Objective:

To report a case of myocarditis in a patient with hepatocellular carcinoma (HCC) following treatment with the PD-1 inhibitor sintilimab, highlighting its significance in the context of existing literature.

Key Findings:

• The patient exhibited elevated cardiac biomarkers and ECG changes indicative of myocarditis, which are critical for early diagnosis.
• CMR showed myocardial edema and other abnormalities consistent with myocarditis, emphasizing the need for advanced imaging in diagnosis.
• EMB revealed myocardial fiber hypertrophy and lymphocytic infiltration, supporting the diagnosis and indicating an immune-mediated process.

Interpretation:

This case highlights the potential for myocarditis as a serious immune-related adverse event associated with PD-1 inhibitors in HCC patients, underscoring the need for vigilance in monitoring.

Limitations:

• The study is based on a single case report, limiting generalizability and potential biases in case reporting.
• Data on ICI-related myocarditis in HCC patients is still limited, necessitating further research.

Conclusion:

The case underscores the importance of early detection and management of ICI-related myocarditis in patients undergoing treatment for HCC, suggesting future research directions to better understand this adverse event.