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Abstract Coronavirus disease 2019 (COVID‐19) vaccination is reportedly safe and effective. The histologic features of post‐COVID‐19 vaccination myocarditis are unknown. We present a case of a 77‐year‐old Japanese woman diagnosed with eosinophilic myocarditis using endomyocardial biopsy, 7 days after the second dose of BNT162b2 COVID‐19 vaccine. Steroid pulse therapy was effective.

Abstract The function of a biomacromolecule is not only determined by its three-dimensional structure but also by its electronic state. Quantum chemical calculations are promising non-empirical methods available for determining the electronic state of a given structure. In this study, we used the fragment molecular orbital (FMO) method, which applies to biopolymers such as proteins, to provide physicochemical property values on representative structures in the SCOP2 database of protein families, a subset of the Protein Data Bank. Our dataset was constructed by over 5,000 protein structures, including over 200 million inter-fragment interaction energies (IFIEs) and their energy components obtained by pair interaction energy decomposition analysis (PIEDA) using FMO-MP2/6-31 G*. Moreover, three basis sets, 6-31 G*, 6-31 G**, and cc-pVDZ, were used for the FMO calculations of each structure, making it possible to compare the energies obtained with different basis functions for the same fragment pair. The total data size is approximately 6.7 GB. Our dataset will be useful for functional analyses and machine learning based on the physicochemical property values of proteins.

Abstract Since Nepal is an earthquake-prone country due to the collision of the Indian and Eurasian plates, it is crucial for its capital of Kathmandu to evaluate ground motion hazards from a future large earthquake. For this purpose, we constructed a realistic scenario earthquake with realistic rupture parameters in a likely location. To obtain the location, a new distribution of the rupture zones of large historical earthquakes along the Main Himalayan Thrust (MHT) was obtained by integrating the distribution from a previous study and the results of trench surveys. Global Navigation Satellite System observations indicated that the plate boundary is strongly coupled from the southern boundary of the MHT to a depth of approximately 10 km and there is almost no lateral change in the coupling. This implies that all regions along the MHT have similar rates of strain increase. Therefore, it is most probable that the rupture zone of the oldest previous event will rupture as a scenario earthquake. In the new distribution, the 1255 earthquake is the oldest. However, large earthquakes occurred in 1934 and 2015 within its rupture zone. Thus, we adopted the area obtained by removing the 1934 and 2015 rupture zones from the western part of the 1255 rupture zone. The relationship between the rupture area size and seismic moment of the 2015 earthquake lies between the scaling formulas for crustal earthquakes and plate-boundary earthquakes, but is closer to the former. Therefore, using this and the scheme for characterized source models, we determined realistic rupture parameters. We then simulated broadband ground motions in Kathmandu using these rupture parameters, our 3-D velocity structure models, and a hybrid method combining the finite-difference method and the stochastic Green’s function method. We obtained the peak ground accelerations (PGAs) of simulated ground motions, and calculated the seismic intensities in the Modified Mercalli intensity scale from the PGAs as indexes of hazards for Kathmandu. Intensities IX coincide with the center of the Kathmandu Valley, and intensities VIII and VII are found in the area surrounded by the sedimentary boundary and the southernmost part of the valley. Graphical abstract

Background: Current L1-based human papillomavirus (HPV) vaccines provide type-specific protection but offer limited cross-protection against non-vaccine HPV types. Therefore, developing a broad-spectrum HPV vaccine is highly desirable. Methods: In this study, we optimized mRNA constructs and developed a multivalent L2-based mRNA vaccine encoding L2 aa 2-130, which includes all known neutralizing epitopes from four prevalent HPV types (HPV-6, -11, -16, and -18). We evaluated its immunogenicity in a mouse model and compared the efficacy of a commercially available mRNA delivery reagent with a custom-synthesized lipid nanoparticle (LNP) formulation. Results: We identified that a construct containing E01 (a 5′-untranslated region) and SL2.7 (a poly(A) polymerase recruitment sequence) significantly increased protein expression. The L2-based mRNA vaccine induced robust and long-lasting humoral immune responses, with significant titers of cross-reactive serum IgG antibodies against L2 epitopes. Notably, the vaccine elicited cross-neutralizing antibodies and conferred cross-protective immunity not only against vaccine-targeted HPV types but also against non-vaccine HPV types, following intravaginal challenge in mice. We also found that LNP delivered mRNA more effectively in vivo. Conclusions: The L2-based mRNA vaccine developed in this study shows significant potential for broad-spectrum protection against multiple HPV types. This approach offers a promising strategy for reducing the global burden of HPV-associated cancers.

Abstract Risk factors of severe coronavirus disease 2019 (COVID-19) have been previously reported; however, histological risk factors have not been defined thus far. The aim of this study was to clarify subclinical hidden interstitial lung disease (ILD) as a risk factor of severe pneumonia associated with COVID-19. We carefully examined autopsied lungs and chest computed tomography scanning (CT) images from patients with COVID-19 for interstitial lesions and then analyzed their relationship with disease severity. Among the autopsy series, subclinical ILD was found in 13/27 cases (48%) in the COVID-19 group, and in contrast, 8/65 (12%) in the control autopsy group (p = 0.0006; Fisher’s exact test). We reviewed CT images from the COVID-19 autopsy cases and verified that subclinical ILD was histologically detectable in the CT images. Then, we retrospectively examined CT images from another series of COVID-19 cases in the Yokohama, Japan area between February–August 2020 for interstitial lesions and analyzed the relationship to the severity of COVID-19 pneumonia. Interstitial lesion was more frequently found in the group with the moderate II/severe disease than in the moderate I/mild disease (severity was evaluated according to the COVID-19 severity classification system of the Ministry of Health, Labor, and Welfare [Japan]) (moderate II/severe, 11/15, 73.3% versus moderate I/mild, 108/245, 44.1%; Fisher exact test, p = 0.0333). In conclusion, it was suggested that subclinical ILD could be an important risk factor for severe COVID-19 pneumonia. A benefit of these findings could be the development of a risk assessment system using high resolution CT images for fatal COVID-19 pneumonia.

Abstract Background Small cell lung cancer (SCLC) is a neuroendocrine tumor with poor prognosis. Neuroendocrine tumors possess characteristics of both nerve cells and hormone‐secreting cells; therefore, targeting the neuronal properties of these tumors may lead to the development of new therapeutic options. Among the endogenous signaling pathways in the nervous system, targeting the glutamate pathway may be a useful strategy for glioblastoma treatment. Perampanel, an antagonist of the synaptic glutamate α‐amino‐3‐hydroxy‐5‐methyl‐4‐isoxazole propionic acid receptor (AMPAR), has been reported to be effective in patients with glioblastoma. In this study, we aimed to investigate the antitumor effects of AMPAR antagonists in human SCLC cell lines. Methods We performed to examine the expression of AMPAR using Western blot and immunohistochemical analysis. The antitumor effects of AMPAR antagonists on human SCLC cell lines were investigated in vitro and in vivo. We also analyzed the signaling pathway of AMPAR antagonists in SCLC cell lines. Statistical analysis was performed by the GraphPad Prism 6 software. Results We first examined the expression of endogenous AMPAR in six human SCLC cell lines, detecting AMPAR proteins in all of them. Next, we tested the anti−proliferative effect of two AMPAR antagonists, talampanel and cyanquixaline, using SCLC cells in vitro and in vivo. Both AMPAR antagonists inhibited cell proliferation and mitogen‐activated protein kinase (MAPK) phosphorylation in SCLC cells in vitro. Further, we observed reduced proliferation of implanted cell lines in an in vivo setting, assessed by Ki‐67 immunohistochemistry. Additionally, using immunohistochemical analysis we confirmed AMPAR protein expression in human SCLC samples. Conclusion AMPAR may be a potential therapeutic target for SCLC.

