A case of ipsilateral three simultaneous renal cell carcinomas with different histologic types

INTRODUCTION: Few reports have presented sporadic multifocal renal cell carcinomas of different histologic types occurring simultaneously in a single kidney. Here, we present a case of three ipsilateral renal cell carcinomas with three histologic types. CASE PRESENTATION: A 44‐year‐old man with end‐stage renal disease due to nephrosclerosis was referred to our hospital for an incidental renal tumor. Following the introduction of hemodialysis, enhanced computed tomography revealed a renal tumor suggestive of clear‐cell renal cell carcinoma with a cystic component. With a preoperative diagnosis of one renal tumor, he underwent laparoscopic radical nephrectomy. However, pathological examination revealed three renal cell carcinomas with three histological diagnoses: clear‐cell, papillary, and clear‐cell papillary renal cell carcinomas. CONCLUSION: Preoperative imaging may not detect all synchronous ipsilateral multifocal renal cell carcinomas. Patients with severe renal function impairment may have synchronous multifocal renal cell carcinomas.