SARS-CoV-2 Associated Pulmonary Pathology

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a novel entry in the betacoronaviridae group of coronaviruses. This is the second member of this group, and the third of the family overall to emerge in the last 20 years, which has caused significant health concerns due to the clinical severity and spread of the disease it causes—coronavirus disease identified in 2019 (COVID-19). While initially emerging as a respiratory disease, and while most cases experience symptoms predominantly from this system, SARS-CoV-2 has emerged as a multisystem pathogen. From a pathomorphological point of view, the severity of changes in the respiratory system can be summed up as diffuse alveolar damage—desquamation of the alveolar epithelium with exudative and proliferative changes—pulmonary hyaline membranes, Clara cell hyperplasia, squamous cell metaplasia, and fibrosis. The second most prominent way the disease affects the lung is through endotheliitis—damage to the endothelial cells of the pulmonary vasculature, predominantly affecting the medium and large caliber blood vessels that cause the well-established clinical phenomenon of thrombosis/thromboembolism of the pulmonary vasculature. As the spread of the disease continues with the emergence of new variants and the number of cases continues to grow, including a large percentage of recurrent cases, it is essential to remember that the viral effects are not only acute but, due to the proliferative phenomena, can produce chronic sequelae. Therefore, in the background of dwindling publication interest, it is critical to focus on the histopathological aspects of the pulmonary disease, with the goal of better understanding the effects of the virus on the organism and identifying probable future complications after infection