COVID-19–RELATED LUNG INJURY: A HISTOPATHOLOGICAL OVERVIEW

Zainab M Jawad Alkhirsan; Esraa A. Alyasiry; Ali M Hussein Abdulhadi

doi:10.61796/jmgcb.v3i1.1601

Authors

Zainab M Jawad Alkhirsan
Zainab.m.jawad@jmu.edu.iq
Jabir Ibn Hayyan University of Medical and Pharmaceutical Sciences, Iraq
Esraa A. Alyasiry Jabir Ibn Hayyan University of Medical and Pharmaceutical Sciences, Iraq
Ali M Hussein Abdulhadi Jabir Ibn Hayyan University of Medical and Pharmaceutical Sciences, Iraq

Vol. 3 No. 1 (2026): Journal of Medical Genetics and Clinical Biology

Articles

December 2, 2025

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Objective: To provide a comprehensive review of the key histopathological features associated with COVID-19–related lung injury and to clarify the extent of vascular and inflammatory involvement in the disease. Method: A literature review analyzing reported histopathological findings in COVID-19 lung specimens, comparing them with other viral infections such as H1N1 influenza, and correlating them with clinical and radiological data. Results: Findings consistently highlight diffuse alveolar damage (exudative and proliferative phases), type II pneumocyte hyperplasia, squamous metaplasia, intra-alveolar hemorrhage, microthrombosis, and occasional osseous metaplasia. Additional observations include inflammatory infiltrates, endothelial injury, and cytokine-related damage (e.g., IL-6 upregulation). COVID-19 shows more extensive alveolar and vascular involvement than many other viral infections, though findings vary across patients and comorbidities. Novelty: The review underscores that although several histopathological features overlap with other viral pneumonias, the severity of vascular injury and the complexity of the inflammatory response in COVID-19 distinguish it. It also stresses the diagnostic value of integrating histopathological, clinical, and radiological evidence to better understand disease pathogenesis.

Alkhirsan, Z. M. J., Alyasiry, E. A., & Abdulhadi, A. M. H. (2025). COVID-19–RELATED LUNG INJURY: A HISTOPATHOLOGICAL OVERVIEW. Journal of Medical Genetics and Clinical Biology, 3(1), 51–65. https://doi.org/10.61796/jmgcb.v3i1.1601

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