Pulmonary pathology and COVID-19: lessons from autopsy. The experience of European Pulmonary Pathologists

Abstract

Since its initial recognition in December 2019, Coronavirus disease 19 (COVID-19) has quickly spread to a pandemic infectious disease. The causative agent has been recognized as a novel coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), primarily affecting the respiratory tract. To date, no vaccines are available nor any specific treatment. To limit the number of infections, strict directives have been issued by governments that have been translated into equally rigorous guidelines notably for post-mortem examinations by international and national scientific societies. The recommendations for biosafety control required during specimen collection and handling have strongly limited the practice of autopsies of the COVID-19 patients to a few adequate laboratories. A full pathological examination has always been considered an important tool to better understand the pathophysiology of diseases, especially when the knowledge of an emerging disorder is limited and the impact on the healthcare system is significant. The first evidence of diffuse alveolar damage in the context of an acute respiratory distress syndrome has now been joined by the latest findings that report a more complex scenario in COVID-19, including a vascular involvement and a wide spectrum of associated pathologies. Ancillary tools such as electron microscopy and molecular biology used on autoptic tissue samples from autopsy are also significantly contributing to confirm and/or identify new aspects useful for a deeper knowledge of the pathogenetic mechanisms. This article will review and summarize the pathological findings described in COVID-19 until now, chiefly focusing on the respiratory tract, highlighting the importance of autopsy towards a better knowledge of this disease.

Prospects for a safe COVID-19 vaccine

“…Lung pathology in COVID-19 disease is characterized by diffuse alveolar damage, with hyaline membrane formation, pneumocyte desquamation, multi-nucleated giant cell formation, neutrophil or macrophage alveolar infiltrates and viral infection of several cell types (7,93,94). Viral proteins can be detected in upper airway and bronchiolar epithelium, submucosal gland epithelium and in type I and type II lung pneumocytes, alveolar macrophages and the hyaline membranes of the lung (94).…”

Expectant management of pneumothorax in intubated COVID-19 positive patients: a case series

“…Expectant management can be quite precarious in this population, but we believe these cases show that observation in ventilated COVID-19 positive patients with a small pneumothorax may be an appropriate option. It has been shown in post-mortem studies that COVID-19 causes diffuse alveolar damage and lymphocytic or cellular fibromyxoid exudate [10]. We hypothesize that this severe exudative process may contribute to sealing the alveolar and pleural injury, allowing for small pneumothoraces to remain stable during positive pressure ventilation.…”

Expectant management of pneumothorax in intubated COVID 19 positive patients: A case series

“…It has been shown in post-mortem studies that COVID-19 causes diffuse alveolar damage and lymphocytic or cellular bromyxoid exudate. 10 We hypothesize that this severe exudative process may contribute to sealing the alveolar and pleural injury, allowing for small pneumothoraces to remain stable during positive pressure ventilation. As the COVID-19 pandemic continues to unfold we will learn more about the exact pathophysiology that occurs.…”