Secondary rhabdoid tumors (RTs) with atypical teratoid/rhabdoid tumor-like features rarely arise from, or coexist with, pleomorphic xanthoastrocytomas (PXAs), and their clinicopathological and molecular characteristics remain poorly understood. We report a 17-year-old girl with a temporal lobe mass that, upon gross total resection, pathologically contained both RT and PXA components. Immunohistochemistry revealed loss of INI1 expression restricted to the RT component, while the PXA area retained INI1. Next-generation sequencing identified a shared BRAF::TRIM24 fusion and homozygous deletion of CDKN2A/2B in both components, indicating a shared clonal origin. Additionally, a germline ATM frameshift mutation (c.5288_5289insGA) was identified in both tumor components, making the first such report in central nervous system tumors. SMARCB1 loss was confined to the RT component, further supporting the hypotheses of clonal evolution and secondary transformation. Despite gross total resection, craniospinal irradiation, and chemotherapy, the patient developed rapid leptomeningeal dissemination and died 5 months after surgery. This case provides clinicopathological and molecular evidence for clonal evolution and secondary transformation of PXA into an RT. The presence of germline ATM mutation may have therapeutic and biological relevance. Further studies are required to clarify the pathogenesis and optimal management of these rare and aggressive tumors.

Purpose: This study compared the outcomes of haploidentical-related donor (HRD) and umbilical cord blood (UCB) hematopoietic stem cell transplantation (HSCT) in pediatric patients with hematologic malignancies. Methods: Data on patients who underwent HRD HSCT with post-transplant cyclophosphamide (n = 41) and UCB HSCT (n = 24) after targeted busulfan-based myeloablative conditioning with intensive pharmacokinetic monitoring between 2009 and 2018 were retrospectively analyzed. Results: The median follow-up durations in the HRD and UCB groups were 7.0 and 10.9 years, respectively. The cumu‑ lative incidence of acute graft-versus-host disease (GVHD) grades II–IV and moderate-to-severe chronic GVHD did not differ significantly between the groups. However, the HRD group demonstrated significantly lower rates of acute GVHD grades III–IV (4.9% vs. 29.2%, p = 0.009) and non-relapse mortality (2.6% vs. 34.2%, p < 0.001) but a higher relapse incidence (32.1% vs. 8.8%, p = 0.004) than the UCB group. The 5-year event-free and overall survival rates were 65.8% and 54.2% (p = 0.204) and 78.0% and 65.7% (p = 0.142) for the HRD and UCB groups, respectively. Multivariate analysis identified disease status as a significant risk factor for overall survival (hazard ratio, 3.24; p = 0.016). Additionally, UCB HSCT exhibited a trend toward worse event-free survival compared to HRD HSCT (hazard ratio, 2.63; p = 0.05). Conclusions These findings indicate that HRD HSCT with post-transplant cyclophosphamide provides promising outcomes compared to UCB HSCT in pediatric patients, with a trend toward improved survival over a long-term follow-up period exceeding a median of 7 years. Thus, HRD HSCT may be a valuable option for pediatric patients with‑ out human leukocyte antigen-matched donors.

Purpose: This study compared the outcomes of haploidentical-related donor (HRD) and umbilical cord blood (UCB) hematopoietic stem cell transplantation (HSCT) in pediatric patients with hematologic malignancies. Methods: Data on patients who underwent HRD HSCT with post-transplant cyclophosphamide (n = 41) and UCB HSCT (n = 24) after targeted busulfan-based myeloablative conditioning with intensive pharmacokinetic monitoring between 2009 and 2018 were retrospectively analyzed. Results: The median follow-up durations in the HRD and UCB groups were 7.0 and 10.9 years, respectively. The cumu‑ lative incidence of acute graft-versus-host disease (GVHD) grades II–IV and moderate-to-severe chronic GVHD did not differ significantly between the groups. However, the HRD group demonstrated significantly lower rates of acute GVHD grades III–IV (4.9% vs. 29.2%, p = 0.009) and non-relapse mortality (2.6% vs. 34.2%, p < 0.001) but a higher relapse incidence (32.1% vs. 8.8%, p = 0.004) than the UCB group. The 5-year event-free and overall survival rates were 65.8% and 54.2% (p = 0.204) and 78.0% and 65.7% (p = 0.142) for the HRD and UCB groups, respectively. Multivariate analysis identified disease status as a significant risk factor for overall survival (hazard ratio, 3.24; p = 0.016). Additionally, UCB HSCT exhibited a trend toward worse event-free survival compared to HRD HSCT (hazard ratio, 2.63; p = 0.05). Conclusions These findings indicate that HRD HSCT with post-transplant cyclophosphamide provides promising outcomes compared to UCB HSCT in pediatric patients, with a trend toward improved survival over a long-term follow-up period exceeding a median of 7 years. Thus, HRD HSCT may be a valuable option for pediatric patients with‑ out human leukocyte antigen-matched donors.

