[A Case of Metastatic Renal Cell Carcinoma with Arthritis and Colitis Due to Immune-Related Adverse Events During Ipilimumab-Nivolumab Combination Therapy].

A 73-year-old man with renal cell carcinoma underwent a left-sided open radical nephrectomy at our center. The pathological diagnosis was Fuhrman Grade 2, stage pT3a, clear cell renal cell carcinoma. A follow-up computed tomography (CT) scan revealed lung metastases 9 months after the surgery. The patient was started on ipilimumab with nivolumab combination therapy; however, after two cycles of administration, he developed arthralgia and swelling of the knee. Furthermore, he developed diarrhea almost simultaneously, resulting in the interruption of the ipilimumab plus nivolumab treatment. We diagnosed arthritis and colitis with immune-related adverse events (irAE) and initiated steroid therapy with rehabilitation. His condition improved dramatically, and nivolumab treatment could be resumed after 3 months of treatment interruption.