Pathological anatomy of lung vessels in COVID-19

Pathological anatomy of pulmonary vascular lesions plays a key role in understanding the patho-genesis and morphogenesis of COVID-19. This review focuses on morphological features of pulmonary vascular injury in COVID-19. The virus is known to be capable of causing not only cytopathic cell damage of various organs and tissues (type II pneumocytes, cardiomyocytes, neurons, epithelial cells of the gas-trointestinal tract) but also endotheliotropic damage that aggravates the development and course of acute alveolar damage to the lungs. We studied the literature on microscopic changes in the vessel walls in lung tissue for 2020–2022. This review discusses the issues of local or systemic vascular lesions, morphologi-cal changes in the vessels over time, the likelihood of the development of microangiopathy, vasculitis, and endotheliitis in COVID-19 patients. Particular attention is paid to possible mechanisms of endotheliopathy in COVID-19 patients and its role in the microthrombi genesis. We speculate that in the future, postmor-tem lung examination in COVID-19 patients using histological, histochemical, and immunohistochemical methods will clarify the features of alterative and inflammatory changes and reparative processes in the blood vessel walls, as well as neoangiogenesis at different stages of the disease. Keywords: pathological anatomy, COVID-19, lungs, endotheliopathy, endotheliitis, microthrombus formation