Background/Aims: Gastric antral vascular ectasia (GAVE) is a rare but important cause of gastrointestinal (GI) bleeding. The clinical course of GAVE is not well-known, and recurrent bleeding from GAVE is a therapeutic challenge. Therefore, we investigated the clinical course of GAVE and identified the risk factors for bleeding from it. Methods: We retrospectively reviewed the records of patients diagnosed with GAVE using upper GI endoscopy at Asan Medical Center between January 2004 and December 2019 and evaluated the clinical course and risk factors for bleeding from GAVE. Results: Of the 348 patients (mean age, 62.3 ± 10.7 years; male, 62%), bleeding from GAVE occurred in 123 (35%) patients during follow-up (median, 17.3 months; interquartile range [IQR], 4.2–46.6). GI bleeding from GAVE was significantly associated with Child–Pugh class B or C liver cirrhosis (odds ratio [OR], 2.55; 95% confidence interval [CI], 1.57–4.16), chronic kidney disease (CKD) (OR, 2.77; 95% CI, 1.52–5.07), use of antithrombotic agents (OR, 2.34; 95% CI, 1.13–4.82), and involvement of the duodenal bulb (OR, 3.21; 95% CI, 1.76–5.86). Rebleeding occurred in 39 of 123 patients (32%), in whom CKD (OR, 2.55; 95% CI, 1.12–5.81) was significantly associated with rebleeding. Endoscopic hemostasis was most commonly performed using argon plasma coagulation, and the median number of endoscopic hemostasis performed was 2 (IQR, 1–3). Conclusions A careful follow-up for bleeding is needed in GAVE patients with liver cirrhosis, CKD, use of antithrombotic agents, and duodenal bulb involvement.

Background: Mycoplasma pneumoniae is a major cause of community-acquired pneumonia (CAP) in children, with a rising incidence of macrolide resistance. Early diagnosis is crucial for reducing the disease burden; however, current diagnostic tools have limitations.We evaluated the diagnostic accuracy of serological assays and their performance based on symptom onset in children with CAP. Methods: From September 2023 to September 2024, we prospectively enrolled children with CAP, classified as M. pneumoniae pneumonia (MPP) or non-MPP, from 16 hospitals in Korea. Serological testing included chemiluminescence immunoassay (CLIA) and ELISA for detecting IgM and IgG, along with particle agglutination (PA) for total antibody measurements. Serological responses were analyzed at different times after symptom onset (0–4, 5–9, and 10–21 days). Results: Among 472 children with CAP (362 MPP, 110 non-MPP), 138 (29.2%) underwent PA testing, and 334 (70.8%) underwent IgM testing. PA at a 1:640 cutoff showed 48.0% sensitivity and 100% specificity. CLIA and ELISA showed comparable sensitivities (69.1% vs. 69.2%) and specificities (76.9% vs. 66.7%) for IgM testing. Seropositivity increased significantly with time since symptom onset (P for trend < 0.001), reaching 97.9% for IgM, 62.5% for IgG, and 94.7% for PA at 10–21 days. Conclusions The time post-symptom onset significantly influenced the diagnostic utility of serological tests for pediatric MPP, which showed limited value during the early stage of illness. These findings emphasize the importance of symptom onset-based interpretation of serological test results and their utility in complementing PCR when optimizing MPP diagnosis in children.

Purpose: We aimed to compare the final adult height (FAH) of male patients with central precocious puberty (CPP) after treatment with a gonadotropin-releasing hormone agonist (GnRHa). Specifically, we compared FAH with the target height (TH) and the predicted adult height (PAH) before and after GnRHa treatment to quantify height gain and identify predictive factors. Methods: We retrospectively reviewed the medical records of 92 male patients with CPP and known FAH after GnRHa treatment at the Department of Pediatrics of Severance Children’s Hospital between January 2000 and June 2024. Results: The mean duration of GnRHa treatment was 2.7±1.3 years. A significant 1.1±0.9 years narrowing was observed in the difference between bone age (BA) and chronological age (CA) during treatment (P<0.001). TH was 172.4±3.4 cm. FAH was 173.6±6.4 cm. FAH was greater than TH by 1.2±5.9 cm (P=0.047). PAH before and after treatment was 179.9±8.1 and 181.2±7.4 cm, respectively. PAH was increased by 1.3±4.9 cm (P=0.012) after treatment. As the PAH standard deviation score (SDS) before GnRHa treatment increased, FAH tended to exceed TH. In contrast, higher testosterone levels before treatment are associated with FAH falling below TH. A longer duration of treatment and taller TH are associated with an FAH SDS greater than height SDS before treatment. Conversely, a greater weight SDS, BA–CA difference, and testis size before treatment are associated with FAH SDS being less than height SDS before GnRHa treatment. Conclusion GnRHa treatment improved FAH and inhibited bone maturation in male patients with CPP.

