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: Current guidelines recommend vaccination at least 2 weeks before chemotherapy initiation to optimize the immune response despite limited evidence. Our previous study indicated no differences in short-term immune response for the 13-valent pneumococcal conjugate vaccine (PCV13) according to the vaccination timing. This study aims to investigate the long-term efficacy of PCV13 and clinical factors associated with the respective antibody response. Materials and Methods: Patients with gastric or colorectal cancer who received adjuvant chemotherapy were enrolled and divided into two groups: vaccinated 2 weeks before chemotherapy (arm A) and vaccinated concurrently with chemotherapy (arm B). Serum samples were collected before vaccination and in one month, 3 years, and 5 years. Immune responses were measured using enzyme-linked immunosorbent assay and multiplex opsonophagocytosis assay. Results: Including 63 patients, both groups showed an initial increase in the geometric mean titers of opsonophagocytic activity and the geometric mean concentrations of serotype-specific IgG levels after one month, followed by a decline at 3 and 5 years, particularly for serotypes 1, 14, 18C, and 19A. Despite the decline, global protection was maintained for 5 years, although global response decreased. The two arms did not show significant differences in immunogenicity nor in factors such as vaccination timing, age, cancer type, or chemotherapy regimen. Conclusion Vaccination timing is not a significant factor for the immunogenicity of PCV13 in cancer patients undergoing adjuvant chemotherapy. Global protection against pneumococcal infection was sustained for > 5 years, and global response remained in over half of patients.

Subglottic stenosis (SGS) and tracheal stenosis (TS) are rare conditions that can cause significant breathing difficulties and, if not properly managed, may lead to life-threatening complications. Despite their clinical importance, debate continues regarding the optimal management of adult SGS and TS, and no comprehensive guidelines have been established to date. The Korean Bronchoesophagological Society appointed a task force to develop clinical practice guidelines with the goal of providing evidence-based recommendations for managing SGS and TS in adults. The task force conducted a systematic review of the relevant literature by searching PubMed, Embase, and the Cochrane Library using predefined search terms aligned with key clinical questions. The quality of evidence was assessed using the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) approach, which also informed the formulation and reporting of the recommendations. The strength of each recommendation reflects the guideline panel’s confidence that the benefits of an intervention outweigh its risks for eligible patients. After drafting the guidelines, feedback was obtained through Delphi questionnaires completed by members of the Korean Bronchoesophagological Society. Ultimately, the committee developed 17 evidence-based recommendations across four categories: initial evaluation, medical management, surgical treatment, and postoperative management and rehabilitation. These guidelines aim to support clinicians in delivering optimal care to adult patients with SGS and TS.

Background: Research on the relationship between the progression of interstitial lung abnormalities (ILA) and serum biomarkers, including white blood cell differential counts and Krebs von den Lungen-6 (KL-6), is limited. This study aimed to examine the clinical characteristics of patients with ILA and evaluate the association between disease progression and serum biomarkers. Methods: This retrospective cohort study analyzed data from 159 patients (63 with ILA and 74 with interstitial lung diseases) between October 2021 and September 2022. Data collected included clinical characteristics, pulmonary function tests, chest computed tomography (CT), complete blood cell counts, and KL-6 levels. In 52 of these patients who had previously undergone chest CT, the utility of serum biomarkers in reflecting radiologic progression was assessed using receiver operating characteristic curve analysis. Results: Patients with ILA exhibited clinical characteristics similar to those with idiopathic pulmonary fibrosis. Serum KL-6 levels did not correlate with forced vital capacity or diffusing capacity of the lung for carbon monoxide in patients with ILA. Among the 52 patients with ILA, 13 demonstrated radiologic progression. Serum KL-6 displayed moderate predictive performance, with area under the curves ranging from 0.57 to 0.89 (p=0.014) for radiologic progression. Levels of KL-6 greater than 400 U/mL were more frequently observed in patients with radiologic progression (61.5% vs. 20.5%, p=0.006). In multivariate analysis, age and KL-6 were independently associated with radiologic progression in patients with ILA. Conclusion Serum KL-6 levels may serve as a potential indicator of ILA progression in asymptomatic patients. Those with KL-6 levels exceeding 400 U/mL should be closely monitored for radiologic progression.

Background: This study investigated the prognostic value of bilaterality and multifocality in papillary thyroid carcinoma (PTC) recurrence, aiming to inform optimal surgical strategies. Methods: In this retrospective cohort, 1,966 patients who underwent total thyroidectomy for PTC (2011–2014) were categorized into four groups according to tumor multifocality and bilaterality confirmed by postoperative histopathology: group 1, unilateral solitary; group 2, unilateral multifocal; group 3, bilateral solitary; group 4, bilateral multifocal. Clinicopathologic features and clinical outcomes were compared across these groups. Results: Group 4 exhibited the highest prevalence of BRAFV600E positivity, nodal metastases, and recurrence. Both bilaterality and multifocality were associated with more aggressive clinicopathologic characteristics. Recurrence risk increased with the number of tumor foci, with the odds ratio (OR) significantly elevated for more than five foci. Satellite pattern was strongly linked to recurrence (OR, 19.49; P<0.001). While tumor multifocality (≥5 foci) and bilaterality were associated with recurrence in univariate analyses, these associations were not independent after adjustment. Kaplan-Meier analysis demonstrated the lowest recurrence-free survival (RFS) in group 4. Patients with bilateral disease had significantly lower RFS than those with unilateral disease (P=0.003), whereas multifocality did not significantly affect RFS compared to solitary disease (P=0.095). Conclusion Tumor bilaterality, multifocality (≥5 foci), and satellite pattern were associated with aggressive features and higher recurrence risk. Although not independent predictors, these factors may serve as useful surrogate markers of aggressive disease biology and help guide personalized surgical strategies in patients with PTC.

