Background/Aims: We investigated whether patients with inflammatory bowel disease (IBD) in Korea have an increased risk of hepatitis A virus (HAV) and hepatitis C virus (HCV) infections and sought to identify the risk factors for these infections. Methods: We performed a nationwide population-based study using 2013–2021 data from the Korean National Health Insurance Claims Database. We calculated the incidence rates and standardized incidence ratios (SIRs) of HAV and HCV infections in patients with IBD compared with the overall Korean population. Results: A total of 43,513 patients were included in this study. A total of 317 cases of HAV were identified in 276,007 perdison- years, while 297 cases of HAV developed in the Korean general population. The SIR of HAV in the patients with IBD was 1.07 (95% confidence interval [CI], 0.96–1.19) and the increase of HAV infection in patients with IBD was not statistically significant. A total of 289 cases of HCV infection were identified in 276,538 person-years, while 242 cases of HCV infection developed in the Korean general population. The SIR of HCV in patients with IBD was 1.19 (95% CI, 1.06–1.34) and the increase of HCV infection in patients with Crohn's disease (SIR, 1.63; 95% CI, 1.31–2.04). Corticosteroid use was identified as a risk factor for HAV and HCV infections in patients with IBD. Conclusions HCV showed an increasing trend in Korean patients with IBD, especially those with Crohn's disease. Corticosteroids use is a risk factor for hepatitis in patients with IBD.

Background: Rosacea is a chronic inflammatory skin disorder characterized by erythema, papules, ocular symptoms, and heightened sensitivity. Patients with neurogenic symptoms such as burning or stinging remain particularly difficult to manage. Current guidelines often underrepresent energy-based devices (EBDs), pigmentary sequelae, psychosocial burden, and ocular comorbidities. Objective: To examine Korean dermatologists’ expert perspectives on rosacea management, focusing on skin sensitivity, neurogenic symptoms, pigmentary changes, psychosocial impact, ocular involvement, and EBD use. Methods: A web-based, 29-item survey was administered to 25 board-certified Korean dermatologists (May–June 2025). Quantitative and qualitative responses were analyzed. Results: Erythematotelangiectatic and papulopustular phenotypes with sensitivity skin predominated. EBDs (pulsed dye laser, intense pulsed light) were frequently used but limited by cost and sensitivity issues. Neurogenic symptoms were recognized but rarely treated with neuromodulators. Post-inflammatory hyperpigmentation was infrequent, yet monitoring was inconsistent.Psychosocial and ocular aspects were acknowledged but seldomly systematically addressed.Respondents expressed interest in emerging adjunctive treatments such as cold plasma, skin boosters, and holistic care approaches. Conclusion Korean dermatologists adopt individualized strategies for rosacea, yet practice gaps remain regarding neurogenic symptoms, pigmentary complications, and psychosocial and ocular comorbidities. Findings support the need for updated multidisciplinary, phenotype-driven guidelines aligned with real-world practice.

Background: s/Aims: This study evaluated the feasibility and outcomes of surgical treatment for metachronous periampullary carcinoma following curative resection of primary extrahepatic bile duct cancer. Methods: A retrospective review was conducted of seven patients who underwent pancreaticoduodenectomy (PD) for metachronous periampullary cancer after prior curative surgery for extrahepatic bile duct cancer. Results: The mean age at the second surgery was 66.7 years (range, 43–81 years). Initial malignancies included three hilar cholangiocarcinomas, one middle bile duct cancer, and three gallbladder cancers. Subsequent primary tumors consisted of three distal bile duct cancers, three pancreatic head cancers, and one duodenal cancer. The mean interval between the first and second cancers was 47 months (range, 13–121 months). No perioperative deaths occurred. Postoperative complications developed in three patients (42.9%):chyle leakage (Clavien–Dindo grade II) in two (28.6%) and a grade C postoperative pancreatic fistula requiring reoperation (grade IIIb) in one (14.3%). Both chyle leaks were managed conservatively. During follow-up, four patients died of recurrence at 5, 12, 19, and 24 months postoperatively. One patient underwent video-assisted thoracoscopic surgery for pulmonary metastasis 2 months after PD and remains alive 22 months later without recurrence. Two patients are disease-free at 38 and 92 months of follow-up. Conclusions PD for second primary periampullary cancer after resection of extrahepatic bile duct cancer appears feasible and potentially effective. Although no perioperative mortality occurred, major complications were observed. Larger studies are needed to confirm these preliminary findings.

