We describe an unusual case in which disseminated histoplasmosis was suspected at the time of of rapid on-site assessment (ROSE) performed during endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA). The patient was a renal transplant recipient with fever, mild anemia, bilateral lung infiltrates and mediastinal lymphadenopathy who underwent EBUS-TBNA of station 11L and 7 lymph nodes. The diagnosis of disseminated histoplasmosis was suggested at the time of ROSE and confirmed several days later by microbiologic cultures. Cytomorphologic findings on routine stains can be a powerful clue to the disseminated form of histoplasmosis.

INTRODUCTION:Limited updated literature exists about the prevalence and spectrum of malignancies involving cerebrospinal fluid (CSF). In this multi-institutional study, we review our experience with focus on first time malignancy diagnosis in CSF samples of adults. MATERIALS AND METHODS:Institutional databases at 4 academic centers were queried retrospectively for CSFs over a 10-year period. The following data elements were collected: total # of CSFs, total # of CSFs with a malignant diagnosis; for each patient with a first time CSF diagnosis of malignancy: age, gender, diagnosis, prior history of malignancy, and ancillary studies. RESULTS:Twenty-four thousand one hundred forty-two CSFs were collected with a positive for malignancy rate of 2.3% (n = 551). Out of 347 (1.4%) adults with a first-time diagnosis of CSF malignancy 182 (52%) were female (age range: 19-89/mean: 57) and 165 (48%) were male (age range: 20-95/mean: 60). Hematolymphoid malignancies (48%, n = 168) were overall the most common neoplasm. In women, metastatic carcinomas (63%, n = 114) were the leading malignancy, of which the majority were breast primaries. In men, lymphomas/leukemias (64%, n = 106) were the leading malignancy, of which the majority were B-cell lymphomas. Ancillary studies aided the final diagnosis in 110 (32%) cases. For 286 (82%) cases, a prior history of malignancy was available to correlate CSF findings. CONCLUSIONS:A malignancy diagnosis in the CSF of adults is rare. The most common malignancies in females and males are metastatic breast carcinoma and hematolymphoid malignancies, respectively. Metastatic neoplasms account for the majority, with primary central nervous system neoplasms being quite uncommon. History of malignancy and ancillary tests can be helpful.

OBJECTIVES Oil Red O (ORO) positivity in bronchoalveolar lavage (BAL) fluid macrophages in the setting of e-cigarette, or vaping, product use-associated acute lung injury (EVALI) has been frequently requested by clinicians based on rare reports and subsequent US Centers for Disease Control and Prevention guidelines. The aim of this study was to determine the specificity of ORO staining in BAL specimens with disease states other than EVALI. METHODS Consecutive BAL specimens (October-December 2019) were stained with ORO. The lipid-laden macrophage index (LLMI) was calculated for each case. RESULTS We studied BAL samples from 50 patients. Indications for BAL were surveillance bronchoscopy for lung transplantation (27/50), suspected infection (12/50), sarcoidosis/suspected sarcoidosis (3/50), nodules or ground-glass opacities (3/50), hemoptysis (2/50), asthma or eosinophilic pneumonia (2/50), and idiopathic pulmonary fibrosis (1/50). ORO staining was seen in BAL fluid macrophages in 45 of 50 cases (focal in 18, moderate in 23, diffuse in 4); LLMI ranged from 0 to 218. Using a threshold of LLMI of 85 or higher as positive, ORO was positive in 7 of 50 (14%) cases (range, 85-218). CONCLUSIONS ORO staining in BAL fluid macrophages is not specific for EVALI. Even when an LLMI of 85 or higher is used as a threshold for positivity, ORO positivity occurs in a significant subset of non-vaping-related cases.

