Acute lymphoblastic leukemia (ALL) primarily affects the bone marrow and peripheral blood. Extramedullary manifestations, especially in the sinonasal cavity, are rare and difficult to diagnose. We report a case of B-cell ALL in a 4-year-old girl who initially presented with a sinonasal mass mimicking a primary malignant neoplasm. The patient developed right eye protrusion upon nasal blowing over a period of 2 weeks. Imaging studies revealed an aggressive-appearing mass in the right maxillary sinus with extensive local invasion. The radiologic differential diagnosis included rhabdomyosarcoma, lymphoma, and other pediatric sinonasal malignancies. Histopathologic examination of the biopsy specimen and subsequent bone marrow evaluation established the diagnosis of B-cell ALL with BCR/ABL1 fusion. This case highlights the importance of including ALL in the differential diagnosis of sinonasal masses in pediatric patients, particularly when imaging features suggest an aggressive malignancy accompanied by hematologic abnormalities. A comprehensive evaluation, including imaging studies, routine laboratory tests, tissue biopsy, and bone marrow examination, is crucial for establishing an accurate diagnosis and initiating appropriate treatment.

Purpose: Processing methods for hematopoietic stem cells vary significantly across institutions, with no standardized guidelines currently in place. This lack of standardization presents challenges in ensuring consistent quality and out‑ comes of stem cell transplantation procedures. This study investigated current practices in peripheral blood stem cell (PBSC) processing and storage among transplant centers in Korea to establish a foundation for the development of standardized guidelines. Methods: A comprehensive questionnaire was distributed to 46 hematopoietic stem cell transplantation centers in Korea, examining five key areas: PBSC collection procedures, use of cryopreservatives, cryopreservation protocols, quality control measures, and thawing protocols. Results: Analysis of the 29 responses revealed significant variations across different stages of PBSC handling. All centers used controlled-rate freezers, and 92.9% stored cells at temperatures below -150 ◦ C . However, other prac‑ tices varied widely. Additional post-collection processing was performed by 53.8% of respondents. DMSO concen‑ trations ranged from 5 to 15%, with diverse combinations of supplementary media. Notably, 28.6% of patients did not undergo post-thaw quality assessment tests. Conclusion This study identified significant heterogeneity in PBSC processing practices across Korean transplant centers. These findings underscore the need for evidence-based standardized guidelines to ensure consistent product quality and improve transplantation outcomes.

Multiple myeloma (MM), a hematological malignancy, is characterized by malignant plasma cell proliferation in the bone marrow. Recent treatment advances have significantly improved patient outcomes associated with MM.In this study, we aimed to develop comprehensive, evidence-based guidelines for the diagnosis, prognosis, and treat‑ ment of MM. We identified 12 key clinical questions essential for MM management, guiding the extensive literature review and meta-analysis of the study. Our guidelines provide evidence-based recommendations by integrating patient preferences with survey data. These recommendations include current and emerging diagnostic tools, thera‑ peutic agents, and treatment strategies. By prioritizing a patient-centered approach and rigorous data analysis, these guidelines were developed to enhance MM management, both in Korea and globally.

Background: The aims of this study are to examine how occupation-related data and information for health (ODH) are collected and managed from census-based surveys and potential occupational illness and injuries (POIS) statistics, and to propose a national strategy for the systematic collection, analysis, and management of ODH by building on the Korean Standard Classification of Occupation (KSCO) and using a job exposure matrix (JEM). Methods: The status of the collection and management of ODH registered as national statistics, drawn not only from the census-based general population and workforce, but also from POIS statistics was reviewed and evaluated. Results: ODH from the Republic of Korea's Census of Population and Labor Force are collected and classified according to the KSCO. In contrast, national statistics on POIS are not systematically collected for KSCO coding, reflecting the lack of an KSCO and related guidelines on how to collect ODH. Key frameworks for the construction of both an KSCO and a reference JEM for public health surveillance are proposed. Conclusions Further research is needed to develop a national system for collecting and managing ODH, which will ultimately contribute to the use of a national KSCO and the construction of JEM for public health surveillance.

