Nishimura, Yoshito

Introduction: Hyaline-vascular type unicentric Castleman disease (HV-UCD) is a classic variant of Castleman disease, characterized by localized lymph node hyperplasia. Due to its rarity, there have been few systematic reports summarizing its clinicopathological features globally. Also, its pathogenesis remains unelucidated. The present study aims to provide a detailed clinicopathological and transcriptomic analysis of HV-UCD to enhance the understanding of its underlying mechanisms at a molecular level. Methods: We conducted a clinicopathological analysis of 51 HV-UCD cases and performed whole transcriptome analysis on frozen lymph node specimens from four cases. Differentially expressed genes (DEGs) and Gene Ontology (GO) analyses were performed to identify significant pathways and biological processes involved in HV-UCD, with reactive lymphoid hyperplasia as control. Results: The mean age of HV-UCD patients was 42.8 years, with no significant gender differences. The most common sites involved were the abdominal cavity (n = 18, 35.3%), mediastinum (n = 11, 21.6%), and retroperitoneum (n = 9, 17.6%), with an average size of the lesions being 4.8 cm. Histologically, 33.3% of cases exhibited “dysplastic follicular dendritic cells (dFDCs)” characterized by multinucleation or large nuclei within and outside follicles, positive for follicular dendritic cells (FDC) markers. DEGs analysis compared to reactive lymphoid hyperplasia revealed significant upregulation of genes related to FDCs and angiogenesis. Notably, the placental growth factor (PGF), a proangiogenic factor and a member of the VEGF family, demonstrated significant overexpression. GO analysis identified significant enrichment of genes involved in angiogenesis, cell adhesion, tissue architecture, and humoral immunity. Discussion: This large cohort of HV-UCD cohort provides potentially novel clinicopathological insights. Gene expression analysis demonstrated increased expression of FDC-related genes, suggesting a pivotal role of FDCs in HV-UCD pathogenesis. The differences in the gene profiles related to angiogenesis may contribute to the distinct mechanisms and histological features of HV-UCD and iMCD-TAFRO, where HV-UCD is associated with hyalinization of vascular walls and iMCD-TAFRO is characterized by angiogenesis with endothelial cell swelling. Conclusion: The present results suggest the crucial role of FDCs in HV-UCD pathogenesis from the molecular features. Currently, there are no objective diagnostic markers for HV-UCD. Identifying these markers may lead to a clearer understanding of the disease pathophysiology and improve diagnostic accuracy for HV-UCD. Further investigation is warranted to verify the findings.

Introduction: Kikuchi-Fujimoto disease (KFD), is a rare inflammatory disease of unknown etiology, typically presenting with transient fever and cervical lymphadenopathy. It is recently classified as a tumor-like lesion in the World Health Organization Classification 5th Edition. There are few large-scale studies on patient demographics and clinical course. This study aims to report detailed clinicopathological features of KFD. Methods: We reviewed 112 cases of KFD diagnosed at Okayama University Department of Pathology and Oncology, Okayama, Japan between 2012 and 2022. Patients who were diagnosed with autoimmune diseases or bacterial/tuberculous lymphadenitis after the initial presentation as KFD were excluded. Results: The average age of the included cases was 29.4 years (range:6 to 77 years) with slight female predominance (n = 51/115, 44.3% for male; n = 61/115, 53.0% for female). For the included cases of 30 years or older, there were more females than males. The cervical lymph nodes were the most commonly affected sites (85%). For the 70 patients who had complete follow-up data available in the electric medical records, the recurrence rate was 23%, without a difference between males and females. Laboratory tests demonstrated significantly lower complement 4 (C4) levels (p = 0.038) and a higher rate of positive antinuclear antibodies (p = 0.007) in the relapsed cases than in the cases without documented recurrence. The mean number of days prior to confirm the diagnosis was 71.5 days. Among the representative lymph node histology classification, proliferative type was the most common (n = 75; 77%), followed by necrotizing (n = 22; 22%), and xanthomatous (n = 1; 1%). The patients with necrotizing type had significantly enlarged lymph nodes (p = 0.047) and longer duration of symptoms (p = 0.009) compared to the proliferating type. Discussion: The present study provides data from a large KFD cohort to provide comprehensive clinicopathological information to date. While KFD is known to predominantly affect female, there were considerably more males up to age 30 than females, Being young and adolescent male KFD patients was associated with atypical features. Future studies are warranted to confirm the findings noted in the results, to clarify clinicopathological differences in the male young adolescent KFD, and further characterize the classical female KFD cases, including histological features, treatment responses, and association with autoimmune or malignant hematology conditions. Conclusion: In this study, we analyzed a large number of KFD cases and clarified characteristics. The comprehensive clinicopathological features provided by the present results may be useful in elucidating the pathogenesis and predicting the clinical course of such clinically challenging cases, including association with autoimmune diseases and its long-term outcomes.

