Successful Treatment of Pembrolizumab-Induced Severe Capillary Leak Syndrome and Lymphatic Capillary Dysfunction.

Although capillary leak syndrome has a high mortality rate, its trigger, diagnosis, and treatment remain a challenge to clinicians because of the poor understanding of its mechanism and lack of treatment guidelines. With the extended use of immune checkpoint inhibitors in modern oncology, immune checkpoint inhibitor-associated immune-related adverse events have also expanded. We present a case of pembrolizumab-induced capillary leak syndrome and lymphatic capillary dysfunction in which the patient had an excellent clinical response to a tailored treatment strategy.