Inflammasome formation in the lungs of patients with fatal COVID-19.

OBJECTIVE: The orf8b protein of the coronavirus SARS-CoV, analogous to SARS-CoV-2, triggers the NLRP3 inflammasome in macrophages in vitro. Deregulated inflammasome-mediated release of interleukin-1 family cytokines is important in hyper-inflammatory syndromes, like happens in SARS-CoV-2-mediated cytokine release syndrome. We propose that an intense inflammasome formation characterizes the lungs of patients with fatal COVID-19 disease due to pneumonia and acute respiratory distress syndrome (ARDS). METHODS: Samples from four patients with confirmed COVID-19 pneumonia who had been hospitalized at the Hospital of the University of Trieste (Italy) and died of ARDS and four lung samples from a historical repository from subjects who had died of cardiopulmonary arrest and had not been placed on mechanical ventilation and without evidence of pulmonary infection at postmortem examination were collected. Pathology samples had been fixed in formalin 10% at time of collection and subsequently embedded in paraffin. We conducted staining for ASC (Apoptosis-associated Speck-like protein containing a Caspase recruitment domain), NLRP3 (NACHT, LRR, and PYD domains-containing protein 3), and cleaved caspase-1. RESULTS: Intense expression of the inflammasome was detected, mainly in leukocytes, within the lungs of all patients with fatal COVID-19 in the areas of lung injury. The number of ASC inflammasome specks per high power fields was significantly higher in the lungs of patients with fatal COVID-19 as compared with the lungs of control subjects (52 ± 22 vs 6 ± 3, P = 0.0064). CONCLUSIONS: These findings identify the presence of NLRP3 inflammasome aggregates in the lungs of fatal COVID-19 pneumonia thus providing the potential molecular link between viral infection and cytokine release syndrome.

Reliability of histopathologic diagnosis of fibrotic interstitial lung disease: an international collaborative standardization project.

BACKGROUND: Current interstitial lung disease (ILD) diagnostic guidelines assess criteria across clinical, radiologic and pathologic domains. Significant interobserver variation in histopathologic evaluation has previously been shown but the specific source of these discrepancies is poorly documented. We sought to document specific areas of difficulty and develop improved criteria that would reduce overall interobserver variation. METHODS: Using an internet-based approach, we reviewed selected images of specific diagnostic features of ILD histopathology and whole slide images of fibrotic ILD. After an initial round of review, we confirmed the presence of interobserver variation among our group. We then developed refined criteria and reviewed a second set of cases. RESULTS: The initial round reproduced the existing literature on interobserver variation in diagnosis of ILD. Cases which were pre-selected as inconsistent with usual interstitial pneumonia/idiopathic pulmonary fibrosis (UIP/IPF) were confirmed as such by multi-observer review. Cases which were thought to be in the spectrum of chronic fibrotic ILD for which UIP/IPF were in the differential showed marked variation in nearly all aspects of ILD evaluation including extent of inflammation and extent and pattern of fibrosis. A proposed set of more explicit criteria had only modest effects on this outcome. While we were only modestly successful in reducing interobserver variation, we did identify specific reasons that current histopathologic criteria of fibrotic ILD are not well defined in practice. CONCLUSIONS: Any additional classification scheme must address interobserver variation in histopathologic diagnosis of fibrotic ILD order to remain clinically relevant. Improvements to tissue-based diagnostics may require substantial resources such as larger datasets or novel technologies to improve reproducibility. Benchmarks should be established for expected outcomes among clinically defined subgroups as a quality metric.

Usefulness of Cyclin D1/Podoplanin Dual Immunohistochemical Stain to Differentiate Malignant Mesothelioma From Reactive Mesothelial Proliferations.