Aim Various approaches have been reported for distinguishing separate primary lung adenocarcinomas from intrapulmonary metastases in patients with two lung nodules. The aim of this study was to determine whether histological assessment is reliable and accurate in distinguishing separate primary lung adenocarcinomas from intrapulmonary metastases using routine molecular findings as an adjunct. Methods We studied resected tumour pairs from 32 patients with lung adenocarcinomas in different lobes. In 15 of 32 tumour pairs, next-generation sequencing (NGS) for common driver mutations was performed on both nodules. The remainder of tumour pairs underwent limited NGS, or EGFR genotyping. Tumour pairs with different drivers (or one driver/one wild-type) were classified as molecularly unrelated, while those with identical low-frequency drivers were classified as related. Three pathologists independently and blinded to the molecular results categorised tumour pairs as related or unrelated based on histological assessment. Results Of 32 pairs, 15 were classified as related by histological assessment, and 17 as unrelated. Of 15 classified as related by histology, 6 were classified as related by molecular analysis, 4 were unrelated and 5 were indeterminate. Of 17 classified as unrelated by histology, 14 were classified as unrelated by molecular analysis, none was related and 3 were indeterminate. Histological assessment of relatedness was inaccurate in 4/32 (12.5%) tumour pairs. Conclusions A small but significant subset of two-nodule adenocarcinoma pairs is inaccurately judged as related by histological assessment, and can be proven to be unrelated by molecular analysis (driver gene mutations), leading to significant downstaging.

Greater than 2000 cases of vaping‐associated pulmonary injury and 39 deaths reported in the United States have heightened public awareness and assumed major public health significance over recent months. Currently, knowledge of the effects of various vaping agents on the respiratory tract is in its infancy. Additional understanding of the agents implicated in these lung injuries as well as a correlation between bronchoalveolar lavage and lung biopsy samples is required.

The ongoing global pandemic of coronavirus disease 2019 (COVID-19) has rapidly disrupted traditional modes of operation in healthcare and education. In March 2020, institutions in the United States began to implement a range of policies to discourage direct contact and encourage social distancing. These measures have placed us in an unprecedented position where education can no longer occur at close quarters - most notably, around a multi-headed microscope - but must instead continue at a distance. This guide is intended to be a resource for pathologists and pathologists-in-training who wish to leverage technology to continue collaboration, teaching, and education in this era. The manuscript is focused mainly on anatomic pathology; however, the technologies easily lend themselves to clinical pathology education as well. Our aim is to provide curated lists of various online resources that can be used for virtual learning in pathology, provide tips and tricks, and share our personal experience with these technologies. The lists include video conferencing platforms, pathology websites, free online educational resources, including social media, and whole-slide imaging collections. We are currently living through a unique situation without a precedent or guidebook, and we hope that this guide will enable the community of pathology educators worldwide to embrace the opportunities that 21st century technology provides.

Since mid-2019, > 2,000 cases of e-cigarette or vaping product use-associated lung injury (EVALI) have been reported. Although initial reports suggested that this entity may be a form of inhalation-related lipoid pneumonia, subsequent studies indicate that EVALI represents various patterns of acute lung injury. Cases of EVALI continue to be reported, and public awareness of the epidemic is increasingly high. However, evidence surrounding optimal management of EVALI remains limited. In this case series, we report 15 cases of EVALI across a spectrum of severity, highlighting key radiologic, pathologic, and cytologic findings, and discuss management implications. In line with national findings, most patients with EVALI in the series vaped liquids containing tetrahydrocannabinol. Our imaging and pathologic findings support the notion that EVALI is a form of