Abstract Background The diagnostic accuracy and safety of transbronchial lung cryobiopsy (TBLC) via a flexible bronchoscope under sedation compared with that of surgical lung biopsy (SLB) in the same patients is unknown. Methods Retrospectively the data of fifty-two patients with interstitial lung diseases (median age: 63.5 years; 21 auto-antibody positive) who underwent TBLC followed by SLB (median time from TBLC to SLB: 57 days) was collected. The samples from TBLC and SLB were randomly labelled to mask the relationship between the two samples. Diagnosis was made independently by pathologists, radiologists, and pulmonary physicians in a stepwise manner, and a final diagnosis was made at multidisciplinary discussion (MDD). In each diagnostic step the specific diagnosis, the diagnostic confidence level, idiopathic pulmonary fibrosis (IPF) diagnostic guideline criteria, and treatment strategy were recorded. Results Without clinical and radiological information, the agreement between the histological diagnoses by TBLC and SLB was 42.3% (kappa [κ] = 0.23, 95% confidence interval [CI]: 0.08–0.39). However, the agreement between the TBLC-MDD and SLB-MDD diagnoses and IPF/non-IPF diagnosis using the two biopsy methods was 65.4% (κ = 0.57, 95% CI: 0.42–0.73) and 90.4% (47/52), respectively. Out of 38 (73.1%) cases diagnosed with high or definite confidence at TBLC-MDD, 29 had concordant SLB-MDD diagnoses (agreement: 76.3%, κ = 0.71, 95% CI: 0.55–0.87), and the agreement for IPF/non-IPF diagnoses was 97.4% (37/38). By adding the pathological diagnosis, the inter-observer agreement of clinical diagnosis improved from κ = 0.22 to κ = 0.42 for TBLC and from κ = 0.27 to κ = 0.38 for SLB, and the prevalence of high or definite diagnostic confidence improved from 23.0% to 73.0% and from 17.3% to 73.0%, respectively. Of all 383 TBLC performed during the same period, pneumothorax occurred in 5.0% of cases, and no severe bleeding, acute exacerbation of interstitial lung disease, or fatal event was observed. Conclusions TBLC via a flexible bronchoscope under deep sedation is safely performed, and the TBLC-MDD diagnosis with a high or definite confidence level is concordant with the SLB-MDD diagnosis in the same patients.

Introduction: Idiopathic multicentric Castleman disease (MCD) has been reported to form lung cysts at a relatively high rate. However, the radiological and pathological features of cystic formation in MCD are unclear. Methods: To clarify these questions, we retrospectively investigated the radiological and pathological findings of cysts in MCD patients. Eight consecutive patients who underwent surgical lung biopsies in our center from 2000 to 2019 were included. Results: The median age was 44.5 years, with three males and five females. On the initial computed tomography, cyst formation was found in seven patients (87.5%). All of the cysts were multiple, round, and thin walled, accompanying ground-glass attenuation (GGA) around cysts. In six patients (75%), cysts increased during their clinical courses, and the new cysts had emerged from GGA, although GGA was improved by treatment. In all four cases, whose pulmonary cysts could be pathologically evaluated, a marked plasma cell infiltration around the cyst wall, and loss of elastic fibers of the alveolar wall were observed. Conclusions: Pulmonary cysts emerged in the area of GGA pathologically consistent with plasma cell infiltration. Cysts in MCD may be formed by the loss of elastic fibers due to marked plasma cell infiltration and may be considered irreversible changes.

Lipid domains play a critical role in signal transduction and transport across cell membranes. The formation of domains in “HLC” ternary lipid bilayers composed of high transition temperature (high- Tm ) lipids, low- Tm lipids, and cholesterol (Chol) has been extensively studied as a raft-like system. Recently, experiments were performed to control the formation of submicron domains in LLC lipid bilayers containing low- Tm phosphatidylethanolamine (PE), low- Tm phosphatidylcholine (PC), and Chol by manipulating the presence or absence of Chol. The formation of microdomains in this LLC mixture was replicated by dissipative particle dynamics simulation. The results show that domain formation can be replicated.

Abstract Caspase‐generated fragmented cytokeratin 18 (fCK18) is recognized as a useful noninvasive biomarker in the diagnosis of nonalcoholic fatty liver disease (NAFLD), particularly nonalcoholic steatohepatitis (NASH). However, fCK18 measurement is not applied clinically due to widely variable cut‐off values under the current enzyme‐linked immunosorbent assay platform. Therefore, we developed a highly sensitive chemiluminescent enzyme immunoassay using newly developed monoclonal antibodies against fCK18 and investigated its relevance in NASH diagnosis. Serum fCK18 levels were measured in the derivation and validation cohort. The correlation between serum fCK18 levels and NAFLD activity score (NAS), fibrosis stage, and liver function was examined. Serum fCK18 levels were significantly correlated with alanine aminotransferase (ALT), aspartate aminotransferase (AST), and gamma‐glutamyl transpeptidase. Serum fCK18 levels were significantly associated with NAS, Brunt's grade/stage, Matteoni's classification, portal inflammation, and fat accumulation in the liver. Notably, hepatocyte ballooning was the only independent variable significantly associated with serum fCK18 in the multivariate linear regression analysis. Serum fCK18 levels were significantly elevated in patients with NAFLD and nonalcoholic fatty liver (NAFL) compared to healthy individuals. They were also significantly elevated in patients with NAFL compared to NASH defined by NAS or Matteoni's classification, with area under the curve values being 0.961 (NAFLD vs. healthy), 0.913 (NAFL vs. healthy), 0.763 (NASH vs. NAFL), and 0.796 (NASH type 3–4 vs. NAFL type 1–2). These results were confirmed by a validation cohort. Notably, changes over time in serum fCK18 levels were significantly correlated with changes in ALT, AST, and the fibrosis‐4 index in 25 patients who underwent lifestyle modification. Serum fCK18 levels were significantly correlated with liver damage associated with NASH pathology. Serum fCK18 levels are accurate in distinguishing patients with NAFL or NASH from healthy individuals and may be useful to monitor NASH over time.

We report the first case with COVID-19-like acute respiratory distress syndrome after mRNA-1273 SARS-CoV-2 vaccination. An 88-year-old woman developed dyspnea several hours after vaccination with the second dose of mRNA-1273. She was hospitalized on day nine due to worsening dyspnea. Chest computed tomography showed bilateral ground-glass opacities and consolidations, mainly in the peripheral lung areas. Repeat polymerase chain reaction tests for SARS-CoV-2 were negative, although the serum level of antibodies against spike protein was extremely elevated. Her condition did not improve with high-dose corticosteroids and high-flow nasal cannula oxygen therapy; she died on day 18. Autopsy findings revealed very early-phase diffuse alveolar damage in the whole lung without other lung diseases. The clinical and pathological findings suggested vaccine-induced acute respiratory distress syndrome. Serological and pathological tests might be useful to differentiate the disease from COVID-19.

