Abstract
The prognosis of patients with post-coronavirus disease 2019 (COVID-19) interstitial lung disease remains unclear. We herein report an autopsy case in which serial progression after the onset of post-COVID-19 interstitial lung disease resulted in an acute exacerbation, leading to a fatal outcome. Autopsy findings included hyaline membrane formation/interstitial inflammatory cell infiltration, suggestive of acute lesions, and severe regional fibrosis, indicating a preexisting chronic condition. In the present case, we histopathologically confirmed the acute exacerbation of post-COVID-19 interstitial lung disease.