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.

Rheumatoid neutrophilic dermatitis (RND) is a rare extra-articular skin lesion associated with rheumatoid arthritis (RA). Lesions typically occur symmetrically on the extensor surfaces of the extremities and present with variable clinical features. A 78-year-old female with a 2-month history of skin rash on the right forearm and left lower leg, with no other systemic symptoms, visited the dermatology department of our hospital. She had been diagnosed with seropositive RA approximately 20 years ago. The skin rash was asymmetrically distributed and presented with localized pustules, purpura, and edema. The biopsy specimen showed dermal infiltration by neutrophils, leukocytoclasia without vasculitis, and a neutrophilic dermal abscess. No fungi or bacteria were detected on any of the stains. The patient was diagnosed with RND. Clinical improvement was noted after treatment with dapsone, followed by colchicine and methylprednisolone. In this case report, we described the case of a female patient with atypically presented RND and conducted a literature review.

Rectal cancer, which accounts for approximately 40% of colorectal cancers, remains a major clinical concern. Recent advances in diagnostic imaging, surgical techniques, radiotherapy, and systemic treatment have steadily improved rectal cancer outcomes. Considering this, the Korean Rectal Cancer Multidisciplinary (KRCM) Committee has aimed to provide clinicians and policymakers with up-to-date, evidence-based clinical practice guidelines to support optimal decision-making, reflecting current evidence, the Korean healthcare context, and patient values and preferences. The Clinical Practice Guidelines for Rectal Cancer version 2.0 were developed through multidisciplinary collaboration with related academic societies, building upon and updating the KRCM Clinical Practice Guidelines version 1.0 (titled “Multidisciplinary guidelines for the management of rectal cancer”). These consensus guidelines of the KRCM were established based on a comprehensive literature review, evidence synthesis, with recommendation development guided by the GRADE (Grading of Recommendations Assessment, Development and Evaluation) methodology, and consideration of applicability in real-world clinical practice under the national health insurance system. Each recommendation has been presented with its strength and level of evidence.

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: The aim of this study is to compare the detection ability of quality of life (QoL) changes and responsiveness of the KOrean QUality of life in Stomach cancer patients Study group (KOQUSS)-40 and European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ). Materials and Methods: A multicenter prospective observational study was conducted to evaluate QoL changes after various gastrectomies between January 2021 and April 2022. Participants were instructed to complete the KOQUSS-40 and EORTC QLQ-C30/STO22 preoperatively and at 1, 3, 6, and 12 months postoperatively. QoL changes over time and QoL responsiveness were assessed for each questionnaire. Results: Data from 491 patients who underwent curative gastrectomy for gastric cancer at 22 institutions were analyzed. The summary scores of the KOQUSS-40 and EORTC QLQ-STO22 showed significant differences between the total and proximal gastrectomy groups (p=0.044 and p=0.038, respectively), but no difference was observed for the EORTC QLQ-C30. Dysphagia on the KOQUSS-40 was significantly different between the total and proximal gastrectomy groups (p=0.031); however, dysphagia on the EORTC QLQ-STO22 did not differ. The responsiveness of the KOQUSS-40 was similar to that of the EORTC QLQ in patients who experienced ≥ 10% body weight loss, but approximately 10% less in patients receiving adjuvant chemotherapy than the EORTC QLQ. Conclusion KOQUSS-40 has several advantages over EORTC QLQ-C30/STO22 when comparing QoL between the total and proximal gastrectomy groups. The findings provide information for researchers investigating the QoL of patients who have undergone curative gastrectomy for gastric cancer.

Objective: : A twig-like middle cerebral artery (T-MCA) is a rare condition characterized by steno-occlusion of the M1 segment of the middle cerebral artery (MCA) with nearby collateral arterial networks. Despite unclear pathophysiology, it is often classified as a congenital anomaly caused by failure of fusion of the plexiform MCA arterial plexus. We aimed to improve understanding of the pathophysiology of T-MCAs by analyzing incidental T-MCA findings and their natural history. Methods: : A retrospective chart review was performed between January 2011 and December 2023 at three medical centers treating both ischemic and hemorrhagic strokes. Patients with suspected MCA lesions were selected through radiology reports from computed tomography, magnetic resonance angiography, and digital subtraction imaging. Results: : We identified 51 T-MCA cases from a radiology report search spanning 13 years across three medical centers. The study included 9875 patients with ischemic stroke and 2097 with hemorrhagic stroke. Of the 51 T-MCA cases, incidental findings accounted for 25 (49.0%), ischemic stroke for 18 (35.3%), and hemorrhagic strokes accounted for eight cases (15.7%). T-MCA related ischemic and hemorrhagic strokes accounted for 0.18–0.38% of all strokes. The RNF213.R4810K mutation was identified in seven of 15 patients (46.7%) tested. We found three cases of a de-novo T-MCA that progressed from a normal MCA architecture. Conclusion : T-MCAs may represent an acquired secondary anomaly rather than a congenital lesion, followed by steno-occlusion of the focal MCA with new arterial network formation. Both Moyamoya angiopathy and chronic atherosclerosis likely contributed to disease progression. Formation of a microaneurysm, dilatation of the lenticulostriate artery, and hemodynamic stress can lead to stroke.