Background: Airway epithelium-derived cytokines are critical to provoke and perpetuate type 2 inflammation in asthma. Yet it is poorly understood how this epithelial cell-driven inflammatory response is negatively regulated. We previously reported that Axl receptor tyrosine kinase was expressed by basal cells in the airway epithelium and had a role in defining their stem cell identity. However, whether and how Axl regulates airway type 2 inflammation remains unknown. Methods: We performed immunofluorescence staining to compare Axl expression in airway epithelium between non-asthmatic subjects, mild-moderate asthma and severe asthma. We confirmed this result by interrogating public databases of global gene expression in endobronchial biopsies. We then quantified eosinophil numbers infiltrating into the trachea of wild-type or Axl-knockout mice that were intranasally treated with house dust mite extracts (HDM). Cell-based assays using siRNA targeting Axl were further performed to identify molecules involved in Axl-mediated regulation of inflammation. Results: Histological assessments and transcriptome analyses revealed decreases in protein and mRNA of Axl in airway basal cells of severe asthmatics. This reduction of Axl expression was correlated with infiltration of eosinophils and mast cells in severe asthmatics. Eosinophil infiltration was more evident in the trachea of Axl-knockout mice in response to repetitive HDM administration. siRNA-mediated knockdown of Axl increased mRNA and protein expression of granulocyte macrophage-colony stimulating factor (GM-CSF) in human bronchial epithelial cells. Conclusions: Axl kinase expressed by basal cells may suppress excessive eosinophilic inflammation via inhibition of GM-CSF in the airway. Axl reduction has clinical implications for the pathogenesis of severe asthma.

Abstract Background Glutaraldehyde (GA)-fixed autologous tissues, including the pericardium, are widely used as patches and valve substitutes in cardiovascular surgery. However, GA treatment causes tissue calcification. No rapid anticalcification method has been established for use during surgery. Here, we aimed to establish a rapid anticalcification method using ethanol, as has already been demonstrated for bioprosthetic valves. Methods Thoracic aorta tissues were first fixed with GA for 3 min and then treated with ethanol for 0 (group 2), 10 (group 3), 20 (group 4), and 30 (group 5) min; untreated tissues (group 1) served as the control. The treated tissues were subdermally implanted into 3-week-old male Wistar rats and kept in place for 28 days. The calcification in each explant was semiquantitatively evaluated by annotating and measuring the area using virtual slides, and the data obtained were statistically analyzed. Results Semiquantitative analysis revealed that calcification of the implants from the untreated group (group 1; P = 0.0014) and groups 4 (P = 0.0014) and 5 (P = 0.0031) was significantly lower than that of implants from group 2. Moreover, implants from group 3 showed a tendency toward decreased calcification, although it was not significant (P = 0.0503). Conclusions A rapid ethanol treatment prevents calcification of GA-fixed tissues in a rat model of subdermal implantation. This method may facilitate effective and rapid anticalcification of autologous tissues for use during cardiovascular surgery.

Abstract Background The usefulness and safety of transbronchial lung cryobiopsy (TBLC) for reassessment of diffuse parenchymal lung disease (DPLD) with progression is still unknown. Our purpose was to clarify the usefulness and safety of TBLC for reassessment of DPLD with progression. Methods This retrospective study included 31 patients with DPLD diagnosed by surgical lung biopsy who progressed in the clinical course and underwent TBLC for reassessment between January 2017 and September 2019 at Kanagawa Cardiovascular & Respiratory Center. Two pulmonologists independently selected the clinical diagnosis, treatment strategy, and confidence level of the treatment strategy based on clinical and radiological information with and without pathological information from TBLC. A consensus was reached among the pulmonologists regarding the clinical diagnosis, treatment strategy, and confidence level of the treatment strategy. Complications of TBLC were also examined. Results Seven (22.6%), 5 (16.1%), and 6 (19.4%) of clinical diagnosis was changed after TBLC for Pulmonologist A, for Pulmonologist B, and for consensus, respectively. The treatment strategy was changed in 7 (22.6%), 8 (25.9%), and 6 (19.4%) cases after TBLC for Pulmonologist A, for Pulmonologist B and for consensus, respectively. The definite or high confidence level of the consensus treatment strategy was 54.8% (17/31) without TBLC and 83.9% (26/31) with TBLC. There were 6 cases of moderate bleeding, but no other complications were noted. Conclusions Pathological information from TBLC may contribute to decision-making in treatment strategies for the progression of DPLD, and it may be safely performed.

Lung metastasis is an uncommon cause of multiple cavitary lung lesions. Herein, we report a case of multiple cavitary lung lesions of colorectal cancer that responded to chemotherapy. An 81-year-old woman was referred to our hospital for abdominal pain. Computed tomography revealed multiple cavitary lung lesions. The patient was diagnosed with lung metastases from colorectal cancer with a lower gastrointestinal endoscopy and bronchoscopy. Following chemotherapy, the cavitary lung lesions shrank. Lung metastases from colorectal cancer may appear as multiple cavitary lung lesions, which may be misdiagnosed as infections. Clinicians should consider lung metastases when multiple cavitary lung lesions are detected.

The technologies used to generate human induced pluripotent stem cell (iPSC) from somatic cells potentially enable the wide application of iPSC-derived differentiated cells in industrial research fields as a replacement for animals. However, as highly trained individuals are required to obtain reproducible results, this approach has limited social implementation. In the research field of iPSC, it is believed that documentable information is not enough for reproducing the quality of the differentiated cells. Therefore, automated culture machines for cell processing should make the starting of iPSC-using researches easier. We developed a programmable all-in-one automated culture machine, with dense and compact constitution that fits within a normal biosafety cabinet (200 mm wide, 233 mm height, and 110 mm depth). This instrument was fabricated using novel x-y-z-axes-rail-system, such as an overhead traveling crane, in a factory, which served as the main handling machinery. This machine enabled stable and efficient expansion of human iPSC under the feeder-free condition, without karyotype alterations, and simultaneously differentiated the cells into various cell types, including cardiomyocytes, hepatocytes, neural progenitors, and keratinocytes. Overall, this machine would facilitate the social implementation of human pluripotent stem cells and contribute to the accumulation of sharable knowledge for the standardization of the entire handling processes of iPSC in pharmaceutical, food, and cosmetic research.

Abstract Fragmented cytokeratin 18 (fCK18) released from epithelial cells undergoing apoptosis is widely studied in various diseases. However, fCK18 measurement is not utilized in clinical practice due to imprecise disease-state cutoff values. Therefore, we set out to generate new monoclonal antibodies (mAbs) and a recombinant fCK18 (rfCK18) calibrator in an effort to develop a highly sensitive chemiluminescent enzyme immunoassay (CLEIA). New capture mAb (K18-624) had a high binding ability compared to the current commercial antibody. New detection mAb (K18-328) recognized 323S-340G of CK18. A rfCK18 was expressed in the soluble fraction of E. coli when the N-terminal region (260 amino acid residues) of CK18 was truncated. Analysis of performance and measurement of human fCK18 were evaluated using K18-624 and K18-328 in a highly sensitive CLEIA. The coefficients of variation (CV) for within-run and between-day repeatability were below 10% and the recoveries were in the range of 15%. The detection sensitivity was 0.056 ng/mL. Serum fCK18 levels were significantly increased in non-alcoholic steatohepatitis (NASH) patients when compared to healthy individuals. Our new fCK18 mAbs showed high affinity and sensitivity. CLEIA using our new antibodies will be useful in measuring fCK18 in human blood thereby generating accurate clinical diagnoses of human liver diseases.