Purpose: This study compared the outcomes of haploidentical-related donor (HRD) and umbilical cord blood (UCB) hematopoietic stem cell transplantation (HSCT) in pediatric patients with hematologic malignancies. Methods: Data on patients who underwent HRD HSCT with post-transplant cyclophosphamide (n = 41) and UCB HSCT (n = 24) after targeted busulfan-based myeloablative conditioning with intensive pharmacokinetic monitoring between 2009 and 2018 were retrospectively analyzed. Results: The median follow-up durations in the HRD and UCB groups were 7.0 and 10.9 years, respectively. The cumu‑ lative incidence of acute graft-versus-host disease (GVHD) grades II–IV and moderate-to-severe chronic GVHD did not differ significantly between the groups. However, the HRD group demonstrated significantly lower rates of acute GVHD grades III–IV (4.9% vs. 29.2%, p = 0.009) and non-relapse mortality (2.6% vs. 34.2%, p < 0.001) but a higher relapse incidence (32.1% vs. 8.8%, p = 0.004) than the UCB group. The 5-year event-free and overall survival rates were 65.8% and 54.2% (p = 0.204) and 78.0% and 65.7% (p = 0.142) for the HRD and UCB groups, respectively. Multivariate analysis identified disease status as a significant risk factor for overall survival (hazard ratio, 3.24; p = 0.016). Additionally, UCB HSCT exhibited a trend toward worse event-free survival compared to HRD HSCT (hazard ratio, 2.63; p = 0.05). Conclusions These findings indicate that HRD HSCT with post-transplant cyclophosphamide provides promising outcomes compared to UCB HSCT in pediatric patients, with a trend toward improved survival over a long-term follow-up period exceeding a median of 7 years. Thus, HRD HSCT may be a valuable option for pediatric patients with‑ out human leukocyte antigen-matched donors.

Background and Objectives: Cardiac resynchronization therapy (CRT) is a treatment option for patients with heart failure and left ventricular (LV) dyssynchrony. However, one-third of CRT patients are non-responders. The objective of this study is to evaluate the feasibility of an in silico electromechanical heart model to predict CRT outcomes. Methods: The three-dimensional heart geometries of 11 patients (age, 64.0 ± 10.7 years, 4 men) with CRT were constructed from cardiac computed tomography images. The finite element method was used to simulate the electrical wave propagation and mechanics in the heart. We coupled cardiac electrical excitation and mechanical contraction with vascular hemodynamics using a lumped parameter model. We predicted the LV end-diastolic and end-systolic volumes and LV ejection fraction (LVEF) after CRT implantation using the in silico CRT simulation model. A CRT responder was defined as a patient with an absolute LVEF increase ≥ 5%. We compared the in silico CRT outcomes with the real CRT outcomes. Results: Two patients were in silico CRT responders, and those 2 patients were also real CRT responders. Nine patients were in silico CRT non-responders, 8 who were real CRT non-responders, and 1 who was a real CRT responder. The in silico CRT outcomes agreed with the real CRT outcomes in 10 of 11 patients. The positive and negative predictive values, accuracy, sensitivity, and specificity of the in silico CRT model were 100%, 88.9%, 90.9%, 66.7%, and 100%, respectively. Conclusion The in silico CRT simulation model is feasible for predicting real CRT outcomes.

Autoimmune hemolytic anemia (AIHA) is a common complication after hematopoietic stem cell transplantation (HSCT). Although post-HSCT AIHA is associated with poor prognosis and is more resistant to treatment than primary AIHA, the standard treatment has not yet been determined. We report a case of post-HSCT AIHA, which occurred 9 years after unrelated donor bone marrow transplantation for acute biphenotypic leukemia. Steroid treatment was initially effective but prolonged steroid usage, due to recurrent relapses, caused avascular necrosis. Although rituximab was unsuccessful in preventing relapses, sirolimus was effective in allowing the discontinuation of steroid treatment and sustaining transfusion-free status. Sirolimus, previously reported to be effective in pediatric post-HSCT AIHA and AIHA after solid organ transplantation, may be effective in adult post-HSCT AIHA as well.

