Lessons from 801 clinical TFE3/TFEB fluorescence in situ hybridization assays performed on renal cell carcinoma suspicious for MiTF family aberrations

OBJECTIVES

Fluorescence in situ hybridization (FISH) assays for the detection of chromosomal rearrangements involving TFE3 and TFEB are considered the gold standard for the diagnosis of MiTF family altered renal cell carcinoma (MiTF-RCC). We reviewed 801 clinical TFE3/TFEB FISH assays performed at our tertiary-level institution between 2014 and 2023 on kidney tumors suspicious at the morphologic or biomarker level for MiTF aberrations.

METHODS

We summarized and analyzed clinical information, TFE3/TFEB FISH results, and available biomarker staining results in a cohort of 453 consecutive kidney tumor cases suspicious for MiTF-RCC.

RESULTS

In total, 61 of 434 (14%) kidney tumors were confirmed for TFE3 translocation; 10 of 367 cases (2.7%) were confirmed for TFEB translocation. Since TFEB amplification interpretation was implemented in our service line, 20 of 306 cases (6.5%) were diagnosed with TFEB amplification. Importantly, TFE3 and TFEB rearrangements were never co-detected within the same kidney tumor. Patients with TFEB amplification were significantly older (P < .001) than patients with TFE3 or TFEB translocation. Kidney tumors with TFEB amplification were seen to be at least 3 times as common as those with TFEB translocation.

CONCLUSIONS

Clinical TFE3/TFEB FISH assays successfully identified and confirmed rare MiTF-RCC with TFE3 and TFEB rearrangements. Although morphologic and biomarker features associated with a kidney tumor may be suggestive of MiTF-RCC, clinical TFE3/TFEB FISH assays are crucial for a confirmation and definitive subclassification of patients with MiTF-RCC.

Clinically Occult Diffuse Pleural Mesothelioma in Patients Presenting With Spontaneous Pneumothorax

OBJECTIVES

To report histologic features of unsuspected diffuse pleural mesothelioma (DPM) in surgical specimens for pneumothorax and demonstrate how ancillary markers support a diagnosis of malignancy in this context. We explored whether pneumothorax may be a clinical manifestation of mesothelioma in situ (MIS).

METHODS

A single-institution database search identified patients who underwent surgical resection for spontaneous pneumothorax (n = 229) and/or were diagnosed with DPM (n = 88) from 2000 to 2020.

RESULTS

Spontaneous pneumothorax without clinical, radiologic, or intraoperative suspicion of mesothelioma was the initial presentation in 2 (2.3%) of 88 patients diagnosed with DPM. This represented 0.9% (2/229) of all patients undergoing surgical management of pneumothorax but accounted for a larger proportion of older patients (12.5% older than 70 years). Immunohistochemistry for BAP-1 and/or MTAP confirmed the diagnosis of DPM in 2 cases. Mesothelioma in situ was identified retrospectively by immunohistochemistry in 1 case of spontaneous pneumothorax from a 77-year-old man who developed invasive DPM 25 months later. No additional cases of MIS were identified in 19 surgical lung resections for spontaneous pneumothorax.

CONCLUSIONS

Histologic examination of bleb resections with ancillary testing for cases with ambiguous features is essential for detection of early DPM. It is uncertain whether spontaneous pneumothorax may represent a clinical manifestation of MIS.

Progression of Peritoneal Mesothelioma In Situ to Invasive Mesothelioma Arising in the Setting of Endometriosis With Germline BAP1 Mutation: A Case Report

Mesothelioma in situ has been proposed as a precursor to malignant mesothelioma arising in the pleura or peritoneum. We report a case of malignant peritoneal mesothelioma which progressed from mesothelioma in situ over a 10-mo period in a 24-yr-old woman with stage IV endometriosis. Initial surgery showed deeply infiltrative endometriosis with progestin effect. Postoperatively the patient had intractable pelvic pain and vaginal discharge. Imaging studies were negative. Repeat laparoscopy 10 mo later revealed vesicular lesions on the omentum and pinpoint white lesions studding the small bowel, appendix, and pelvic peritoneum. A diagnosis of epithelioid mesothelioma was established on biopsy of the omentum and confirmed by immunohistochemistry showing complete loss of BRCA1-associated protein-1 (BAP1) nuclear staining. Retrospectively, BAP1 loss was identified in the cytologically bland, single-layer surface mesothelium of the prior resection specimen, consistent with mesothelioma in situ . The patient underwent genetic testing and was found to have a pathogenic germline mutation in BAP1 .

Syndrome of Combined Pulmonary Fibrosis and Emphysema: An Official ATS/ERS/JRS/ALAT Research Statement

Background: The presence of emphysema is relatively common in patients with fibrotic interstitial lung disease. This has been designated combined pulmonary fibrosis and emphysema (CPFE). The lack of consensus over definitions and diagnostic criteria has limited CPFE research. Goals: The objectives of this task force were to review the terminology, definition, characteristics, pathophysiology, and research priorities of CPFE and to explore whether CPFE is a syndrome. Methods: This research statement was developed by a committee including 19 pulmonologists, 5 radiologists, 3 pathologists, 2 methodologists, and 2 patient representatives. The final document was supported by a focused systematic review that identified and summarized all recent publications related to CPFE. Results: This task force identified that patients with CPFE are predominantly male, with a history of smoking, severe dyspnea, relatively preserved airflow rates and lung volumes on spirometry, severely impaired DlCO, exertional hypoxemia, frequent pulmonary hypertension, and a dismal prognosis. The committee proposes to identify CPFE as a syndrome, given the clustering of pulmonary fibrosis and emphysema, shared pathogenetic pathways, unique considerations related to disease progression, increased risk of complications (pulmonary hypertension, lung cancer, and/or mortality), and implications for clinical trial design. There are varying features of interstitial lung disease and emphysema in CPFE. The committee offers a research definition and classification criteria and proposes that studies on CPFE include a comprehensive description of radiologic and, when available, pathological patterns, including some recently described patterns such as smoking-related interstitial fibrosis. Conclusions: This statement delineates the syndrome of CPFE and highlights research priorities.

