Delayed-onset organizing pneumonia following perioperative COVID-19 after lobectomy.

Delayed-onset organizing pneumonia as a manifestation of post-acute coronavirus disease 2019 (COVID-19) syndrome has not been documented in the perioperative setting. Here, a 61-year-old man underwent left lower lobectomy complicated by persistent air leakage requiring seven pleurodesis procedures. He developed COVID-19 on postoperative Day 10 and initially recovered but was readmitted on Day 27 with fever and respiratory failure. Chest computed tomography revealed progressive consolidations with ground-glass opacities. Initial methylprednisolone pulse therapy showed limited response, necessitating a second course with cyclosporine A addition. The patient achieved substantial radiological improvement by postoperative Day 104. Based on the biphasic clinical course, distinctive radiological progression, and limited steroid response, delayed-onset organizing pneumonia secondary to post-acute COVID-19 syndrome was diagnosed. This case highlights the importance of extended monitoring in post-lung resection patients with COVID-19 to enable early recognition and prompt intervention of delayed pulmonary complications.