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.

Objective: To investigate the associations between T2-weighted imaging (T2WI) features and clinicopathologic characteristics in invasive breast cancer, as well as their relationship with treatment response to neoadjuvant chemotherapy (NAC). Materials and Methods: This retrospective study included 179 women with invasive breast cancer who underwent preoperative 3T breast MRI between November 2020 and February 2021. Intratumoral T2 signal intensity (SI) and peritumoral edema were graded on T2WI, and T2 relaxation times were calculated both including and excluding necrotic or cystic areas. T2 relaxation times were compared across T2 SI grades using the Kruskal–Wallis test. Associations between T2 features and clinicopathologic factors were assessed using chi-square tests and logistic regression analyses. In patients who received NAC (n = 68), associations between T2 features and NAC outcomes were also evaluated. Results: Higher intratumoral T2 SI and peritumoral edema grades were significantly associated with longer T2 relaxation times (P < 0.001). Intratumoral T2 SI grades were associated with higher clinical T category, axillary lymph node metastasis, and tumor multiplicity (all P < 0.05). Longer intratumoral T2 relaxation times were associated with higher clinical T category, hormone receptor (HR) negativity, and the triple-negative subtype (all P < 0.05), even after excluding necrotic or cystic areas.Higher peritumoral edema grades were associated with advanced clinical T category, HR negativity, and the triple-negative subtype (all P < 0.05). T2 relaxation times of peritumoral edema showed no significant associations, except with higher clinical T category (P = 0.005) and estrogen receptor status (P = 0.030). In the NAC subgroup, higher intratumoral T2 SI grades and longer T2 relaxation times were significantly associated with disease progression during NAC (P < 0.05), but not with non-pathologic complete response. Peritumoral edema showed no significant association with NAC outcomes (P > 0.05). Conclusion T2-weighted MRI features were associated with clinicopathologic factors, including clinical T category, HR status, triple-negative subtype, and disease progression during NAC.

Objective: To systematically evaluate the long-term trajectory of pulmonary function test (PFT) and CT findings in COVID-19 survivors. Materials and Methods: A systematic literature search of PubMed and EMBASE was performed to identify studies published from January 2020 to June 2024 reporting PFT and/or chest CT outcomes at ≥6 months post-COVID-19, up to 36 months. The reference lists of relevant articles were also manually reviewed. Two investigators independently extracted study characteristics, patient demographics, and PFT and CT outcomes at prespecified follow-up intervals (6, 12, 24, and 36 months). Multivariate meta-analyses were conducted to evaluate temporal trends in lung function and radiological abnormalities. Sensitivity analyses, including stratification by disease severity and pooled analyses of studies with multiple follow-up time points, were performed to confirm the robustness of the findings. Results: In total, 152 studies (n = 25,766; mean age, 56.7 ± 13.2 years; 14,999 men) were included: 133 reporting PFT outcomes and 80 reporting CT findings. Diffusion capacity (DLCO) impairment was the most common abnormality, showing gradual improvement from 42% at 6 months to 35% at 36 months (P = 0.008) with a corresponding increase in the % predicted DLCO. Similarly, the prevalence of forced vital capacity (FVC) impairment decreased over time, accompanied by an increase in the % predicted FVC. On chest CT, the proportion of patients with no relevant findings remained stable at 30%–40% (P = 0.14).The prevalence of ground-glass opacities (GGO) decreased from 32% at 6 months to 20% at 36 months (P = 0.01), while that of fibrosis persisted at 27%–47% without a significant change (P = 0.28). Subgroup analysis based on disease severity revealed similar temporal trends in both low-severity and high-severity cohorts. Conclusion DLCO, FVC, and GGO findings improved gradually up to 36 months post-COVID-19; however, over one-third of the patients continued to exhibit reduced DLCO. Fibrosis persists with limited evidence of resolution over a 3-year period, suggesting a stable but nonprogressive pattern.