OBJECTIVES: To examine the potential of cyclin D1/podoplanin dual immunohistochemical stain to differentiate malignant mesothelioma from reactive mesothelial proliferations. METHODS: Cyclin D1/podoplanin dual immunohistochemistry was performed on 34 surgical cases of reactive mesothelial proliferations, malignant mesothelioma, and nonmesothelioma malignancies. RESULTS: All 15 reactive mesothelial proliferations demonstrated less than 50% cyclin D1 staining with variable to diffuse podoplanin staining. In 6 (60%) of 10 cases of epithelioid malignant mesothelioma, the dual stain supported the diagnosis. Less than 50% cyclin D1 staining was noted in the remaining four cases, including small biopsy specimens or cases with focal papillary architecture. The five cases of sarcomatoid/desmoplastic/biphasic mesothelioma showed more than 50% cyclin D1 staining with focal to absent podoplanin staining. Well-differentiated papillary mesothelioma appears to demonstrate less than 25% cyclin D1 staining. CONCLUSIONS: The cyclin D1/podoplanin dual stain is reliable and may be used to aid in differentiation of benign mesothelial proliferations from malignant tumors. In addition, histologic features and other ancillary testing may support the classification of cases with an inconclusive cyclin D1/podoplanin staining.

Too Sensitive or Just Right?

OBJECTIVES: To compare the performance of the rabbit monoclonal antihuman CD246 antibody (D5F3 clone) with the established ALK1 clone for immunohistochemical assessment of anaplastic large cell lymphoma (ALCL). METHODS: Archival cases of ALCL (n = 27) were assessed immunohistochemically by use of ALK1 and D5F3 clones under standard Clinical Laboratory Improvement Amendments-compliant conditions. The intensity of cytoplasmic staining (0 = none; 1 = faint; 2 = moderate; 3+ = strong) and proportion of neoplastic cells (0%, <5%, 5%-50%, >50%) were evaluated and compared with clinical ALK break-apart fluorescence in situ hybridization (FISH) assays. RESULTS: Nine ALCL specimens were positive for ALK expression by ALK1 staining (33%; 1 = 1+; 0 = 2+; 8 = 3+), while 14 were positive by D5F3 staining (48%; 3 = 1+; 1 = 2+; 10 = 3+). Across the cohort, D5F3 staining showed a significantly greater proportion of cells staining positive (P = .02) and greater intensity (P = .03). Of 3 cases positive for D5F3 only with FISH results, none showed rearrangements, although 1 showed copy number gains at the ALK locus in a subset of cells. CONCLUSIONS: Overall, D5F3 showed greater stain intensity and proportion staining than ALK1 in ALK-positive ALCL cases, which is especially helpful in limited samples. Caution and consideration of orthogonal ALK testing types is recommended, especially for cases with weak or focal staining.

Preferential human epidermal growth factor receptor 2 expression in myometrial and lymphovascular invasion of a uterine carcinosarcoma: A case report.

This case report describes a unique pattern of human epidermal growth factor receptor 2 expression in a patient with uterine carcinosarcoma. The endometrial tumor showed biphasic morphology composed of serous carcinoma and a heterologous high-grade sarcoma component. Human epidermal growth factor receptor 2 immunostaining showed positive (3+) expression in foci of myoinvasion, lymphovascular invasion, and lymph node metastasis but was negative in both the endometrial surface tumor and sarcomatous component. Fluorescent in situ hybridization testing for human epidermal growth factor receptor 2 confirmed no amplification within the endometrial surface carcinoma component and amplification of the lymphovascular invasion component. As the use of human epidermal growth factor receptor 2 immunohistochemical evaluation becomes more commonplace for therapeutic consideration in patients with uterine carcinosarcoma, interpretation of the immunohistochemical should be performed preferentially on large tissue sections including both a surface, myoinvasive portions, and suspected areas of lymphovascular invasion and lymph node metastasis.

Caspase 9b Drives Cellular Transformation, Lung Inflammation, and Lung Tumorigenesis.

