AIRE illuminates the feature of medullary thymic epithelial cells in thymic carcinoma

Despite the clear distinction between cortical (cTECs) and medullary thymic epithelial cells (mTECs) in physiology, the cell of origin of thymic carcinomas (TCs) and other thymic epithelial tumors remained enigmatic. We addressed this issue by focusing on AIRE, an mTEC-specific transcriptional regulator that is required for immunological self-tolerance. We found that a large proportion of TCs expressed AIRE with typical nuclear dot morphology by immunohistochemistry. AIRE expression in TCs was supported by the RNA-seq data in the TCGA-THYM database. Furthermore, our bioinformatics approach to the recent single-cell RNA-seq data on human thymi has revealed that TCs hold molecular characteristics of multiple mTEC subpopulations. In contrast, TCs lacked the gene signatures for cTECs. We propose that TCs are tumors derived from mTECs

Combined immunohistochemistry of β-catenin, cytokeratin 7, and cytokeratin 20 is useful in discriminating primary lung adenocarcinomas from metastatic colorectal cancer

BACKGROUND: It is important to discriminate between primary and secondary lung cancer. However, often, the discriminating diagnosis of primary lung acinar adenocarcinoma and lung metastasis of colorectal cancer based on morphological and pathological findings is difficult. The purpose of this study was to evaluate the clinical usefulness of immunohistochemistry of β-catenin, cytokeratin (CK) 7, and CK20 for the discriminating diagnosis of lung cancer. METHODS: We performed immunohistochemistry of β-catenin, CK7, and CK20 in 19 lung metastasis of colorectal cancer samples, 10 corresponding primary colorectal cancer samples and 11 primary lung acinar adenocarcinoma samples and compared the levels of accuracy of the discriminating diagnosis by using antibodies against these antigens. RESULTS: Positive staining of β-catenin was observed in all the lung metastasis of colorectal cancer samples as well as in the primary colorectal cancer samples but in none of the primary lung acinar adenocarcinoma samples. Positive staining of CK7 was observed in 90.9% of the primary lung acinar adenocarcinoma samples and in 5.3% of the lung metastasis of colorectal cancer samples, but in none of the primary colorectal cancer samples. Positive staining of CK20 was observed in all the primary colorectal cancer samples and in 84.2% of the lung metastasis of colorectal cancer samples, but in none of the primary lung acinar adenocarcinoma samples. CONCLUSION: Combined immunohistochemistry of β-catenin, CK7, and CK20 is useful for making a discriminating diagnosis between lung metastasis of colorectal cancer and primary lung acinar adenocarcinoma. This method will enable accurate diagnosis of a lung tumor and will be useful for selecting appropriate therapeutic strategies, including chemotherapeutic agents and operation methods

AIRE illuminates the feature of medullary thymic epithelial cells in thymic carcinoma

Abstract Despite the clear distinction between cortical (cTECs) and medullary thymic epithelial cells (mTECs) in physiology, the cell of origin of thymic carcinomas (TCs) and other thymic epithelial tumors remained enigmatic. We addressed this issue by focusing on AIRE, an mTEC‐specific transcriptional regulator that is required for immunological self‐tolerance. We found that a large proportion of TCs expressed AIRE with typical nuclear dot morphology by immunohistochemistry. AIRE expression in TCs was supported by the RNA‐seq data in the TCGA‐THYM database. Furthermore, our bioinformatics approach to the recent single‐cell RNA‐seq data on human thymi has revealed that TCs hold molecular characteristics of multiple mTEC subpopulations. In contrast, TCs lacked the gene signatures for cTECs. We propose that TCs are tumors derived from mTECs

Initial intravenous immunoglobulin therapy without aspirin for acute Kawasaki disease: a retrospective cohort study with a Bayesian inference

Objective To clarify the necessity of acetylsalicylic acid (ASA) administration combined with intravenous immunoglobulin (IVIG) therapy in the treatment of acute Kawasaki disease.Design Retrospective cohort study.Setting Multicentre.Participants This study included 735 patients with Kawasaki disease aged ≤10 years and hospitalised between 4 and 10 days of illness in eight Japanese hospitals from January 2016 to December 2020.Exposures High-dose (HD) ASA was administered with initial IVIG to 333 patients in 6 hospitals (HD group). ASA was not administered routinely to 402 patients in the other two hospitals, and low-dose ASA was only administered when patients developed coronary artery lesions or pericardial effusion (non-HD group).Primary and secondary outcome measures The primary outcome was the presence of coronary artery lesions, defined as a coronary artery diameter >+2.5 SD of body surface area within 1 month of onset. The secondary outcome was responsiveness to the initial IVIG therapy. Adjusted risk ratios for the outcomes were calculated using modified Poisson regression models. Bayesian analysis was conducted to estimate the posterior probability of the treatment effect of HD ASA under several prior distributions.Results The incidence of coronary artery lesions was not significantly higher in the HD group than in the non-HD group (12/333 (3.6%) vs 15/402 (4.0%)). The proportion of non-responders to initial IVIG was similar between the two groups (HD group: 78/333 (23%); non-HD group: 83/402 (22%)). In the Bayesian analysis, considering a difference of ≤2% to be of no clinical importance, there was only a 9.3% chance of reduced risk of coronary artery lesions in the HD group compared with the non-HD group even with a strongly enthusiastic prior for HD treatment.Conclusions Compared with HD ASA treatment, treatment without ASA in the acute phase of Kawasaki disease was not associated with increased complications from Kawasaki disease

Histological analysis of ECIPAS

Background : Epidermoid cysts in intrapancreatic accessory spleen (ECIPAS) are a rare lesion. Its pathogenesis, including the origin of cystic epithelium, is not well established. We aimed to elucidate new aspects of the pathological features of ECIPAS to clarify its pathogenesis. Methods : Six cases of ECIPAS were included in this study. As well as histopathological analysis, to elucidate the features and nature of cystic epithelial cells, immunohistochemical analysis including Pbx1 and Tlx1 and imaging mass spectrometry was performed. Results : Histologically, the cysts were covered by either monolayered or multilayered epithelium. Immunohistochemistry revealed that the epithelial cells in multilayered epithelium exhibited different attributes between the basal and superficial layers. Few epithelial cells had abundant clear cytoplasm and were immunohistochemically positive for adipophilin, suggesting lipid-excreting function. The intracystic fluid contained cholesterol clefts and foamy macrophages, and imaging mass spectrometry revealed the accumulation of lipids. Immunohistochemical analysis indicated that the epithelial cells were positive for Pbx1 in some cases. Conclusion : Novel histological features of epithelial cells of ECIPAS were indicated. Although more cases need to be evaluated, we propose that the cause of ECIPAS may be different from that of pancreatic ductal origin