CRP and abscess: After four cycles of nivolumab and ipilimumab, the patient was admitted to the emergency room with clinical signs of an acute abdomen showing elevated C-reactive protein (CRP) levels (20.5 mg/dL; normal range < 0.5 mg/dL) and an indurated abdominal swelling caused by abscesses in the abdominal wall at the sites of the former subcutaneous and peritoneal metastases.