Allergen immunotherapy (AIT) has been used for over a century and has been demonstrated to be effective in treating patients with various allergic diseases. AIT allergens can be administered through various routes, including subcutaneous, sublingual, intralymphatic, oral, or epicutaneous routes. Sublingual immunotherapy (SLIT) has recently gained clinical interest, and it is considered an alternative treatment for allergic rhinitis (AR) and asthma. This review provides an overview of the current evidence-based studies that address the use of SLIT for treating AR, including (1) mechanisms of action, (2) appropriate patient selection for SLIT, (3) the current available SLIT products in Korea, and (4) updated information on its efficacy and safety. Finally, this guideline aims to provide the clinician with practical considerations for SLIT.

Allergen immunotherapy (AIT) is a causative treatment of allergic diseases in which allergen extracts are regularly administered in a gradually escalated doses, leading to immune tolerance and consequent alleviation of allergic diseases. The need for uniform practice guidelines in AIT is continuously growing as the number of potential candidates for AIT increases and new therapeutic approaches are tried. This updated version of the Korean Academy of Asthma Allergy and Clinical Immunology recommendations for AIT, published in 2010, proposes an expert opinion by specialists in allergy, pediatrics, and otorhinolaryngology. This guideline deals with the basic knowledge of AIT, including mechanisms, clinical efficacy, allergen standardization, important allergens in Korea, and special consideration in pediatrics. The article also covers the methodological aspects of AIT, including patient selection, allergen selection, schedule and doses, follow-up care, efficacy measurements, and management of adverse reactions. Although this guideline suggests the optimal dosing schedule, an individualized approach and modifications are recommended considering the situation for each patient and clinic.

Purpose: We used arterial spin labeling (ASL) perfusion magnetic resonance (MR) imaging to evaluate cerebral perfusion abnormalities in patients with seizures within 24 hours of symptom onset. Materials and Methods: A retrospective search of our institutional database identified 27 patients who had undergone ASL perfusion studies for seizures or seizure-like symptoms.The inclusion criteria were as follows: 1) history of seizure, 2) MR examination performed within 24 hour of seizure onset, and 3) localized perfusion abnormality on ASL. We evaluated the presence, location, and extent of perfusion abnormalities on ASL and signal abnormalities on fluid-attenuated inversion recovery (FLAIR), diffusion-weighted image (DWI), and susceptibility-weighted image (SWI), respectively. All pathological MR findings, accompanying focal neurological symptoms, and electroencephalogram (EEG) findings were compared. Results: The mean time from symptom onset to MR examination was 5 h 54 min. All patients (n = 27) showed localized increased perfusion on ASL perfusion imaging. On FLAIR imaging, 20 patients (74.1%) showed hyperintensity in the area of perfusion abnormality.In 19 patients (70.4%), DWI showed hyperintensity of the lesion with decreased apparent diffusion coefficient value (ADC). Seven patients (25.9%) showed a focal parenchymal area of pseudo-narrowed cortical veins on SWI, associated with focal hyperperfusion. In 20 patients (74.1%), the extent of perfusion abnormalities on ASL was greater than that of signal abnormalities on FLAIR or DWI. In 14/16 patients (87.5%) with abnormal EEG findings, the area with EEG findings and the location of the hyperperfusion abnormality on ASL corresponded. Conclusion In patients with seizures within 24 hours of symptom onset, ASL perfusion imaging revealed localized hyperperfusion, which was more frequent than signal intensity abnormalities on FLAIR or DWI. The locations of hyperperfusion areas correlated with EEG abnormalities. Thus, the ASL sequence may be a useful clinical assessment protocol for evaluating patients with seizures.

