Morphopathological features induced by SARS-CoV-2 infection - a series of 57 autopsies.

Background: COVID-19 is a systemic disease with multiorgan damage, which requires a better understanding and deepening of histopathogenesis in order to improve treatment. Autopsy remains a gold standard to establish certain diagnoses and to integrate the morphological spectrum of lung lesions, explaining the cause of death, into a clinical context.

Methods And Results: The study included 57 autopsies performed during 2020-2021 associated with SARS-CoV-2 infection. Among the autopsies we performed, diffuse alveolar damage (DAD) was the most common pulmonary morphological change, 31.8% of them with acute or exudative phase and 33.3% with proliferative phase of DAD. Acute fibrous organizing pneumonia or organizing pneumonia with fibrous remodeling processes and pulmonary fibrosis were rarely observed. The most unfavorable outcome and death associated with SARS-CoV-2 infection was frequent in older men, with a high rate of comorbidities. Microscopically, SARS-CoV-2 presents many common aspects with MERS-CoV and SARS-CoV-1, such as alveolar hyaline membrane, desquamated alveolar cells, alveolar edema and alveolar and interstitial lymphocyte and monocytes infiltration.

Conclusions: Our study includes a large number of autopsies on patients with SARS-CoV-2 infection performed in Romania. COVID 19 associated pneumonia combines classical aspects of alveolar and interstitial pneumonia with some peculiarities. Autopsies are of major importance in understanding SARS-CoV-2 infection.