Idiopathic Pulmonary Fibrosis (an Update) and Progressive Pulmonary Fibrosis in Adults: An Official ATS/ERS/JRS/ALAT Clinical Practice Guideline

Background: This American Thoracic Society, European Respiratory Society, Japanese Respiratory Society, and Asociación Latinoamericana de Tórax guideline updates prior idiopathic pulmonary fibrosis (IPF) guidelines and addresses the progression of pulmonary fibrosis in patients with interstitial lung diseases (ILDs) other than IPF. Methods: A committee was composed of multidisciplinary experts in ILD, methodologists, and patient representatives. 1) Update of IPF: Radiological and histopathological criteria for IPF were updated by consensus. Questions about transbronchial lung cryobiopsy, genomic classifier testing, antacid medication, and antireflux surgery were informed by systematic reviews and answered with evidence-based recommendations using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach. 2) Progressive pulmonary fibrosis (PPF): PPF was defined, and then radiological and physiological criteria for PPF were determined by consensus. Questions about pirfenidone and nintedanib were informed by systematic reviews and answered with evidence-based recommendations using the GRADE approach. Results:1) Update of IPF: A conditional recommendation was made to regard transbronchial lung cryobiopsy as an acceptable alternative to surgical lung biopsy in centers with appropriate expertise. No recommendation was made for or against genomic classifier testing. Conditional recommendations were made against antacid medication and antireflux surgery for the treatment of IPF. 2) PPF: PPF was defined as at least two of three criteria (worsening symptoms, radiological progression, and physiological progression) occurring within the past year with no alternative explanation in a patient with an ILD other than IPF. A conditional recommendation was made for nintedanib, and additional research into pirfenidone was recommended. Conclusions: The conditional recommendations in this guideline are intended to provide the basis for rational, informed decisions by clinicians.

Usual Interstitial Pneumonia is the Most Common Finding in Surgical Lung Biopsies from Patients with Persistent Interstitial Lung Disease Following Infection with SARS-CoV-2

BACKGROUND

There is increasing interest in persistent interstitial lung disease (ILD) following resolution of acute COVID-19. No studies have yet reported findings in surgical lung biopsies (SLB) from this patient population.

METHODS

Our Michigan Medicine pathology database was queried for SLB reviewed between January 2020 and April 2021 from patients with persistent ILD following recovery from acute COVID-19. Slides for our retrospective observational study were independently reviewed by two thoracic pathologists, who were blinded to patient clinical data, radiographic findings, and previous pathologic diagnosis.

FINDINGS

Eighteen cases met inclusion criteria. Of these, nine had usual interstitial pneumonia (UIP). These included two patients with superimposed acute lung injury (ALI). Five cases showed a spectrum of ALI that ranged from persistent diffuse alveolar damage to organizing pneumonia. Four patients had desquamative interstitial pneumonia (1), acute and organizing bronchopneumonia (1), or no diagnostic abnormality (2). Compared to patients without UIP, those with UIP tended to be older and have pre-existing lung disease prior to COVID-19. In patients with UIP, pre-SLB chest computed tomography changes included groundglass with interstitial thickening or peripheral reticulations with bronchiectasis; no UIP patients had groundglass only. The most common radiographic finding in patients without UIP was groundglass opacities only.

INTERPRETATION

UIP was the most common pathologic finding in patients undergoing evaluation for post-COVID-19 ILD. Our preliminary data suggests that CT changes described as interstitial thickening, peripheral reticulations, and/or bronchiectasis may be helpful in identifying patients with underlying fibrotic chronic interstitial pneumonia for which UIP is the chief concern.

FUNDING

No intramural or extramural funding sources supported this work.

Characterization of SARS-CoV-2 and host entry factors distribution in a COVID-19 autopsy series

Background

SARS-CoV-2 is a highly contagious virus that causes the disease COVID-19. We have recently reported that androgens regulate the expression of SARS-CoV-2 host entry factors ACE2 and TMPRSS2, and androgen receptor (AR) in lung epithelial cells. We also demonstrated that the transcriptional repression of the AR enhanceosome inhibited SARS-CoV-2 infection in vitro.

Methods

To better understand the various sites of SARS-CoV-2 infection, and presence of host entry factors, we extensively characterized the tissue distribution and localization of SARS-CoV-2 virus, viral replication, and host entry factors in various anatomical sites sampled via autopsy. We applied RNA in-situ-hybridization (RNA-ISH), immunohistochemistry (IHC) and quantitative reverse transcription polymerase chain reaction (qRT-PCR) approaches. We also assessed histopathological changes in SARS-CoV-2 infected tissues.

Results

We detect SARS-CoV-2 virus and viral replication in pulmonary tissues by RNA-ISH and IHC and a variety of non-pulmonary tissues including kidney, heart, liver, spleen, thyroid, lymph node, prostate, uterus, and colon by qRT-PCR. We observe heterogeneity in viral load and viral cytopathic effects among various organ systems, between individuals and within the same patient. In a patient with a history of kidney transplant and under immunosuppressant therapy, we observe an unusually high viral load in lung tissue by RNA-ISH, IHC and qRT-PCR. SARS-CoV-2 virus is also detected in this patent’s kidney, liver and uterus. We find ACE2, TMPRSS2 and AR expression to overlap with the infection sites.

