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.

Background/Aims: Biliary tract cancer (BTC) is a rare malignancy with poor prognosis. We investigated genomic determinants of clinical benefit from gemcitabine, cisplatin, and nab-paclitaxel (GAP) versus gemcitabine and cisplatin (GC) in advanced BTC. Methods: Clinical and genomic data using TruSight Oncology 500 were analyzed from patients treated with GAP (N=198) or GC (N=89) as first-line therapy. Results: With a median follow-up of 33.0 months, GAP modestly improved progression-free survival (PFS) (hazard ratio [HR] 0.764; 95% confidence interval [CI] 0.591–0.989) without significant overall survival (OS) difference compared to GC. Genomic profiling revealed frequent alterations in TP53 (35.2%), KRAS (16.4%), SMAD4 (10.5%), and TNFRSF14 (10.5%), involving RTK/RAS (44.3%), TP53 (41.8%), and PI3K (20.2%) pathways. Single-gene mutations did not predict treatment benefit. However, pathway-level analysis identified PI3K pathway activation as significantly associated with inferior PFS (HR 2.148; 95% CI 1.478–3.124) and OS (HR 2.096; 95% CI 1.413–3.109) in patients receiving GAP, an effect not observed with GC. Importantly, GAP conferred clinical benefit only in patients without PI3K pathway activation, while no survival advantage was seen in those with such alterations (Pinteraction=0.023 for PFS, Pinteraction=0.003 for OS). Similar results were obtained in the independent validation cohort treated with GAP (N=103) or GC (N=64) for BTC. Conclusions Genomic profiling using next-generation sequencing identified PI3K pathway activation as key molecular determinant that differentiates patient outcomes between GAP and GC treatments in advanced BTC.

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: s/Aims: Reported incidence of extrahepatic bile duct cancer is higher in Asians than in Western populations. Korea, in particular, is one of the countries with the highest incidence rates of extrahepatic bile duct cancer in the world. Although research and innovative therapeutic modalities for extrahepatic bile duct cancer are emerging, clinical guidelines are currently unavailable in Korea. The Korean Society of Hepato-Biliary-Pancreatic Surgery in collaboration with related societies (Korean Pancreatic and Biliary Surgery Society, Korean Society of Abdominal Radiology, Korean Society of Medical Oncology, Korean Society of Radiation Oncology, Korean Society of Pathologists, and Korean Society of Nuclear Medicine) decided to establish clinical guideline for extrahepatic bile duct cancer in June 2021. Methods: Contents of the guidelines were developed through subgroup meetings for each key question and a preliminary draft was finalized through a Clinical Guidelines Committee workshop. Results: In November 2021, the finalized draft was presented for public scrutiny during a formal hearing. Conclusions The extrahepatic guideline committee believed that this guideline could be helpful in the treatment of patients.

Viral load and the duration of viral shedding of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are important determinants of the transmission of coronavirus disease 2019.In this study, we examined the effects of viral doses on the lung and spleen of K18-hACE2 transgenic mice by temporal histological and transcriptional analyses. Approximately, 1×105 plaque-forming units (PFU) of SARS-CoV-2 induced strong host responses in the lungs from 2 days post inoculation (dpi) which did not recover until the mice died, whereas responses to the virus were obvious at 5 days, recovering to the basal state by 14 dpi at 1×102 PFU. Further, flow cytometry showed that number of CD8+ T cells continuously increased in 1×102 PFU-virusinfected lungs from 2 dpi, but not in 1×105 PFU-virus-infected lungs. In spleens, responses to the virus were prominent from 2 dpi, and number of B cells was significantly decreased at 1×105PFU; however, 1×102 PFU of virus induced very weak responses from 2 dpi which recovered by 10 dpi. Although the defense responses returned to normal and the mice survived, lung histology showed evidence of fibrosis, suggesting sequelae of SARS-CoV-2 infection. Our findings indicate that specific effectors of the immune response in the lung and spleen were either increased or depleted in response to doses of SARS-CoV-2. This study demonstrated that the response of local and systemic immune effectors to a viral infection varies with viral dose, which either exacerbates the severity of the infection or accelerates its elimination.

In this study, the Ti6Al4V specimens were fabricated using selective laser melting (SLM) method (Ti6Al4V-AS group). These specimens were performed to heat treatment at 950℃ and 550℃ using vacuum electric furnace (Ti6Al4V-HT group). The mechanical properties, metallographic shape, crystalline structure, and chemical compositions of the alloy specimens before and after heat treatment were analyzed. The Ti6Al4V-AS group showed ultimate tensile strength (UTS) and low elongation values. Acicular crystal grains were observed in metallographic image and the α'-Ti phase was dominant. After heat treatment (Ti6Al4V-HT group), the UTS was lowered and the elongation was increased. In addition, a lamellar structure in which columnar crystal grains are arranged was observed, α+β-Ti phase was formed, and crystallinity increased. As a result of analyzing the chemical composition, the Ti6Al4V-AS specimen contained a higher carbon content than the Ti6Al4V-HT specimen. This high carbon content could be related to the formation of α'-phase, high strength and low elongation of the Ti6Al4V-AS specimen. Ti6Al4V-HT specimen showed that the overall carbon content was low, but the carbon content was locally high in the α-Ti phase region. Therefore, it is necessary to control effectively the incorporation of carbon gas in the production of Ti6Al4V specimens using SLM.

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.

Purpose: This study aimed to evaluate the usefulness of two-dimensional shear wave elastography (2D-SWE) in diagnosing hepatic veno-occlusive disease (VOD) in pediatric patients. Methods: This study retrospectively included pediatric patients who underwent hematopoietic stem cell transplantation (HSCT) between November 2019 and January 2021. All 34 patients (8.7±5.0 years) were examined using 2D-SWE for an initial diagnosis. A subgroup analysis was performed using the data from follow-up examinations of patients diagnosed with VOD. The characteristics of the initial VOD diagnosis were compared with the longitudinal changes observed in VOD patients who underwent multiple ultrasound examinations. Results: In total, 19 patients were diagnosed with VOD at 17.6±9.4 days after HSCT. All VOD patients showed hepatomegaly, ascites, and gallbladder wall thickening. Liver stiffness was higher in VOD patients than in non-VOD patients (12.4±1.1 vs. 6.3±0.8 kPa, P<0.001). Liver stiffness values above 7.2 kPa showed 84.2% sensitivity and 93.3% specificity in distinguishing VOD from non-VOD (area under the curve, 0.925; 95% confidence interval, 0.780 to 0.987; P<0.001). A subgroup analysis of 11 patients showed a linear decrease in liver stiffness values after VOD diagnosis with treatment (first, second, and third follow-ups; 13.5±1.7, 11.3±1.4, and 9.5±0.8 kPa, respectively), but without statistical significance in the pairwise analysis. Conclusion Liver stiffness measured using 2D-SWE increased in pediatric patients who develop VOD after HSCT. Therefore, liver stiffness can be a predictive and quantitative parameter for diagnosing VOD.