acute lung injury. Since mid-2019, > 2,000 cases of e-cigarette or vaping product use-associated lung injury (EVALI) have been reported. Although initial reports suggested that this entity may be a form of inhalation-related lipoid pneumonia, subsequent studies indicate that EVALI represents various patterns of acute lung injury. Cases of EVALI continue to be reported, and public awareness of the epidemic is increasingly high. However, evidence surrounding optimal management of EVALI remains limited. In this case series, we report 15 cases of EVALI across a spectrum of severity, highlighting key radiologic, pathologic, and cytologic findings, and discuss management implications. In line with national findings, most patients with EVALI in the series vaped liquids containing tetrahydrocannabinol. Our imaging and pathologic findings support the notion that EVALI is a form of acute lung injury. e-Cigarette or vaping product use-associated lung injury (EVALI) first reached public attention when a cluster of young patients presenting with severe hypoxia, dyspnea, and diffuse pulmonary infiltrates were identified in Illinois and Wisconsin.1Centers for Disease Control and PreventionOutbreak of lung injury associated with the use of e-cigarette, or vaping, products.https://www.cdc.gov/tobacco/basic_information/e-cigarettes/severe-lung-disease.htmlDate accessed: October 4, 2019Google Scholar,2Layden E.L. Ghinai I. Pray I. et al.Pulmonary illness related to e-cigarette use in Illinois and Wisconsin-final report.N Engl J Med. 2020; 382: 903-916Crossref PubMed Scopus (479) Google Scholar The correlation between tetrahydrocannabinol (THC) and the risk of EVALI is increasingly apparent, with most patients reporting vaping liquids containing THC prior to symptom onset. Initial reports of lipid-laden macrophages on BAL fluid of these patients led to the hypothesis that vaping THC had resulted in acute lipoid pneumonia.3Davidson K. Brancato A. Heetderks P. et al.Outbreak of electronic-cigarette–associated acute lipoid pneumonia — North Carolina, July–August 2019.MMWR Morb Mortal Wkly Rep. 2019; 68: 784-786Crossref PubMed Scopus (81) Google Scholar,4Maddock S.D. Cirulis M.M. Callahan S.J. et al.Pulmonary lipid-laden macrophages and vaping.N Engl J Med. 2019; 381: 1488-1489Crossref PubMed Scopus (141) Google Scholar Although subsequent biopsy studies have not identified classic features of exogenous lipoid pneumonia in these patients, the role that vitamin E acetate may play in the development of EVALI is of increasing interest.5Mukhopadhyay S. Mehrad M. Dammert P. et al.Lung biopsy findings in severe pulmonary illness associated with e-cigarette use (vaping).Am J Clin Pathol. 2019; 153: 30-39Google Scholar, 6Butt Y.M. Smith M.L. Tazelaar H.D. et al.Pathology of vaping associated lung injury.N Engl J Med. 2019; 381: 1780-1781Crossref PubMed Scopus (208) Google Scholar, 7Blount B.C. Karwowski M.P. Morel-Espinosa M. et al.Evaluation of bronchoalveolar lavage fluid from patients in an outbreak of e-cigarette, or vaping, product use–associated lung injury—10 states, August–October 2019.MMWR Morb Mortal Wkly Rep. 2019; 68: 1040-1041Crossref PubMed Scopus (121) Google Scholar To date, a wide range of imaging and pathology findings have been described. However, there is minimal literature summarizing the full clinical presentation of EVALI. Guidance on management is also limited. In this case series, we report 15 cases of EVALI across a spectrum of severity, highlighting the correlation between key radiologic and pathologic findings. Eighteen patients with suspected EVALI were identified at Cleveland Clinic, Cleveland, Ohio. Cases were reviewed to confirm that Centers for Disease Control and Prevention1Centers for Disease Control and PreventionOutbreak of lung injury associated with the use of e-cigarette, or vaping, products.https://www.cdc.gov/tobacco/basic_information/e-cigarettes/severe-lung-disease.htmlDate accessed: October 4, 2019Google Scholar criteria for probable or confirmed EVALI were met. On initial case review, three cases were excluded because of the presence of a competing diagnosis considered more plausible by the evaluating physician. Electronic medical records, imaging, lung biopsy, and cytology specimens of included patients were reviewed retrospectively by independent thoracic radiologists, pathologists, cytopathologists, and pulmonologists. Results were collated into a deidentified database. Descriptive statistical analysis was performed on deidentified, coded