ABSTRACT
Objective:To observe the morphological characteristics of lungs in patients with critical corona virus disease 2019 (COVID-19), and to analyze the clinical-pathological relationship.Methods:Two critical patients with COVID-19 who died in Beijing You′an Hospital, Capital Medical University on February 13 and 14, 2020, respectively, were examined by bilateral lungs biopsy. The obtained samples were dehydrated, paraffin embedded, sectioned, stained with hematoxylin-eosin as routine methods, and then observed under light microscope.Results:The pulmonary morphology changes of patients with COVID-19 showed diffuse alveolar damage. Case one was an elderly patient with underlying diseases and her lesions were mainly exudation and hyaline membrane formation, which showed an acute exudation stage of diffuse alveolar damage. Case two was a patient without underlying diseases and his pathological changes were diffuse inflammatory cell infiltration, extensive fibrosis of alveolar wall, filling of necrotizing inflammatory cellulosic exudate in alveolar airspace, extensive destruction of alveoli and pulmonary consolidation, which was characterized by organized stage of diffuse alveolar damage complicated with bacterial pneumonia. The injury of paracronchial submucosal gland was not observed in the two patients.Conclusions:Diffused alveolar damage is the main pathological feature of critical COVID-19. Diffused alveolar damage can induce or aggravate the underlying diseases of elderly patients in the early stage. Extensive destruction of alveoli, pulmonary consolidation and secondary infection are the main causes of respiratory failure in the late stage.