Caspase 9 undergoes alternative splicing to produce two opposing isoforms: proapoptotic Caspase 9a and pro-survival Caspase 9b (C9b). Previously, our laboratory reported that C9b is expressed in majority of non-small cell lung cancer tumors and directly activates the NF-κB pathway. In this study, the role of C9b in activation of the NF-κB pathway in vivo, lung inflammation and immune responses, and lung tumorigenesis were examined. Specifically, a transgenic mouse model expressing human C9b in the lung pneumocytes developed inflammatory lung lesions, which correlated with enhanced activation of the NF-κB pathway and increased influx of immunosuppressive myeloid-derived suppressor cells in contrast to wild-type mice. C9b mice presented with facial dermatitis, a thickened and disorganized dermis, enhanced collagen depth, and increased serum levels of IL6. C9b mice also developed spontaneous lung tumors, and C9b cooperated with oncogenic KRAS in lung tumorigenesis. C9b expression also cooperated with oncogenic KRAS and p53 downregulation to drive the full cell transformation of human bronchial epithelial cells (e.g., tumor formation). IMPLICATIONS: Our findings show that C9b can directly activate NF-κB pathway in vivo to modulate lung inflammation, immune cell influx, and peripheral immune responses, which demonstrates that C9b is key factor in driving cell transformation and lung tumorigenesis.

Breast-Conserving Surgeries With and Without Cavity Shave Margins Have Different Re-excision Rates and Associated Overall Cost: Institutional and Patient-Driven Decisions for Its Utilization.

BACKGROUND: Reducing the rate of margin positivity and reoperations remains a paramount goal in breast-conserving surgery (BCS). This study assesses the effectiveness of standard partial mastectomy with cavity shave margins (CSM) compared with partial mastectomy with selective margin resection (SPM), with regard to outcomes of the initial surgeries, re-excisions, and overall costs. PATIENTS AND METHODS: This is a retrospective review of 122 eligible breast cancer patients who underwent BCS at one institution. The CSM and SPM groups each included 61 patients, matched for presurgical diagnoses and clinical stage. Data including margin status, rates and reason for re-excision, associated operation times, and costs were analyzed. RESULTS: Patients undergoing CSM had less than half the rate of positive margins (PMs) (10% vs. 23%; P = .03) and re-excisions (8% vs. 23%; P = .02) compared with SPM. In the former group, the margin involvement was focal, and re-excisions were performed almost exclusively for PMs. For SPM, the majority (92%) of PMs were on the main lumpectomy specimen rather than the selective margins, and re-excisions included, in addition to PMs, extensive or multifocal negative but close margins. Reduced breast tissue volumes were removed with CSM, particularly for patients undergoing a single surgery (47 vs. 165 cm3; P < .001). The initial surgery with CSM is on average 27% more costly than that for SPM (P < .001), due to the increased pathology costs which are partially offset by the increased re-excision rates in SPM. CONCLUSION: Circumferential cavity shaving, associated with consistent lower PMs, tissue volumes excised, and re-excision rates, is appropriate for routine implementation as a method offering superior surgical outcomes.

Oncogenic B-Myb Is Associated With Deregulation of the DREAM-Mediated Cell Cycle Gene Expression Program in High Grade Serous Ovarian Carcinoma Clinical Tumor Samples.

Cell cycle control drives cancer progression and treatment response in high grade serous ovarian carcinoma (HGSOC). MYBL2 (encoding B-Myb), an oncogene with prognostic significance in several cancers, is highly expressed in most HGSOC cases; however, the clinical significance of B-Myb in this disease has not been well-characterized. B-Myb is associated with cell proliferation through formation of the MMB (Myb and MuvB core) protein complex required for transcription of mitotic genes. High B-Myb expression disrupts the formation of another transcriptional cell cycle regulatory complex involving the MuvB core, DREAM (DP, RB-like, E2F, and MuvB), in human cell lines. DREAM coordinates cell cycle dependent gene expression by repressing over 800 cell cycle genes in G0/G1. Here, we take a bioinformatics approach to further evaluate the effect of B-Myb expression on DREAM target genes in HGSOC and validate our cellular model with clinical specimens. We show that MYBL2 is highly expressed in HGSOC and correlates with expression of DREAM and MMB target genes in both The Cancer Genome Atlas (TCGA) as well as independent analyses of HGSOC primary tumors (N = 52). High B-Myb expression was also associated with poor overall survival in the TCGA cohort and analysis by a DREAM target gene expression signature yielded a negative impact on survival. Together, our data support the conclusion that high expression of MYBL2 is associated with deregulation of DREAM/MMB-mediated cell cycle gene expression programs in HGSOC and may serve as a prognostic factor independent of its cell cycle role. This provides rationale for further, larger scale studies aimed to determine the clinical predictive value of the B-Myb gene expression signature for treatment response as well as patient outcomes.