Continuous renal replacement therapy (CRRT) has become the standard modality of renal replacement therapy (RRT) in critically ill patients. However, consensus is lacking regarding the criteria for discontinuing CRRT. Here we validated the usefulness of the prediction model for successful discontinuation of CRRT in a multicenter retrospective cohort. Methods: One temporal cohort and four external cohorts included 1,517 patients with acute kidney injury who underwent CRRT for >2 days from 2018 to 2020. The model was composed of four variables: urine output, blood urea nitrogen, serum potassium, and mean arterial pressure. Successful discontinuation of CRRT was defined as the absence of an RRT requirement for 7 days thereafter. Results: The area under the receiver operating characteristic curve (AUROC) was 0.74 (95% confidence interval, 0.71–0.76). The probabilities of successful discontinuation were approximately 17%, 35%, and 70% in the low-score, intermediate-score, and highscore groups, respectively. The model performance was good in four cohorts (AUROC, 0.73–0.75) but poor in one cohort (AUROC, 0.56). In one cohort with poor performance, attending physicians primarily controlled CRRT prescription and discontinuation, while in the other four cohorts, nephrologists determined all important steps in CRRT operation, including screening for CRRT discontinuation. Conclusion: The overall performance of our prediction model using four simple variables for successful discontinuation of CRRT was good, except for one cohort where nephrologists did not actively engage in CRRT operation. These results suggest the need for active engagement of nephrologists and protocolized management for CRRT discontinuation.

Whether advanced age is associated with poor outcomes of elderly patients with acute kidney injury (AKI) requiring continuous renal replacement therapy (CRRT) is controversial. This study aimed to evaluate age effect and predictors for mortality in elderly AKI patients undergoing CRRT. Methods: Data of 480 elderly AKI patients who underwent CRRT were retrospectively analyzed. Subjects were stratified into two groups according to age: younger-old (age, 65–74 years; n = 205) and older-old (age, ≥75 years; n = 275). Predictors for 28-day and 90-day mortality and age effects were analyzed using multivariable Cox regression analysis and propensity score matching. Results: Urine output at the start of CRRT (adjusted hazard ratio [aHR], 0.99; 95% confidence interval [CI], 0.99–1.00; p = 0.04), operation (aHR, 0.53; 95% CI, 0.30–0.93; p = 0.03), and use of an intra-aortic balloon pump (aHR, 3.60; 95% CI, 1.18–10.96; p = 0.02) were predictors for 28-day mortality. Ischemic heart disease (aHR, 1.74; 95% CI, 1.02–2.98; p = 0.04) and use of a ventilator (aHR, 0.56; 95% CI, 0.36–0.89; p = 0.01) were predictors for 90-day mortality. The older-old group did not exhibit a higher risk for 28- day or 90-day mortality than the younger-old group in multivariable or propensity score-matched models. Conclusion: Advanced age was not a risk factor for mortality among elderly AKI patients undergoing CRRT, suggesting that advanced age should not be considered for therapeutic decisions in critically ill elderly patients with AKI requiring CRRT.

Background: This study focuses on assessing occupational risk for the health hazards encountered during maintenance works (MW) in semiconductor fabrication (FAB) facilities. Objectives: The objectives of this study include: 1) identifying the primary health hazards during MW in semiconductor FAB facilities; 2) reviewing the methods used in evaluating the likelihood and severity of health hazards through occupational health risk assessment (OHRA); and 3) suggesting variables for the categorization of likelihood of exposures to health hazards and the severity of health effects associated with MW in FAB facilities. Methods: A literature review was undertaken on OHRA methodology and health hazards resulting from MW in FAB facilities. Based on this review, approaches for categorizing the exposure to health hazards and the severity of health effects related to MW were recommended. Results: Maintenance workers in FAB facilities face exposure to hazards such as debris, machinery entanglement, and airborne particles laden with various chemical components. The level of engineering and administrative control measures is suggested to assess the likelihood of simultaneous chemical and dust exposure. Qualitative key factors for mixed exposure estimation during MW include the presence of safe operational protocols, the use of air-jet machines, the presence and effectiveness of local exhaust ventilation system, chamber post-purge and cooling, and proper respirator use. Using the risk (R) and hazard (H) codes of the Globally Harmonized System alongside carcinogenic, mutagenic, or reprotoxic classifications aid in categorizing health effect severity for OHRA. Conclusion Further research is needed to apply our proposed variables in OHRA for MW in FAB facilities and subsequently validate the findings.