Conclusions

This study portrays the impact of dispersed SARS-CoV-2 infection in diverse organ systems, thereby facilitating avenues for systematic therapeutic approaches.

To understand SARS-CoV-2 infection of human organs, we characterized the tissue distribution of SARS-CoV-2 virus, and the presence of host factors that enable the virus to enter cells, in postmortem tissues from six patients who had COVID-19. We assessed the presence of SARS-CoV-2 viral RNA and the expression of human genes that facilitate virus entry in host cells, using several techniques. We observed that SARS-CoV-2, and factors that facilitate virus entry in host cells, were present in the same location in pulmonary and multiple nonpulmonary tissues, including lung, bronchus, trachea, kidney, heart, liver, spleen, thyroid, lymph node, prostate, uterus, and colon. We also reported changes in the microscopic appearance of SARS-CoV-2 infected tissues at various sites. Such findings will guide future coronavirus biology studies on patients with advanced disease.

Wang et al. characterize the tissue distribution of SARS-CoV-2 viral infection and replication as well as the expression of host cell entry factors in postmortem samples from six patients with COVID-19. They report the co-existence of SARS-CoV-2 infection and host entry factors in multiple pulmonary and non-pulmonary tissues.

Cryobiopsy for Identification of Usual Interstitial Pneumonia and Other Interstitial Lung Disease Features. Further Lessons from COLDICE, a Prospective Multicenter Clinical Trial

Rationale: Transbronchial lung cryobiopsy (TBLC) is an emerging technique for interstitial lung disease diagnosis. Good histopathologic agreement between TBLC and surgical lung biopsy (SLB) was demonstrated in the COLDICE (Cryobiopsy versus Open Lung Biopsy in the Diagnosis of Interstitial Lung Disease Alliance) study; however, diagnostic confidence was frequently lower for TBLC than SLB. Objectives: To characterize specific features of TBLC predictive of usual interstitial pneumonia (UIP) in corresponding SLB and to identify clinical indices predictive of biopsy concordance. Methods: The COLDICE study was a prospective, multicenter study investigating diagnostic agreement between TBLC and SLB. The participants underwent both procedures with blinded pathologist analysis of specimens, applying international guideline criteria. The TBLC features predictive of UIP in the paired SLB and predictive features of overall concordance were analyzed. Measurements and Main Results: A total of 65 patients (66.1 ± 9.3 yr; FVC, 84.7 ± 14.2%; Dl_CO, 63.4 ± 13.8%) participated in the COLDICE study. UIP was identified in 33/65 (50.8%) SLB, and 81.5% were concordant with corresponding TBLC (κ, 0.61; 95% confidence interval [CI], 0.38-0.77). The UIP guideline criteria of "predominantly subpleural or paraseptal fibrosis" was infrequently reported in TBLC (8/33, 24.2%), whereas "patchy fibrosis," "fibroblast foci," and the "absence of alternative diagnostic features" were frequently observed in TBLC. The combination of these three features strongly predicted UIP in paired SLB (odds ratio [OR], 23.4; 95% CI, 6.36-86.1; P < 0.0001). Increased numbers of TBLC samples predicted histopathologic concordance with SLB (OR, 1.8; 95% CI, 1.08-3.01; P = 0.03). The predictors of discordance included older age, family history, and radiologic asymmetry. Conclusions: Subpleural and/or paraseptal fibrosis were not essential for diagnosing UIP in TBLC, provided that other guideline criteria features were present. The diagnostic accuracy of TBLC was strengthened when increased numbers of samples were taken. Clinical trial registered with www.anzctr.org.au (ACTRN12615000718549).

Interstitial lung disease pathology in systemic sclerosis

Interstitial lung disease is a relatively frequent manifestation of systemic sclerosis with approximately one-third of patients developing clinical restrictive lung disease. Fibrotic nonspecific interstitial pneumonia is the most common cause of diffuse parenchymal lung disease in patients with systemic sclerosis-associated interstitial lung disease (SSc-ILD), followed by usual interstitial pneumonia (UIP). Radiographic pleuroparenchymal fibroelastosis-like changes may accompany other forms of interstitial lung disease, most commonly UIP. In an appropriate clinical setting with supportive high-resolution computed tomography findings, lung biopsy is not needed to confirm the presence of interstitial lung disease and surgical lung biopsies are often reserved for atypical presentations. In this review, we discuss the histological findings that define the most common patterns of SSc-ILD and outline other findings sometimes encountered in lung biopsies obtained from systemic sclerosis patients, including pulmonary vascular changes, aspiration, chronic pleuritis, and diffuse alveolar damage.

A contemporary practical approach to the multidisciplinary management of unclassifiable interstitial lung disease

Fibrotic interstitial lung diseases (ILDs) frequently have nonspecific and overlapping clinical and radiological features, resulting in approximately 10-20% of patients with ILD lacking a clear diagnosis and thus being labelled with unclassifiable ILD. The objective of this review is to describe how patients with unclassifiable ILD should be evaluated and what impact specific clinical, radiological, and histopathological features may have on management decisions, focusing on patients with a predominantly fibrotic phenotype. We highlight recent data that have suggested an increasing role for antifibrotic medications in a variety of fibrotic ILDs, but justify the ongoing importance of making an accurate ILD diagnosis given the benefit of immunomodulatory therapies in many patient populations. We provide a practical approach to support management decisions that can be used by clinicians and tested by clinical researchers, and further identify the need for additional research to support a rational and standardised approach to the management of patients with unclassifiable ILD.