Background: Researchers have proposed that there is a potential link between folliclestimulating hormone (FSH) and cognitive function, yet the evidence remains inconclusive.The current study aims to identify the association between serum FSH levels and cognitive performance, and to examine whether this association varies by cognitive diagnosis, serum estradiol (E2) levels, or cognitive domain. Methods: This multicenter cross-sectional study used a clinical database comprising female visitors to memory clinics at three referral hospitals in Korea. Venous blood samples were collected to determine serum FSH and E2 concentrations via immunoradiometric assay.Cognitive performance was evaluated using either the Korean version of the Consortium to Establish a Registry for Alzheimer’s Disease or the Seoul Neuropsychological Screening Battery, while cognitive diagnoses were made via clinical diagnostic interviews. Results: Among the 159 participants (normal cognition [NC], n = 70; mild cognitive impairment [MCI], n = 52; Alzheimer’s disease [AD] dementia, n = 37), there were no significant differences in serum FSH levels associated with cognitive diagnosis. In women with NC, serum FSH levels were found to be positively correlated with cognitive performance in global cognition, nonverbal memory, and executive function, even after adjusting for serum E2 level and its interaction with serum FSH level. However, no significant correlations were observed in women with MCI and AD dementia. Conclusion The association between circulating FSH and cognition may be independent from circulating E2, but it may depend on disease progression or cognitive domains. This suggests a potential role of gonadotropin in cognitive decline in elderly women.

Emerging evidence suggests that systemic inflammation may play a critical role in neurological disorders. Recent studies have shown the connection between inflammatory bowel diseases (IBD) and neurological disorders, revealing a bidirectional relationship through the gut-brain axis.Immunotherapies, such as Treg cells infusion, have been proposed for IBD. However, the role of adaptive immune cells in IBD-induced neuroinflammation remains unclear. In this study, we established an animal model for IBD in mice with severe combined immune-deficient (SCID), an adaptive immune deficiency, to investigate the role of adaptive immune cells in IBD-induced neuroinflammation. Mice were fed 1%, 3%, or 5% dextran sulfate sodium (DSS) for 5 days. We measured body weight, colon length, disease activity index (DAI), and crypt damage. Pro-inflammatory cytokines were measured in the colon, while microglial morphology, neuronal count, and inflammatory cytokines were analyzed in the brain. In the 3% DSS group, colitis symptoms appeared at day 7, with reduced colon length and increased crypt damage showing colitis-like symptoms. By day 21, colon length and crypt damage persisted, while DAI showed recovery. Although colonic inflammation peaked at day 7, no significant increase in inflammatory cytokines or microglial hyperactivation was observed in the brain. By day 21, neuroinflammation was detected, albeit with a slight delay, in the absence of adaptive immune cells. The colitis-induced neuroinflammation model provides insights into the fundamental immune mechanisms of the gut-brain axis and may contribute to developing immune cell therapies for IBD-induced neuroinflammation.

Background: Researchers have proposed that there is a potential link between folliclestimulating hormone (FSH) and cognitive function, yet the evidence remains inconclusive.The current study aims to identify the association between serum FSH levels and cognitive performance, and to examine whether this association varies by cognitive diagnosis, serum estradiol (E2) levels, or cognitive domain. Methods: This multicenter cross-sectional study used a clinical database comprising female visitors to memory clinics at three referral hospitals in Korea. Venous blood samples were collected to determine serum FSH and E2 concentrations via immunoradiometric assay.Cognitive performance was evaluated using either the Korean version of the Consortium to Establish a Registry for Alzheimer’s Disease or the Seoul Neuropsychological Screening Battery, while cognitive diagnoses were made via clinical diagnostic interviews. Results: Among the 159 participants (normal cognition [NC], n = 70; mild cognitive impairment [MCI], n = 52; Alzheimer’s disease [AD] dementia, n = 37), there were no significant differences in serum FSH levels associated with cognitive diagnosis. In women with NC, serum FSH levels were found to be positively correlated with cognitive performance in global cognition, nonverbal memory, and executive function, even after adjusting for serum E2 level and its interaction with serum FSH level. However, no significant correlations were observed in women with MCI and AD dementia. Conclusion The association between circulating FSH and cognition may be independent from circulating E2, but it may depend on disease progression or cognitive domains. This suggests a potential role of gonadotropin in cognitive decline in elderly women.

Background and Objectives: The risk profiles, procedural characteristics, and clinical outcomes for women undergoing bifurcation percutaneous coronary intervention (PCI) are not well defined compared to those in men. Methods: COronary BIfurcation Stenting III (COBIS III) is a multicenter, real-world registry of 2,648 patients with bifurcation lesions treated with second-generation drug-eluting stents.We compared the angiographic and procedural characteristics and clinical outcomes based on sex. The primary outcome was 5-year target lesion failure (TLF), a composite of cardiac death, myocardial infarction, and target lesion revascularization. Results: Women (n=635, 24%) were older, had hypertension and diabetes more often, and had smaller main vessel and side branch reference diameters than men. The pre- and post-PCI angiographic percentage diameter stenoses of the main vessel and side branch were comparable between women and men. There were no differences in procedural characteristics between the sexes. Women and men had a similar risk of TLF (6.3% vs. 7.1%, p=0.63) as well as its individual components and sex was not an independent predictor of TLF. This finding was consistent in the left main and 2 stenting subgroups. Conclusions In patients undergoing bifurcation PCI, sex was not an independent predictor of adverse outcome.