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.

Purpose: This study explored the experiences of physicians and nurses providing end-oflife care in Korean acute care hospitals. It aimed to identify the challenges faced in caring for dying patients and to suggest strategies for improving hospital-based end-of-life care. Methods: A qualitative exploratory design was employed using focus group interviews.Eleven healthcare professionals (five physicians and six nurses) working in tertiary or general hospitals participated in the study between July and August 2018. The interviews were conducted using a semi-structured guide covering seven thematic areas. All sessions were audio-recorded, transcribed verbatim, and analyzed thematically following Braun and Clarke’s framework. Results: Six major themes emerged: (1) communication with patients and families, (2) physical care for dying patients, (3) psychological and spiritual support, (4) hospital environment and system constraints, (5) moral distress and emotional burden on healthcare providers, and (6) suggestions for improvement. The participants described difficulties in open communication, limited resources for comfort care, emotional strain from invasive treatment at the end of life, and the absence of standardized institutional protocols.They emphasized the need for structured communication training, multidisciplinary collaboration, and integration of palliative care principles into acute care practice. Conclusion Physicians and nurses play a pivotal yet emotionally demanding role in providing end-oflife care in acute hospitals. Institutional reforms, including education, protocol development, and supportive environments, are essential to ensuring dignified, patient-centered care and sustain healthcare providers in their professional roles.

Persistent idiopathic dentoalveolar pain (PIDAP) is a chronic orofacial pain condition characterized by persistent pain in the absence of detectable dental pathology. Due to its ambiguous clinical presentation, PIDAP is frequently overlooked or misdiagnosed, leading to prolonged patient suffering and unnecessary dental treatments. This review provides a structured educational overview of PIDAP for dental students and early-career clinicians, covering its definition, taxonomy, differential diagnosis, pathophysiology, clinical significance, and management principles. A narrative literature review was conducted using PubMed and Scopus databases with the following search terms: “persistent dentoalveolar pain,” “atypical odontalgia,” “PIDAP,” “orofacial pain,” and “chronic overlapping pain conditions.” The search covered publications up to December 2024, limited to English-language articles. Priority was given to relevant classification guidelines, epidemiological data, and studies addressing diagnostic challenges, nomenclature changes, pathophysiology, and the relationship between PIDAP and chronic overlapping pain conditions (COPCs). Thirty-four key references were included after screening. Current diagnostic criteria, the historical evolution of PIDAP taxonomy, and major pathophysiological hypotheses—including peripheral sensitization, central sensitization, and nociplastic pain mechanisms—are summarized. The high rate of comorbidity with COPCs and the frequent misdiagnosis of PIDAP highlight its clinical importance, as epidemiological data indicate that diagnostic delays may range from several months to years. Improving awareness and understanding of PIDAP among dental students and clinicians can facilitate early recognition, reduce misdiagnosis, and contribute to more effective management. Incorporating PIDAP-related education into undergraduate dental curricula and continuing education programs may further bridge current knowledge gaps and improve patient outcomes.

This study aimed to determine the prevalence of human epidermal growth factor receptor 2 (HER2)–ultralow breast cancer among cases initially classified as HER2 immunohistochemistry (IHC) 0 and assess interobserver variability in interpreting low-level HER2 expression. Methods: In this multicenter retrospective study, all invasive breast cancer cases diagnosed between January and December 2022 across 10 Korean institutions were retrieved. Institutional pathologists reexamined HER2 IHC slides originally reported as IHC 0 according to the 2018 American Society of Clinical Oncology/College of American Pathologists guidelines and reclassified them as HER2-null (0), HER2-ultralow (0+), or HER2-low (1+). Slides from 10% of HER2-null and HER2-ultralow cases were digitized for central review and independently assessed by two pathologists, with discrepancies resolved by consensus. Results: Among 8,026 cases, 2,836 cases (35.5%) were initially reported as IHC 0. Upon re-review, 1,673 (59.0%), 1,139 (40.2%), and 24 (0.8%) cases were reclassified as HER2-null, HER2-ultralow, and HER2-low, respectively. The prevalence of HER2-ultralow breast cancer varied considerably across institutions (23.7%–78.1%). Central review of 268 digitized cases showed concordance in 193 cases (72.0%). Among the 75 discordant cases, 54 tumors (72.0%) were upgraded from HER2-null to HER2-ultralow, and 18 (24.0%) tumors were upgraded from HER2-ultralow to HER2-low. Furthermore, two tumors (2.7%) were downgraded from HER2-ultralow to HER2-null. Conclusions: Approximately 40% of cases initially categorized as IHC 0 were reclassified as HER2-ultralow. The substantial inter-institutional variability observed in interpreting low-level HER2 expression highlights the need for standardized training and quality assurance to ensure accurate identification of patients eligible for HER2-targeted antibody–drug conjugates.

