Partial nephrectomy of a horseshoe kidney associated with renal cell carcinoma and ureteral stone: A clinical case report.

Key Clinical Message: Although anatomical and vascular abnormalities of the horseshoe kidney might be challenging, complete preoperative imaging evaluations and accurate organ-sparing surgical planning can lead to much lower complications. Abstract: Horseshoe kidney (HK) is one of the most common renal fusion anomalies. Renal carcinoids are rarely reported in HK patients. Here, we described a rare case of advanced right renal cell carcinoma (RCC) along with proximal left ureter stone in a 41-year-old man who presented with a complaint of turbid urine. Early blood tests revealed a blood urea nitrogen of 44 mg/dL and serum creatinine of 1.35 mg/dL. The urine analysis showed microscopic hematuria (6-8 RBCs) and few calcium oxalate crystals. The imaging evaluations revealed an HK anomaly with a solid mass on the right side and a 4 mm stone in the proximal left ureter. The findings suggested RCC which was confirmed by histopathology examination. Consequently, the patient was scheduled for an organ-preserving open surgery of a right kidney tumor with concomitant left ureterolithotomy. The 16-month follow-up showed no urological complications, metastasis, or tumor proliferation. Although the anatomical and vascular abnormalities of HK might be challenging, organ-sparing surgical treatment should be considered in feasibly resectable tumors. Complete preoperative imaging evaluations to identify the characteristics of HK, as well as accurate surgical planning, can lead to much lower complications.