Background: Cardiac resynchronization therapy (CRT) is an effective treatment option for patients with heart failure (HF) and left ventricular (LV) dyssynchrony. However, the problem of some patients not responding to CRT remains unresolved. This study aimed to propose a novel in silico method for CRT simulation. Methods: Three-dimensional heart geometry was constructed from computed tomography images. The finite ele‑ ment method was used to elucidate the electric wave propagation in the heart. The electric excitation and mechani‑ cal contraction were coupled with vascular hemodynamics by the lumped parameter model. The model parameters for three-dimensional (3D) heart and vascular mechanics were estimated by matching computed variables with measured physiological parameters. CRT effects were simulated in a patient with HF and left bundle branch block (LBBB). LV end-diastolic (LVEDV) and end-systolic volumes (LVESV), LV ejection fraction (LVEF), and CRT responsiveness measured from the in silico simulation model were compared with those from clinical observation. A CRT responder was defined as absolute increase in LVEF ≥ 5% or relative increase in LVEF ≥ 15%. Results: A 68-year-old female with nonischemic HF and LBBB was retrospectively included. The in silico CRT simu‑ lation modeling revealed that changes in LVEDV, LVESV, and LVEF by CRT were from 174 to 173 mL, 116 to 104 mL, and 33 to 40%, respectively. Absolute and relative ΔLVEF were 7% and 18%, respectively, signifying a CRT responder.In clinical observation, echocardiography showed that changes in LVEDV, LVESV, and LVEF by CRT were from 162 to 119 mL, 114 to 69 mL, and 29 to 42%, respectively. Absolute and relative ΔLVESV were 13% and 31%, respectively, also signifying a CRT responder. CRT responsiveness from the in silico CRT simulation model was concordant with that in the clinical observation. Conclusion This in silico CRT simulation method is a feasible technique to screen for CRT non-responders in patients with HF and LBBB.

Purpose: Acute promyelocytic leukemia (APL) is a rare disease in children and there are some different characteristics between children and adult. We aimed to evaluate incidence, clinical characteristics and treatment outcomes of pediatric APL in Korea. Materials and Methods: Seventy-nine pediatric APL patients diagnosed from January 2009 to December 2016 in 16 tertiary medical centers in Korea were reviewed retrospectively. Results: Of 801 acute myeloid leukemia children, 79 (9.9%) were diagnosed with APL. The median age at diagnosis was 10.6 years (range, 1.3 to 18.0). Male and female ratio was 1:0.93. Thirty patients (38.0%) had white blood cell (WBC) count greater than 10×109/L at diagnosis. All patients received induction therapy consisting of all-trans retinoic acid and chemotherapy. Five patients (6.6%) died during induction chemotherapy and 66 patients (86.8%) achieved complete remission (CR) after induction chemotherapy. The causes of death were three intracranial hemorrhage, one cerebral infarction, and one sepsis. Five patients (7.1%) suffered a relapse during or after maintenance chemotherapy. The estimated 4-year event-free survival and overall survival (OS) rates were 82.1%±4.4%, 89.7%±5.1%, respectively. The 4-year OS was significantly higher in patients with initial WBC < 10×109/L than in those with initial WBC ≥ 10×109/L (p=0.020). Conclusion This study showed that the CR rates and survival outcomes in Korean pediatric APL patients were relatively good. The initial WBC count was the most important prognostic factor and most causes of death were related to serious bleeding in the early stage of treatment.

Anhydrous ammonia is a commonly used chemical in industry. Ammonia gas inhalation causes thermal injuries and alkali burns in the airway and lung parenchyma. Previous case reports have stated that respiratory sequelae after acute ammonia inhalation burns were associated with structural lung disease, such as bronchiectasis or interstitial lung disease. We herein report two cases of long-term sequelae with persistent airflow limitation after ammonia inhalation burns.

Background: Drug-resistance surveillance (DRS) data provide key information for building an effective treatment regimen in patients with multidrug-resistant tuberculosis (MDR-TB).This study was conducted to investigate the patterns and trends of additional drug resistance in MDR-TB patients in South Korea. Methods: Phenotypic drug susceptibility test (DST) results of MDR-TB patients collected from seven hospitals in South Korea from 2010 to 2019 were retrospectively analyzed. Results: In total, 633 patients with MDR-TB were included in the analysis. Of all patients, 361 (57.0%) were new patients. All patients had additional resistance to a median of three antiTB drugs. The resistance rates of any fluoroquinolone (FQ), linezolid, and cycloserine were 26.2%, 0.0%, and 6.3%, respectively. The proportions of new patients and resistance rates of most anti-TB drugs did not decrease during the study period. The number of additional resistant drugs was significantly higher in FQ-resistant MDR-TB than in FQ-susceptible MDR-TB (median of 9.0 vs. 2.0). Among 26 patients with results of minimum inhibitory concentrations for bedaquiline (BDQ) and delamanid (DLM), one (3.8%) and three (11.5%) patients were considered resistant to BDQ and DLM with interim critical concentrations, respectively. Based on the DST results, 72.4% and 24.8% of patients were eligible for the World Health Organization's longer and shorter MDR-TB treatment regimen, respectively. Conclusion The proportions of new patients and rates of additional drug resistance in patients with MDR-TB were high and remain stable in South Korea. A nationwide analysis of DRS data is required to provide effective treatment for MDR-TB patients in South Korea.