Immune checkpoint inhibitors are widely used in the adjuvant treatment of renal cell carcinoma. Although immune-related adverse effects are well described, myocarditis remains an uncommon complication. Ealy multisystem immune-related toxicity after limited exposure to therapy is uncommon and may be difficult to recognize in older patients.
An 84-year-old woman receiving adjuvant pembrolizumab for renal cell carcinoma presented with dyspnea shortly after her second dose. She was found to have a new left bundle branch block, with marked troponin elevation and mild left ventricular dysfunction. Additional findings were consistent with myositis, pneumonitis, and nephritis. Coronary angiography showed nonobstructive coronary disease. Pembrolizumab was discontinued, and high-dose corticosteroids were initiated, resulting in gradual clinical improvement.
This case shows the early presentation of pembrolizumab-associated myocarditis with multisystem immune-related toxicity involvement in an elderly patient, and it highlights the importance of early recognition and multidisciplinary management.
Early recognition and rapid initiation of corticosteroids are critical in suspected immune checkpoint inhibitor-associated myocarditis.
JACC. Case reports. 2026 Feb 23 [Epub ahead of print]
Raj Nandan Chennuri, Makarand Madine, Reshmanth Prathipati, Raam Mannam, Sandhya Rani Reddy, Prudhvi Davala, Jaswinder Kaur Chilana, Fazal Bari
Department of Internal Medicine, NYMC/St. Clare's and St. Mary's Hospital, Denville, New Jersey, USA. Electronic address: ., Department of Internal Medicine, NYMC/St. Clare's and St. Mary's Hospital, Denville, New Jersey, USA., Department of Oncology & Hematology, Oncology & Hematology Specialists Group, Denville, New Jersey, USA.