We present a 76-year-old man who visited our center because of persistent dyspnea with hypoxia on exertion 6 months after onset of coronavirus disease 2019. Chest computed tomography showed bilateral extensive subpleural reticulation with traction bronchiectasis predominantly in the lower lung lobes. Transbronchial lung cryobiopsy revealed spatially and temporally intermittent interstitial fibrosis with mild lymphoid cell infiltration. Not only were there membranous fibrotic scars on the alveolar septa, but there were scattered foci of alveolar collapse with young fibroblastic proliferations, suggesting progressive interstitial fibrotic lesions. In addition to fibrotic phase of diffuse alveolar damage, the acceleration of subclinical preexisting interstitial lung abnormalities might have affected his respiratory condition.

BackgroundFragmented cytokeratin 18 (fCK18) is released from damaged hepatocytes undergoing apoptosis and is recognized as a liver condition biomarker. We have developed a highly sensitive serum fCK18 CLEIA and reported that serum levels of this caspase-derived protein were significantly associated with hepatocyte ballooning, thus assisting in the accurate diagnosis of nonalcoholic steatohepatitis (NASH). We aim to investigate serum fCK18 levels in a variety of chronic liver diseases and to explore its potential as a prognostic marker of survival in hepatocellular carcinoma (HCC) patients.MethodsSerum fCK18 levels were measured using a highly sensitive CLEIA in 497 chronic liver disease patients (297 outpatients and 200 hospitalized with HCC).ResultsIn 497 chronic liver disease patients, serum fCK18 levels were significantly correlated with overall liver condition, including ALT, FIB-4 index and albumin-bilirubin (ALBI) score and were significantly increased in patients with HCC. In 200 HCC patients, serum fCK18 levels were significantly correlated with alpha-fetoprotein (AFP) and des-gamma-carboxy prothrombin (DCP), and were significantly associated with HCC stage, whereas FIB-4 index and ALBI score were not changed based on HCC stage. The Survival group had significantly lower levels of serum fCK18, AFP, DCP, FIB-4 index and ALBI score. A ROC analysis yield area under the curve (AUC) value of 0.728 for serum fCK18 is a significantly high value when compared to AUC measurements for other factors. Notably, AUROC values for serum fCK18 levels were constant in the short- and long-term by time-dependent ROC analysis for the prediction of HCC patient survival. HCC patients with serum fCK18 measured at < 1.15 ng/mL, AFP < 7.7 ng/mL, DCP < 133 mAU/mL, ALBI score < -2.97 or FIB-4 index < 6.4 had significantly longer rates of survival when compared to patients with values exceeding these thresholds. Serum fCK18 (HR, 3.5; P < 0.0001), DCP (HR, 3.2; P < 0.0001) and Barcelona Clinic Liver Cancer (BCLC) (HR, 2.4; P = 0.001) values were independent predictors of patient survival. [Conclusion] Serum fCK18 levels reflect overall liver function, the level of liver fibrosis and the progression of HCC, and are a potential predictor of survival in HCC patients.

Abstract The geriatric nutritional risk index (GNRI) is widely used for nutritional assessment in older inpatients and is associated with postoperative complications and cancer prognosis. We investigated the use of GNRI to predict long-term outcomes in hepatocellular carcinoma of all etiologies after hepatectomy. Overall, 346 patients were examined after propensity score matching. We dichotomized the GNRI score into high GNRI (> 98: N = 173) and low GNRI (≤ 98: N = 173) and evaluated recurrence-free survival (RFS) and overall survival (OS) between both groups. Clinicopathological characteristics between the low- and high-GNRI groups were similar after propensity score matching except for the components of the GNRI score (body mass index and serum albumin level), Child–Pugh score (comprising serum albumin level), and preoperative alpha-fetoprotein level (p

Abstract Background Intrahepatic cholangiocarcinoma (ICC) is primary cancer of the liver with poor prognosis because of its high potential for recurrence and metastasis. We experienced a rare case of ICC with hematogenous metastasis to the falciform ligament. We aimed to clarify the route of metastasis to the mesentery by increasing the accuracy of preoperative imaging and establish a hepatectomy to control cancer. Case presentation An 85-year-old woman was referred to our hospital for a detailed study of progressively increasing liver tumors. She had no subjective symptoms. Her medical history showed hypertension, aneurysm clipping for cerebral hemorrhage, and gallstones. A detailed physical examination and laboratory data evaluation included tumor markers but did not demonstrate any abnormalities. On computed tomography scan, contrast-enhanced ultrasound, and magnetic resonance imaging with gadolinium ethoxybenzyl diethylenetriamine penta-acetic acid, the tumor appeared to be located in liver segment IV, protruding outside the liver. It appeared to contain two distinct components; we suspected ICC in the intrahepatic tumor component. Laparoscopic observation revealed that the extrahepatic lesion was an intra-falciform ligament mass; laparoscopic left hepatectomy was performed. Microscopically, the main tumor in segment IV was 15 mm in diameter and was diagnosed as moderately and poorly differentiated ICC. The tumor of the intra-falciform ligament was not continuous with the main intrahepatic nodule and was also diagnosed as ICC with extensive necrosis. There were no infiltrates in the round ligament of the liver, and several tumor thrombi were found in the small veins of the falciform ligament. Conclusions To date, there have been a few reports of metastases of primary liver cancer to the falciform ligament. At the time of preoperative imaging and pathological diagnosis, this case was suggestive of considering that the malignant liver tumor might be suspected of metastasizing to the falciform ligament. Our case improves awareness of this pathology, which can be useful in the future when encountered by hepatic specialists and surgeons.

Hepatic epithelioid hemangioendothelioma (EHE) is a rare malignant tumor with unknown pathogenesis. Herein, we report a case of a hepatic EHE presenting synchronously with a hepatocellular carcinoma (HCC). To the best of our knowledge, this is the second case report of synchronous hepatic EHE and HCC. An 84-year-old man presented with back pain. During examination, a tumor in liver segment 3 was coincidentally detected. Tumor marker (carbohydrate antigen 19-9, alpha-fetoprotein, and protein induced by vitamin K absence or antagonist-II) levels were elevated. Contrast-enhanced computed tomography revealed perinodular enhancement in the arterial and portal phases. Another tumor was detected in liver segment 2, which was homogeneously enhanced in the arterial phase, followed by washout in the portal and late phases. Based on these imaging findings, we diagnosed the tumor in segment 3 as a solitary cholangiocellular carcinoma and the tumor in segment 2 as a solitary HCC. Lateral sectionectomy of the liver was performed. Microscopically, spindle-shaped and epithelioid cells were present in the tumor in segment 3. On immunohistochemistry, the tumor cells were positive for CD31 and CD34, focally positive for D2-40, and negative for AE1/AE3. Therefore, the tumor in segment 3 was ultimately diagnosed as an EHE and the tumor in segment 2 as a well-differentiated HCC. Preoperative diagnosis of EHE is difficult owing to the lack of specific findings. Intratumoral calcification, halo sign, and lollipop sign are occasionally found in EHE and are useful imaging findings for diagnosis. Clinical behavior is unpredictable, ranging from indolent growth to rapid progression. Clinical or pathological predictors of the course of EHE are urgently required.