Utility of CDC Screening Guidelines and Autopsy Findings in Identifying Decedents Who Die of SARS-CoV-2 Infection

ABSTRACT

We assess the utility of a Centers for Disease Control and Prevention (CDC) guidelines-based coronavirus disease 2019 (COVID-19) screening checklist for postmortem severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) surveillance, detailing the relationship between the histologic findings at autopsy and attribution of death to COVID-19.SARS-CoV-2 nasopharyngeal swabs were collected at the time of autopsy in all "checklist-positive" decedents. Additional "checklist-negative" decedents were randomly tested daily. Lung slides were blindly reviewed by 3 pathologists, assessing for the presence of diffuse alveolar damage (DAD) and other findings. Sixteen decedents had positive postmortem SARS-CoV-2 nasopharyngeal swabs and underwent complete autopsies. Seven decedents had positive screening checklists. Of these, 4 had DAD and 1 had COVID-19-associated thromboembolic disease. Of the 9 decedents with negative screening checklists, 2 had DAD, but only 1 was attributed to COVID-19; the other was likely drug related. Acute bronchopneumonia was the second most common finding, and aspiration was the likely etiology in cases without concomitant DAD. COVID-19-related DAD was identified more commonly in decedents who screened positive by CDC checklist, but false-negatives did occur. Medical examiner offices should maintain a low threshold for random testing of decedents even when COVID-19 is not suspected.

Severe Acute Respiratory Syndrome Coronavirus 2 Surveillance in Decedents in a Large, Urban Medical Examiner's Office

Background

SARS-CoV-2 has become a global pandemic. Given the challenges in implementing widespread SARS-CoV-2 testing, there is increasing interest in alternative surveillance strategies.

Methods

We tested nasopharyngeal swabs from 1094 decedents in the Wayne County Medical Examiner’s office for SARS-CoV-2. All decedents were assessed by a COVID-19 checklist, and decedents flagged by the checklist (298) were preferentially tested. A random sample of decedents not flagged by the checklist were also tested (796). We statistically analyzed the characteristics of decedents (age, sex, race, and manner of death), differentiating between those flagged by the checklist and not and between those SARS-CoV-2 positive and not.

Results

A larger percentage of decedents overall were male (70% vs 48%) and Black (55% vs 36%) compared to the catchment population. Seven-day average percent positivity among flagged decedents closely matched the trajectory of percent positivity in the catchment population, particularly during the peak of the outbreak (March and April). After a lull in May to mid-June, new positive tests in late June coincided with increased case detection in the catchment. We found large racial disparities in test results: despite no statistical difference in the racial distribution between those flagged and not, SARS-CoV-2 positive decedents were substantially more likely to be Black (82% vs 51%). SARS-CoV-2 positive decedents were also more likely to be older and to have died of natural causes, including of COVID-19 disease.

Conclusions

Disease surveillance through medical examiners and coroners could supplement other forms of surveillance and may serve as a possible early outbreak warning sign.

Utility of a Molecular Classifier as a Complement to High-Resolution Computed Tomography to Identify Usual Interstitial Pneumonia

Rationale: Usual interstitial pneumonia (UIP) is the defining morphology of idiopathic pulmonary fibrosis (IPF). Guidelines for IPF diagnosis conditionally recommend surgical lung biopsy for histopathology diagnosis of UIP when radiology and clinical context are not definitive. A "molecular diagnosis of UIP" in transbronchial lung biopsy, the Envisia Genomic Classifier, accurately predicted histopathologic UIP.Objectives: We evaluated the combined accuracy of the Envisia Genomic Classifier and local radiology in the detection of UIP pattern.Methods: Ninety-six patients who had diagnostic lung pathology as well as a transbronchial lung biopsy for molecular testing with Envisia Genomic Classifier were included in this analysis. The classifier results were scored against reference pathology. UIP identified on high-resolution computed tomography (HRCT) as documented by features in local radiologists' reports was compared with histopathology.Measurements and Main Results: In 96 patients, the Envisia Classifier achieved a specificity of 92.1% (confidence interval [CI],78.6-98.3%) and a sensitivity of 60.3% (CI, 46.6-73.0%) for histology-proven UIP pattern. Local radiologists identified UIP in 18 of 53 patients with UIP histopathology, with a sensitivity of 34.0% (CI, 21.5-48.3%) and a specificity of 96.9% (CI, 83.8-100%). In conjunction with HRCT patterns of UIP, the Envisia Classifier results identified 24 additional patients with UIP (sensitivity 79.2%; specificity 90.6%).Conclusions: In 96 patients with suspected interstitial lung disease, the Envisia Genomic Classifier identified UIP regardless of HRCT pattern. These results suggest that recognition of a UIP pattern by the Envisia Genomic Classifier combined with HRCT and clinical factors in a multidisciplinary discussion may assist clinicians in making an interstitial lung disease (especially IPF) diagnosis without the need for a surgical lung biopsy.

Diffuse alveolar damage (DAD) resulting from coronavirus disease 2019 Infection is Morphologically Indistinguishable from Other Causes of DAD

Aims

Diffuse alveolar damage (DAD) is a ubiquitous finding in inpatient coronavirus disease 2019 (COVID‐19)‐related deaths, but recent reports have also described additional atypical findings, including vascular changes. An aim of this study was to assess lung autopsy findings in COVID‐19 inpatients, and in untreated severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2)‐positive individuals who died in the community, in order to understand the relative impact of medical intervention on lung histology. Additionally, we aimed to investigate whether COVID‐19 represents a unique histological variant of DAD by comparing the pathological findings with those of uninfected control patients.

