Abstract and Introduction
Objectives: Although diffuse alveolar damage, a subtype of acute lung injury (ALI), is the most common microscopic pattern in coronavirus disease 2019 (COVID-19), other pathologic patterns have been described. The aim of the study was to review autopsies from COVID-19 decedents to evaluate the spectrum of pathology and correlate the results with clinical, laboratory, and radiologic findings.
Methods: A comprehensive and quantitative review from 40 postmortem examinations was performed. The microscopic patterns were categorized as follows: "major" when present in more than 50% of cases and "novel" if rarely or not previously described and unexpected clinically.
Results: Three major pulmonary patterns were identified: ALI in 29 (73%) of 40, intravascular fibrin or platelet-rich aggregates (IFPAs) in 36 (90%) of 40, and vascular congestion and hemangiomatosis-like change (VCHL) in 20 (50%) of 40. The absence of ALI (non-ALI) was novel and seen in 11 (27%) of 40. Compared with ALI decedents, those with non-ALI had a shorter hospitalization course (P = .02), chest radiographs with no or minimal consolidation (P = .01), and no pathologically confirmed cause of death (9/11). All non-ALI had VCHL and IFPAs, and clinically most had cardiac arrest.
Conclusions: Two distinct pulmonary phenotypic patterns—ALI and non-ALI—were noted. Non-ALI represents a rarely described phenotype. The cause of death in non-ALI is most likely COVID-19 related but requires additional corroboration.
Coronavirus disease 2019 (COVID-19) is widespread globally, yet there are relatively limited data on its underlying pulmonary pathology. COVID-19 pathology has been described only in limited case reports and mostly small case series.[1–16] Overall, these comprise a combination of surgical resections, complete autopsies, or postmortem biopsy sampling.
The most commonly described pathology is acute lung injury (ALI) with hyaline membranes consistent with diffuse alveolar damage (DAD), which corresponds clinically to acute respiratory distress syndrome (ARDS). In a minority of cases, DAD was absent, and organizing pneumonia, chronic inflammation, congestion,[6,8,9] and bronchopneumonia were present. Fibrin deposition[4,10,11] or microthrombi[5,12–14] have also been described, most often in conjunction with DAD.
While the current literature indicates that ALI is the primary pulmonary pathology in patients with COVID-19, it also suggests that some patients may have multiple additional or concurrent pathologic manifestations. Which pathologic findings are directly attributable to COVID-19 and which are unrelated remain unclear. A systematic and multidisciplinary approach with correlation among clinical, radiologic, and pathologic findings in a large series may improve our understanding of the spectrum of disease in COVID-19.
The aim of the current study, conducted at an academic teaching hospital in New York City, the epicenter of the pandemic in the United States, is to describe the pulmonary pathology seen in a large series of autopsies from decedents with confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection based on real-time reverse transcription polymerase chain reaction (RT-PCR) and to correlate the results with imaging, clinical, and laboratory data.
Am J Clin Pathol. 2020;154(6):748-760. © 2020 American Society for Clinical Pathology