Pericardial Mesotheliomas.

Primary pericardial mesothelioma (PM) is a rare tumor arising from the mesothelial cells of the pericardium. It has an incidence of <0.05% and comprises <2% of all mesotheliomas; however, it is the most common primary malignancy of the pericardium. PM should be distinguished from secondary involvement by the spread of pleural mesothelioma or metastases, which are more common. Although data are controversial, the association between asbestos exposure and PM is less documented than that with other mesotheliomas. Late clinical presentation is common. Symptoms may be nonspecific but are usually related to pericardial constriction or cardiac tamponade, and diagnosis can be challenging usually requiring multiple imaging modalities. Echocardiography, computed tomography, and cardiac magnetic resonance demonstrate heterogeneously enhancing thickened pericardium, usually encasing the heart, with findings of constrictive physiology. Tissue sampling is essential for diagnosis. Histologically, similar to mesotheliomas elsewhere in the body, PM is classified as epithelioid, sarcomatoid, or biphasic, with the biphasic type being the most common. Combined with morphologic assessment, the use of immunohistochemistry and other ancillary studies is helpful for distinguishing mesotheliomas from benign proliferative processes and other neoplastic processes. The prognosis of PM is poor with about 22% 1-year survival. Unfortunately, the rarity of PM poses limitations for comprehensive and prospective studies to gain further insight into the pathobiology, diagnosis, and treatment of PM.

Thymomas With Intravascular and Intracardiac Growth.

Thymomas are derived from the epithelial component of the thymus and constitute the most common tumor of the anterior mediastinum. These neoplasms are considered malignant for their potential for invasion and metastases. Several histopathologic subclassification schemes have been proposed over the years, however, correlation of histotypes with prognosis remains controversial. In contrast, studies invariably have shown that staging and resection status correlate with oncologic behavior and disease outcomes. In this regard, several staging systems have been presented, though transcapsular invasion and degree of involvement of adjacent anatomic structures are common denominators of all schemes. Involvement of the great vessels and heart most commonly results from direct invasion, which may lead to unusual clinical presentations such as superior vena cava syndrome. Moreover, intravascular and intracardiac growth with or without direct mural invasion rarely occurs. We provide an overview of thymomas with intravascular and intracardiac involvement.

Prospective cohort of cryobiopsy in interstitial lung diseases: a single center experience.

RATIONALE: Transbronchial cryobiopsy has been increasingly used to diagnose interstitial lung diseases. However, there is uncertainty regarding its accuracy and risks, mainly due to a paucity of prospective or randomized trials comparing cryobiopsy to surgical biopsy. OBJECTIVES: To evaluate the diagnostic yield and complications of cryobiopsy in patients selected by multidisciplinary discussion. METHODS: This was a prospective cohort from 2017 to 2019. We included consecutive patients with suspected interstitial lung diseases being considered for lung biopsy presented at our multidisciplinary meeting. MEASUREMENTS AND MAIN RESULTS: Of 112 patients, we recommended no biopsy in 31, transbronchial forceps biopsy in 16, cryobiopsy in 54 and surgical biopsy in 11. By the end of the study, 34 patients had had cryobiopsy and 24 patients, surgical biopsy. Overall pathologic and multidisciplinary diagnostic yield of cryobiopsy was 47.1% and 61.8%, respectively. The yield increased over time for both pathologic (year 1: 28.6%, year 2: 54.5%, year 3: 66.7%, p = 0.161) and multidisciplinary (year 1: 50%, year 2: 63.6%, year 3: 77.8%, p = 0.412) diagnosis. Overall rate of grade 4 bleeding after cryobiopsy was 11.8%. Cryobiopsy required less chest tube placement (11.8% vs 100%, p < 0.001) and less hospitalizations compared to surgical biopsy (26.5% vs 95.7%, p < 0.001), but hospitalized patients had a longer median hospital stay (2 days vs 1 day, p = 0.004). CONCLUSIONS: Diagnostic yield of cryobiopsy increased over time but the overall grade 4 bleeding rate was 11.8%.

Donor-derived human herpesvirus 8 and development of Kaposi sarcoma among 6 recipients of organs from donors with high-risk sexual and substance use behavior.

Kaposi sarcoma (KS) can develop following organ transplantation through reactivation of recipient human herpesvirus 8 (HHV-8) infection or through donor-derived HHV-8 transmission. We describe 6 cases of donor-derived HHV-8 infection and KS investigated from July 2018 to January 2020. Organs from 6 donors, retrospectively identified as HHV-8-positive, with a history of drug use disorder, were transplanted into 22 recipients. Four of 6 donors had risk factors for HHV-8 infection reported in donor history questionnaires. Fourteen of 22 organ recipients (64%) had evidence of posttransplant HHV-8 infection. Lung recipients were particularly susceptible to KS. Four of the 6 recipients who developed KS died from KS or associated complications. The US opioid crisis has resulted in an increasing number and proportion of organ donors with substance use disorder, and particularly injection drug use history, which may increase the risk of HHV-8 transmission to recipients. Better awareness of the risk of posttransplant KS for recipients of organs from donors with HHV-8 infection risk could be useful for recipient management. Testing donors and recipients for HHV-8 is currently challenging with no validated commercial serology kits available. Limited HHV-8 antibody testing is available through some US reference laboratories and the Centers for Disease Control and Prevention.