Methods and results

Lung sections from autopsy cases were reviewed by three pulmonary pathologists, including two who were blinded to patient cohort. The cohorts included four COVID‐19 inpatients, four cases with postmortem SARS‐CoV‐2 diagnoses who died in the community, and eight SARS‐CoV‐2‐negative control cases. DAD was present in all but one SARS‐CoV‐2‐positive patient, who was asymptomatic and died in the community. Although SARS‐CoV‐2‐positive patients were noted to have more focal perivascular inflammation/endothelialitis than control patients, there were no significant differences in the presence of hyaline membranes, fibrin thrombi, airspace organisation, and ‘acute fibrinous and organising pneumonia’‐like intra‐alveolar fibrin deposition between the cohorts. Fibrinoid vessel wall necrosis, haemorrhage and capillaritis were not features of COVID‐19‐related DAD.

Conclusions

DAD is the primary histological manifestation of severe lung disease in COVID‐19 patients who die both in hospital and in the community, suggesting no contribution of hyperoxaemic mechanical ventilation to the histological changes. There are no distinctive morphological features with which to confidently differentiate COVID‐19‐related DAD from DAD due to other causes.

Frontline Workers in the Backrooms of COVID-19

Objectives

To review the response to the coronavirus disease 2019 (COVID-19) pandemic in a forensics center that integrates an academic department of pathology with multiple regional county medical examiners’ offices.

Methods

Faculty and staff were asked to volunteer stories, data, and photographs describing their activities from March through May 2020. The information was assembled into a narrative summary.

Results

Increased deaths challenged capacity limits in a hospital morgue and a large urban medical examiner’s office (MEO) successfully managed by forensic teams and monitored by an institutional command center. Autopsies of suspected and proven cases of COVID-19 were performed in both facilities. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) testing of decedents was performed in a MEO serving a large urban area. Scene investigators worked directly with families to meet needs unique to a pandemic. Artful photographs of decedent’s hands and/or tattoos were offered to those unable to have in-person viewings. Pathologists and social workers were available to families of the deceased and created novel solutions to facilitate the grieving process.

Conclusions

Forensic pathology is important to successfully navigating emerging diseases like the COVID-19 pandemic. Direct conversations with families are common in forensic pathology and serve as a model for patient- and family-centered care.

Diagnosis of Hypersensitivity Pneumonitis in Adults. An Official ATS/JRS/ALAT Clinical Practice Guideline

Background: This guideline addresses the diagnosis of hypersensitivity pneumonitis (HP). It represents a collaborative effort among the American Thoracic Society, Japanese Respiratory Society, and Asociación Latinoamericana del Tórax.Methods: Systematic reviews were performed for six questions. The evidence was discussed, and then recommendations were formulated by a multidisciplinary committee of experts in the field of interstitial lung disease and HP using the GRADE (Grading of Recommendations, Assessment, Development, and Evaluation) approach.Results: The guideline committee defined HP, and clinical, radiographic, and pathological features were described. HP was classified into nonfibrotic and fibrotic phenotypes. There was limited evidence that was directly applicable to all questions. The need for a thorough history and a validated questionnaire to identify potential exposures was agreed on. Serum IgG testing against potential antigens associated with HP was suggested to identify potential exposures. For patients with nonfibrotic HP, a recommendation was made in favor of obtaining bronchoalveolar lavage (BAL) fluid for lymphocyte cellular analysis, and suggestions for transbronchial lung biopsy and surgical lung biopsy were also made. For patients with fibrotic HP, suggestions were made in favor of obtaining BAL for lymphocyte cellular analysis, transbronchial lung cryobiopsy, and surgical lung biopsy. Diagnostic criteria were established, and a diagnostic algorithm was created by expert consensus. Knowledge gaps were identified as future research directions.Conclusions: The guideline committee developed a systematic approach to the diagnosis of HP. The approach should be reevaluated as new evidence accumulates.

Postmortem Lung Findings in a Patient With Asthma and Coronavirus Disease 2019

Asthma is increasingly recognized as an underlying risk factor for severe respiratory disease in patients with coronavirus disease 2019 (COVID-19), particularly in the United States. Here, we report the postmortem lung findings from a 37-year-old man with asthma, who met the clinical criteria for severe acute respiratory distress syndrome and died of COVID-19 less than 2 weeks after presentation to the hospital. His lungs showed mucus plugging and other histologic changes attributable to asthma, as well as early diffuse alveolar damage and a fibrinous pneumonia. The presence of diffuse alveolar damage is similar to descriptions of autopsy lung findings from patients with severe acute respiratory syndrome coronavirus and Middle East respiratory syndrome coronavirus, and the absence of a neutrophil-rich acute bronchopneumonia differs from the histologic changes typical of influenza. The relative contribution of mucus plugging to his hypoxemia is unknown.

Diagnosis of Idiopathic Pulmonary Fibrosis. An Official ATS/ERS/JRS/ALAT Clinical Practice Guideline

BACKGROUND

This document provides clinical recommendations for the diagnosis of idiopathic pulmonary fibrosis (IPF). It represents a collaborative effort between the American Thoracic Society, European Respiratory Society, Japanese Respiratory Society, and Latin American Thoracic Society.

METHODS

The evidence syntheses were discussed and recommendations formulated by a multidisciplinary committee of IPF experts. The evidence was appraised and recommendations were formulated, written, and graded using the Grading of Recommendations, Assessment, Development, and Evaluation approach.