Abstract Background Pancreatic trauma is a rare condition with a wide presentation, ranging from hematoma or laceration without main pancreatic duct involvement, to massive destruction of the pancreatic head. The optimal diagnosis of pancreatic trauma and its management approaches are still under debate. The East Association of Surgery for Trauma (EAST) guidelines recommend operative management for high-grade pancreatic trauma; however, several reports have reported successful outcomes with nonoperative management (NOM) for grade III/IV pancreatic injuries. Herein, we report a case of grade IV pancreatic injury that was nonoperatively managed through endoscopic and percutaneous drainage. Case presentation A 47-year-old Japanese man was stabbed in the back with a knife; upon blood examination, both serum amylase and lipase levels were within normal limits. Contrast-enhanced computed tomography (CT) showed extravasation of the contrast medium around the pancreatic head and a hematoma behind the pancreas. Abdominal arterial angiography revealed a pseudo aneurysm in the inferior pancreatoduodenal artery, as well as extravasation of the contrast medium in that artery; coil embolization was thus performed. On day 12, CT revealed a wedge-shaped, low-density area in the pancreatic head, as well as consecutive pseudocysts behind the pancreas; thereafter, percutaneous drainage was performed via the stab wound. On day 22, contrast radiography through the percutaneous drain revealed the proximal and distal parts of the main pancreatic duct. The injury was thus diagnosed as a grade IV pancreatic injury based on the American Association for the Surgery of Trauma guidelines. On day 26, an endoscopic nasopancreatic drainage tube was inserted across the disruption; on day 38, contrast-enhanced CT showed a marked reduction in the fluid collection. Finally, on day 61, the patient was discharged. Conclusions Although the EAST guidelines recommend operative treatment for high-grade pancreatic trauma, NOM with appropriate drainage by endoscopic and/or percutaneous approaches may be a promising treatment for grade III or IV trauma.

Abstract Background Hepatopancreatoduodenectomy (HPD) for diffusely spreading bile duct cancer (DSBDC) usually involves a major hepatectomy and a concomitant pancreatoduodenectomy, and is still challenging surgery because of postoperative liver failure. The present case report demonstrated two cases of DSBDC where we could achieve successful HPD with central liver resection (CHPD) as liver parenchymal sparing surgery. Case presentation In Case 1, endoscopic retrograde cholangiography (ERC) with multiple biopsies revealed that she had DSBDC with Bismuth-Corlette type IIIA. 3D integrated images reconstructed by contrast enhanced CT and CT with drip infusion cholecystocholangiography data revealed the right antero-ventral bile duct (RAVD) confluent to the right hepatic duct and the right antero-dorsal bile duct (RADD) independently confluent to the right posterior bile duct (RPD). Tumor extended common bile duct including intrapancreatic bile duct to the left hepatic duct and RAVD, but the RADD and RPD were spared. Because the future liver remnant (FLR) was assumed not to achieve desirable volume by preoperative portal vein embolization for left or right trisegmentectomy, CHPD including resection of the segments IV and I, and the right antero-ventral segment was done and achieved R0. This procedure is tailored to the anatomical extent of disease in the context of variable biliary anatomy as a modified CHPD, and to our knowledge, this is the first reported case of modified CHPD with antero-dorsal segment preservation. In Case 2, preoperative imaging revealed DSBDC with Bismuth Corlette type IIIA. FLR volume was assumed insufficient for major hepatectomy, CHPD including resection of the segments IV and I, and the right anterior sector was done with R0. The remnant liver volumes of these cases were spared by 55.1% and 25% respectively, and postoperative course was uneventful in both. Conclusion CHPD should be considered a valid option for well-selected cases of DSBDC. This is the first case report of modified CHPD with antero-dorsal segment preservation.

Abstract Background Reactive lymphoid hyperplasia (RLH) of the liver is a benign disorder. It is usually observed in the skin, orbit, thyroid, lung, breast, or gastrointestinal tract, but rarely in the liver. Since the first report of RLH of the liver in 1981, only 75 cases have been described in the past literature. Herein, we report a case of RLH of the liver in a patient with autoimmune hepatitis (AIH), which was misdiagnosed as hepatocellular carcinoma (HCC) preoperatively and resected laparoscopically. Case presentation A 43-year-old Japanese woman with autoimmune hepatitis was followed up for 5 years. During her medical checkup, a hypoechoic nodule in segment 6 of the liver was detected. The nodule had been gradually increasing in size for 4 years. Abdominal ultrasound (US) revealed a round, hypoechoic nodule, 12 mm in diameter. Contrast-enhanced computed tomography (CT) demonstrated that the nodule was slightly enhanced in the arterial dominant phase, followed by perinodular enhancement in the portal and late phases. A magnetic resonance imaging (MRI) scan showed low signal intensity on the T1-weighted image (T1WI) and slightly high signal intensity on the T2-weighted image (T2WI). The findings of the Gd-EOB-DTPA-enhanced MRI were similar to those of contrast-enhanced CT. Tumor markers were all within the normal range. The preoperative diagnosis was HCC and a laparoscopic right posterior sectionectomy was performed. Pathological examination revealed that the nodular lesion was infiltrated by small lymphocytes and plasma cells, and germinal centers were present. Immunohistochemistry was positive for B cell and T cell markers, indicating polyclonality. The final diagnosis was RLH of the liver. Conclusions The pathogenesis of RLH of the liver remains unknown, and a definitive diagnosis based on imaging findings is extremely difficult. If a small, solitary nodule is found in female patients with AIH, the possibility of RLH of the liver should be considered.

Abstract Background Primary malignant melanoma of the lung (PML) is extremely rare. No precursor lesions of PML have been identified, and little is known about the genetic mutations associated with the disease. Typically, 15–20% of malignant melanomas possess NRAS gene mutations, but no cases of NRAS-mutated PML have been reported in the English literature. We present a case of PML involving an NRAS mutation. Case presentation Clinical summary A 74-year-old Japanese female presented with worsening dyspnea and was admitted to hospital. Computed tomography (CT) revealed a right lung (S10) mass and pleural dissemination. Cytology of the pleural effusion in the right lung was performed, and malignant melanoma or clear cell sarcoma was suspected. A dermatological examination and gallium scintigraphy were conducted to determine the primary tumor site, but no suspicious lesions, expect for the right lung mass, were found. After admission, CT showed complicating bilateral pneumonia, and an antibiotic drug was administered, but the pleural effusion got worse. About 2 weeks later, the patient died of respiratory failure and cardiac arrest. An autopsy was performed to determine the histological diagnosis. Autopsy findings A 26x15x20-mm black and pale yellow mass was found in the right lower lobe. Many disseminated nodules were found in the right lobe. The tumor had invaded the right diaphragm. Subcarinal lymph node metastasis was also detected. Immunohistochemically, the tumor cells exhibited positivity for S-100 and HMB45 staining. The patient was diagnosed with malignant melanoma. Sanger sequencing of the tumor detected an NRAS mutation. Conclusions We found an NRAS D54N mutation in PML, which has not been reported previously anywhere in the world. Previous reports indicated that most cases of PML can be classified into the triple-wild-type, but BRAF mutation status was only analyzed in a few cases. We should analyze the mutation patterns of PML to determine whether any subtypes other than the triple-wild-type exist. PML might be a form of de novo cancer.

