Introduction: Postoperative recurrence of chromophobe renal cell carcinoma is rare, and its metastatic process remains unclear. We here report a case of a solitary metastasis in the residual ureter detected 9 years after the primary surgery and discuss its possible recurrence mechanism based on our immunohistochemical study.
Case presentation: A 67-year-old woman received nephrectomy for a left renal tumor, which was diagnosed as chromophobe renal cell carcinoma with urinary collecting system invasion. Nine years postoperatively, a tumor was found in the residual ureteral stump and was surgically excised. The recurrent tumor was histologically diagnosed as chromophobe renal cell carcinoma surrounded by normal urothelial cells. On immunohistochemical staining, the tumor cells showed a high expression of uroplakin-2, a urothelium-specific marker.
Conclusion: In our case, highly adhesive uroplakin-2-positive cancer cells spilled from the primary site and attached to the residual ureteral stump, growing slowly while being gradually covered by normal urothelial cells.
Keywords: late metastasis; renal cell carcinoma; residual ureter.
© 2025 The Author(s). IJU Case Reports published by John Wiley & Sons Australia, Ltd on behalf of Japanese Urological Association.