Relationship between miR‐155 expression and clear cell papillary renal cell carcinoma in the dialyzed kidney

INTRODUCTION: Clear cell papillary renal cell carcinoma often develops in the context of the dialyzed kidney (end‐stage renal disease). However, the relationship between clear cell papillary renal cell carcinoma and microRNA expression in patients with end‐stage renal disease remains unclear. CASE PRESENTATION: A left renal tumor measuring 22 mm was detected and a radical nephrectomy was performed on a 50‐year‐old man who had received hemodialysis for the past 6 years. A pathological diagnosis of pT1aNxMx, clear cell papillary renal cell carcinoma was made. We studied the expression of miR‐155 in this case and compared it to the expression in nondialysis kidney tissue. The expression level of miR‐155 was upregulated in tumor tissue compared with expression levels in the renal cortex for the present case. The expression level of miR‐155 in the renal cortex was lower in the present case than in nondialysis kidney tissues. CONCLUSION: We demonstrated upregulation of miR‐155 in a case of clear cell papillary renal cell carcinoma arising from end‐stage renal disease.