BACKGROUND: Neuroendocrine tumors of the kidney may develop within the renal parenchyma or may arise from the pelvic urothelial mucosa. They are characterized by neuroendocrine differentiation based on light microscopic morphology and immunohistochemistry. They occur primarily in adults, with equal sex distribution. In 2016 the World Health Organization updated the classification of neuroendocrine tumors based on the differentiation as well-differentiated neuroendocrine tumor, large cell neuroendocrine carcinoma (LC-NEC), and small cell neuroendocrine carcinoma. As a group they are rare, and actually there are only 6 cases of renal LC-NEC reported in the literature. CASE: A 60-year-old diabetic male patient who had been on dialysis for the previous 2 years was diagnosed with a renal mass. CONCLUSION: Here we describe the first case of renal LC-NEC with sarcomatoid differentiation. © Science Printers and Publishers, Inc.