Right supernumerary kidney with urothelial carcinoma: A case report

Area of Science:

• Urology
• Oncology
• Medical Imaging

Background:

• Supernumerary kidney is an extremely rare renal anomaly, with fewer than 100 cases reported globally.
• Only two cases of right unilateral supernumerary kidneys have been documented previously.
• No prior reports exist of urothelial carcinoma specifically within a supernumerary kidney.

Observation:

• A 73-year-old female presented with persistent gross hematuria.
• Computed tomography revealed a dysplastic supernumerary kidney adjacent to the normal right kidney.
• Ureteroscopy identified a Y-shaped ureter and a mass within the supernumerary kidney's ureter, diagnosed as urothelial carcinoma.

Findings:

• The patient underwent a nephroureterectomy and partial cystectomy, followed by chemotherapy and intravesical epirubicin.
• Postoperative follow-up at 13 months showed no evidence of recurrence or metastasis on computed tomography.
• This case represents the first documented instance of urothelial carcinoma arising in a supernumerary kidney.

Implications:

• This case underscores that malignancy can occur in supernumerary kidneys, despite their rarity.
• It emphasizes the importance of thorough investigation for rare renal anomalies presenting with hematuria.
• Further research may be needed to understand the oncogenesis and management of malignancies in supernumerary kidneys.