Purpose: Previous studies from mostly Western populations have suggested possible associations between obesity and melanoma risk. This study aimed to investigate associations between obesity status and melanoma using a nationwide cohort of Koreans. Materials and Methods: A total of 4,441,403 adults who received a national health examination in 2012 were included from the Korean National Health Insurance Service database, and followed until December 31, 2022. Obesity status was defined based on the body mass index at the baseline health examination. Cox proportional hazards analyses were performed to evaluate associations between obesity status and incident melanoma, with adjustment for confounders. Stratified analyses were performed by sex and menopausal status (in women). Results: Overall, melanoma risk increased according to obesity status (p for trend=0.024); adjusted hazard ratios (95% confidence intervals) for melanoma risk were 0.766 (0.438–1.340) in underweight; 1.292 (1.072–1.557) in overweight; 1.202 (1.002–1.442) in obesity; and 1.191 (0.798–1.778) in severe obesity compared to normal weight (reference). In stratified analyses, similar trends to those of the overall study population were observed among men and premenopausal women (p for trend=0.052 in men and 0.036 in premenopausal women). Among premenopausal women, the risk of melanoma increased linearly with obesity status. Meanwhile, among postmenopausal women, melanoma risk showed no significant difference or trend according to obesity status. Conclusion Overweight and obesity were associated with increased risk of melanoma in a population-based cohort of Koreans. Obese individuals, especially men and premenopausal women, may require more thorough prevention and screening strategies for melanoma.

Limited data exist regarding the real-world practices and clinical outcomes in patients with ischemic heart failure with reduced left ventricular ejection fractions (LVEFs).Using nationwide registry data from South Korea, we aimed to investigate long-term outcomes and clinical practices, especially implantable cardioverter defibrillators (ICDs) implantation, in patients with reduced LVEFs at least 40 days after acute myocardial infarction (AMI). Of 13,056 patients with AMI between 2011 and 2015, we analyzed 350 (median age, 66 years [interquartile range, 56-75]) who had LVEFs <40% on follow-up transthoracic echocardiogram 40 days after the index event. The primary outcome was cardiac-cause mortality at 3 years. Secondary outcomes comprised major cardiovascular events as well as outcomes defined by the use of ICDs, cardiac resynchronization therapy defibrillators (CRT-Ds), and electrophysiology studies. Among 350 patients, 39 (11.1%) died from cardiac causes during 3 years of follow-up. Eleven (3.1%) were hospitalized for ventricular tachycardia. The rate of ICD or CRT-D implantation up to 3 years was 5.7% (20/350). Cox time-to-event analysis revealed older age, LVEF <30%, diabetes mellitus, and previous MI or revascularization as positively associated with cardiac death, whereas the use of statins and body weight <67 kg were negatively associated. This nationwide Korean registry demonstrated that only 5.7% of patients who had reduced LVEFs after 40 days of AMI underwent ICD implantations over 3 years. Considering the high mortality, concerted efforts are needed to improve clinical outcomes for patients who may have been candidates for ICD implantation.

Objectives: . Differentiated thyroid cancer (DTC) has a favorable prognosis. However, indeterminate lymph nodes (LNs) are common, making it challenging to distinguish recurrent from persistent DTC. Previous studies have not specifically compared the prognosis between recurrent and persistent DTC. Therefore, we aimed to compare prognosis and oncologic characteristics between these two groups. Methods: . This retrospective cohort study was conducted at a single tertiary care institution and included 265 patients with DTC (recurrent, 109; persistent, 156) who underwent reoperation between November 1, 1999, and August 31, 2018, for structural disease. Patients with distant metastasis at the time of initial diagnosis were excluded. Clinical and oncological characteristics, patterns of LN metastasis, disease-free survival (DFS), and overall survival (OS) were compared between the two groups. For DFS, time zero was defined as the date of the second operation. Results: . Recurrent DTC had a higher incidence of central LN metastasis (P=0.003), infield recurrence (P<0.001), and distant metastasis (P<0.001). In contrast, persistent DTC more frequently exhibited lateral LN metastasis (P=0.003) and outfield recurrence (P<0.001). The most common site of neck LN metastasis was ipsilateral level VI/VII (51.4%) in recurrent DTC and ipsilateral level IV (43.0%) in persistent DTC. Ten-year DFS was significantly lower in recurrent DTC than in persistent DTC (41.0% vs. 67.9%; P<0.001). Recurrent DTC, older age, a higher number of metastatic LNs at the second operation (first reoperation), and R1/R2 resection at the second operation were associated with decreased DFS. OS did not significantly differ between recurrent and persistent DTC (P=0.160). Conclusion . Recurrent DTC is associated with poorer DFS than persistent DTC, although OS does not significantly differ between the two groups.

