Sarcomatoid and Aggressive Variants in High R.E.N.A.L. Score T1b RCC: Outcomes After Laparoscopic and Robotic Radical Nephrectomy

<b>Objectives:</b> To assess the outcomes of laparoscopic radical nephrectomy (LRN) in patients with moderate-to-high R.E.N.A.L. score T1b renal cell carcinoma (RCC), with particular attention to the incidence and prognostic implications of sarcomatoid and other aggressive pathological variants. The management of T1b RCC with moderate-to-high R.E.N.A.L. nephrometry scores presents unique challenges in surgical decision-making. Although partial nephrectomy has shown benefits in renal function preservation, the optimal approach for complex tumors remains debatable. <b>Methods:</b> A retrospective analysis was performed on patients who underwent LRN for T1b RCC with moderate-to-high R.E.N.A.L. scores (≥8) between 2008 and 2024. Primary outcomes included perioperative complications, renal function preservation, and pathological findings. All patients return for follow-up one month after surgery with laboratory tests. An upper abdominal and urinary tract ultrasound is performed at three months, and an additional CT or ultrasound examination is recommended during the first postoperative year, then every six months for the first three years, and annually thereafter. Creatinine levels were monitored preoperatively and at multiple time points postoperatively up to 30 months. <b>Results:</b> A total of 118 patients (62 male; 56 female) with a mean age of 66.9 years underwent LRN. The average R.E.N.A.L. score was 10.02, with a mean tumor diameter of 6.0 cm by CT and 4.7 cm by pathology. Mean operative time was 151.6 min, with average blood loss of 75.2 mL. A total of nine complications were reported (7.6%). Pathological analysis revealed aggressive features in 29.7% of cases, including high-grade tumors (G3), multiple tumors, and rare aggressive variants. <b>Conclusions:</b> LRN appears to be a safe and effective treatment option for T1b RCC with moderate-to-high R.E.N.A.L. scores, providing adequate oncological control while maintaining acceptable renal function. The high incidence of aggressive pathological features (29.7%) supports the role of radical nephrectomy in this patient population.