COVID-19

WKP

Definition : Coronavirus disease 2019 (COVID-19) is an infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).

The disease was first identified in 2019 in Wuhan, the capital of China’s Hubei province, and has since spread globally, resulting in the ongoing 2019–2020 coronavirus pandemic.

The pathological findings of human SARS‐CoV‐2 infection have been limited due to the rare number of biopsies or autopsies.

In a case reported by Xu et al in 2019, a 50‐year‐old man died 14 days after admission due to respiratory failure and cardiac arrest. The primary finding of biopsy at autopsy was bilateral diffuse alveolar damage with cellular fibromyxoid exudates and interstitial mononuclear inflammatory infiltrates dominated by lymphocytes.

Multinucleated syncytial cells with atypical enlarged pneumocytes characterized by large nuclei, amphophilic granular cytoplasm, and prominent nucleoli were identified in the intraalveolar spaces, showing viral cytopathic‐like changes.

No obvious intranuclear or intracytoplasmic viral inclusions were identified.

These pathological features show great similarities to SARS‐CoV and MERS‐CoV infection.

In addition, liver and heart were studied. There is moderate microvascular steatosis and mild lobular and portal activity in the liver tissue and a few interstitial mononuclear inflammatory infiltrates in the heart tissue.

Synopsis

 COVID-19 pneumonia / coronavirus pneumonia

• viral pneumonia
• giant cell pneumonia
• diffuse alveolar damage (DAD)

Macroscopy

 respiratory mucosal hyperemia
 pleural effusion
 pulmonary swelling
 variegated pulmonary pleura and serosa
 focal hemorrhage and edema of the cut surface of the lung
 enlarged mesenteric lymph nodes

Microscopy

 pulmonary anomalies / 2019‐nCoV pneumonia

• pulmonary alveoli edema
• pulmonary interstitial edema
• pulmonary hemorrhage
• alveolar epithelial shedding
• serous exudation （or） fibrinous exudation in the alveoli
• formation of viral inclusions
• formation of fibrin membranes
  • diffuse alveolar damage
  • severe acute respiratory failure (SARF)
  • acure respiratory distress syndrome (ARDS)

• infiltration of inflammatory cells that mainly consisted of macrophages and lymphocytes in interstitial substance and alveoli.

 leukoerythroblastic reaction (32212392)
 disseminated intravascular coagulation (32212240)

Viral pulmonary infections often affected the heart and gastrointestinal tract.

Transmission electron microscopy imaging of SARS-CoV-2 : 32202257

Open references

 Identification of Immunohistochemical Reagents for In Situ Protein Expression Analysis of Coronavirus-associated Changes in Human Tissues. 2020. doi : 10.1097/PAI.0000000000000878

 Autopsy in suspected COVID-19 cases. Hanley B, Lucas SB, Youd E, Swift B, Osborn M. J Clin Pathol. 2020 Mar 20. pii: jclinpath-2020-206522. doi : 10.1136/jclinpath-2020-206522 PMID: 32198191 Free

 Review and Prospect of Pathological Features of Corona Virus Disease. Wang HJ, Du SH, Yue X, Chen CX. Fa Yi Xue Za Zhi. 2020 Feb 25;36(1):16-20. doi : 10.12116/j.issn.1004-5619.2020.01.004 PMID: 32198986 Free

 Retrospective Analysis of 61 Cases of Children Died of Viral Pneumonia. Chen XB, Du SH, Lu JC, Tan XH, Li DR, Yue X, Wang Q, Wang HJ, Qiao DF. Fa Yi Xue Za Zhi. 2020 Mar 25;36(2). doi : 10.12116/j.issn.1004-5619.2020.02.002 PMID: 32212512 Free

 Severe Acute Respiratory Syndrome: Historical, Epidemiologic, and Clinical Features. Hui DSC, Zumla A. Infect Dis Clin North Am. 2019 Dec;33(4):869-889. doi : 10.1016/j.idc.2019.07.001. Review PMID: 31668196 Free

 Coronavirus disease 2019: What we know?. https://onlinelibrary.wiley.com/doi/full/10.1002/jmv.25766

 Pathogenesis of Middle East respiratory syndrome coronavirus. van den Brand JM, Smits SL, Haagmans BL. J Pathol. 2015 Jan;235(2):175-84. doi : 10.1002/path.4458. Review PMID: 25294366 Free

 Middle East Respiratory Syndrome Coronavirus (MERS-CoV) infection: epidemiology, pathogenesis and clinical characteristics. Nassar MS, Bakhrebah MA, Meo SA, Alsuabeyl MS, Zaher WA. Eur Rev Med Pharmacol Sci. 2018 Aug;22(15):4956-4961. doi : 10.26355/eurrev_201808_15635 PMID: 30070331 Free

Paywall references

 [A pathological report of three COVID-19 cases by minimally invasive autopsies]. Yao XH, Li TY et al. Zhonghua Bing Li Xue Za Zhi. 2020 Mar 15;49(0):E009. doi : 10.3760/cma.j.cn112151-20200312-00193. Chinese PMID: 32172546

 Xu Z, Shi L, Wang Y, et al. Pathological findings of COVID‐19 associated with acute respiratory distress syndrome. Lancet Respir Med. 2020. doi : 10.1016/S2213‐2600(20)30076‐X