Objective: To evaluate the performance of supplemental automated breast ultrasound (ABUS) added to mammography-based breast cancer screening for women with nondense breasts. Materials and Methods: A retrospective search of radiology databases at two tertiary institutions identified asymptomatic women with nondense breasts who underwent breast cancer screening using both digital mammography (DM) and supplemental ABUS between January 2020 and December 2023. We excluded women without sufficient follow-up data or those without an established final diagnosis, including histopathologic results. The performance measures of DM alone and ABUS combined with DM (ABUS plus DM) were compared. The primary outcome was the cancer detection rate (CDR), and the secondary outcomes were sensitivity and specificity. Subgroup analyses were performed for women with scattered fibroglandular density and almost entirely fatty breasts. Results: A total of 2,904 pairs of screening examinations were performed in 1,683 women (59 ± 10 years), detecting 26 cancers. In comparison with DM alone, ABUS plus DM showed higher CDR (9.0 vs. 7.9 per 1,000 examinations, P < 0.001), higher sensitivity (100% [26/26] vs. 88.5% [23/26], P < 0.001), and lower specificity (95.0% [2,735/2,878] vs. 97.9% [2,817/2,878], P < 0.001). In women with scattered fibroglandular density, ABUS increased the CDR from 7.4 to 8.5 per 1,000 examinations and improved the sensitivity from 87.0% [20/23] to 100% [23/23] (P < 0.001). In women with almost entirely fatty breasts, ABUS plus DM showed the same CDR (16.4 per 1,000 examinations) and sensitivity (100% [3/3]) as DM alone. Three cancers (11.5% [3/26]), all of which were stage T1N0, were detected only by supplemental ABUS. Conclusion Supplemental ABUS improved cancer detection and sensitivity in women with nondense breasts, with the benefits primarily observed in those with scattered fibroglandular density.

Background: Hair drying is a routine cosmetic practice; however, excessive heat exposure and non-uniform airflow can compromise cuticle integrity, degrade hair sensory properties, and induce scalp discomfort. This study aimed to (i) identify a practical thermal window that minimizes perturbation of hair fiber surface and quantify late-stage thermal amplification during the drying process using percentage-based analysis. Methods: Temperature-dependent hair fiber surface morphology was examined by scanning electron microscopy (SEM) after controlled exposure to 41°C, 60°C, 80°C, and 90°C using virgin and chemically damaged hair. The drying efficacy was assessed using the surface and internal moisture indices under airflow shaping (test) and uniform airflow (control) conditions. Hair fluttering (maximum angular displacement) was evaluated before and after drying under warm-cool alternating (60°C-80°C) versus constant hot airflow (80°C). Results: SEM revealed temperature-dependent cuticle disruption, with markedly greater surface perturbation at 90°C than at 80°C. Infrared thermography demonstrated pronounced late-stage thermal amplification: at 150 seconds, the surface temperature increased by 295% (from 24.2°C to 72.0°C) at 90°C, compared with 207% (from 24.2°C to 50.7°C) at 80°C. Airflow shaping promoted preferential surface moisture removal (–13.6%) while limiting internal dehydration (–9.4%), whereas the control condition exhibited minimal surface drying (–4.6%) but substantial internal moisture loss (–22.2%). Warm-cool modulation increased hair fluttering by +11.0%, whereas constant hot airflow reduced it (–3.7%). Conclusion These findings indicate that spatial and temporal control of heat delivery represents a clinically relevant design strategy beyond the nominal temperature specification in hair-drying devices.

Background: Rosacea is a chronic inflammatory disorder characterized by flushing, erythema, papules/pustules, and telangiectasia. Several clinical studies have investigated the efficacy of botulinum neurotoxin A (BoNT/A) in the treatment of rosacea, but its mechanism of action remains unclear. Objective: This study aims to examine the potential role of BoNT/A in a mouse model of rosacea-like skin lesions induced by the 37-amino acid C-terminal cathelicidin peptide (LL-37). Methods: Mice were randomly divided into 4 groups: Control, LL-37, LL-37 + BoNT/A, and LL-37 + dexamethasone. Results: BoNT/A treatment alleviated skin damage, reduced skin thickness, and decreased mast cell infiltration. Furthermore, BoNT/A improved redness score severity and redness area while enhancing skin barrier function by suppressing transepidermal water loss and increasing skin hydration. At the molecular level, BoNT/A decreased the mRNA levels of interleukin (IL)-6 and tumor necrosis factor-α, which are known as pro-inflammatory cytokines. It also downregulated the expression of pyrin domain-containing protein 3, caspase-1, and IL-1 beta in the LL-37-injected dorsal skin. Furthermore, BoNT/A prevented LL-37-mediated upregulation of neurovascular-associated factors, including CD31, transient receptor potential vanilloid 1, calcitonin-related polypeptide alpha, vascular endothelial growth factor, chymase 1, and tryptase alpha/beta 1. Conclusion These results indicate that BoNT/A effectively alleviates inflammatory and vascular responses in a rosacea mouse model, highlighting its potential as a promising preventive approach for rosacea.