data using R version 3.6 (R Foundation for Statistical Computing, GNU General Public License). Approval for this study was provided by the Cleveland Clinic Institutional Review Board (No. 19-1220). Fifteen cases of EVALI met eligibility for inclusion (Table 1). Of these, 13 were classified as definite EVALI and two as probable EVALI. There were nine men and six women, with a median age of 30 years. Detailed information about vape use, including substance vaped, timing of vaping initiation, and frequency of vape use, had been obtained from eight patients. In this group, the median duration of vaping prior to symptom onset was 3 months. All 15 patients had urine toxicology positive for THC; however, only 11 patients reported vaping the product. Three patients reported vaping a mix of THC and nicotine, and four reported cigarette use in addition to vaping.Table 1Clinical, Radiologic, and Pathologic Characteristics of e-Cigarette or Vaping Product Use-Associated Lung Injury CasesCase No.Age (y)/SexVape Device/ SubstanceDuration (mo)Presenting SymptomsImaging FindingsPathologySettingTreatmentMechanicalVentilation134/FVuse Alto3Cough, dyspneaClustered micronodules and ground glass opacitiesGranulomatosisOutpatientSupportive careNo221/MJuul/dabbingNot availableFever, cough, dyspneaMixed ground glass opacities with dorsal lung parenchymal consolidation…ICUIV methylprednisoloneYes357/MTHCNot availableChills, dyspnea, coughPatchy central ground glass opacities with septal thickening (Fig 1)Organizing pneumoniaInpatientSupportive careNo4aPathology data reported in a previous publication.22/MDank VapeNot availableChills, abdominal pain, coughDiffuse lower lobe predominant consolidation, ground glass opacitiesOrganizing pneumoniaInpatientPrednisoneNo5aPathology data reported in a previous publication.35 MTHCNot availableNausea, cough, abdominal painPeripheral, perilobular arcade-like curvilinear opacities sparing the pleural surface and ground glass opacities (Fig 2)Diffuse alveolar damageInpatientIV methylprednisoloneNo618/MHome-made oils/THCNot availableCough, dyspnea, feverLower lobe predominant alveolar and interstitial infiltrates…InpatientPrednisoneNo738/FTHCNot availableDyspnea, cough, chest tightnessDiffuse ground glass opacities and mild septal thickening…ICUIV methylprednisoloneYes819/FTHC12Dyspnea, cough, abdominal pain, feversSymmetric air space opacities with subpleural sparing, septal thickening…InpatientPrednisoneNo928/MTHC6Cough, dyspnea, emesisUpper lobe predominant clustered centrilobular nodules and ground glass opacities with interlobular septal thickeningOrganizing pneumoniaInpatientIV methylprednisoloneNo1019/MTHCNot availableNausea, myalgiasPatchy peribronchial and some peripheral consolidations, septal thickening and mild midlower lung zone ground glass opacities…ICUIV methylprednisoloneYes1124/MTHC1Dyspnea, coughCentrally distributed diffuse ground glass opacities with septal and peribronchial thickening…ICUIV methylprednisoloneNo1235/FSuicide Bunny18Dyspnea, cough, night sweats, diarrheaDiffuse bilateral centrilobular ground glass opacities; arcade-like peripheral curvilinear consolidative opacities with subpleural sparing in the basesAcute fibrous organizing pneumoniaInpatientIV methylprednisoloneNo13aPathology data reported in a previous publication.60/FTHC1Abdominal pain, cough, chest painDiffuse centrilobular ground glass nodules, basilar septal thickening (Fig 3)Organizing acute lung injuryICUPrednisoneNo1456/MTHC1.5Fever, cough, dyspneaDense left lower lobe consolidation; patchy ground glass opacification…ICUPrednisone/IV methylprednisoloneNo1530/FTHCNot availableCough, chest pain, dyspneaPeripheral and peribronchial consolidations in both lung, patchy ground glass opacities and nodules…InpatientSupportive careNoF = female; M = male; THC = tetrahydrocannabinol.a Pathology data reported in a previous publication. Open table in a new tab F = female; M = male; THC = tetrahydrocannabinol. All patients reported prodromal symptoms, ranging from cough and dyspnea to night sweats, and GI symptoms. At time of presentation, 12 patients had hypoxia requiring supplemental oxygen. Of these, seven had profound hypoxia requiring intensive care admission; however, only three progressed in severity to the point where mechanical ventilation was required. Extracorporeal membrane oxygenation was required in one case. There were no deaths attributable to EVALI in the cohort. Thirteen patients received broad-spectrum antibiotic therapy at initial