Working Paper Case Report Version 4 This version is not peer-reviewed

Clinical Pathology of Critical Patient with Novel Coronavirus Pneumonia (COVID-19)

Version 1 : Received: 26 February 2020 / Approved: 27 February 2020 / Online: 27 February 2020 (12:30:45 CET)
Version 2 : Received: 27 February 2020 / Approved: 27 February 2020 / Online: 27 February 2020 (16:06:23 CET)
Version 3 : Received: 29 February 2020 / Approved: 2 March 2020 / Online: 2 March 2020 (15:32:55 CET)
Version 4 : Received: 9 March 2020 / Approved: 9 March 2020 / Online: 9 March 2020 (10:31:10 CET)

A peer-reviewed article of this Preprint also exists.


Background Critical patients with novel coronavirus pneumonia ( COVID-19) have worse outcome and high mortality. However, the histopathology of critical patient with COVID-19 remains undisclosed. Methods We performed the whole lung biopsy, and described the pathological changes of critical COVID-19 patient done with transplant by HE staining, immunohistochemistry and special staining observed under the microscopy. Findings The whole lungs displayed diffuse congestive appearance and partly haemorrhagic necrosis on gross examination. The haemorrhagic necrosis was prominently present in outer edge of the right lower lung. The cut surfaces of the lung displayed severe congestive and haemorrhagic changes. The main pathological changes showed massive pulmonary interstitial fibrosis, and partly hyaline degeneration, variable degrees of hemorrhagic pulmonary infarction. Small vessels hyperplasia, vessel wall thickening, lumen stenosis, occlusion and microthrombosis formation. Focal monocytes, lymphocytes and plasma cells infiltrating into pulmonary interstitium. Bronchiolitis and alveolitis with proliferation, atrophy, desquamation and squamous metaplasia of epithelial cells. Atrophy, vacuolar degeneration, proliferation, desquamation and squamous metaplasia in alveolar epithelial cells. Alveolar cavity congestion was prominent, and contained mucus, edema fluid, desquamated epithelial cells, and inflammatory cells. We also found several multinucleate giant cells and intracytoplasmic viral inclusion bodies. Special stains including Masson stain, sirius red staining, reticular fibers staining indicated massive pulmonary interstitial fibrosis. Immunohistochemistry showed positive for immunity cells including CD3, CD4, CD8, CD20, CD79a, CD5, CD38 and CD68. Interpretation We demonstrate the pathological findings of critical patient with COVID-19, which might provide a deep insight of the pathogenesis and severity of this disease.


Novel coronavirus pneumonia; COVID-19; SARS-CoV-2; Pathology; Critical patient


Medicine and Pharmacology, Pathology and Pathobiology

Comments (1)

Comment 1
Received: 9 March 2020
Commenter: Weiren Luo
Commenter's Conflict of Interests: Author
Comment: Main changes
1)In Results section, figure 1, the gross morphology of the right lung was kept to display the main gross changes of the injured lung.
2)In Results section, An independent image about special stains ( figure 4) was add: pulmonary interstitial fibrosis, as well as thickening of the vessel wall and fibrinous exudate were displayed by Masson staining (figure 4A-E). Enlarged and ruptured alveolar septum, massive pulmonary hemorrhage in alveolar cavity were found (figure 4F). In addition, extensive pulmonary interstitial fibrosis was also confirmed by other special stains including sirius red staining (figure 4G), reticular fibers staining (figure 4H) and PAS staining (figure 4I).
3)In Discussion section, added some explanations about clinical correlation with vascular wall thickening, lumen stenosis and occlusion. “vascular wall thickening, lumen stenosis and occlusion occurred frequently under the microscopy, which might explain why some critical patients have pulmonary hypertension in later stage. However, the cause about vascular wall thickening and lumen stenosis need to be further investigated. ”
4)In disclose section, “As to the images in this academic case report, no reproduction in public without permission. No other potential conflicts of interest were disclosed”.
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