Radiologically Undetectable Latent Pulmonary Lymphocyte Infiltration Suggesting the Need for Early Glucocorticoid Therapy: An Autopsy Case of Rapidly Progressive COVID-19 Pneumonia with Lymphopenia.

We herein report a fatal case of coronavirus disease 2019 (COVID-19) pneumonia with rapid progression of respiratory failure and lymphopenia. Excessive recruitment and sequestration of lymphocytes in the lung were suggested as the pathophysiology underlying COVID-19-associated lymphopenia. Interestingly, the autopsy in this case revealed lymphocytic infiltration in the lungs even at sites that appeared normal on autopsy imaging. These findings suggest that in COVID-19 cases with risk factors of severe exacerbation, early glucocorticoid administration should be considered, especially if lymphopenia is present, even if the imaging findings show only mild abnormalities.