Background: s/Aims: The patatin-like phospholipase domain-containing protein 3 (PNPLA3) I148M variant has been implicated in metabolic dysfunction-associated steatotic liver disease (MASLD), but its role in hepatocellular carcinoma (HCC) development is unclear. This study examines the association between the PNPLA3 I148M variant and HCC occurrence. Methods: A total of 562 MASLD patients, with and without HCC, were prospectively and consecutively enrolled at two universityaffiliated hospital between June 2024 and June 2025. Genomic DNA was extracted from buccal swabs or liver biopsy samples, and single nucleotide polymorphism genotyping was performed to determine the rs738409 genotype at codon 148 of PNPLA3. The histological grade of HCC was assessed using the Edmondson-Steiner (ES) grading system in patients who underwent core-needle liver biopsy. Results: Among 474 non-HCC patients, the GG genotype was found in 39.9%, GC in 37.1%, and CC in 23.0%. In 88 HCC patients, these frequencies were 45.5%, 36.4%, and 18.2%, respectively. No significant differences in GG genotype distribution were observed between HCC and non-HCC groups (P=0.509), nor in subgroups by sex, age, obesity status, cirrhosis status, fibrosis-4 index, or liver stiffness measurement. However, among HCC patients with histological grading, the GG genotype was significantly associated with higher ES grades (P=0.0076). Conclusions The PNPLA3 I148M GG genotype was not significantly associated with increased HCC occurrence in Korean MASLD patients within the present cohort. Although the GG genotype is known to play a role in development and progression of MASLD, further studies are warranted to clarify its contribution to tumor initiation and dedifferentiation.

Purpose: Botulinum toxin type A (BoNT-A) injections are used to manage spasticity in children with low-functioning cerebral palsy (CP), particularly in cases involving the hip adductor muscles. Despite their widespread use, research on the impact of BoNT-A injections on gross motor function in children with CP within Gross Motor Function Classification System (GMFCS) levels III–V remains limited, prompting us to evaluate their effectiveness in this population. Materials and Methods: This retrospective study included 100 preschool children (mean age, 3.9 years) with CP (GMFCS levels III–V) who received BoNT-A injections targeting the adductor muscles at a tertiary hospital (2006–2024). Gross motor function was assessed using the Gross Motor Function Measure (GMFM) within 1 month before injection and between 3 weeks and 4 months post-injection. Subgroup analyses were conducted by GMFCS level and by injection site. Pre- and post-injection assessments were compared using the Wilcoxon signed-rank test. Results: GMFM scores improved significantly across all GMFCS levels (p<0.05). Children at GMFCS levels III and IV demonstrated improvements across all domains (A–E), whereas those at GMFCS level V showed significant gains in domains A, B, and C (p<0.05).Further analyses showed significant improvements in all three groups: adductors alone, adductors and hamstrings, and adductors and distal muscles (p<0.05). Conclusion BoNT-A injections into hip adductor muscles improved gross motor function in children with low-functioning CP, affecting both overall and specific functional domains. This effect was observed in children who received injections into the adductors alone, as well as in combination with injections into the hamstrings or distal muscles.

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.

Background: and Objective: Maternal hypothyroidism increases the risk of adverse pregnancy outcomes, making appropriate levothyroxine (LT4) replacement essential. However, the optimal initial LT4 dose for women newly diagnosed with subclinical hypothyroidism (SCH) or overt hypothyroidism (OH) during pregnancy remains unclear.This study evaluated the appropriate starting LT4 dose based on baseline thyroid-stimulating hormone (TSH) and body mass index (BMI). Materials and Methods: This single-center retrospective cohort study included 126 pregnant women from June 2018 to April 2025. After pregnancy was confirmed, all participants started LT4.Patients were categorized by baseline TSH (2.5-4, 4-10, and ＞10 mIU/L) and BMI (＜23, 23-＜25, and ≥25 kg/m2 ) to determine the appropriate LT4 dose. The treatment goal was a TSH level ＜2.5 mIU/L. Results: Among the 126 patients, 101 (80.2%) were diagnosed with SCH or OH in the first trimester. The mean baseline TSH was 5.19 mIU/L, and 29.4% had autoimmune thyroiditis. Baseline TSH (r=0.315, p＜0.001) was positively associated with weight-based LT4 dose, whereas body weight (r=−0.304, p＜0.001) and BMI (r=−0.248, p=0.005) were inversely associated. The median weight-based LT4 dose was 0.45 μg/kg/day for TSH 2.5-4.0 mIU/L, 0.71 μg/kg/day for TSH 4.0-10 mIU/L, and 1.34 μg/kg/day for TSH ＞10 mIU/L (p for trend ＜0.001). Patients with TSH ＞10 mIU/L required more time to achieve TSH ＜2.5 mIU/L, and those with BMI ≥25 kg/m2 received lower weight-based LT4 doses. Conclusion Initial LT4 dosing should be tailored based on baseline TSH and BMI.