in phase I to 14.3% in phase II (p=0.043). A history of hypotension treated with vasoactive medication within 1 week after birth (adjusted odds ratio, 7.39; p=0.025) was found to be an independent risk factor for mortality. When comparing major morbidities of surviving infants, those in phase II were significantly more likely to have undergone surgery for necrotizing enterocolitis (NEC) (29.2% vs. 0.0%; p=0.027). Additionally, rates of late-onset sepsis (45.8% vs. 14.3%; p=0.049) and central nervous system infection (25.0% vs. 0.0%; p=0.049) were significantly higher in phase II survivors than in phase I survivors. Conclusion : In-hospital mortality in preterm infants with severe IVH decreased over the last decade, whereas major neonatal morbidities increased, particularly surgical NEC and sepsis. This study suggests the importance of multidisciplinary specialized medical and surgical neonatal intensive care in preterm infants with severe IVH.

Gastrointestinal (GI) emergencies in neonates and infants encompass from the beginning to the end of the GI tract. Both congenital and acquired conditions can cause various GI emergencies in neonates and infants. Given the overlapping or nonspecific clinical findings of many different neonatal and infantile GI emergencies and the unique characteristics of this age group, appropriate imaging is key to accurate and timely diagnosis while avoiding unnecessary radiation hazard and medical costs. In this paper, we discuss the radiological findings of essential neonatal and infantile GI emergencies, including esophageal atresia and tracheoesophageal fistula, hypertrophic pyloric stenosis, duodenal atresia, malrotation, midgut volvulus for upper GI emergencies, and jejunoileal atresia, meconium ileus, meconium plug syndrome, meconium peritonitis, Hirschsprung disease, anorectal malformation, necrotizing enterocolitis, and intussusception for lower GI emergencies.

Purpose: To evaluate the effect of the emergence of coronavirus disease-19 (COVID-19) on pediatric intussusception. Materials and Methods: Patients (< 18 years) who were diagnosed with intussusception and received enema reduction from 2011 to 2020 were included. We reviewed the demographics, yearly/monthly/seasonal incidence of intussusception, method and failure rate of enema reduction, recurrence rate of intussusception, surgical record, and pathologic report. Subsequently, we investigated the differences in mean age, failure rate of enema reduction, and recurrence rate of intussusception between the cases in 2020 and those in the period from 2011 to 2019. Results: A total of 859 enema reductions were performed during the past decade, more in males and in the age < 1 year (mean age, 22.2 months). The yearly incidence was highest in 2014 and lowest in 2020, and the monthly incidence was highest on December and September. The cases in 2020 (n = 27) had a lower mean age (18.1 months vs. 22.8 months), higher failure rate of enema reduction (7.4% vs. 2.4%), and higher recurrence rate of intussusception (14.8% vs 7.3%) compared with those that occurred between 2011 and 2019 (n = 832). However, these results did not show statistical significance (p = 0.07, p = 0.15, p = 0.14, respectively). Conclusion With the emergence of COVID-19, the number of enema reductions was remarkably decreased with a lower mean age, higher failure rate, and higher recurrence rate.

Purpose: Despite the well-known mortality of pediatric drowning, there is a paucity of evidence on the implications of an initial evaluation on the relevant outcome of drowning. This study aimed to investigate the association of initial clinical findings with outcome of children undergoing drowning. Methods: This retrospective study was conducted using the medical records of 56 children undergoing drowning who visited 3 Korean academic hospitals from January 2000 through May 2020. We analyzed information regarding the prehospital resuscitation, drowning time, a 4-tiered chest radiographic grade, and the baseline characteristics. The grade was defined based on the findings of initial chest radiographs. The poor outcomes were defined as the need for intensive care unit care or death aftercare. We analyzed the association of the prehospital resuscitation, submersion time, and the radiographic grade with the poor outcomes using binary logistic regression. Results: Among the 56 children, 31 (55.4%) were aged 1-4 years. Prehospital resuscitation and 1-5 minutes of submersion time were noted in the 25 (44.6%) and 30 children (53.6%), respectively. The chest radiographic grades 1 through 4 accounted for 17 (30.4%), 20 (35.7%), 12 (21.4%), and 3 children (5.4%), respectively. Poor outcomes occurred in 17 children (30.4%), including 3 deaths (5.4%). The association with the poor outcomes was noted in the submersion time of longer than 5 minutes (adjusted odds ratio, 21.49; 95% confidence interval, 1.11-415.73; compared with < 1 minute) while not in the submersion time and chest radiographic grade. Conclusion This study confirms that submersion time is an outcome predictor of drowning.

Objective: To describe the anatomic locations and imaging features of posterior lung herniation in unilateral pulmonary agenesis and aplasia, focusing on radiograph-CT/MRI correlation. Materials and Methods: A total of 10 patients (seven with pulmonary agenesis and three with pulmonary aplasia, male:female = 1:9, mean age 7.3 years, age range from 1 month to 20 years) were included. Chest radiographs (n = 9), CT (n = 9), and MRI (n = 1) were reviewed to assess the type of lung underdevelopment, presence of anterior and posterior lung herniation, bronchus origin, supplying artery, and draining vein of the herniated lung. Results: Pulmonary agenesis/aplasia more commonly affected the left lung (n = 7) than the right lung (n = 3). Anterior lung herniation was observed in nine of the 10 patients. Posterior lung herniation was observed in seven patients with left pulmonary agenesis/aplasia. Two patients showed posterior lung herniation crossing the midline but not beyond the aorta, and five patients showed the posteriorly herniated right lower lobe crossing the midline to extend into the left hemithorax farther beyond the descending thoracic aorta through the space between the esophagus and the aorta. This anatomical configuration resulted in a characteristic radiographic finding of a radiolucent area with a convex lateral border and a vertical medial border in the left lower lung zone, revealing a tongue-like projection on CT and MRI. Conclusion Posterior lung herniation occurs in unilateral left lung agenesis/aplasia. Approximately 70% of the cases of posterior lung herniation reveal a unique radiolucent tongue-like projection in the left lower lung zone on imaging studies, which is caused by the extension of the posteriorly herniated right lung farther beyond the descending aorta.

Purpose: Although ultrasonography is the gold standard of diagnosing intussusception, plain abdomen radiograph (AXR) is often used to make differential diagnosis for pediatric patients with abdominal pain. In intussusception patients, we aimed to analyze the AXR and clinical data to determine the characteristics of early AXR findings associated with diagnosis of intussusception and recurrence after reduction. Methods: Between January 2011 and June 2018, 446 patients diagnosed with intussusception based on International Classification of Diseases-10 code of K56.1 were admitted. We retrospectively reviewed medical records of 398 patients who received air reduction; 51 of them have recurred after initial reduction. We evaluated six AXR features including absent ascending colon gas, absent transverse colon gas, target sign, meniscus sign, mass, and ileus. Clinical data and AXR features were compared between single episode and recurrence groups. Results: Two groups did not show significant differences regarding clinical data. Mean time to recurrence from air reduction was 3.4±3.2 days. Absent ascending colon gas (63.9%) was the most common feature in intussusception, followed by mass (29.1%). All of six AXR features were observed more frequently in the recurrence group. Absent transverse colon gas was the most closely associated AXR finding for recurrence (odds ratio, 2.964; 95% confidence interval, 1.327–6.618; p=0.008). Conclusion In our study, absence of ascending colon gas was the most frequently seen AXR factor in intussusception patients. Extended and careful observation after reduction may be beneficial if such finding on AXR is found in intussusception patients.