RESULTS

The guideline panel updated the diagnostic criteria for IPF. Previously defined patterns of usual interstitial pneumonia (UIP) were refined to patterns of UIP, probable UIP, indeterminate, and alternate diagnosis. For patients with newly detected interstitial lung disease (ILD) who have a high-resolution computed tomography scan pattern of probable UIP, indeterminate, or an alternative diagnosis, conditional recommendations were made for performing BAL and surgical lung biopsy; because of lack of evidence, no recommendation was made for or against performing transbronchial lung biopsy or lung cryobiopsy. In contrast, for patients with newly detected ILD who have a high-resolution computed tomography scan pattern of UIP, strong recommendations were made against performing surgical lung biopsy, transbronchial lung biopsy, and lung cryobiopsy, and a conditional recommendation was made against performing BAL. Additional recommendations included a conditional recommendation for multidisciplinary discussion and a strong recommendation against measurement of serum biomarkers for the sole purpose of distinguishing IPF from other ILDs.

CONCLUSIONS

The guideline panel provided recommendations related to the diagnosis of IPF.

A Review of Smoking-Related Interstitial Fibrosis, Respiratory Bronchiolitis, and Desquamative Interstitial Pneumonia: Overlapping Histology and Confusing Terminology

Smoking-related lung diseases traverse a spectrum of clinicopathologic entities, with cases often comprising a complex mixture of findings. The complexity of the diagnostic process extends beyond the histologic findings to the nomenclature, which is murky from a seemingly unending expansion of terms being applied to a handful of pathologic changes. Here, we focus our review on smoking-related interstitial fibrosis, respiratory bronchiolitis, and desquamative interstitial pneumonia, 3 entities that perhaps show the most histologic overlap and suffer from competing terminology.

Reprint of: Nonspecific interstitial pneumonia: pathologic features and clinical implications

Nonspecific interstitial pneumonia (NSIP) is a form of chronic interstitial pneumonia that should be separated from the other idiopathic interstitial pneumonias, including most importantly, usual interstitial pneumonia (UIP). Diagnosis is predicated on identification of characteristic findings in a surgical lung biopsy in the appropriate clinical and radiological context. Affected patients may have a variety of underlying or associated conditions, although most have a form of idiopathic lung disease associated with a more favorable prognosis than UIP/idiopathic pulmonary fibrosis (IPF). Keys to distinguishing NSIP from UIP include absence of heterogeneous lung involvement, architectural distortion in the form of fibrotic scarring and/or honeycomb change, and fibroblast foci in NSIP.

Hypersensitivity Pneumonitis: Radiologic Phenotypes Are Associated With Distinct Survival Time and Pulmonary Function Trajectory

BACKGROUND

Hypersensitivity pneumonitis (HP) is an interstitial lung disease with a better prognosis, on average, than idiopathic pulmonary fibrosis (IPF). We compare survival time and pulmonary function trajectory in patients with HP and IPF by radiologic phenotype.

METHODS

HP (n = 117) was diagnosed if surgical/transbronchial lung biopsy, BAL, and exposure history results suggested this diagnosis. IPF (n = 152) was clinically and histopathologically diagnosed. All participants had a baseline high-resolution CT (HRCT) scan and FVC % predicted. Three thoracic radiologists documented radiologic features. Survival time is from HRCT scan to death or lung transplant. Cox proportional hazards models identify variables associated with survival time. Linear mixed models compare post-HRCT scan FVC % predicted trajectories.

RESULTS

Subjects were grouped by clinical diagnosis and three mutually exclusive radiologic phenotypes: honeycomb present, non-honeycomb fibrosis (traction bronchiectasis and reticulation) present, and nonfibrotic. Nonfibrotic HP had the longest event-free median survival (> 14.73 years) and improving FVC % predicted (1.92%; 95% CI, 0.49-3.35; P = .009). HP with non-honeycomb fibrosis had longer survival than IPF (> 7.95 vs 5.20 years), and both groups experienced a significant decline in FVC % predicted. Subjects with HP and IPF with honeycombing had poor survival (2.76 and 2.81 years, respectively) and significant decline in FVC % predicted.

CONCLUSIONS

Three prognostically distinct, radiologically defined phenotypes are identified among patients with HP. The importance of pursuing a specific diagnosis (eg, HP vs IPF) among patients with non-honeycomb fibrosis is highlighted. When radiologic honeycombing is present, invasive diagnostic testing directed at determining the diagnosis may be of limited value given a uniformly poor prognosis.

Development and validation of a radiological diagnosis model for hypersensitivity pneumonitis

High-resolution computed tomography (HRCT) may be useful for diagnosing hypersensitivity pneumonitis. Here, we develop and validate a radiological diagnosis model and model-based points score.Patients with interstitial lung disease seen at the University of Michigan Health System (derivation cohort) or enrolling in the Lung Tissue Research Consortium (validation cohort) were included. A thin-section, inspiratory HRCT scan was required. Thoracic radiologists documented radiological features.The derivation cohort comprised 356 subjects (33.9% hypersensitivity pneumonitis) and the validation cohort comprised 424 subjects (15.5% hypersensitivity pneumonitis). An age-, sex- and smoking status-adjusted logistic regression model identified extent of mosaic attenuation or air trapping greater than that of reticulation ("MA-AT>Reticulation"; OR 6.20, 95% CI 3.53-10.90; p<0.0001) and diffuse axial disease distribution (OR 2.33, 95% CI 1.31-4.16; p=0.004) as hypersensitivity pneumonitis predictors (area under the receiver operating characteristic curve 0.814). A model-based score >2 (1 point for axial distribution, 2 points for "MA-AT>Reticulation") has specificity 90% and positive predictive value (PPV) 74% in the derivation cohort and specificity 96% and PPV 44% in the validation cohort. Similar model performance is seen with population restriction to those reporting no exposure (score >2: specificity 91%).When radiological mosaic attenuation or air trapping are more extensive than reticulation and disease has diffuse axial distribution, hypersensitivity pneumonitis specificity is high and false diagnosis risk low (<10%), but PPV is diminished in a low-prevalence setting.