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.

Spinal cord infarction (SCI) is a rare but devastating complication of venoarterial extracorporeal membrane oxygenation (VA-ECMO). We report the case of a 62-year-old man who developed paraplegia with sensory deficits following VA-ECMO for septic shock. Magnetic resonance imaging demonstrated posterior spinal artery (PSA) infarction at the T11–T12 level. Electrodiagnostic studies revealed atypical findings, including absent sensory nerve action potentials and compound muscle action potentials, along with denervation of the lumbar paraspinal muscles. These abnormalities are not fully explained by PSA infarction alone and suggest the coexistence of central and peripheral mechanisms. This case illustrates a rare presentation of posterior SCI following VA-ECMO with atypical neurophysiological features and highlights the importance of multimodal evaluation for accurate diagnosis and rehabilitation planning.

Perineural (Nabors type II) cysts are typically located at the dorsal root ganglion (DRG) and are rarely reported in the cervical spine. When present, they are usually solitary and confined to the DRG level. We report a rare case of cervical perineural cysts occurring both at the DRG and proximal to the DRG within the same nerve root sleeve. A 53-year-old woman presented with intermittent left arm pain and numbness involving the left thumb, index finger, and thenar region, suggestive of C6 radiculopathy. Magnetic resonance imaging revealed a central-to-left C5-C6 disc herniation that mildly indented the ventral epidural space without significant compression of the C6 nerve root, as well as a central C6–C7 disc herniation that did not narrow the neural foramen or contact the C7 nerve root. Notably, a perineural cyst proximal to the DRG directly compressed the left C6 dorsal nerve root. Electrodiagnostic studies were normal. This case demonstrates that perineural cysts can occur proximal to the DRG and may contribute to radicular symptoms. Recognition of atypical cyst locations may improve diagnostic accuracy.

Neuropathic pain markedly impairs quality of life and imposes a substantial socioeconomic burden, while available treatments often provide only partial relief and are limited by safety concerns. The Neuropathic Pain Special Interest Group of the International Association for the Study of Pain (NeuPSIG-IASP) first published pharmacologic recommendations in 2007, followed by a major update in 2015 and a new guideline in 2025. This narrative review specifically compares the 2015 and 2025 NeuPSIG-IASP guidelines, outlining key methodological changes and therapeutic shifts. The 2025 guideline is based on a larger, more rigorous meta-analysis, maintains α2δ-ligands (adds mirogabalin), serotonin-noradrenaline reuptake inhibitors, and tricyclic antidepressants as first-line drugs, downgrades tramadol into the opioid third-line group. It also introduces high-frequency motor-cortex repetitive transcranial magnetic stimulation as a weakly recommended third-line option and discusses implications for Korean clinical practice.

Background: The Xpert MTB/RIF Ultra (Xpert Ultra) was introduced to enhance the sensitivity of tuberculosis detection, particularly in smear-negative cases, compared with its predecessor, Xpert MTB/RIF (Xpert). However, its performance in high-resource, intermediateburden settings remains unassessed. We prospectively compared the diagnostic accuracy of Xpert Ultra and Xpert for detecting Mycobacterium tuberculosis (MTB) and rifampin resistance in Korea. Methods: In total, 309 respiratory specimens were analyzed using both assays. We used two reference standards: mycobacterial culture and a composite reference standard based on clinical diagnosis and treatment decisions. Diagnostic performance, including sensitivity, specificity, and agreement between the two assays, was assessed. Spiking experiments using 13 MTB isolates with known rpoB mutations were performed to evaluate rifampin resistance detection. Results: Xpert Ultra showed increased, albeit not significantly, sensitivity (73.7% vs. 65.8% with culture; 63.8% vs. 53.2% with the composite reference standard) over Xpert. Its specificity was comparable to that of Xpert; however, a few false-positive results were observed among trace- and very low-positives. Among six culture-negative but Xpert Ultra-positive cases, two were clinically diagnosed as tuberculosis. Of the 13 rpoB mutant strains, Xpert correctly detected all mutations in the rifampin resistance-determining region, whereas Xpert Ultra yielded indeterminate results for Q432P and Q429H/L430P/H445Q. Conclusions Xpert Ultra tends to have increased sensitivity; however, it shows potential diagnostic ambiguity associated with trace- or very low-positive results. These findings highlight the importance of clinical correlation, particularly in culture-negative cases. Indeterminate results in certain rpoB mutations require cautious interpretation.