Background: Multiplex gene-panel tests have recently been developed, including the Oncomine Dx Target Test multi-CDx system (ODxTT), and are commonly used to determine the adaptation of molecular-targeting drugs in non-small cell lung cancer. However, in actual clinical settings, we obtain false results owing to the small biopsy samples. We aimed to optimize tissue preparation methods to improve the success rate. Patients and methods: We investigated 88 biopsy samples. The area and nucleated cell count in the first cut section were quantified using a morphometric software. Pathological parameters, including “total tissue area” and “total nucleated cell count,” were calculated by multiplying the total number of slides submitted to ODxTT. Optimal cutoff values to obtain the best success rate were also determined. Additionally, we morphometrically measured actual tumor cell proportions and attempted to determine the lower limit possible to detect mutations. Results: Optimal cutoff values for “total nucleated cell count” and “total tissue area” were 132,885 and 32.94 mm2, respectively. The actual tumor cell proportions ranged from 4.6 to 97.7%. Even in cases with actual tumor cell proportions of less than 20% (ranging from 4.6 to 19.7%), there was no false negative. Conclusion: Thus, we proposed the pathological criteria for accurate ODxTT. Our result suggested that tumor cell proportions of less than 20% (around 5%) could be applicable for ODxTT. We hope that our results will help pathologists to choose between the multi-plex test (ODxTT) or single-plex test in routine diagnostics.

A 54-year-old woman presented with persistent productive cough, found to have an endobronchial tumor which obstructed the left upper lobe bronchus. Histopathological examination of a transbronchial biopsy of the endobronchial tumor suggested leiomyosarcoma. A positron emission tomography (PET)-CT revealed uterus tumor with moderate uptake of 18F-fluorodeoxyglucose, suggesting uterine malignancies. From the results of histological findings of the resected uterus and the biopsied bronchial specimen, she was diagnosed with uterine leiomyosarcoma and endobronchial metastasis. The systematic use of PET-CT could be useful for patients presenting with tumors that cause endobronchial metastasis of leiomyosarcomas.

Abstract Axl receptor tyrosine kinase is involved in the growth and metastasis and is an indicator of poor prognosis in several cancers including lung cancers. Although a mitogen-activated protein kinase (MAPK) pathway and an epithelial-to-mesenchymal transition (EMT) program are critical, molecular mechanisms underlying the Axl-driven cancer progression have not been fully elucidated. We aimed to identify molecules up-regulated by Axl kinase in lung adenocarcinomas. Through the global gene expression analysis and the functional annotation clustering, we found that AXL expression positively correlated with mRNA expressions of immune checkpoint molecules and chemokine receptors in non-small-cell lung cancers. Validation cohorts including our biobank confirmed that the AXL expression significantly correlated with expression of genes encoding programmed death-ligand1 (PD-L1) and CXC chemokine receptor 6 (CXCR6) in lung adenocarcinoma, especially in epidermal growth factor receptor (EGFR) mutation-positive adenocarcinoma. Pharmacological inhibition of Axl kinase activity decreased mRNA expressions of PD-L1 and CXCR6 in EGFR mutation-positive cell lines. Our data indicates the novel role of Axl kinase as a driver of immune checkpoint molecules and chemokine signalling pathways in the progression of lung adenocarcinomas. This study also highlights the necessity of clinical trials in order to test the efficacy of Axl kinase inhibition in the Axl-highly expressing subset of lung adenocarcinomas.

Abstract Background Liver is a common location of colorectal metastasis, but intrabiliary growth of liver metastasis is not well recognized. Furthermore, intrabiliary metastasis that discovered over 10 years after excision has rarely been described. Case presentation An 80-year-old man was admitted due to the presence of a liver mass in segment 5 (S5) concomitant with elevated carcinoembryonic antigen (CEA), and carbohydrate antigen (CA) 19–9. He underwent right hemicolectomy for colon cancer 12 years prior. Enhanced computed tomography (CT) showed dilated bile ducts with periductal enhancement in S5; hence, cholangiocarcinoma was suspected. Upon anterior segmentectomy, we observed that the cut surface of the specimen exhibited a yellowish-white tumor within the bile ducts. Histologically, the tumor formed within the papillary process, extended along the lumen, and replaced the normal bile duct epithelium. Immunohistochemical studies showed that the liver tumor and primary colon cancer were negative for cytokeratin (CK) 7 and positive for CK20 and Caudal-type homeobox transcription factor 2 (CDX-2). In addition, both tumors showed a same KRAS mutation. We diagnosed the liver tumor as liver metastasis recurrence from colon cancer. Conclusion Intrabiliary growth type of metastasis (IGM) is difficult to distinguish from cholangiocarcinoma, and sometimes develops long after surgery; thus, careful examination of a patient’s history is needed in such cases.

Summary: The ongoing coronavirus disease 2019 (COVID-19) pandemic is a major global public health concern. Although rapid point-of-care testing for detecting viral antigen is important for management of the outbreak, the current antigen tests are less sensitive than nucleic acid testing. In our current study, we produce monoclonal antibodies (mAbs) that exclusively react with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and exhibit no cross-reactivity with other human coronaviruses, including SARS-CoV. Molecular modeling suggests that the mAbs bind to epitopes present on the exterior surface of the nucleocapsid, making them suitable for detecting SARS-CoV-2 in clinical samples. We further select the optimal pair of anti-SARS-CoV-2 nucleocapsid protein (NP) mAbs using ELISA and then use this mAb pair to develop immunochromatographic assay augmented with silver amplification technology. Our mAbs recognize the variants of concern (501Y.V1-V3) that are currently in circulation. Because of their high performance, the mAbs of this study can serve as good candidates for developing antigen detection kits for COVID-19.

Background. Serum Krebs von den Lungen-6 (KL-6) measurement is widely used to assess disease activity or prognosis in patients with interstitial lung diseases (ILDs). However, the clinical differences between high and low serum KL-6 levels at the time of acute exacerbation (AE) of ILD are not well known. Methods. Clinical parameters including age, sex, Charlson Comorbidity Index score (CCIS), blood biomarkers, high-resolution CT findings, and disease mortality were retrospectively compared between high and low KL-6 (cutoff value: 1000 U/mL) patients at the time of diagnosis of AE of ILDs. Results. Thirty-eight high serum KL-6 and 57 low serum KL-6 patients were included. There was no significant difference in 6-month mortality between them (P = 0.685), whereas serum lactate dehydrogenase was a significant predictor of 6-month mortality in the high serum KL-6 patients (odds ratio (OR): 1.006; 95% confidence interval (CI): 1.003–1.009; P

Abstract We describe the case of a 29‐year‐old female non‐smoker who was treated with steroid therapy for a subacute exacerbation of multisystem Langerhans cell histiocytosis (MS‐LCH) with worsening lung, skin, and oral mucosal lesions. The patient developed pneumonia, and computed tomography (CT) showed multiple thin‐walled cavities. Transbronchial lung cryobiopsy (TBLC) specimens revealed Langerhans cells, which were positive for CD1a and S‐100 expression. Similar histological findings were detected in the submandibular gland, skin, and tooth. On the basis of these findings, the patient was diagnosed with MS‐LCH and subsequently treated with steroid therapy. From the literature review, case reports of non‐smokers with pulmonary lesions that worsened and required treatment are rare. Almost all cases recurred and needed additional treatment. This case study contributes to our understanding of the potential role of steroid therapy in MS‐LCH treatment. Additionally, TBLC is a novel, potentially safer, diagnostic tool that has not been previously described for LCH.