Primary mammary analogue secretory carcinoma of the lung: a case report

Mammary analogue secretory carcinoma (MASC) is a recently discovered salivary gland tumor described mostly in the major salivary glands and occasionally in the skin. We report a primary endobronchial tumor with histology, immunophenotype, and ETV6 rearrangement characteristic of MASC in a 62-year-old woman. The diagnosis was initially made on a transbronchial biopsy with fluorescence in situ hybridization confirmation of ETV6 rearrangement. The patient underwent lobectomy demonstrating a large endobronchial mass. To our knowledge, this is the first report of MASC arising as a primary pulmonary tumor. This tumor was unusual in that it is the largest (8.5 cm) MASC ever reported, showed an increased mitotic count (6/10 high-power fields) without high-grade cytology, and presented with advanced-stage disease that included visceral pleural invasion and lymph node metastasis.

Frozen sections in patients undergoing breast conserving surgery at a single ambulatory surgical center: 5 year experience

OBJECTIVES

To evaluate outcomes of our breast frozen section (FS) practice in its first 5 years, including our specialized FS of margins (FSM) procedure for breast conserving therapy (BCT) patients.

METHODS

One thousand two hundred and forty eight patients undergoing 1303 breast FSM and/or sentinel lymph node (SLN) FS were included. Clinicopathologic features were assessed by chart review.

RESULTS

Use of SLN FS declined, from 43.5% of FS cases before to 19.2% of FS cases after 2012. FSM patients had a decline in overall reexcision to 12.3% in 2013-2014 (p = 0.063). There was also decline in reexcision for focally close margins (p < 0.0001) but no change in reexcision for extensively close margins. Reexcision was significantly associated with lobular subtype, multifocality and larger (≥T2) size. False negative FSM cases were most often influenced by extensively close or positive final (reexcised) margins sent for permanent section only (96/148; 64.9%).

CONCLUSIONS

Despite changing surgical practices, FSM remains a valuable service that reduces reexcision in BCT patients.

Multicentre evaluation of multidisciplinary team meeting agreement on diagnosis in diffuse parenchymal lung disease: a case-cohort study

BACKGROUND

Diffuse parenchymal lung disease represents a diverse and challenging group of pulmonary disorders. A consistent diagnostic approach to diffuse parenchymal lung disease is crucial if clinical trial data are to be applied to individual patients. We aimed to evaluate inter-multidisciplinary team agreement for the diagnosis of diffuse parenchymal lung disease.

METHODS

We did a multicentre evaluation of clinical data of patients who presented to the interstitial lung disease unit of the Royal Brompton and Harefield NHS Foundation Trust (London, UK; host institution) and required multidisciplinary team meeting (MDTM) characterisation between March 1, 2010, and Aug 31, 2010. Only patients whose baseline clinical, radiological, and, if biopsy was taken, pathological data were undertaken at the host institution were included. Seven MDTMs, consisting of at least one clinician, radiologist, and pathologist, from seven countries (Denmark, France, Italy, Japan, Netherlands, Portugal, and the UK) evaluated cases of diffuse parenchymal lung disease in a two-stage process between Jan 1, and Oct 15, 2015. First, the clinician, radiologist, and pathologist (if lung biopsy was completed) independently evaluated each case, selected up to five differential diagnoses from a choice of diffuse lung diseases, and chose likelihoods (censored at 5% and summing to 100% in each case) for each of their differential diagnoses, without inter-disciplinary consultation. Second, these specialists convened at an MDTM and reviewed all data, selected up to five differential diagnoses, and chose diagnosis likelihoods. We compared inter-observer and inter-MDTM agreements on patient first-choice diagnoses using Cohen's kappa coefficient (κ). We then estimated inter-observer and inter-MDTM agreement on the probability of diagnosis using weighted kappa coefficient (κw). We compared inter-observer and inter-MDTM confidence of patient first-choice diagnosis. Finally, we evaluated the prognostic significance of a first-choice diagnosis of idiopathic pulmonary fibrosis (IPF) versus not IPF for MDTMs, clinicians, and radiologists, using univariate Cox regression analysis.

FINDINGS

70 patients were included in the final study cohort. Clinicians, radiologists, pathologists, and the MDTMs assigned their patient diagnoses between Jan 1, and Oct 15, 2015. IPF made up 88 (18%) of all 490 MDTM first-choice diagnoses. Inter-MDTM agreement for first-choice diagnoses overall was moderate (κ=0·50). Inter-MDTM agreement on diagnostic likelihoods was good for IPF (κw=0·71 [IQR 0·64-0·77]) and connective tissue disease-related interstitial lung disease (κw=0·73 [0·68-0·78]); moderate for non-specific interstitial pneumonia (NSIP; κw=0·42 [0·37-0·49]); and fair for hypersensitivity pneumonitis (κw=0·29 [0·24-0·40]). High-confidence diagnoses (>65% likelihood) of IPF were given in 68 (77%) of 88 cases by MDTMs, 62 (65%) of 96 cases by clinicians, and in 57 (66%) of 86 cases by radiologists. Greater prognostic separation was shown for an MDTM diagnosis of IPF than compared with individual clinician's diagnosis of this disease in five of seven MDTMs, and radiologist's diagnosis of IPF in four of seven MDTMs.

