Pathophysiology of COVID-19

Since the beginning of the pandemic, it has been clear to the forensic and clinical pathology community that autopsy data are fundamental to understanding the pathophysiology of SARS-CoV-2 infection. Despite an initial reluctance to perform autopsies due to the fear of contagion, more and more knowledge about the macro- and microscopic findings in such cases has been gradually collected. SARS-CoV-2 could affect many organs and not only the lung, even if the pulmonary manifestations are the most frequent. In particular, some authors demonstrated there is direct vascular involvement. Moreover, the role of the host’s inflammatory response and the possible development of a “cytokine storm” are other two fundamental aspects of the pathologic features of the infection. Therefore, COVID-19 should be considered a systemic disease. In this Chapter, we aim to summarize the current evidence concerning autopsy and histopathologic findings of SARS-CoV-2 decedents, to highlight the complex network of pathophysiologic mechanisms that underlie this disease.