Background Ante mortem diagnosis of amyloidosis of the respiratory system is rare. Few data are available regarding clinical presentation, precursor proteins, diagnostic procedures, comorbidities, complications, and outcome. We assessed clinical features of a series of patients with amyloidosis of the respiratory system in two Japanese centres. Methods Medical records of 16 patients with amyloidosis of the respiratory system were retrospectively analysed. Amyloid was diagnosed by polarisation microscopy using Congo red-stained tissue specimens and classified immunohistochemically. Results Median patient age was 71 years, and median follow-up period was 5 years. Immunoglobulin light-chain (AL)-λ amyloidosis was found in eight and AL-κ in five patients. Two patients harboured wild-type transthyretin and one harboured serum amyloid A-derived amyloid. Five different forms of amyloidosis of the respiratory system were observed: nodular pulmonary amyloidosis (seven patients), diffuse alveolar-septal amyloidosis (five), mediastinal lymph node amyloidosis (three), tracheobronchial amyloidosis (one), and pleural amyloidosis (one). One patient had diffuse alveolar-septal amyloidosis and mediastinal lymph node amyloidosis. Three of five patients with diffuse alveolar-septal amyloidosis were diagnosed by transbronchial lung biopsy as having concurrent diffuse alveolar haemorrhage or pneumocystis pneumonia. Two of three patients with mediastinal lymph node amyloidosis were diagnosed by endobronchial ultrasound-guided transbronchial needle aspiration. Conclusions Not only nodular pulmonary amyloidosis, diffuse alveolar-septal amyloidosis, and tracheobronchial amyloidosis but also mediastinal lymph node amyloidosis and pleural amyloidosis should be considered in the differential diagnosis of amyloidosis of the respiratory system. Useful diagnostic methods include transbronchial lung biopsy for diffuse alveolar-septal amyloidosis and endobronchial ultrasound-guided transbronchial needle aspiration for mediastinal lymph node amyloidosis.

An 83-year-old man with a history of interstitial lung disease (ILD) presented with a 1-week history of progressive dyspnea. Computed tomography of the chest revealed right lung-predominant, diffuse, ground glass opacities superimposed upon reticular opacities. Despite methylprednisolone pulse therapy under a diagnosis of acute exacerbation (AE) of ILD, lung involvement and renal dysfunction worsened and disseminated intravascular coagulation developed. The patient died on day 5 of hospitalization. Pathological examination at autopsy revealed diffuse alveolar hemorrhage (DAH) superimposed upon organizing diffuse alveolar damage and usual interstitial pneumonia. We reached a final diagnosis of DAH-predominant AE of idiopathic pulmonary fibrosis (IPF). Abundant expression of the oxidative stress marker hemeoxygenase-1 (HO-1) was observed in alveolar macrophages. These suggest that HO-1 expression in the lungs may offer a useful biomarker for this atypical histological subtype of AE of IPF. Keywords: Diffuse alveolar damage, Diffuse alveolar hemorrhage, Disseminated intravascular coagulation, Hemeoxygenase-1, Oxidative stress

We reported consecutive five patients with BRAF V600E-mutant recurrent or advanced non-small cell lung cancer who were identified between April 2016 and June 2019.All five patients had high programmed death ligand 1 (PD-L1) tumor proportion scores (50, 55, 75, 95 and 100%). Four of the five patients received regimens including pembrolizumab. Of them, one patient experienced a partial response, but two patients experienced progressive disease and one patient was not evaluable. Three of the four patients received regimens including pemetrexed were able to continue long-term treatment.The presence of a BRAF mutation may be associated with higher levels of PD-L1 expression. The effect of immune checkpoint inhibitors therapy in patients with BRAF mutation was similar to the previous reports in patients with previously treated advanced non-small cell lung cancer with PD-L1 tumor proportion score ≥50%. Chemotherapy regimens including pemetrexed may have a positive effect in patients with BRAF V600E-mutant lung adenocarcinoma. Accumulation of additional Case series is necessary to confirm our results.

Abstract Background We experienced a rare case of benign arterial stricture of the right posterior hepatic artery (RPHA) caused by atherosclerosis in a patient with hilar cholangiocarcinoma. Case presentation A 75-year-old man was referred to our hospital for the detailed investigation of serum hepatobiliary enzyme elevation. The patient had a history of hypertension, type 2 diabetes mellitus, and an operative history of coronary artery bypass grafting 10 years before. Endoscopic retrograde cholangiography found strictures of the right and left hepatic ducts with involvement of right anterior and posterior bile ducts. Adenocarcinoma was evident by brush cytology. We diagnosed these findings as hilar cholangiocarcinoma and planned left trisectionectomy including bile duct reconstruction. Although the tumor and RPHA were not adjacent, preoperative multidetector computed tomography revealed a stricture of the RPHA that was 5.6 mm in length. We suspected that atherosclerosis caused the stricture, and we performed digital subtraction angiography and intravascular ultrasonography that showed stricture of the RPHA accompanied by thick plaques in the arterial wall. We placed a bare-metal stent in the RPHA and then performed left trisectionectomy. Since this patient developed bile leakage postoperatively, percutaneous drainage was performed. The bile leakage was successfully controlled, and the patient was discharged 3 months after surgery. Unfortunately, 4 months after hepatectomy, he was re-hospitalized with multiple pyogenic liver abscesses. We performed intensive multimodal treatment for the liver abscesses and stabilized the disease; however, we eventually lost this patient due to liver failure 14 months after surgery. Conclusion To the best of our knowledge, there is no previous literature on atherosclerosis of the RPHA, which was evident preoperatively in our case. Because arterial complications may lead to critical biliary complications in patients who undergo left trisectionectomy, we first performed prophylactic arterial stent placement. We speculate that existing chronic microscopic injury of the peribiliary plexus might have caused the liver abscesses. We successfully diagnosed atherosclerosis of the RPHA preoperatively. However, further investigation of patients is warranted to determine if left trisectionectomy is contraindicated in these patients.

Pulmonary tumor thrombotic microangiopathy (PTTM) is a rare complication of cancer. It is histologically characterized by fibrocellular intimal proliferation in small pulmonary arteries and arterioles in patients with metastatic carcinoma. It is most frequently caused by adenocarcinoma. We report a case of PTTM caused by uterine carcinosarcoma in a 62-year-old female, who exhibited reductions in blood pressure and oxygen saturation. This is the first case report about uterine carcinosarcoma-induced PTTM. Histologically, the primary uterine carcinosarcoma included serous carcinoma and homologous sarcoma components. Many tumor emboli were observed across large regions of both lungs. PTTM was found in the lower lobes. Interestingly, the embolized tumor cells were all derived from the adenocarcinoma component. Immunohistologically, the primary carcinosarcomaexhibited weak positivity for tissue factor (TF), but was negativefor vascular endothelial growth factor-A (VEGF-A). The PTTM tumor cells were positive for TF and weakly positive for VEGF-A. This case suggests that any tumor containing adenocarcinoma can cause PTTM, and immunostaining of the primary tumor might be worthless for determining whether PTTM will develop. PTTM should always be considered during the differential diagnosis of dyspnea in patients with adenocarcinoma. Keywords: Pulmonary tumor thrombotic microangiopathy, Pulmonary tumor embolism, Vascular endothelial growth factor, Tissue factor, Uterine carcinosarcoma

Abstract Background Pulmonary emphysema combined with systemic sclerosis (SSc)-associated interstitial lung disease (ILD) occurs more often in smokers but also in never-smokers. This study aimed to describe a new finding characterized by peculiar emphysematous change with SSc-associated ILD (SSc-ILD). Methods We conducted a retrospective review of 21 consecutive patients with SSc-ILD diagnosed by surgical lung biopsy and focused on the radio-pathological correlation of the emphysematous change. Results Pathological pulmonary emphysema (p-PE) with SSc-ILD was the predominant complication in 16 patients (76.2%) with/without a smoking history, of whom 62.5% were never-smokers. A low attenuation area (LAA) within interstitial abnormality on high-resolution computed tomography (HRCT) was present in 31.3%. Diffusing capacity of the lung for carbon monoxide (DLCO) was lower, disease extent on HRCT higher, and intimal/medial thickening in muscular pulmonary arteries more common in the patients with p-PE with SSc-ILD. However, forced vital capacity (FVC) was well preserved regardless of whether p-PE was observed. Most SSc-ILD patients had pulmonary microvasculature changes in arterioles (90.5%), venules (85.7%), and interlobular veins (81.0%). Conclusions Pulmonary emphysematous changes (LAA within interstitial abnormalities on HRCT and destruction of fibrously thickened alveolar walls) are specific and novel radio-pathological features of SSc-ILD. Peripheral vasculopathy may help to destroy the fibrously thickened alveolar walls, resulting in emphysematous change in SSc-ILD.

