Clear Cell Papillary Renal Cell Carcinoma Incidentally Discovered in a Patient With Normal Renal Function: A Case Report

Introduction

Clear cell papillary renal cell carcinoma is a distinct histopathological entity first characterized in patients with end-stage renal disease. Although increasingly reported in patients with normal renal function, it remains relatively unfamiliar in routine clinical practice.

Case Presentation

A 75-year-old male with normal renal function presented with an incidentally discovered left renal mass. Radiological evaluation revealed a mass with a distinct enhancement pattern. Considering the patient's preference for surgical management, robot-assisted partial nephrectomy was performed, confirming clear cell papillary renal cell carcinoma, with immunohistochemistry demonstrating diffuse cytokeratin 7-positivity, alpha-methylacyl-CoA racemase-negativity, and cup-shaped carbonic anhydrase IX staining.

Conclusion

This case demonstrated the characteristic features of clear cell papillary renal cell carcinoma in a patient with normal renal function. Nephron-sparing surgery and rigorous follow-up protocols are crucial management strategies. Future studies with larger cohorts are needed to define the natural history and optimal management of clear cell papillary renal cell carcinoma.