Abstract Background and Purpose: There is no consensus on the most appropriate way to extract the kidney after laparoscopy. A previous study evaluated the reduction in total kidney volume and incision size (40%) after perfusion with a 5% hypertonic solution in a porcine model. The purpose of the current study was to compare the histopathologic renal tumor diagnosis before and after this perfusion. Furthermore, fluid drained from the renal vein was analyzed for the presence of neoplastic cells. Materials and Methods: After radical nephrectomy, specimens of 21 cases of renal tumors were studied. A small piece of the tumor was removed and fixed in formaldehyde. After that, 500 mL of a 5% NaCL solution was infused through the renal artery. The first 10 mL drained from the vein was collected and sent for cytologic study. The specimens and the fragment were analyzed. The parameters studied were histologic subtypes, Fuhrman grade, necrosis, and microvascular invasion. Results: Clear-cell renal carcinoma was found in 81% of the cases. Two cases of chromophobic renal carcinoma, one case of papillary tumor, and one case of oncocytoma were found. There were no differences in histologic subtypes, Fuhrman grade, necrosis, and microvascular invasion before and after perfusion in most of the cases. All cytologic analysis of drained liquid from the renal vein was negative for neoplastic cells. Conclusions: Renal perfusion with 5% NaCL solution after laparoscopic radical nephrectomy did not interfere with the histopathologic and cytologic characteristics of the kidney. In addition, all samples from the liquid drained from the renal vein were negative for neoplastic cells. These findings suggest that renal shrinkage with hypertonic saline after laparoscopic radical nephrectomy is feasible and might be useful for patients with kidney cancer. Validation of our results as well as their impact on clinical outcomes is warranted.