Abstract A 77‐year‐old man who had a persistent productive cough for one month was admitted to our hospital. Chest computed tomography (CT) revealed subpleural nodular opacities, irregular pleural thickening with bilateral basal predominance, and a small right pleural effusion. Aspirated fluid was exudative and had the appearance of chylothorax without malignant cells. Surgical lung biopsy specimen showed focal proliferation of neoplastic epithelial cells with lepidic‐predominant pattern and abundant mucus in the alveolar spaces, consistent with invasive mucinous adenocarcinoma (IMA). The results of PD‐L1 expression and the EGFR, ALK, ROS1, and BRAF mutation status analyzed by next generation sequencer were all negative. IMA should be considered in the differential diagnosis of subpleural micronodular opacities accompanied by pleural effusion (chylothorax) on chest CT. Key points Significant findings of the study This case showed subpleural micronodular opacities and chylothorax as unusual chest computed tomography (CT) patterns for invasive mucinous adenocarcinoma (IMA). What this study adds Invasive mucinous adenocarcinoma (IMA) should be considered in the differential diagnosis of subpleural micronodular opacities accompanied by pleural effusion on chest CT.

Erdheim‐Chester disease (ECD), a rare form of non‐Langerhans cell histiocytosis, affects long bones, the retroperitoneal region, and the central nervous, cardiovascular, and pulmonary systems. Most patients with ECD show interlobular septal thickening, centrilobular micronodules, and ground glass opacities on chest computed tomography (CT). We encountered a 66‐year‐old man with ECD who presented at first visit with randomly distributed multiple pulmonary nodules and who then developed large tumour shadows, observed on chest CT. To our knowledge, this random distribution pattern of multiple pulmonary nodules has not previously been reported.

We investigated the significance of MUC21 in EGFR-mutated lung adenocarcinoma (LADC). Two-hundred forty-one surgically resected LADCs (116 EGFR-mutated and 125 wild-type tumors) were examined for immunohistochemical expression of MUC21 protein. A polyclonal antibody and two monoclonal antibodies (heM21C and heM21D) that bind differentially glycosylated MUC21 epitopes were used, and MUC21 proteins detected by these antibodies were named MUC21P, MUC21C, and MUC21D, respectively. MUC21 mRNA levels were semi-quantified and classified into "high" and "low". Among the immunohistochemical expression detected by three different antibodies, high expressors tended to be related to EGFR mutations. The three varieties of the immunohistochemical expressions were related to different histological elements in the EGFR-mutated LADCs. Either MUC21P or MUC21C high expressors had a higher proportion of lepidic elements with low papillary structure and micropapillary elements. MUC21D high expressors had a significantly higher proportion of micropapillary elements (Mann-Whitney test P ≤0.0001). Furthermore, MUC21D high expressors showed high incidence of lymphatic canal invasion and lymph node metastasis (Pearson x2 test, P = 0.0021, P = 0.0125), and a significantly higher recurrence rate (5-year recurrence-free survival 50.7% vs. 73.8%, log-rank test P = 0.0495). MUC21 proteins with a specific glycosylation status may be involved in the progression of EGFR-mutated LADCs, particularly at the stage where tumors are transforming from pure lepidic to micropapillary through low papillary lepidic lesions.

A 53-year-old Japanese female was admitted to our hospital with 3-week history of cough and worsening dyspnea. Chest computed tomography revealed unilateral focal consolidation in the right lower lobe. She underwent transbronchial lung cryobiopsy (TBLC) and histology showed acute fibrinous and organizing pneumonia (AFOP). High-dose methylprednisolone treatment improved her respiratory condition and radiological findings. AFOP is a rare histologic interstitial pneumonia pattern and has been diagnosed by surgical lung biopsy or autopsy in most cases. To our knowledge, this is the first detailed report of AFOP diagnosed by TBLC. TBLC can be performed safely with less invasion and be a useful diagnostic technique for rapidly progressive diffuse lung disease such as AFOP. Keywords: Cryobiopsy, Acute fibrinous and organizing pneumonia, Cryptogenic organizing pneumonia

The purpose of this study was to define histological features determining the malignant potential of EGFR-mutated lung adenocarcinoma (LADC). Surgically resected tumors (EGFR-mutated LADCs with (21) and without (79) lymph node metastasis and EGFR wild-type LADCs with (26) and without (108) lymph node metastasis) and biopsy samples from inoperably advanced tumors (EGFR-mutated LADCs (78) and EGFR wild-type LADCs (99)) were examined. In surgically resected tumors, the EGFR-mutated LADCs with lymph node metastasis had the micropapillary element in a significantly greater proportion than others (Mann-Whitney tests P ≤0.026). The proportion of micropapillary element was higher in the EGFR-mutated LADC at the advanced stage (stage II, III, or IV) than in the tumor at the early stage (stage I) (Mann-Whitney test, P

Birt-Hogg-Dubé syndrome (BHD) is an inherited disorder caused by genetic mutations in the folliculin (FLCN) gene. Individuals with BHD have multiple pulmonary cysts and are at a high risk for developing renal cell carcinomas (RCCs). Currently, little information is available about whether pulmonary cysts are absolutely benign or if the lungs are at an increased risk for developing neoplasms. Herein, we describe 14 pulmonary neoplastic lesions in 7 patients with BHD. All patients were confirmed to have germline FLCN mutations. Neoplasm histologies included adenocarcinoma in situ (n = 2), minimally invasive adenocarcinoma (n = 1), papillary adenocarcinoma (n = 1), micropapillary adenocarcinoma (n = 1), atypical adenomatous hyperplasia (n = 8), and micronodular pneumocyte hyperplasia (MPH)-like lesion (n = 1). Five of the six adenocarcinoma/MPH-like lesions (83.3%) demonstrated a loss of heterozygosity (LOH) of FLCN. All of these lesions lacked mutant alleles and preserved wild-type alleles. Three invasive adenocarcinomas possessed additional somatic events: 2 had a somatic mutation in the epidermal growth factor receptor gene (EGFR) and another had a somatic mutation in KRAS. Immunohistochemical analysis revealed that most of the lesions were immunostained for phospho-mammalian target of rapamycin (p-mTOR) and phospho-S6. Collective data indicated that pulmonary neoplasms of peripheral adenocarcinomatous lineage in BHD patients frequently exhibit LOH of FLCN with mTOR pathway signaling. Additional driver gene mutations were detected only in invasive cases, suggesting that FLCN LOH may be an underlying abnormality that cooperates with major driver gene mutations in the progression of pulmonary adenocarcinomas in BHD patients.