Purpose: Although gastric cancer (GC) exhibits significant genomic heterogeneity, the clinical implications of its immune microenvironment remain poorly understood. Materials and Methods: We retrospectively evaluated patients with GC who underwent gastrectomies between 2011 and 2014. The tumors were analyzed for Epstein–Barr virus (EBV), microsatellite instability-high (MSI-H), tumor-infiltrating lymphocytes (CD3), tumor-associated macrophages (CD68 and CD163), and programmed death-ligand 1 (PD-L1) expression. Tumors were classified using the modified The Cancer Genome Atlas scheme, and their clinical characteristics were compared. Results: A total of 567 patients were classified into EBV (6%), MSI-H (10%), chromosomal instability-like (36%), and genomically stable-like (48%) subtypes. EBV tumors exhibited the highest PD-L1 expression (85%) and immune infiltration by CD3+ T cells (86%), CD68+ macrophages (58%), and CD163+ macrophages (40%). High CD68+ macrophage tumors were associated with advanced stages and worse 5-year disease-free survival (83% vs. 95%; P<0.001);however, this association was not independently significant after adjusting for the tumor-nodemetastasis stage. PD-L1 expression did not significantly affect the survival outcomes. Conclusions GC subtypes have distinct immune microenvironments that influence prognosis. Our findings highlight the prognostic and therapeutic potential of immune profiling in GC.

Purpose: This study aimed to develop and evaluate the effectiveness of the Trauma-nursing Education and Skill Support (TESS) program based on the ADDIE model (Analysis, Design, Development, Implementation, Evaluation model). The program was designed to enhance trauma nurses’ clinical competencies, including trauma-related knowledge, self-efficacy, and problem-solving ability, through the integration of theoretical education and simulation-based practice. Methods: A quasi-experimental study using a non-equivalent control group pretest–posttest design was conducted. Participants included 108 trauma nurses from regional trauma centers, military trauma centers, and emergency care facilities, who were assigned to an experimental group (n=52) or a control group (n=56). The TESS program consisted of a 2-day, 14-hour blended-learning course that included eight lecture sessions and four simulation-based practice stations. Data were collected at baseline, immediately after the intervention, and at 6 months using validated instruments measuring trauma-related knowledge, self-efficacy, and problem-solving ability. Two-way repeated-measures analysis of variance was used for data analysis. Results: The experimental group demonstrated significant improvements in trauma-related knowledge, self-efficacy, and problem-solving ability compared with baseline (all p<.001). These improvements were sustained at 6 months, although trauma-related knowledge scores showed a slight decline compared with immediate posttest levels. Between-group analyses confirmed significant group-by-time interaction effects for all outcomes: trauma-related knowledge (η2=0.12, p<.001), self-efficacy (η2=0.09, p=.002), and problem-solving ability (η2=0.08, p=.003). Conclusion The TESS program effectively enhanced trauma nurses’ trauma-related knowledge, self-efficacy, and problem-solving ability, with effects sustained for up to 6 months. Incorporating blended learning and simulation-based training into standardized trauma nursing education may strengthen clinical competencies and ultimately contribute to improved patient outcomes.

The surgical options for arthritis of the first metatarsophalangeal (MTP) joint include cheilectomy, interpositional arthroplasty, and arthrodesis. Arthrodesis provides reliable pain relief but sacrifices joint motion. Therefore, motion-preserving interpositional arthroplasty is preferred for selected active patients. This paper reports a case and early outcomes of interpositional arthroplasty of the first MTP joint using a collagen patch allograft circumferentially wrapped around the metatarsal head, secured with symmetric 1.6-mm mini suture anchors, and protected by temporary transarticular K-wire fixation. At 6 weeks, the pain decreased (VAS 8→3), and the active dorsiflexion/ plantarflexion improved to approximately 45°/45°, without wound complications or radiographic loosening. The collagen patch allograft provided uniform coverage and mechanical stability while avoiding donor-site morbidity associated with autografts. This technique is a reproducible, motion-preserving alternative for patients seeking to maintain joint mobility. Nevertheless, longer-term studies will be required to evaluate the durability and comparative outcomes.

