Recurrent Pericardial Effusion in a Patient With Delayed Progression of Melanoma Treated With Immune Checkpoint Inhibitors.

Two commonly used immune checkpoint inhibitors (ICIs) utilized in the treatment of metastatic melanoma are nivolumab, a programmed death (PD-1) checkpoint inhibitor, and ipilimumab, a cytotoxic T-lymphocyte antigen (CTLA-4) checkpoint inhibitor. However, due to the activation of the immune system, ICIs have been associated with cardiotoxic immune-related adverse events (irAEs). Here, we present a 40-year-old male with stage 4 metastatic melanoma treated with nivolumab and ipilimumab who developed recurrent pericardial effusions and subsequent constrictive pericarditis 10 months after initiation of treatment. He initially received a total of four cycles and was started on maintenance nivolumab on 8/2022. On 3/23/2023, he complained of chest pain and was found to be hypotensive. He subsequently underwent an emergent pericardiocentesis where 330cc of serosanguinous fluid was drained. Repeat echo on 3/24 demonstrated a re-accumulation of a moderate-sized pericardial effusion, and a subxiphoid pericardial window was placed. He again presented on 5/24/2023 with similar complaints, and a CT scan of chest showed enlarged pericardial effusion with new bilateral pleural effusions.  To our knowledge, this is one of few case reports discussing pericardial effusions in the setting of nivolumab and ipilimumab ICI immunotherapy.