Abstract
INTRODUCTION: Neuroendocrine tumors originating in the kidney are rare, and standard treatments are not established. CASE PRESENTATION: An 80-years-old man was referred to our hospital with renal dysfunction and a left renal mass. Based on CT and bone scintigraphy results, he was diagnosed as having a large left renal tumor with a thrombus in the inferior vena cava, harboring lymph node, liver, lung, and left iliac bone metastasis. The renal biopsy indicated a large-cell neuroendocrine carcinoma. Treatment with nivolumab + ipilimumab was introduced. The local and metastatic tumors had shrunk. Subsequently, treatment with nivolumab has remained effective for >2 years. CONCLUSION: This case demonstrates the efficacy of treatment with the immune-checkpoint inhibitors against large-cell neuroendocrine carcinoma of the kidney.