In forensic medicine, age estimation commonly involves assessing age-related changes in teeth and skeletal structures. Vertebral morphological alterations, such as osteophyte formation, serve as age indicators. Recent studies using deep-learning techniques, such as neural networks, for age estimation from radiographic images have been conducted, reporting significantly higher accuracy than previous studies. This study aimed to estimate age using neural network-based deep-learning techniques applied to computed tomography (CT) cross-sectional images of the spine and evaluate its feasibility. Postmortem CT scans of 214 cadavers with varying decomposition levels were used. Coronal and sagittal cross-sectional images penetrating the center of each vertebral body were extracted for the 11th and 12th thoracic vertebrae and the first to fifth lumbar vertebrae. Using these images, along with the chronological ages of deceased individuals, an age estimation model was developed through regression analysis in PyTorch, employing a convolutional neural networks architecture with five-fold cross-validation. The model achieved a mean absolute error of 5.385 years, root mean squared error of 7.029 years, and coefficient of determination of 0.793. Although the sample size was relatively small, the results suggested the potential applicability of vertebral imagingbased age estimation in the Korean population. Further research using a larger dataset may improve the accuracy and reliability of the model.

Objective: This study aimed to evaluate the accuracy of predicting final adult height (FAH) in Korean girls with central precocious puberty (CPP) using artificial intelligence (AI)-derived bone age assessments integrated into the Bayley–Pinneau (BP) or Korean National Growth Chart (KGC) prediction models. Materials and Methods: This single-center, retrospective study included 122 Korean girls with CPP who received gonadotropinreleasing hormone agonist (GnRHa) treatment for at least two years between January 2000 and November 2022. We assessed bone age and predicted adult height at the initiation and completion of GnRHa treatment. We used three bone age assessment methods: human expert assessment based on the Greulich-Pyle (GP) atlas (Human-GP), AI-derived GP (AI-GP), and AI-weighted GP scoring (AI-GPw). We calculated predicted adult heights (PAHs) using both the BP and KGC models, generating 12 PAH estimates per patient (2 time points x 3 bone-age methods x 2 height-prediction models). We assessed prediction accuracy and agreement with FAH using linear regression analysis and Bland–Altman plots and performed multivariable analysis to identify significant predictors of FAH. Results: Human-GP, AI-GP, and AI-GPw demonstrated comparable overall performance in predicting FAH (R 2 : 0.470–0.646 and 0.691–0.822 for treatment initiation and completion, respectively). AI-GPw combined with BP yielded slightly better point estimates but showed no statistically significant differences. At both time points, the BP model demonstrated consistently narrower 95% limits of agreement (LoA) than the KGC model. Multivariable analysis identified AI-GPw-BP and height percentile score as significant predictors of FAH at both time points; mid-parental height was significant only at treatment initiation. Conclusion Human-GP, AI-GP, and AI-GPw demonstrated comparable accuracy in predicting FAH. The BP model demonstrated consistently narrower 95% LoA than did the KGC model. AI-GPw-BP was an independent predictor of FAH. These findings support the clinical utility of AI-derived bone age assessments for individualized FAH prediction in patients with CPP.

Background: Seborrheic dermatitis (SD) is a chronic inflammatory scalp disorder associated with Malassezia dysbiosis and increased sebum production. AMPamide has been suggested to have anti-inflammatory and sebum-regulating effects, but its clinical efficacy and microbiome-modulating effects in SD remain unclear. Objective: To evaluate the clinical efficacy and scalp microbiome changes following 4 weeks of use of an AMPamide-containing shampoo in patients with SD. Methods: In this observational study, 30 patients with SD applied an AMPamide-containing shampoo for 4 consecutive weeks. Clinical outcomes, including sebum levels and overall severity scores, were assessed. Scalp bacterial and fungal communities were analyzed to evaluate α- and β-diversity and changes in Malassezia composition. Results: Treatment resulted in significant reductions in sebum levels and clinical severity scores, particularly in erythema, dandruff, and pruritus. Bacterial community composition remained largely stable, while fungal α-diversity increased, and β-diversity analysis revealed a decrease in the ratio of Malassezia restricta to Malassezia globosa. Conclusion AMPamide-containing shampoo was associated with improved clinical symptoms and a shift toward a more balanced fungal community composition in patients with SD, supporting its potential as a non-steroidal therapeutic option for SD.

