Summary

A 64-year-old Japanese man with renal cell carcinoma (RCC) and tumour thrombus in the inferior vena cava was treated with sunitinib. Two weeks after treatment, he was hospitalised for disturbance of consciousness. Laboratory tests revealed high-grade hypoglycaemia, hyponatraemia, liver dysfunction and thrombocytopaenia with disseminated intravascular coagulation. Sunitinib was discontinued and the patient recovered after a protracted platelet transfusion. At 5 months after treatment, CT revealed that the tumour thrombus had disappeared and other lesions had regressed. MRI at 15 months revealed further regression and suggested the possibility of histological remission according to the signal intensity of fibrosis. A partial response persisted at 20 months after treatment, despite residual accumulation in the renal tumour evident on positron emission tomography. In summary, we present a case of locally advanced RCC accompanied by severe adverse events that showed a significant and durable response to treatment with sunitinib for just 2 weeks.