Dual Immune Checkpoint Blockade in Synchronous Hepatocellular and Renal Cell Carcinoma: A Real-World Case Report of...

Background: The synchronous occurrence of hepatocellular carcinoma (HCC) and clear cell renal cell carcinoma (ccRCC) is rare and poses significant therapeutic challenges, particularly in elderly patients with comorbidities. Although both malignancies may respond to immune checkpoint inhibitors (ICIs), evidence supporting a unified immunotherapeutic approach remains limited. This report aims to describe the clinical course and outcomes of dual immune checkpoint blockade (ICB) in a patient with synchronous HCC and ccRCC. Case Description: We describe a patient in their 80s with synchronous advanced HCC and ccRCC, with underlying cirrhosis related to hepatitis C virus infection and cardiovascular comorbidities. Following multidisciplinary evaluation, treatment with nivolumab plus ipilimumab was initiated. Early radiologic assessment demonstrated a partial response in the renal lesion and an apparent increase in the hepatic lesion, consistent with pseudoprogression. Continued therapy led to progressive reduction of the hepatic lesion and sustained control of the renal tumor. At approximately 18 months of follow-up, both lesions showed durable radiologic response with excellent tolerability and no immune-related adverse events. At the time of writing (April 2026), the patient remains on treatment. Conclusions: This case highlights the feasibility and potential efficacy of a unified immunotherapeutic strategy in synchronous immunogenic malignancies. It also underscores the importance of careful interpretation of radiologic findings during immunotherapy, particularly in HCC where atypical response patterns such as pseudoprogression may occur. These findings provide real-world insight into personalized immunotherapy approaches for complex oncologic scenarios.