In patients with ossification of the posterior longitudinal ligament (OPLL), the risk of incidental durotomy (ID) during anterior cervical spine surgery is relatively high. However, the anterior surgical approach is technically demanding because of limited visualization and restricted operative space, which makes direct dural repair difficult. As a result, indirect repair techniques are typically employed, but these approaches can pose significant postoperative management challenges, particularly in cases of symptomatic cerebrospinal fluid (CSF) leakage. A 68-year-old male patient presented with right-sided symptoms involving both the upper and lower extremities. Radiological evaluation revealed C3–4–5 anterolisthesis, OPLL at the C4–5 level, and bilateral foraminal stenosis at C3–4 and C4–5. During anterior cervical discectomy and fusion (ACDF), an ID occurred at the anterior aspect of the C4–5 segment and was managed with primary indirect repair. Approximately 2 weeks postoperatively, the patient developed symptomatic CSF leakage. Under fluoroscopic guidance, a needle was precisely positioned adjacent to the interbody cage at the anterior aspect of the C4–5 segment—the site of the durotomy—to administer a targeted anterior epidural blood patch (EBP). The procedure was completed successfully without complications and resulted in effective resolution of the CSF leak. ID at the anterior aspect of the spinal canal during ACDF may lead to persistent symptoms due to CSF leakage. In such cases, a minimally invasive strategy, such as a targeted anterior EBP performed under fluoroscopic guidance, may represent an effective alternative to surgical re-exploration for symptom resolution.

Objective: Thoracic pedicle screw fixation is technically demanding because of the natural variability in pedicle anatomy, a challenge that is further exacerbated in patients with spinal tumors who often have compromised pedicles. The L-point entry, juxtapedicular, and endplate-parallel trajectory (L-JET) technique was developed to provide a uniform entry point, a predictable screw trajectory, and the capacity to accommodate larger-diameter screws at levels T3–10. This study aimed to evaluate the safety and feasibility of the L-JET technique in comparison with the conventional transpedicular method. Methods: A comparative analysis of consecutively collected data was performed to evaluate outcomes associated with the L-JET technique in patients undergoing surgery for thoracic extradural spinal tumors. The L-point was defined as the intersection of a vertical line along the lateral margin of the facet joint and a horizontal line along the upper edge of the transverse process. The screw trajectory was planned with 30° of medial convergence in the axial plane, creating a juxtapedicular path, and a straightforward trajectory in the sagittal plane. Primary outcome measures included screw diameter, screw length, cortical breach rate, and the need for revision surgery, as assessed using computed tomography scans and medical records. Results: A total of 108 screws were placed in 22 patients using the L-JET technique, while 98 screws were placed in 18 patients using the conventional technique. The L-JET group used significantly larger-diameter screws (6.06±0.65 mm) than the conventional group (5.74±0.80 mm, p=0.02), with no significant difference observed in screw length between groups. Medial cortical breach occurred in one screw in each group, and no supra- or infrapedicular breaches were identified. No screw-related neurovascular complications or revision surgeries occurred in either group. Conclusion The L-JET technique enables consistent screw placement with larger-diameter screws, even in compromised pedicles associated with thoracic spinal tumors, without increasing the risk of complications or the need for revision surgery.