Background: Transthyretin amyloidosis, a protein-misfolding disorder characterized by systemic amyloid deposition, can be classified as wild-type transthyretin amyloidosis (ATTRwt) or hereditary transthyretin amyloidosis (ATTRv), depending on the presence of transthyretin (TTR) gene variants. We examined the genetic distribution of TTR variants in Korean patients diagnosed with ATTRv. Methods: We retrospectively reviewed 801 participants who underwent TTR analysis at Samsung Medical Center from 2012 to 2024. The participants were categorized into two groups: in-house probands or relatives, and externally referred probands or relatives. Results: Pathogenic or likely pathogenic TTR variants were detected in 36 of 165 in-house probands (21.8%), among which D38A was the most frequent variant (50.0%; 18/36), followed by M13dup and E89K (8.3% each). Among referred probands, D38A was predominant (54.5%; 12/22), followed by M13dup (22.7%; 5/22). Cardiac amyloid involvement was the most common manifestation, observed in 97.2% (35/36) of in-house probands with ATTRv, followed by peripheral nervous system (PNS; 94.4%) and autonomic nervous system (ANS; 88.9%) involvement. In contrast, ANS involvement was most prevalent among in-house relatives who underwent organ evaluation (61.5%; 24/39), followed by cardiac (52.1%; 25/48) and PNS (48.7%; 19/39) involvement. Five of the eight in-house relatives harboring M13dup (62.5%) showed organ involvement, primarily in the ANS, supporting the pathogenicity of this variant. Conclusions This study provides the largest single-institution dataset of Korean patients with ATTRv, incorporating systematic organ assessments. The predominance of the unique TTR variants D38A and M13dup delineates a distinct genetic landscape that may facilitate accurate and timely diagnosis of ATTRv in the Korean population.

Purpose: To evaluate clinical and radiographic outcomes after the surgical treatment of trimalleolar ankle fractures in patients aged ≥65 years and to identify the prognostic factors for poor clinical outcomes. Materials and Methods: Sixty-three patients aged ≥65 years who underwent surgery for trimalleolar ankle fractures (2013~2022) were reviewed retrospectively. Pathologic fractures, open fractures, and follow-up <6 months were excluded. The candidate prognostic variables included the demographics, fracture classification (Lauge–Hansen and Danis–Weber), bone mineral density, body mass index, comorbidities, associated injuries, posterior malleolar fixation status, and syndesmotic injury. The reduction quality was graded using the Burwell–Charnley criteria. The outcomes were the American Orthopaedic Foot and Ankle Society (AOFAS) Ankle–Hindfoot Score and final ambulation status. The continuous variables were compared using Student’s t-test or the Mann–Whitney U-test, and the categorical variables were analyzed using the chi-square test or Fisher’s exact test, where appropriate. Multivariable logistic regression was performed to identify the independent prognostic factors for poor clinical outcomes. Results: The mean age was 73.4 years, and the mean follow-up was 14.8 months; 39 patients were male, and 24 were female. Radiographic reduction was anatomic in 81.0% and fair in 19.0%. The mean time to union was 5 months, and the mean AOFAS score was 82.4. Final ambulation, limping gait, cane use, and wheelchair use were normal in 23.8%, 47.6%, 22.2%, and 6.3%, respectively. Infection and delayed union occurred in 6.3% and 9.5%, respectively, with no cases of nonunion or peri-implant fracture. Multivariable analysis showed that comorbidities and associated injuries were independently associated with poor clinical outcomes. Conclusion Surgical treatment generally achieved satisfactory radiographic reduction and union in patients aged ≥65 years, but functional recovery was variable, and many patients required walking aids. Comorbidities and concomitant injuries independently predicted poor outcomes, underscoring the importance of careful perioperative risk assessment and multidisciplinary postoperative management in this population.

The Pheochromocytoma of the Adrenal Gland Scaled Score (PASS) is widely used for risk stratification in pheochromocytoma and paraganglioma (PPGL), but its clinical utility is limited by inter-observer variability of its parameters and inconsistent predictive performance. Methods: We conducted a multicenter retrospective study of 1,518 patients with PPGL from five tertiary referral centers in Korea. Prognostic utility of PASS system was assessed using logistic regression, Kaplan-Meier analysis, and receiver operating characteristic (ROC) curve analysis. Inter-observer variability was inferred by comparing area under the ROC curve (AUCs) across institutions. Simplified PASS systems were developed based on multivariable analysis of key histopathological parameters. Results: The PASS system was a significant predictor of adverse events and recurrence-free survival. Although the PASS system demonstrated only modest discriminative ability (AUC, 0.673), it showed a high negative predictive value (NPV, 0.885), supporting its usefulness as a screening tool for benign behavior. However, there was significant inter-institutional variability in PASS performance (AUC; range, 0.513 to 0.727; p < .05). The 3-factor Simple PASS, which incorporates necrosis, spindling, and mitotic figures, exhibited less inter-observer variation. The 4-factor Simple PASS, which adds vascular invasion to the 3-factor model, also showed reduced inter-observer variability and improved AUC and NPV compared to the original PASS system. Conclusions: In this multicenter cohort, the PASS system demonstrated high NPV and screening potential, but significant inter-observer variability remains a challenge. Simplification of the PASS system and enhanced pathologist training may improve reproducibility and clinical utility in PPGL risk stratification.