The pulmonary pathology of COVID-19.

A growing number of international postmortem studies identify acute and organizing diffuse alveolar damage (DAD) as the main pathologic feature of lung injury in patients with COVID-19. Other forms of acute lung injury, including organizing pneumonia, and acute fibrinous and organizing pneumonia are seen. Acute neutrophilic infiltrates have been observed, most frequently as the manifestation of a superimposed bacterial pneumonia. SARS-CoV-2 has been detected in type I and type II pneumocytes and bronchial epithelial cells using electron microscopy, immunohistochemistry, and in situ hybridization, and likewise, viral transcripts were localized with RNA probes in pneumocytes. However, the presence of true viral cytopathic effect seen with light microscopy remains to be defined. Interestingly, vascular changes are frequently observed in association with DAD, which include severe endothelial injury/endothelialitis, hemorrhage, and thrombotic and microangiopathic vasculopathy. Since similar vascular changes also occur in cases of DAD independent of the etiology, whether the vascular pathology in COVID lungs has unique features and represents a separate pathologic process is under investigation.

A single-institution study of concordance of pathological diagnoses for interstitial lung diseases between pre-transplantation surgical lung biopsies and lung explants.

BACKGROUND: By comparing diagnoses made by pre-transplant surgical lung biopsy (SLB) and the final pathologic diagnosis of the explanted pathology (EP), we aimed to study the factors that could impact pathologic diagnoses in patients with interstitial lung disease (ILD). METHODS: We retrospectively reviewed the lung transplant database at Cleveland Clinic [01/01/2006-12/31/2013] to include all lung transplant recipients with a prior diagnosis of ILD. Two pulmonary pathologists independently reviewed each SLB and lung explant. The diagnoses were labeled as concordant (same diagnosis on SLB and explant) or discordant (diagnosis on SLB and explant were different) by consensus. RESULTS: Of 389 patients transplanted for ILD, 217 had an SLB before transplant. Pathological diagnoses were concordant in 190 patients (87.6%) [165 UIP (86.8%), 13 NSIP (6.8%), 8 CHP (4.2%) and 4 other diagnoses (2.1%). In 27 cases (12.4%), the diagnosis on SLB differed from EP. 8/27 were diagnosed with UIP on SLB and of these, 5 were re-classified as NSIP. 14/19 (73.7%) patients with a SLB diagnosis "other than UIP" were re-categorized as UIP based on explant. Discordant cases had a greater time between SLB and EP than concordant cases (1553 days vs 1248 days). CONCLUSIONS: The pathologic diagnosis of ILD by SLB prior to lung transplant is accurate in most patients, but may be misleading in a small subset of patients. The majority of discordant cases that were reclassified as UIP could be due to a sampling error, or perhaps, an increased time from the date of the SLB to transplant. Future studies examining how multidisciplinary consensus diagnosis affects this discordance are necessary.

Scleroderma-related interstitial lung disease: principles of management.

INTRODUCTION: Interstitial lung disease (ILD) is the most common cause of mortality in systemic sclerosis; accounting for approximately 35% of deaths. Although immunosuppression is currently opted as first line therapy for scleroderma-related ILD (SSc-ILD), the benefits from it remain modest with concerns for systemic toxicity from long term use. Areas covered: We review the important facets in monitoring a patient with SSc-ILD, including recognizing various patterns of ILD, identifying those at risk for disease progression and discuss the strength of evidence for immunosuppressant drugs and lung transplantation. We also discuss the potential role of anti-fibrotic agents and the existing evidence for myeloablative stem-cell transplantation. Expert commentary: Non-specific interstitial pneumonia (NSIP) is the most common radiologic and histopathologic pattern seen, but other forms of ILD may also be appreciated. Mycophenolate mofetil and cyclophosphamide are most commonly used as first line therapy for SSc-ILD; however, the efficacy of mycophenolate is comparable to cyclophosphamide with a better tolerability profile. Selected patients with SSc-ILD may be candidates for lung transplantation, although meticulous assessment for co-morbidities is crucial. Further studies are required to deduce the role of anti-fibrotic medications, biologic agents and effects of myeloablative stem cell transplantation in SSc.

Endobronchial pleomorphic adenoma.

Pleomorphic adenomas are the most common tumors of the salivary glands. Rarely, they occur as benign lesions in the lungs in both the central airways and the lung parenchyma. Herein, we present a case of a 60-year-old smoker who was incidentally found to have an endobronchial mass while undergoing evaluation for a lung nodule. During bronchoscopy, a smooth globular nodule was identified at the main carina and removed using electrocautery snare. Histopathology examination revealed this to be a pleomorphic adenoma.