Thoracic lymphangitis as an immune-related adverse event: a case report.

The efficacy of immune checkpoint inhibitors (ICIs) has been widely recognized in several cancers and is now being used in the perioperative setting for lung cancer.We recently encountered an immune-related adverse event that has not been previously reported: thoracic lymphangitis, which occurred after postoperative ICI treatment for lung cancer. The patient complained of breathlessness and her condition rapidly progressed to hypoxia grade 3. Chest computed tomography revealed significant lymphostasis. With high-dose steroid treatment, the patient showed improvement.Therefore, as the frequency of neoadjuvant, adjuvant, and perioperative ICI use is expected to increase, it is crucial to understand and monitor this adverse event.