INTERPRETATION

Agreement between MDTMs for diagnosis in diffuse lung disease is acceptable and good for a diagnosis of IPF, as validated by the non-significant greater prognostic separation of an IPF diagnosis made by MDTMs than the separation of a diagnosis made by individual clinicians or radiologists. Furthermore, MDTMs made the diagnosis of IPF with higher confidence and more frequently than did clinicians or radiologists. This difference is of particular importance, because accurate and consistent diagnoses of IPF are needed if clinical outcomes are to be optimised. Inter-multidisciplinary team agreement for a diagnosis of hypersensitivity pneumonitis is low, highlighting an urgent need for standardised diagnostic guidelines for this disease.

FUNDING

National Institute of Health Research, Imperial College London.

Histopathology of Explanted Lungs From Patients With a Diagnosis of Pulmonary Sarcoidosis

BACKGROUND

Pathologic features of end-stage pulmonary sarcoidosis (ESPS) are not well defined; anecdotal reports have suggested that ESPS may mimic usual interstitial pneumonia (UIP). We hypothesized that ESPS has distinct histologic features.

METHODS

Twelve patients who received a diagnosis of pulmonary sarcoidosis and underwent lung transplantation were included. Control subjects were 10 age- and sex-matched lung transplant patients with UIP. Hematoxylin and eosin-stained tissue sections were examined for the following features: extent/pattern of fibrosis; presence and quantity (per 10 high-power fields) of fibroblast foci and granulomas; distribution and morphology of granulomas; and presence and extent of honeycomb change. Extent of fibrosis and honeycomb change in lung parenchyma was scored as follows: 1 = 1% to 25%; 2 = 26% to 50%; 3 = 51% to 75%; 4 = 76% to 100% of lung parenchyma.

RESULTS

Eight of 12 cases demonstrated histologic findings typical of ESPS. All showed well-formed granulomas with associated fibrosis distributed in a distinct lymphangitic fashion. Granulomas were present in hilar or mediastinal lymph nodes from six of six patients with ESPS and none of eight control subjects. The extent of fibrosis, honeycomb change, and fibroblast foci was significantly lower in ESPS cases compared with control cases. Two patients with remote histories of sarcoidosis showed histologic features of diseases other than ESPS (UIP and emphysema) without granulomas. Two patients with atypical clinical findings demonstrated nonnecrotizing granulomas combined with either severe chronic venous hypertension or UIP.

CONCLUSIONS

ESPS and UIP have distinct histopathologic features in the lungs. Patients with a pretransplant diagnosis of sarcoidosis may develop other lung diseases that account for their end-stage fibrosis.

Evaluation of napsin A, TTF-1, p63, p40, and CK5/6 immunohistochemical stains in pulmonary neuroendocrine tumors

OBJECTIVE

A panel of immunohistochemical (IHC) stains frequently used to subclassify non-small cell lung cancers (NSCLCs) includes napsin A, TTF-1, CK5/6, p40, and p63. The expression profiles of these stains in neuroendocrine tumors have not been systematically evaluated.

METHOD

Sixty-eight resected pulmonary neuroendocrine tumors, including 52 typical carcinoids (TCs), eight atypical carcinoids (ACs), seven small cell carcinomas (SCLCs) and one large cell neuroendocrine carcinoma (LCNEC), were stained for napsin A, TTF-1, p63, p40, and CK5/6. Tumors were scored as positive (>1% tumor cells reactive) or negative, and percentage of reactive tumor cells was recorded.

RESULTS

Napsin A, p63, p40, and CK5/6 were consistently negative in neuroendocrine tumors. TTF-1 was positive in 17 of 52 TCs, 4 of 8 ACs, 5 of 7 SCLCs, and 0 of 1 LCNECs.

CONCLUSION

Pulmonary neuroendocrine tumors have a distinct but nonspecific profile on IHC panel commonly applied to subclassify NSCLCs. They are napsin A-/p40-/p63-/CK5/6-/TTF-1±. Recognizing this profile may have value in separating neuroendocrine tumors from NSCLCs.

Pulmonary necrotizing granulomas of unknown cause: clinical and pathologic analysis of 131 patients with completely resected nodules

BACKGROUND

The cause of pulmonary necrotizing granulomas is often unclear, even after histologic examination. Our aim was to determine the clinical significance of histologically unexplained necrotizing granulomas.

METHODS

Pulmonary necrotizing granulomas surgically resected at the Mayo Clinic (1994-2004) were retrieved and reviewed retrospectively. Cases in which a cause was evident at the time of initial histologic examination were excluded. The analysis cohort comprised 131 completely resected histologically unexplained pulmonary necrotizing granulomas. Clinical and laboratory information was abstracted from medical records, chest CT scans were reviewed, histologic slides were reexamined, and additional ancillary studies were performed in selected cases.

RESULTS

A cause was determined on review in more than one-half of the histologically unexplained necrotizing granulomas (79 of 131, 60%) by reexamining histologic slides (47), incorporating the results of cultures (26), fungal serologies (14), and other laboratory studies (eight), and correlating histologic findings with clinical and radiologic information (13). Infections accounted for the majority (64 of 79), the most common being histoplasmosis (37) and nontuberculous mycobacterial infections (18). Noninfectious diagnoses (15 of 79) were rheumatoid nodule (five), granulomatosis with polyangiitis (Wegener) (five), sarcoidosis (four), and chronic granulomatous disease (one). Many cases remained unexplained even after extensive review (52 of 131, 40%). Most of these patients received no medical therapy and did not progress clinically or develop new nodules (median follow-up, 84 months).

CONCLUSIONS

A cause, the most common being infection, can be established in many surgically resected pulmonary necrotizing granulomas that appear unexplained at the time of initial histologic diagnosis. Patients whose granulomas remain unexplained after a rigorous review have a favorable outcome. Most do not develop new nodules or progress clinically, even without medical therapy.