Incidental renal pelvis and ureteral verrucous carcinoma: A case report and literature review.

RATIONALE: Verrucous carcinoma (VC) of the upper urinary tract is an extremely rare disease, with only 7 cases reported in the literature to date. We report a successfully treated case of VC involving the renal pelvis and ureter, along with a literature review to explore its pathogenesis and optimal treatment strategies.

PATIENT CONCERNS: A 79-year-old male presented with "recurrent right flank pain for over 10 years and fever for 1 week."

DIAGNOSES: VC of the right renal pelvis and ureter (pT1N0M0); right renal and ureteral calculi and right pyonephrosis.

INTERVENTIONS: After initial percutaneous nephrostomy to manage the infection, the patient underwent nephrectomy and partial ureterectomy.

OUTCOMES: Histopathological analysis revealed VC in the renal pelvis and ureter, with no muscular invasion or lymph node metastasis. Postoperative recovery was uneventful, and at the 3-month follow-up, no recurrence or residual disease was observed on imaging and cystoscopy.

LESSONS: patients with long-standing renal calculi and chronic inflammation should be carefully monitored for potential malignant transformation. Early treatment of predisposing factors is essential. Contrast-enhanced imaging and thorough pathological evaluation can aid in diagnosis.