Purpose: To investigate results of the single-loop suture scleral fixation technique with long-term follow-up. Methods: This retrospective study analyzed patients who underwent scleral fixation using the single-loop suture technique between January 2010 and June 2024 with a minimum follow-up period of one year. Ophthalmic outcomes and complications including polypropylene suture type and re-operation rates were evaluated. Results: A total of 215 eyes in 201 patients were included. Polypropylene suture types used included 10-0 in 52.1% (112 of 215), 9-0 in 44.2% (95 of 215), and 3.7% (8 of 215) remained unconfirmed. The re-operation rate was 22.3% (25 of 112) with 10-0 polypropylene, 1.1% (1 of 95) with 9-0 polypropylene, and 12.1% (26 of 215) in total. Intraocular lens repositioning was needed in 0.9% (2 of 215). Postoperative intraocular pressure (IOP) elevation occurred in 51.6% (83 of 161) of patients without baseline glaucoma history; 94.0% (78 of 83) of cases were well controlled with glaucoma medication and 44.6% (37 of 83) were able to discontinue it. Conclusions Single-loop suture scleral fixation is a safe and effective surgical technique with a low incidence of serious complications.This technique leads to stable lens centering with a low rate of lens repositioning. Polypropylene suture type can affect the re-operation rate. Close monitoring of IOP is recommended.

Background: Postoperative liver regeneration is essential for maintaining hepatic function. This study evaluated the rate, determinants, and volumetric patterns of early liver regeneration after hemihepatectomy. Methods: A retrospective review was conducted of 50 patients who underwent right or left hemihepatectomy between April 2019 and March 2025. Liver and spleen volumes (SV) were assessed preoperatively, at postoperative day (POD) 1 week, and at POD 3 months. Early liver regeneration rate (LRR) was defined as the percentage increase in remnant liver volume at POD 1 week relative to the preoperative future liver remnant (FLR), and patients were categorized into low (<50%) and high (≥50%) LRR groups. Clinical, biochemical, and volumetric variables were compared, and predictors of regeneration were identified using multivariable analyses. Regeneration patterns were also examined according to whether the FLR/standard liver volume (SLV) ratio was <50% or ≥50%. Results: FLR/SLV was the strongest independent predictor of rapid early liver regeneration (p<0.001). Remnants with FLR/SLV <50% exhibited rapid and sustained regeneration, whereas those with FLR/SLV ≥50% showed slower regrowth that plateaued after reaching approximately 90% of SLV. SV increased at POD 1 week in all patients; however, only the FLR/SLV ≥50% group showed a reduction by POD 3 months, whereas the <50% group maintained elevated volumes. Conclusions FLR/SLV reliably predicts early postoperative liver regeneration. Smaller remnants regenerate more rapidly, whereas persistent splenic enlargement suggests a sustained portal hemodynamic burden. Combined evaluation of FLR/SLV and SV may enhance perioperative risk assessment and surgical planning.

Background: The taxonomic status of house mice (Mus musculus) on the Korean Peninsula has long been debated due to conflicting morphological classifications and limited genetic evidence. Historically, three subspecies (M. m.molossinus, M. m. utsuryonis, and M. m. yamashinai) have been proposed based on external traits, although the validity of these proposals remains uncertain. Thus, this study aimed to integrate genetic and morphological analyses to clarify the phylogenetic relationships of Korean mice relative to the well-known primary M. musculus subspecies and evaluate the taxonomic distinctiveness. Results: Genetic analysis of mitochondrial DNA (cytb gene) from mice across Korea, including islands, mountains, and agricultural fields, confirmed that these mice belong to the Eurasian M. m. musculus lineage. Morphologically, Korean mice exhibited tail ratios consistent with previously assigned subspecies, suggesting these traits represent intraspecific variation within M. m. musculus. Craniometric analyses revealed distinctive features, such as a shorter, narrower premaxillary tooth-patch width and a longer maxillary tooth-row length, thereby distinguishing these mice from laboratory strains derived from M. m. domesticus. These cranial configurations, visualized via three-dimensional micro-computed tomography scans, further supported the morphological divergence of these mice from other subspecies. Conclusions Our findings indicate that Korean house mice belong to a single subspecific group within M. m.musculus, with observed morphological variations reflecting local adaptation rather than distinct taxonomic divisions.The Korean Peninsula likely served as an ecological bridge, facilitating the spatiotemporal diversification of M. m.musculus across East Eurasia. This study resolves longstanding taxonomic ambiguities and underscores the subspecific status of Korean house mice within M. m. musculus. These insights provide a foundation for understanding the biogeographic history of human commensal species and future biomedical research utilizing wild-derived mouse models.