ABSTRACT
A 71-year-old man with a history of drug-induced interstitial pneumonia was diagnosed with COVID-19 infection and simultaneously found to have a pulmonary mass, suggesting a coexisting lung cancer. Approximately 1 month after COVID-19 pneumonia resolved, the patient electively underwent right upper lobectomy. Postoperatively, acute exacerbation of interstitial pneumonia occurred and the patient died on the fifteenth postoperative day. By quantitative reverse transcription polymerase chain reaction, high levels of COVID-19-derived RNA were detected in the specimen of lung parenchyma. Despite resolved COVID-19 infection, it may persist locally in the lungs, with the risk of acute exacerbation of interstitial pneumonia due to secondary stressors including surgery.