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.

This case describes a male with a history of type 1 autoimmune pancreatitis (AIP) who had a concomitant branch-duct intraductal papillary mucinous neoplasm under long-term surveillance. During follow-up, new high-risk radiologic features developed within the pancreatic cyst, raising concern for malignant transformation and ultimately leading to surgical resection. However, final histopathologic examination revealed recurrent type 1 AIP rather than malignant progression of branch-duct intraductal papillary mucinous neoplasm, a finding that represents an uncommon and diagnostically challenging manifestation. This case suggests that when new imaging changes are observed during surveillance of pancreatic cystic lesions, clinicians should consider not only malignant transformation but also the possibility of recurrence or coexistence of underlying diseases such as AIP.

Objective: : This study investigated the relationship between arterial partial pressure of oxygen (PaO2) levels in the first 24 hours of intensive care unit (ICU) admission and clinical outcomes in neurocritically ill brain tumor patients. Methods: : In this single-center retrospective study of 2123 brain tumor patients, we analyzed PaO2 levels from arterial blood gas samples within 24 hours of ICU admission. The primary endpoint was 28-day mortality. Analysis utilized multivariable logistic regression and inverse probability of treatment weighting (IPTW). Results: : PaO2 exceeding 91.5 mmHg was defined as hyperoxia. The non-hyperoxia group showed higher 28-day mortality than the hyperoxia group (15.5% vs. 6.0%, p<0.002), a trend that persisted after IPTW adjustment (10.7% vs. 6.6%, p=0.019). In IPTW-adjusted regression, non-hyperoxia remained significant (adjusted odds ratio [OR], 3.24; 95% confidence interval [CI], 1.82–5.77). Survival analysis demonstrated significantly higher survival rates in the hyperoxia group (p<0.001). Subgroup analysis revealed significant heterogeneity across tumor types (p for interaction <0.001), with protective effects observed in malignant brain tumors (adjusted OR, 3.5; 95% CI, 1.88– 6.51) and brain metastases (adjusted OR, 3.86; 95% CI, 2.31–6.44), but not in benign tumors (adjusted OR, 1.14; 95% CI, 0.22–5.87). Conclusion : Elevated PaO2 levels within the first 24 hours of ICU admission were associated with decreased mortality rates, suggesting oxygenation as a potential therapeutic target in brain tumor patients. The protective effects were most pronounced in patients with malignant brain tumors and brain metastases, supporting a tumor type-specific approach to oxygenation management.

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.

Composite gangliocytomaeuroma and neuroendocrine tumors (CoGNETs) are extremely rare periampullary neoplasms composed of neuroendocrine epithelial, Schwannian spindle, and ganglion cells. Although endoscopic papillectomy or surgery have been used to treat ampullary CoGNETs, underwater endoscopic mucosal resection (UEMR) for periampullary lesions has not been previously described. In this study, we present a case of a 53-year-old man referred to our hospital with an incidentally detected subepithelial tumor in the second portion of the duodenum. Endoscopic ultrasound revealed a 13×10-mm homogeneous, hypoechoic, and well-demarcated submucosal mass. UEMR was performed under conscious sedation without submucosal injection, achieving safe en bloc resection within 12 min. Histopathology revealed a 2.0×1.5×1.2-cm lesion composed of mixed neuroendocrine epithelial, Schwannian spindle, and ganglion cells. Immunohistochemical staining was positive for chromogranin A, synaptophysin, CD56, neuron-specific enolase, and S-100, confirming CoGNET with a Ki-67 index of <1% and no lymphovascular or perineural invasion. Follow-up endoscopy 3 months later revealed only a post-resection scar without residual or recurrent tumors. This appears to be the first reported case of periampullary CoGNET successfully treated with UEMR. Therefore, UEMR might represent a safe and effective therapeutic option for selected periampullary subepithelial tumors.

It is difficult to determine a cause of bile duct stricture and dilatation. Eosinophilic cholangitis, a rare benign condition, may be one cause of bile duct stricture and dilatation. It can be evaluated using various methods of histopathology, radiographs, endoscopy, and hematologic findings. Treatment generally involves steroid therapy which can lead to improvement. This case report will discuss eosinophilic cholangitis, emphasizing that while it can easily be overlooked but should be considered in differential diagnoses.

Background and Objectives: Pediatric chronic rhinosinusitis (CRS) significantly affects children’s quality of life and learning abilities. This study aimed to evaluate the postoperative outcomes in pediatric patients who underwent functional endoscopic sinus surgery (FESS) for CRS. Methods: A retrospective review was conducted on pediatric patients who underwent FESS for CRS at 11 university hospitals. The inclusion criteria were patients under 20 years old with bilateral disease who were operated on between January 2005 and December 2021. The data collected included demographics, clinical history, blood tests, preoperative computed tomography, and preoperative and postoperative symptom control. The Kruskal-Wallis and Fisher exact tests were used to compare the quantitative and qualitative data, respectively. Results: In total, 213 patients were enrolled. The mean age was 13.4±3.0 years, and 145 (68.1%) were male. One hundred sixty-four patients (77.0%) had nasal polyps and 33 patients (15.5%) underwent revision FESS. The preoperative symptoms, in order of prevalence, included nasal obstruction (87.8%), rhinorrhea (71.8%), a sense of postnasal drip (58.2%), hyposmia (44.6%), cough (24.4%), and facial fullness (18.3%). These symptoms were significantly alleviated for up to 3 years after surgery (p<0.001). At the time of the last follow-up, 121 patients (56.8%) were controlled, 80 (37.6%) were partly controlled, and 12 (5.6%) were uncontrolled. Patients in the uncontrolled group had higher Lund-Mackay scores, longer follow-up durations, and more instances of revision surgery compared to those in the controlled and partly controlled groups. When age was categorized into three groups, those aged 16 years or older tended to have lower Lund-Mackay scores and better control. Conclusion FESS significantly improves both the postoperative symptoms and the long-term quality of life in pediatric CRS patients. Better symptom control is associated with older age and a lower disease burden.

Background: and Purpose: Plasma biomarkers, including phosphorylated tau (ptau217), glial fibrillary acidic protein (GFAP), and neurofilament light chain (NfL), are promising tools for detecting Alzheimer’s disease (AD) pathology. However, cross-laboratory reproducibility remains a challenge, even when using identical analytical platforms such as single-molecule array (Simoa). This study aimed to compare plasma biomarker measurements (ptau217, GFAP, and NfL) between 2 laboratories, the University of Gothenburg (UGOT) and DNAlink, and evaluate their associations with amyloid positron emission tomography (PET) imaging. Methods: Plasma biomarkers were measured using Simoa platforms at both laboratories:the UGOT and DNAlink Incorporation. Diagnostic performance for predicting amyloid PET positivity, cross-laboratory agreement, and the impact of normalization techniques were assessed. Bland-Altman plots and correlation analyses were employed to evaluate agreement and variability. Results: Plasma ptau217 concentrations exhibited strong correlations with amyloid PET global centiloid values, with comparable diagnostic performance between laboratories (area under the curve=0.94 for UGOT and 0.95 for DNAlink). Cross-laboratory agreement for ptau217 was excellent (r=0.96), improving further after natural log transformation. GFAP and NfL also demonstrated moderate to strong correlations (r=0.86 for GFAP and r=0.99 for NfL), with normalization reducing variability. Conclusions Plasma biomarker measurements were consistent across laboratories using identical Simoa platforms, with strong diagnostic performance and improved agreement after normalization. These findings support the scalability of plasma biomarkers for multicenter studies and underscore their potential for standardized applications in AD research and clinical practice.