- Pathologic findings of early stage COVID-19 pneumonia may include1:
- Proteinaceous exudate
- Globule and focal reactive hyperplasia of pneumocytes with patchy inflammatory cellular infiltration
- Multinucleated giant cells
- No prominent hyaline membranes
- No prominent neutrophil infiltration
- Possible pathologic features of later stage COVID-19 pneumonia2-4 :
- Alveolar exudative inflammation
- Interstitial inflammation
- Focal hemorrhage
- Interstitial fibrosis
- Diffuse destruction of alveolar structure :
- Formation of hyaline membrane
- Fibrin exudates
- Epithelial damage
- Diffuse hyperplasia of pneumocyte type II
- Vasocongestion of alveolar capillaries
- In some cases, a superimposed bacterial pneumonia can also be found4.
- In terms of histopathologic findings, the lungs are the most affected organs by SARS-CoV-2 infection, compared to the heart, liver and kidney.
- The pulmonary pathological findings of COVID-19 have shares similarities to those of SARS and MERS3,4.
This data comes from 4 articles.
Tian S., Hu W., et al present a case series of two patients who underwent lung lobectomies for malignancy and who retrospectively were found to have had SARS-CoV-2 at the time of the procedure, although they had not exhibited any respiratory symptoms. Pathologic specimens were examined to determine the histopathology of pneumonia caused by SARS-CoV-2 in its early pre-symptomatic phase.
Xianhong Y., et al present a case series of three patients who died of COVID-19 pneumonia who underwent of post-mortem autopsy, where multiple specimens of different organs were obtained and examined for pathological findings.
Ji H., et al present a review article presenting elevated levels of plasminogen as a risk factor in patients with comorbidities infected by SARS-CoV-2.
Tian S., Xiong Y., et al report a case series of four deceased patients from Zhongnan Hospital diagnosed with COVID-19 pneumonia who underwent of post-mortem needle biopsy of multiple organs. Specimens were collected and histopathologic findings were descripbed.
- Tian S., Hu W., Liu H., et al (February 20, 2020). Pulmonary Pathology of Early-Phase 2019 Novel Coronavirus (COVID-19) Pneumonia in Two Patients With Lung Cancer. Journal of Thoracic Oncology. https://doi.org/10.1016/j.jtho.2020.02.010.
- Xiaohong Y., Tingyuan L., Yifang P., et al (2020). Histopathological study on multiple sites of puncture of the remains of 3 cases of novel coronavirus pneumonia (COVID-19). Chinese Journal of Pathology. https://doi.org/10.3760/cma.j.cn112151-20200312-00193.
- Ji H., Zhao R., Matalon S., et al (April 3, 2020). Elevated Plasmin(ogen) as a Common Risk Factor for COVID-19 Susceptibility. American Physiological Society. https://doi.org/10.1152/physrev.00013.2020.
- Tian, S., Xiong, Y., Liu, H. et al. (March 23, 2020). Pathological study of the 2019 novel coronavirus disease (COVID-19) through postmortem core biopsies. Mod Pathol. https://doi.org/10.1038/s41379-020-0536-x.