Transforaminal endoscopic lumbar foraminotomy (TELF) is widely performed as a full-endoscopic surgical procedure for the treatment of lumbar foraminal stenosis. The technique involves the use of a small-caliber endoscopic system introduced through Kambin triangle to accomplish the primary surgical steps. However, anatomical barriers are frequently encountered in the lower lumbar segments, particularly at L4–5 and L5–S1, which may limit the feasibility of the transforaminal approach. Although various advanced transforaminal techniques have been developed to overcome these anatomical barriers, these techniques often make the procedure more technically demanding and may prolong operative time. In this video presentation, we report 2 cases in which a full-endoscopic paraspinal lumbar foraminotomy was performed to achieve adequate decompression of the exiting nerve root (ENR) without being constrained by these anatomical limitations. We also outline the procedural details and technical characteristics of this approach. Both patients presented with lumbar foraminal stenosis at the L5–S1 level, where anatomical barriers such as a high iliac crest, large transverse process, and sacral ala were present. A full-endoscopic paraspinal foraminotomy was performed at this level using a large-caliber endoscopic system, allowing sufficient decompression of the ENR and resulting in marked relief of radicular leg pain. We report a surgical procedure for full-endoscopic paraspinal lumbar foraminotomy using a large-caliber endoscopic system that permits the use of instruments of various sizes and configurations. When applied in appropriate clinical scenarios, this technique may facilitate more convenient and expedited decompression of the ENR.

The recent approval of trastuzumab deruxtecan for human epidermal growth factor receptor 2 (HER2)–low and HER2-ultralow breast cancer mandates an adequate assessment of these categories. Methods: Seven breast pathologists from the Breast Pathology Study Group of the Korean Society of Pathologists held an on-site expert consensus meeting. Fifteen sets of virtual whole slide images (WSI) of hematoxylin and eosin stain and HER2 immunohistochemistry were provided. The pathologists were given 60 minutes to submit their diagnosis of HER2 expression into null, ultralow, 1+, 2+, or 3+. Afterwards, in-depth discussion and consensus diagnoses were made by real-time visualization of the WSI. Results: After the consensus meeting, unanimous 100% agreements were seen only in five (33.3%) of the examined cases, which consisted of three 1+ cases and two 2+ cases. Two cases (13.3%) had mild disagreement, with only one pathologist’s disagreement. Of note, eight cases (53.3%) showed significant disagreement, defined by more than two pathologists’ disagreement. All HER2-null cases were reclassified as ultralow after consensus review, suggesting potential widespread underclassification of ultralow cases in clinical practice. Conclusions: Experts had significant discrepancies in interpreting HER2-low/ultralow status. It is important to assess if the distinction between HER2-low and ultralow is strictly required and if HER2-null breast cancer exists in reality.

Purpose: To investigate the clinical characteristics, onset timing, and anatomical and functional outcomes of MEK inhibitor–associated retinopathy (MEKAR) in Korean patients receiving systemic MEK inhibitor therapy. Methods: This retrospective study included 16 patients diagnosed with MEKAR between January 2011 and August 2025. Best-corrected visual acuity (BCVA), central macular thickness (CMT), subfoveal choroidal thickness (CT), and optical coherence tomography (OCT) findings were evaluated at baseline, at MEKAR onset, and at final follow-up. Results: Mean age was 57.8 ± 10.6 years, with a male predominance (68.8%). Colorectal cancer was the most common primary malignancy (56.3%), followed by lung cancer and malignant melanoma (18.7% each). MEKAR developed after a median of 3.3 weeks (IQR, 1.9–4.4 weeks) following therapy initiation, and the median time to initial improvement was 2.4 weeks (IQR, 1.3–8.1 weeks). At onset, 62.6% of patients reported ocular symptoms, while 37.4% were asymptomatic. OCT showed reversible retinal changes, most commonly ellipsoid zone thickening (68.8%) and focal subretinal fluid (43.8%), all of which resolved completely. CMT increased transiently at onset compared with baseline (p = 0.002) and normalized at final follow-up (p < 0.001), with no baseline–final difference (p = 0.489). CT remained stable (p = 0.159). BCVA was preserved, with a median of 0.00 logMAR at baseline, onset and final follow-up. Patients undergoing dose modification or interruption showed faster improvement than those continuing therapy (median, 9 vs. 81 days; p = 0.004). One patient showed multiple recurrent episodes, all of which resolved without visual deterioration. Conclusions MEKAR developed early after treatment initiation and followed a transient, fully reversible course with preserved visual function. Although dose modification accelerated anatomical recovery, long-term outcomes remained favorable even with continued therapy, supporting close monitoring and individualized management rather than routine interruption, particularly in mild or asymptomatic cases.

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.