Intimal sarcoma of the pulmonary artery treated with neoadjuvant radiation prior to pulmonary artery resection and reconstruction.

Intimal sarcoma (IS) is a rare malignancy arising in the great vessels or heart, most commonly in the pulmonary artery, primarily treated with surgical intervention. We report a case of IS of the pulmonary artery diagnosed after an endarterectomy to remove a suspected pulmonary embolism. The tumor could not be entirely resected and showed interval growth at post-operative follow up. Neoadjuvant radiotherapy was then delivered to improve resectability. Imaging confirmed decreased tumor size, and a surgical resection with pulmonary artery reconstruction and right upper lobectomy was then successfully performed. Adjuvant gemcitabine and docetaxel was later initiated. Four months post-operatively, the patient is alive without disease recurrence. While prior reports in the literature document use of adjuvant chemotherapy and radiotherapy for treatment of IS of the pulmonary artery, no prior experience has documented utility of neoadjuvant radiotherapy for improvement of resectability. Our experience suggests that neoadjuvant radiation should be considered to improve resectability in cases of borderline resectable IS of the pulmonary artery.

The oncogenicity of tumor-derived mutant p53 is enhanced by the recruitment of PLK3.

p53 mutations with single amino acid changes in cancer often lead to dominant oncogenic changes. Here, we have developed a mouse model of gain-of-function (GOF) p53-driven lung cancer utilizing conditionally active LSL p53-R172H and LSL K-Ras-G12D knock-in alleles that can be activated by Cre in lung club cells. Mutation of the p53 transactivation domain (TAD) (p53-L25Q/W26S/R172H) eliminating significant transactivation activity resulted in loss of tumorigenicity, demonstrating that transactivation mediated by or dependent on TAD is required for oncogenicity by GOF p53. GOF p53 TAD mutations significantly reduce phosphorylation of nearby p53 serine 20 (S20), which is a target for PLK3 phosphorylation. Knocking out PLK3 attenuated S20 phosphorylation along with transactivation and oncogenicity by GOF p53, indicating that GOF p53 exploits PLK3 to trigger its transactivation capability and exert oncogenic functions. Our data show a mechanistic involvement of PLK3 in mutant p53 pathway of oncogenesis.

Flower lose, a cell fitness marker, predicts COVID-19 prognosis.

Risk stratification of COVID-19 patients is essential for pandemic management. Changes in the cell fitness marker, hFwe-Lose, can precede the host immune response to infection, potentially making such a biomarker an earlier triage tool. Here, we evaluate whether hFwe-Lose gene expression can outperform conventional methods in predicting outcomes (e.g., death and hospitalization) in COVID-19 patients. We performed a post-mortem examination of infected lung tissue in deceased COVID-19 patients to determine hFwe-Lose's biological role in acute lung injury. We then performed an observational study (n = 283) to evaluate whether hFwe-Lose expression (in nasopharyngeal samples) could accurately predict hospitalization or death in COVID-19 patients. In COVID-19 patients with acute lung injury, hFwe-Lose is highly expressed in the lower respiratory tract and is co-localized to areas of cell death. In patients presenting in the early phase of COVID-19 illness, hFwe-Lose expression accurately predicts subsequent hospitalization or death with positive predictive values of 87.8-100% and a negative predictive value of 64.1-93.2%. hFwe-Lose outperforms conventional inflammatory biomarkers and patient age and comorbidities, with an area under the receiver operating characteristic curve (AUROC) 0.93-0.97 in predicting hospitalization/death. Specifically, this is significantly higher than the prognostic value of combining biomarkers (serum ferritin, D-dimer, C-reactive protein, and neutrophil-lymphocyte ratio), patient age and comorbidities (AUROC of 0.67-0.92). The cell fitness marker, hFwe-Lose, accurately predicts outcomes in COVID-19 patients. This finding demonstrates how tissue fitness pathways dictate the response to infection and disease and their utility in managing the current COVID-19 pandemic.