hospital admission. Early discontinuation of antibiotics was rare, even after the diagnosis of EVALI was reached. Three patients were treated with supportive care alone, all of whom had symptom resolution within 2 to 4 weeks of vaping abstinence. The remainder of patients received corticosteroid therapy. Dosing, route of administration, and duration varied among patients. Four patients received oral prednisone alone. Three of the four patients who received oral steroids began treatment with 1 mg/kg of oral prednisone, followed by a slow taper, similar to the doses used to treat cryptogenic organizing pneumonia.8Lazor R. Vandevenne A. Pelletier A. et al.Cryptogenic organizing pneumonia: characteristics of relapses in a series of 48 patients.Am J Respir Crit Care Med. 2000; 162: 571-577Crossref PubMed Scopus (231) Google Scholar Eight patients were initiated on IV methylprednisolone, with transition to oral prednisone once symptoms improved. In all but one case, response to corticosteroids was rapid, with improvement in 24 to 72 h, regardless of dosing or route of administration. All cases had abnormal findings on chest imaging. Within the cohort, two distinct imaging patterns were common. Findings suggestive of diffuse alveolar damage (DAD) were present in seven cases, and consisted of ground glass opacities, heterogeneous consolidations, crazy-paving (ground glass opacities with septal thickening), or a combination of some of these, with predominant involvement of the posterior dependent portions of the lungs. A pattern suggestive of organizing pneumonia was present in five cases. This was characterized by bilateral patchy ground glass opacities, consolidation, or a combination of both in a peripheral or perilobular distribution. Unusual patterns were noted in the remaining three cases. Two had features suggestive of acute hypersensitivity pneumonitis, with upper and midlung predominant ground glass opacity and ill-defined centrilobular ground glass nodules. One case mimicked the imaging appearance of sarcoidosis, including bilateral clusters of micronodules and ground glass opacities, and mild enlargement of mediastinal lymph nodes. Transbronchial lung biopsies were performed in seven cases. The pathologic findings in three of these have been described in a prior publication from our group (cases 4, 5, and 13).5Mukhopadhyay S. Mehrad M. Dammert P. et al.Lung biopsy findings in severe pulmonary illness associated with e-cigarette use (vaping).Am J Clin Pathol. 2019; 153: 30-39Google Scholar Acute lung injury patterns were the most common finding: three biopsies showed organizing pneumonia (Fig 1), and one case each with DAD (Fig 2), acute fibrinous, and organizing pneumonia and organizing acute lung injury (not further classifiable) with patchy interstitial chronic inflammation (Fig 3). Case 1 uniquely lacked evidence of acute lung injury; instead, biopsy showed rare granulomas in the form of epithelioid histiocytes and occasional multinucleated giant cells. Variable numbers of macrophages were present within the airspaces in six cases. Classic features of exogenous lipoid pneumonia were absent in all cases.Figure 2A-D, Case 5. A, Axial image from a high-resolution CT chest scan showing peripheral, perilobular arcade-like curvilinear opacities sparing the pleural surface, and scattered ground glass opacities. B, Axial image from a repeat high-resolution CT chest scan 1 week after initial presentation with new and worsening ground glass abnormalities in the lower lobes. C, Diffuse alveolar damage in the acute and organizing stages (hematoxylin and eosin stain, original magnification ×200). Note detaching hyaline membranes, thickened interstitium, and prominent reactive type 2 pneumocytes. D, Scant acute inflammatory cells and associated macrophages with small microvacuoles (Papanicolaou stain, original magnification 60×).View Large Image Figure ViewerDownload Hi-res image Download (PPT)Figure 3A-D, Case 13. A-B, Axial images from a high-resolution CT chest scan with diffuse ill-defined, centrilobular ground glass nodules throughout both lungs with basilar septal thickening. C, Organizing acute lung injury with interstitial chronic inflammation (hematoxylin and eosin stain, original magnification ×200). D, Scant acute inflammatory cells and associated pulmonary macrophages (Papanicolaou stain, original magnification 60×).View Large Image Figure ViewerDownload Hi-res image Download (PPT) Special stains for microorganisms (Ziehl-Neelsen for acid-fast