Pathological changes of fatal coronavirus disease 2019 (COVID-19) in the lungs: report of 10 cases by postmortem needle autopsy

Abstract

Objectives: To observe the pulmonary changes with coronavirus disease 2019 (COVID-19) in postmortem needle specimens, to detect the presence of 2019 novel coronavirus(2019-nCoV) in the lung tissues, and to analyze the clinicopathological characteristics. Methods: For 10 decedents with 2019-nCoV infection in Wuhan, bilateral lungs underwent ultrasound-guided percutaneous multi-point puncture autopsy, and pulmonary pathological changes were described in routine hematoxylin-eosin staining (HE) slides. Electron microscopy was also performed. The reverse transcription polymerase chain reaction (RT-PCR) was employed to detect 2019-nCoV nucleic acid in lung tissue, and the pathological characteristics were demonstrated in combination with clinical data analysis. Results: Of the 10 deaths associated with COVID-19, 7 were male and 3 were female. The average age was 70 (39-87) years. Medical record showed that 7 patients had underlying diseases. The average course of disease was 30 (16-36) days. Nine cases showed fibrinous and suppurative exudation in the alveolar cavity accompanied by the formation of hyaline membrane, and fibroblastic proliferation of alveolar septum. Type Ⅱ alveolar epithelial cells showed reactive hyperplasia and desquamation. Many macrophages accumulated in the alveolar cavity. Capillary hyaline thrombus and intravascular mixed thrombus were noted. In some cases, acute bronchiolitis with mucous membrane exfoliation, accumulation of bronchiolar secretions, and bronchiolar epithelial metaplasia occurred. In the cohort, a large number of bacteria (cocci) were detected in 1 case and a large number of fungi (yeast type) were detected in 1 case. Nine cases were positive for the nucleic acids of 2019-nCoV while one case remained negative by RT-PCR. Coronavirus particles were detected in the cytoplasm of type Ⅱ alveolar epithelium. Conclusions: The pulmonary pathological changes of fatal COVID-19 are diffuse alveolar damage (DAD), mainly in the acute exudative stage and the organic proliferative stage. There are fibrinous exudate aggregation in alveolar cavity with hyaline membrane formation, fibroblastic proliferation in alveolar septum, and alveolar epithelial cell injuries with reactive hyperplasia and desquamation of type Ⅱ alveolar epithelial cells. A large amount of neutrophils and monocytes infiltration is present in most cases and bacteria and fungi are detected in some cases, suggesting a serious bacterial or fungal infection secondary to the DAD.