Peyronie disease: a clinicopathologic study of 71 cases with emphasis on histopathologic patterns and prevalent metaplastic ossification.

Peyronie disease (PD) is a benign, superficial fibromatosis involving the fascial structures of the penis, causing deformity, pain, and loss of function, for which there are few contemporary studies of the histopathology. We performed a multi-institutional review of 74 routine and consultation specimens submitted with clinical concern for PD. Of these, three non-PD lesions were identified and excluded (a myointimoma, a mammary-type myofibroblastoma, and fibrocalcific atherosclerosis). Of the 71 confirmed to be PD, the majority of patients were white (83%), with a median age of 55 years (range: 26-88). The dorsal aspect of the penis was the most common site involved (78%), followed by lateral (12%) and ventral (10%) aspects. The median degree of curvature was 70° (range: 20-360°). On review, three overall histologic patterns characterized the lesions resected: dense fibrotic plaque (61%), dense fibrotic plaque with focal or patchy metaplastic ossification (35%), and plaque composed predominantly of metaplastic ossification (4%). The fibrotic component was predominantly nodular (18%), hyalinized/lamellar (46%), or mixed (32%), excepting two cases consisting entirely of metaplastic bone. Chronic inflammation, when present, was most often focal and perivascular in distribution. In one case, an excision after collagenase treatment showed myxoid change and increased stromal cellularity. Overall, these findings define the range of PD histology, particularly emphasizing that the calcification noted clinically nearly always represents bona fide metaplastic ossification. Such context will be of value in evaluating specimens prospectively, in light of changing practices and the use of new technologies for treatment.

Loss of BAP1 Expression in Atypical Mesothelial Proliferations Helps to Predict Malignant Mesothelioma.

Distinguishing reactive mesothelial proliferation from malignant mesothelioma (MM) can be difficult, particularly on small biopsies. In this scenario, a diagnosis of atypical mesothelial proliferation might be rendered. However, the distinction between a reactive process and MM is important for prognosis and treatment. Recently, loss of BRCA1-associated protein 1 (BAP1) expression and/or homozygous deletion of CDKN2A were identified in some MM, but not in reactive mesothelial proliferations. We studied 34 cases of atypical mesothelial proliferation from our institutional files (1993 to 2016) for BAP1 expression, deletion of CDKN2A, and clinical outcome. Fifteen of 34 patients (44%) were subsequently diagnosed with MM. BAP1 expression was lost in 6 of these 15 (40%) patients. Ten of 15 (67%) patients died of disease within a median time of 18.2 months. BAP1 expression was also lost in 1 case of probable MM. In this case atypical mesothelial proliferation was identified in the pleura during a lobectomy procedure for lung adenocarcinoma. Follow-up of 57.0 months was remarkable for visceral and parietal pleural thickening with continued unilateral effusion identified on imaging studies but no subsequent definitive diagnosis of MM. CDKN2A studies by fluorescence in situ hybridization (performed in 31 cases) found no homozygous deletion of that gene in any case. In conclusion, loss of BAP1 expression in atypical mesothelial proliferation helps to predict MM and is a useful adjunct test in these cases. Homozygous deletion of CDKN2A in mesothelial cell proliferations did not prove to be useful to predict MM in cases of atypical mesothelial proliferation.

Esophageal Actinomycoses Mimicking Malignancy.

Actinomycosis is caused by anaerobic bacteria and rarely affects the esophagus. We present a case of esophageal actinomycosis in a 55-year old woman that mimicked malignancy. The patient presented with dysphagia and weight loss. Preoperative esophagogastroscopic biopsy revealed purulent material, but was inconclusive. Endoscopic ultrasonography suggested esophageal cancer, and chest computed tomography showed a mass in the lower esophagus surrounded by inflammation. The patient underwent esophagogastrectomy, and histopathology examination of the specimen revealed distal esophageal actinomycosis. Preoperative diagnosis of esophageal actinomycosis is difficult, but clinicians should be aware of its unusual presentations and its ability to mimic malignancy.