Unbalanced t(2;19) and t(2;16) in a neurofibroma

Neurofibromas are a benign heterogeneous group of tumors arising from peripheral nerve sheaths; they consist of a mixture of Schwann cells, fibroblasts, perineural cells, neuronal processes, and mast cells. Neurofibromas may present as dermal (cutaneous or subcutaneous) or plexiform (diffuse growths, spinal tumors, nodular or diffuse) tumors. They may present as isolated sporadic tumors in the general population or occur as a part of an autosomal dominant tumor diathesis in von Recklinghausen neurofibromatosis type 1 (NF1)

Well-differentiated Papillary Mesothelioma With Invasive Foci

Well-differentiated papillary mesotheliomas (WDPMs) are usually encountered as incidental findings in the peritoneal cavity in women. Most WDPMs are benign, and the histologic features that indicate a more aggressive course are controversial. We report 20 cases of WDPM, which contained invasive foci. Thirteen cases arose in the peritoneal cavity, 1 in a hernia sac, 3 in the pleural cavity, and 3 in hydroceles. The female:male ratio was 16:4, and age range was 7 to 74 years. Tumor was multifocal in 15 cases. Some tumors showed back-to-back papillae, a pattern mimicking invasion but discernible on pan-keratin stain as compressive crowding. True invasive patterns ranged from simple bland-appearing glands invading the stalks of the papillae to solid foci of invasive tumor of higher cytologic grade than the original WDPM. All 5 tested cases were negative for p16 deletion by fluorescence in situ hybridization, but 2/3 had abnormal karyotypes. Recurrences were seen in 8 patients, and in 4 multiple recurrences were documented. Of 16 patients with follow-up, 14 are alive from periods of 6 months to 6 years (average 3.5 y), and 2 have known recurrent disease. One patient died of disseminated tumor at 8 years but without histologic confirmation of the nature of the tumor. We conclude that WDPM with invasive foci in the papillae appear to be prone to multifocality and recurrence, but that they rarely give rise to life-threatening disease. We suggest that these lesions be called WDPM with invasive foci to alert clinicians to the possibility of recurrence

Prevalence and Mechanisms of Mucus Accumulation in COVID-19 Lung Disease

Rationale: The incidence and sites of mucus accumulation, and molecular regulation of mucin gene expression, in COVID-19 lung disease have not been reported. Objectives: Characterize incidence of mucus accumulation and the mechanisms mediating mucin hypersecretion in COVID-19 lung disease. Methods: Airway mucus and mucins were evaluated in COVID-19 autopsy lungs by AB-PAS and immunohistochemical staining, RNA in situ hybridization, and spatial transcriptional profiling. SARS-CoV-2-infected human bronchial epithelial (HBE) cultures were utilized to investigate mechanisms of SARS-CoV-2-induced mucin expression and synthesis and test candidate countermeasures. Measurements and Main Results: MUC5B and variably MUC5AC RNA levels were increased throughout all airway regions of COVID-19 autopsy lungs, notably in the sub-acute/chronic disease phase following SARS-CoV-2 clearance. In the distal lung, MUC5B-dominated mucus plugging was observed in 90% of COVID-19 subjects in both morphologically identified bronchioles and microcysts, and MUC5B accumulated in damaged alveolar spaces. SARS-CoV-2-infected HBE cultures exhibited peak titers 3 days post inoculation, whereas induction of MUC5B/MUC5AC peaked 7-14 days post inoculation. SARS-CoV-2 infection of HBE cultures induced expression of EGFR ligands and inflammatory cytokines (e.g., IL-1α/β) associated with mucin gene regulation. Inhibiting EGFR/IL-1R pathways, or dexamethasone administration, reduced SARS-CoV-2-induced mucin expression. Conclusions: SARS-CoV-2 infection is associated with a high prevalence of distal airspace mucus accumulation and increased MUC5B expression in COVID-19 autopsy lungs. HBE culture studies identified roles for EGFR and IL-1R signaling in mucin gene regulation post SARS-CoV-2 infection. These data suggest that time-sensitive mucolytic agents, specific pathway inhibitors, or corticosteroid administration may be therapeutic for COVID-19 lung disease. This article is open access and distributed under the terms of the Creative Commons Attribution Non-Commercial No Derivatives License 4.0 (http://creativecommons.org.libproxy.lib.unc.edu/licenses/by-nc-nd/4.0/)

Validation of Interobserver Agreement in Lung Cancer Assessment: Hematoxylin-Eosin Diagnostic Reproducibility for Non–Small Cell Lung Cancer: The 2004 World Health Organization Classification and Therapeutically Relevant Subsets

Precise subtype diagnosis of non–small cell lung carcinoma is increasingly relevant, based on the availability of subtype-specific therapies, such as bevacizumab and pemetrexed, and based on the subtype-specific prevalence of activating epidermal growth factor receptor mutations