bacteria and Grocott methenamine silver for fungi) were negative in all cases where they were performed. Immunohistochemical stains, performed in 2 cases, showed cluster of differentiation (CD) 3 (T-cell) predominant chronic inflammatory infiltrates within the interstitium with only occasional CD20-positive B lymphocytes. CD68 confirmed the presence of increased numbers of macrophages within airspaces. Other miscellaneous findings included prominent fibrinous airspace exudates (n = 3), acute inflammation (n = 1), reactive type 2 pneumocytes (n = 6), and rare eosinophils (n = 2). Two cases had mild acute inflammation and hemosiderin laden macrophages with no evidence of vacuolization. One case had moderate acute inflammation and blood and hemosiderin laden macrophages with no evidence of vacuolization. One case lacked inflammation, hemorrhage, and hemosiderin, but had macrophages with small (1-2 μm), otherwise nonspecific vacuoles, as commonly seen in routine BAL specimens. The large, coarse vacuoles typically seen in exogenous lipoid pneumonia were not identified. This case series highlights the significant variation in clinical presentation, severity, and management of EVALI. Our findings support existing literature, and suggest that EVALI represents a spectrum of disease related to inhalation-induced acute lung injury. Within this cohort, there was limited correlation between imaging findings, pathology, and degree of severity. On imaging, DAD was the most common finding, whereas a range of acute lung injury patterns were seen histologically. The variation in imaging and pathology between patients may be explained by several factors, including the heterogeneity of the substance and the duration and intensity of vaping. Notably, BAL and biopsy studies showed no evidence of exogenous lipoid pneumonia. The patients' presentations varied in degrees of severity, ranging from minimally symptomatic individuals to critically ill patients requiring mechanical ventilation. Case 1 specifically highlights the possibility that vaping may be associated with more subtle lung injury, in addition to the classic acute presentation. The clinicopathologic diagnosis of EVALI proved challenging in the cases, particularly in those patients who presented prior to the widespread recognition of the harmful pulmonary effects of vaping. Physician awareness about the importance of obtaining a detailed vaping history is increasing. However, information about the contents of e-cigarette cartridges and the quantification of vaping use may not be precisely known by patients. We strongly encourage physicians who see patients with EVALI to make an attempt to obtain a detailed history of the precise substance vaped and duration of vaping prior to the onset of symptoms. Most patients with EVALI that were treated with corticosteroid therapy in the series improved rapidly, regardless of the route of administration. Oral prednisone was effective for all but the most critically ill patients. Whether tapering of corticosteroid therapy is necessary remains to be determined; however, it was done routinely in this cohort. Notably, a small subset of patients in the cohort improved with supportive care alone, highlighting the role that cessation of the inhalational exposure plays in recovery. Although the initial response to corticosteroid therapy has been promising thus far, the long-term consequences of EVALI, including the risk of pulmonary fibrosis, remain unknown. In most of the cases, bronchoscopy did not significantly change management, even after histologic evaluation of tissue sampling. Although lung biopsies and cultures of BAL are helpful to exclude infection, the need to pursue invasive testing, in particular considering its potential risks, should be evaluated on a case by case basis. Furthermore, the histopathologic findings observed in the series are mostly those of acute lung injury, and are not specific for EVALI. Finally, although data increasingly suggests that vaped THC may be the primary driver of EVALI, associated nicotine dependence should not be ignored. All patients presenting with EVALI should be evaluated and treated for nicotine dependence. This series highlights the wide spectrum of clinical presentations, and imaging and pathologic findings seen in patients with EVALI. Rapid recovery after initiation of corticosteroid therapy was seen in most cases. Supportive therapy alone, when combined with vaping cessation, may be sufficient for patients with mild disease.

