Is frozen section analysis in nephron sparing surgery necessary? A clinicopathological study of 301 cases

Purpose: One of the basic principles of nephron sparing surgery for renal cell carcinoma is resection of the tumor with normal tissue margins verified by frozen section analysis. In cases of positive tumor margins the surgeon is committed to complete the local resection or to perform radical nephrectomy. In this study we retrospectively evaluated the yield of frozen section analysis performed during nephron sparing surgeries, especially concerning compatibility with the final histological report and the long-term oncological outcome. Materials and Methods: Between 1988 and 2003, 172 men and 129 women with a mean age of 59 years (range 16 to 83) underwent nephron sparing surgery due to suspected renal tumors. Mean tumor size was 3.56 cm (range 1 to 12.5). Frozen section analysis was routinely performed during surgery. Results: Positive tumor margins in frozen section analysis were found in 2 cases (0.7%). In both cases the tumor was centrally located. Those 2 patients underwent immediate radical nephrectomy but no residual tumor was subsequently found in the radical nephrectomy specimens. Paraffin sections disclosed positive tumor margins in 4 other cases (1.3%) in whom the frozen section analysis had shown tumor negative margins. Of the 4 patients 1 underwent radical nephrectomy for tumor recurrence after 9 months. The other 3 patients showed no evidence of disease recurrence after 26, 59 and 120 months of followup. Conclusions: Our results suggest that frozen section analysis during nephron sparing surgery has minimal clinical significance and hence routine incorporation in urological practice should be reconsidered.