Purpose: Neoadjuvant treatment (NAT) is now the standard for borderline resectable pancreatic cancer (RPC) and is being considered for RPC. Early recurrence after curative surgery in RPC is often seen as a treatment failure, prompting considerations for NAT. Our goal was to develop an artificial intelligence (AI)-based predictive model utilizing preoperatively available factors to forecast early recurrences of resected RPC. Methods: This study included 469 patients who underwent surgery for RPC between 2011 and 2019. Clinicopathologic and oncologic data were retrospectively reviewed. Preoperative variables, including laboratory data and imaging findings, were collected. Early recurrence was defined as recurrence occurring within a year after surgery. Deep neural networks were then used to select variables by assessing their importance. A new model predicting early recurrence of RPC was subsequently developed. Results: Of the patients evaluated, 199 (42.4%) experienced early recurrence. The predictive model included 14 preoperative variables: CA 19-9, preoperative pancreatitis, serum albumin, platelet count, lymphocyte count, the American Society of Anesthesiologists physical status classification, tumor size, monocyte count, age, body mass index, CRP, hemoglobin, WBC count, and CEA. The area under the curve for the model was 0.786 in the training set and 0.734 in the test set. Conclusion We developed an AI-based model to predict the early recurrence of RPC using preoperative parameters. By identifying patients at risk of early recurrence, optimal individualized treatments such as NAT can be considered. Future prospective studies are crucial to establish clear indications for NAT in RPC.

Purpose: Postoperative complications following gastric cancer surgery significantly impact patient outcomes, yet standardized definitions for these events have not been consistently applied across institutions in Korea. This study aimed to develop a consensus-based, standardized complication classification system specific to gastrectomy for gastric cancer as part of the Korean Quality Improvement Platform in Surgery (K-QIPS) initiative. Methods: As part of K-QIPS, a dedicated task force team (TFT) was formed with surgical experts from fourteen high-volume hospitals across Korea. The TFT conducted ten formal meetings to review existing literature and international guidelines, and incorporated findings from randomized controlled trials. The final complication list was developed through expert consensus and structured into a standardized framework. A Data Entry Manual was created to support consistent data collection by surgical clinical reviewers. Results: The TFT defined specific postoperative complications following gastrectomy for gastric cancer, including anastomotic leakage, duodenal stump leakage, pancreatic fistula, intra-abdominal and luminal bleeding, delayed gastric emptying, and internal hernia. Notably, internal hernia was described in standardized form for the first time. General complications were developed first and overlapped in part with the gastric cancer-specific list. The task force also produced a Data Entry Manual that provides practical instructions to ensure consistency and accuracy in complication reporting. Conclusion This nationwide consensus initiative established the first standardized complication classification system for gastric cancer surgery in Korea. The proposed definitions and data entry system are expected to improve complication reporting, enable multicenter research, support surgical quality benchmarking, and ultimately enhance patient outcomes.

Recurrent scalp compromise following deep brain stimulation (DBS) implantation remains a challenging reconstructive problem, particularly in patients with chronic infection and repeated revision procedures. We present an acellular dermal matrix (ADM)-assisted salvage strategy using rotational scalp flap coverage with adjunctive calvarial recession for preservation of exposed DBS hardware. After debridement and subperiosteal flap elevation, ADM was applied over the exposed hardware as a biologic reinforcement layer prior to tension-free closure. Adjunctive calvarial recession was performed to reduce hardware prominence. Postoperative computed tomography demonstrated decreased hardware projection, and stable wound healing without recurrent dehiscence or infection was maintained during follow-up. This combined approach may represent an effective salvage option for recurrent DBS scalp compromise while preserving functional neuromodulation hardware.