Objectives INSM1 has been described as a sensitive and specific neuroendocrine marker. This study aims to compare INSM1 with traditional neuroendocrine markers in gastrointestinal neuroendocrine neoplasms. Methods Retrospective review (2008-2018) was used to retrieve paraffin-embedded tissue from 110 gastrointestinal neuroendocrine neoplasms and controls that was subsequently stained with INSM1, synaptophysin, chromogranin, CD56, and Ki-67. Results INSM1 was positive in 16 of 17 (94.1%) gastric, 17 of 18 (94.4%) pancreatic, 13 of 18 (72.2%) small bowel, 17 of 21 (81.0%) colonic, and 26 of 36 (72.2%) appendiceal tumors. INSM1 was positive in 58 of 70 (82.9%) well-differentiated neuroendocrine tumors, 17 of 20 (85.0%) poorly differentiated neuroendocrine carcinomas, 8 of 11 (72.7%) low-grade goblet cell adenocarcinomas (grade 1), and 6 of 9 (66.7%) high-grade goblet cell adenocarcinomas (grade 2/3). INSM1 sensitivity for neuroendocrine neoplasms (80.9%) was less than that of synaptophysin (99.1%), chromogranin (88%), and CD56 (95.3%); specificity was higher (95.7% vs 86.0%, 87.3%, and 86.0%, respectively). Conclusions INSM1 is a useful marker of neuroendocrine differentiation in gastrointestinal neuroendocrine and mixed neuroendocrine neoplasms. Compared with traditional neuroendocrine markers, INSM1 is less sensitive but more specific.

The ongoing global pandemic of coronavirus disease 2019 (COVID-19) has rapidly disrupted traditional modes of operation in health care and education. In March 2020, institutions in the United States began to implement a range of policies to discourage direct contact and encourage social distancing. These measures have placed us in an unprecedented position where education can no longer occur at close quarters-most notably, around a multiheaded microscope-but must instead continue at a distance. This guide is intended to be a resource for pathologists and pathologists-in-training who wish to leverage technology to continue collaboration, teaching, and education in this era. The article is focused mainly on anatomic pathology; however, the technologies easily lend themselves to clinical pathology education as well. Our aim is to provide curated lists of various online resources that can be used for virtual learning in pathology, provide tips and tricks, and share our personal experience with these technologies. The lists include videoconferencing platforms; pathology Web sites; free online educational resources, including social media; and whole slide imaging collections. We are currently living through a unique situation without a precedent or guidebook, and we hope that this guide will enable the community of pathology educators worldwide to embrace the opportunities that 21st century technology provides.

Since mid-2019, > 2,000 cases of e-cigarette or vaping product use-associated lung injury (EVALI) have been reported. Although initial reports suggested that this entity may be a form of inhalation-related lipoid pneumonia, subsequent studies indicate that EVALI represents various patterns of acute lung injury. Cases of EVALI continue to be reported, and public awareness of the epidemic is increasingly high. However, evidence surrounding optimal management of EVALI remains limited. In this case series, we report 15 cases of EVALI across a spectrum of severity, highlighting key radiologic, pathologic, and cytologic findings, and discuss management implications. In line with national findings, most patients with EVALI in the series vaped liquids containing tetrahydrocannabinol. Our imaging and pathologic findings support the notion that EVALI is a form of acute lung injury.

CONTEXT.—:Social media sites are increasingly used for education, networking, and rapid dissemination of medical information, but their utility for facilitating research has remained largely untapped. OBJECTIVE.—:To describe in detail our experience using a social media platform (Twitter) for the successful initiation, coordination, and completion of an international, multi-institution pathology research study. DESIGN.—:Following a tweet describing a hitherto-unreported biopsy-related histologic finding in a mediastinal lymph node following endobronchial ultrasound-guided transbronchial needle aspiration, a tweet was posted to invite pathologists to participate in a validation study. Twitter's direct messaging feature was used to create a group to facilitate communication among participating pathologists. Contributing pathologists reviewed consecutive cases of mediastinal lymph node resection following endobronchial ultrasound-guided transbronchial needle aspiration and examined them specifically for biopsy site changes. Data spreadsheets containing deidentified data and digital photomicrographs of suspected biopsy site changes were submitted via an online file hosting service for central review by 5 pathologists from different institutions. RESULTS.—:A total of 24 pathologists from 14 institutions in 5 countries participated in the study within 143 days of study conception, and a total of 297 cases were collected and analyzed. The time interval between study conception and acceptance of the manuscript for publication was 346 days. CONCLUSIONS.—:To our knowledge, this is the first time that a social media platform has been used to generate a research idea based on a tweet, recruit coinvestigators publicly, communicate with collaborating pathologists, and successfully complete a pathology study.