System-wide transcriptome damage and tissue identity loss in COVID-19 patients

The molecular mechanisms underlying the clinical manifestations of coronavirus disease 2019 (COVID-19), and what distinguishes them from common seasonal influenza virus and other lung injury states such as acute respiratory distress syndrome, remain poorly understood. To address these challenges, we combine transcriptional profiling of 646 clinical nasopharyngeal swabs and 39 patient autopsy tissues to define body-wide transcriptome changes in response to COVID-19. We then match these data with spatial protein and expression profiling across 357 tissue sections from 16 representative patient lung samples and identify tissue-compartment-specific damage wrought by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, evident as a function of varying viral loads during the clinical course of infection and tissue-type-specific expression states. Overall, our findings reveal a systemic disruption of canonical cellular and transcriptional pathways across all tissues, which can inform subsequent studies to combat the mortality of COVID-19 and to better understand the molecular dynamics of lethal SARS-CoV-2 and other respiratory infections., • Across all organs, fibroblast, and immune cell populations increase in COVID-19 patients • Organ-specific cell types and functional markers are lost in all COVID-19 tissue types • Lung compartment identity loss correlates with SARS-CoV-2 viral loads • COVID-19 uniquely disrupts co-occurrence cell type clusters (different from IAV/ARDS) , Park et al. report system-wide transcriptome damage and tissue identity loss wrought by SARS-CoV-2, influenza, and bacterial infection across multiple organs (heart, liver, lung, kidney, and lymph nodes) and provide a spatiotemporal landscape of COVID-19 in the lung

SARS-CoV-2 infection produces chronic pulmonary epithelial and immune cell dysfunction with fibrosis in mice

A subset of individuals who recover from coronavirus disease 2019 (COVID-19) develop post-acute sequelae of SARS-CoV-2 (PASC), but the mechanistic basis of PASC-associated lung abnormalities suffers from a lack of longitudinal tissue samples. The mouse-adapted severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) strain MA10 produces an acute respiratory distress syndrome (ARDS) in mice similar to humans. To investigate PASC pathogenesis, studies of MA10-infected mice were extended from acute to clinical recovery phases. At 15 to 120 days post-virus clearance, pulmonary histologic findings included subpleural lesions composed of collagen, proliferative fibroblasts, and chronic inflammation, including tertiary lymphoid structures. Longitudinal spatial transcriptional profiling identified global reparative and fibrotic pathways dysregulated in diseased regions, similar to human COVID-19. Populations of alveolar intermediate cells, coupled with focal up-regulation of pro-fibrotic markers, were identified in persistently diseased regions. Early intervention with antiviral EIDD-2801 reduced chronic disease, and early anti-fibrotic agent (nintedanib) intervention modified early disease severity. This murine model provides opportunities to identify pathways associated with persistent SARS-CoV-2 pulmonary disease and test countermeasures to ameliorate PASC., After recovery from acute SARS-CoV-2 infection, mice exhibit chronic lung disease similar to some humans, allowing for testing of therapeutics

SARS-CoV-2 Reverse Genetics Reveals a Variable Infection Gradient in the Respiratory Tract

The mode of acquisition and causes for the variable clinical spectrum of coronavirus disease 2019 (COVID-19) remain unknown. We utilized a reverse genetics system to generate a GFP reporter virus to explore severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pathogenesis and a luciferase reporter virus to demonstrate sera collected from SARS and COVID-19 patients exhibited limited cross-CoV neutralization. High-sensitivity RNA in situ mapping revealed the highest angiotensin-converting enzyme 2 (ACE2) expres-sion in the nose with decreasing expression throughout the lower respiratory tract, paralleled by a striking gradient of SARS-CoV-2 infection in proximal (high) versus distal (low) pulmonary epithelial cultures. COVID-19 autopsied lung studies identified focal disease and, congruent with culture data, SARS-CoV-2-in-fected ciliated and type 2 pneumocyte cells in airway and alveolar regions, respectively. These findings high-light the nasal susceptibility to SARS-CoV-2 with likely subsequent aspiration-mediated virus seeding to the lung in SARS-CoV-2 pathogenesis. These reagents provide a foundation for investigations into virus-host in-teractions in protective immunity, host susceptibility, and virus pathogenesis

Prognostic considerations of the new World Health Organization classification of lung adenocarcinoma

The 2015 World Health Organization (WHO) lung adenocarcinoma classification divides tumours into categories of indolent pre-invasive, minimally invasive and predominantly lepidic and, by examining predominant patterns of invasion, allows for further stratification into intermediate and high-grade tumours. The impact of the 2015 classification on prognosis was reviewed by a PubMed search for search terms “adenocarcinoma”, “lung pathology” and “prognosis” and relevant publications reviewed. These were sorted for data on stage and survival as impacted by histological classification, and survival studies were separated into all stage versus stage 1 studies. Predictive aspects of histological classification were also examined, but molecular correlates were not. The separation of adenocarcinoma in situ and minimally invasive adenocarcinoma from invasive subtypes as distinct prognostic entities and the prognostic significance, for disease specific and overall survival for low- and high-grade categories, are discussed. The impact on stage at presentation including risk of node metastasis by histology is examined, as well as histology in relation to recurrence after surgery. Early data with regard to the value of predominant histology in the prediction of chemotherapy response will also be explored