An 18-year-old previously healthy Filipino male presented with abdominal pain, vomiting, dyspnoea and fever. Initial investigations revealed severe hepatosplenomegaly, pancytopaenia, elevated liver enzymes, coagulopathy and extremely high ferritin levels. Bone marrow biopsy confirmed an abnormal CD8+ T-cell population with haemophagocytosis. Extensive workup was performed, and he was ultimately diagnosed with haemophagocytic lymphohistiocytosis (HLH) secondary to Epstein-Barr virus-positive T-cell lymphoma of childhood (EBV-TCL), a rare and aggressive malignancy. Despite the initiation of modified dexamethasone, methotrexate, ifosfamide, L-asparaginase and etoposide (SMILE) chemotherapy along with high-dose glucocorticoids, the patient did not respond to the treatment and expired. This case underscores the critical importance of early recognition and prompt intervention in EBV-TCL-associated HLH which is a unique condition and a rare entity. The diagnosis of this entity can be particularly challenging, given its rapid progression and high mortality rate. Therefore, timely diagnosis and the initiation of appropriate therapy are essential for improving patient outcomes. General medicine providers play a key role in identifying warning signs to avoid delays in treatment initiation.

AbstractBackground and ObjectivesSubstance use disorders (SUD) are a major public health concern in the United States. This study examined racial/ethnic and state‐level disparities in SUD mortality in the United States from 2000 to 2019.MethodsAge‐standardized mortality rates for SUD were obtained for 5 racial/ethnic groups (White respondents, Black respondents, Latino, Asian‐Pacific Islander [API], American Indian/Alaska Native [AIAN]) by state and sex from 2000 to 2019. Joinpoint regression analysis was used to model temporal trends overall and by demographic factors.ResultsFrom 2000 to 2019, the overall mortality rate increased from 8.0 to 28.8 deaths per 100,000 population across all groups. AIANs had the highest mortality in 2019 (57.8 per 100,000), followed by Black respondents, White respondents, Latinos, and APIs. Significant increases occurred across all racial/ethnic groups, with the greatest average annual percentage change (AAPC2000–2019) among White respondents (6.7%; 95% confidence interval [CI]: 6.2%–7.3%), APIs (6.0%, 95% CI: 5.6%–6.2%), and AIANs (5.9%, 95% CI: 5.6%–6.2%). Mortality rates increased more rapidly for females than males among White respondents, AIANs, Black respondents, and Latinos. Substantial state‐level variation emerged, with the highest mortality rates in 2019 seen in West Virginia, the District of Columbia, Delaware, Ohio, and Pennsylvania.Discussion and ConclusionsRacial/ethnic and geographic disparities in SUD mortality have widened significantly from 2000 to 2019, highlighting priority areas for prevention efforts.Scientific SignificanceThis study provides detailed insights into long‐term trends in racial, ethnic, and geographic disparities in SUD mortality across the United States, informing targeted prevention and intervention strategies.

AbstractBackgroundAdverse effects of medical treatment (AEMT) pose significant risks to paediatric patients. However, the mortality trends associated with AEMT in this population have been unclear.ObjectiveWe aimed to clarify the trends in the incidence, disability‐adjusted life years (DALYs) and mortality rates of AEMT for children in the US from 2000 to 2019.MethodsData were retrieved from the Global Burden of Disease study 2019. We estimated age‐standardized incidence, DALYs and mortality rates of paediatric AEMT per 100,000 children in the US using a Bayesian meta‐regression model. We also analysed incidence, DALYs and mortality in different age groups, and employed Joinpoint regression models to assess the age‐ and sex‐specific trends.ResultsThe number of deaths due to AEMT in children, the number of cases, and DALYs were 105.1, 551,076 and 145,555 in 2019, decreased by 37.5%, 6% and 28% from those in 2000, respectively. Age‐standardized mortality rates decreased across all age groups, while the incidence increased across all age groups with an average annual percentage change (AAPC) of 2.2% in those children <1 year and 4.5% in 5–9 years of age. The increases in DALYs over time was higher in children aged 1–4 years (AAPC: 0.51, 95% CI: 0.47, 0.62) and 5–9 years (AAPC: 0.33, 95% CI: 0.15, 0.50), with the 1–4 year age group being the highest.ConclusionThe study reveals declining AEMT mortality but rising incidence and DALYs, emphasizing a disproportionate burden in <1, 1–4 and 5–9 years. To develop effective mitigation strategies, future research is warranted to identify the causes of increased AEMT in children, especially young males.