α-Melanocyte-stimulating hormone (α-MSH) is a key physiological inducer of melanogenesis and melanocyte activation. Reactive oxygen species (ROS) function as secondary messengers in intracellular signaling pathways that regulate α-MSH-mediated melanogenesis. However, the mechanism by which α-MSH induces ROS generation in melanocytes remains incompletely understood. Here, we investigated the sources and regulatory mechanisms of α-MSH-induced ROS in murine B16F10 and human MNT-1 melanoma cells. Confocal microscopy revealed that α-MSH predominantly stimulated cytosolic rather than mitochondrial ROS generation. Western blot analysis showed that α-MSH upregulated the expression of NADPH oxidases NOX1 and NOX4 at early time points, key enzymes involved in cytosolic ROS production. Pharmacological inhibition of NOX1/4 significantly reduced α-MSH-induced ROS levels and melanin content, accompanied by decreased phosphorylation of MITF, a melanogenic transcription factor. These findings indicate that α-MSH is a key physiological inducer of melanogenesis and melanocyte-related signaling in melanoma cells. Our study highlights NOX4, together with NOX1, as potential targets for anti-pigmentation strategies.

Purpose: The triggering receptor expressed on myeloid cells 2 (TREM2) creates an immunosuppressive environment, but the effects of anticancer treatment on TREM2 and the tumor microenvironment (TME) are not well established. This study investigates the impact of chemotherapy on TREM2-expressing macrophages within the lung adenocarcinoma TME. Materials and Methods: Using single-cell RNA sequencing datasets of paired normal-appearing lung tissue (NL) and tumor (Tu), human and mouse lung cancer tissue, and THP-1 cells, we observed the effects of anticancer drugs on them. Results: Myeloid cells (MY) were the second-most abundant non-epithelial component in the Tu, though less prevalent than in NL. Specific MY subclusters abundant in Tu showed overexpression of TREM2. In lung cancer-induced Kras-G12D mice, M2 proportion increased in Tu compared to NL; cisplatin increased TREM2+ M2 proportion in Tu. TREM2+ cells in Tu showed interactions with cell clusters showing characteristics of interstitial macrophage such as mo-lineage, mono-Mc, and CD163/LGMN cells via FN:CD44 and MIF:CD74+CXCR4, suggesting that they influence the recruitment of those cells to Tu and TME reshape. In M0-state THP-1 cells, cisplatin and osimertinib treatments induced polarization towards M1 and M2 states and increased TREM2 expression. Cisplatin promoted uptake of phosphatidylserine-coated latex beads by M0 cells, whereas osimertinib reduced uptake by polarized macrophages. These findings suggest anticancer treatments impact the lung immune microenvironment by altering the TREM2+ cells. Conclusion Given TREM2’s central inhibitory role in the tumor immune environment, effects of chemotherapeutic agents should be considered in developing TREM2-targeting therapies.

Purpose: Malignant hepatocellular neoplasm, not otherwise specified (HCN-NOS) is a provisional diagnostic entity, characterised by intermediate or a combination of hepatoblastoma and pediatric hepatocellular carcinoma (p-HCC) features. We compared the characteristics of HCN-NOS with hepatoblastoma and p-HCC. Materials and Methods: The records of 148 pediatric patients diagnosed with hepatocellular malignancy after resection were retrieved from the institutional database. Clinical parameters and histopathology slides were reviewed to re-establish each patient’s diagnosis. Molecular analyses were conducted in 37 patients. Results: Patients were profiled as 21 (14.2%) with HCN-NOS, 109 (73.6%) with hepatoblastoma, and 18 (12.2%) with p-HCC. The median age was 8.6 years in HCN-NOS, 1.2 years in hepatoblastoma, and 7.9 years in p-HCC. Background liver disease was frequently observed in p-HCC (11/18, 61%) but infrequent in HCN-NOS (4/21, 19%) and hepatoblastoma (4/109, 3.7%). HCN-NOS presented with a more advanced PRETEXT stage (p=0.012), metastasis (p < 0.001), and lymphovascular invasion (p < 0.001) than hepatoblastoma and p-HCC. Patients with HCN-NOS received longer cycles of preoperative chemotherapy; however, they reported a lower decrease in serum alpha-fetoprotein and tumor size than hepatoblastoma (p=0.043, p=0.004, and p=0.044, respectively). HCN-NOS was an independent poor prognostic factor for event-free survival (hazard ratio, 4.968; 95% confidence interval, 2.004 to 12.32; p < 0.001). Conclusion The possibility of HCN-NOS should be considered in pediatric patients with liver cancer, especially those ≥ 5 years old with no background liver disease. Because HCN-NOS exhibits poor chemoresponsiveness and unfavourable postoperative prognosis, liver transplantation should be strongly considered.