Reliability of intraoperative frozen section for the diagnosis of renal tumors suspicious for malignancy in children and adolescents

Abstract

Background The ability of Intraoperative Frozen Section (IFS) to reliably diagnose renal tumors in children and adolescents is largely unknown. The objective of our study is to evaluate the ability of IFS to establish a histologic diagnosis for renal tumors in this population. Methods We reviewed our experience with patients who underwent IFS at the time of surgery for a renal tumor suspicious for malignancy from 2005–15. The IFS was compared to the final pathology (FP). Data on concordance and reliability were analyzed. Results 130 patients underwent surgical interventions for a renal tumor suspicious for malignancy, and 32 (25%) patients underwent IFS. Median turnaround time for IFS was 20 minutes (range 13 – 44). The histologic IFS diagnosis correlated with FP in 26 (81.2%) cases, was discrepant in 3 (9.4%) cases, and IFS was deferred to FP in 3 (9.4%) cases (kappa 0.71, 95% CI 0.52–0.899, p<0.001). The IFS correctly distinguished between Wilms tumor and non-Wilms tumor in 30 (94%) cases (kappa 0.874, 95% CI 0.705–1, p<0.001). A total of 17 of 19 (89.5%) Wilms tumors were correctly diagnosed by IFS, yielding a sensitivity of 0.89 (95% CI 0.67–0.99) and a specificity of 1 (95% CI 0.75–1). Conclusion IFS is a reliable tool to establish a histologic diagnosis, and to differentiate between Wilms and non-Wilms tumors in children and adolescents with renal tumors. The use of IFS should be encouraged in cases where obtaining a diagnosis will provide guidance for important “real-time” medical decision making, specifically additional adjunctive surgical procedures.

Pediatric Small Renal Masses: Can Tumor Size Predict Histology and the Potential for Nephron-sparing Surgery?

“…Carrasco et al showed that IFS on a nephrectomy specimen is a reliable method to determine final pathology for the diagnosis of renal tumors at the time of resection, with a sensitivity and specificity for correct identification of tumor histology of 0.92 and 1, respectively. 22 Additionally, they reported that IFS correctly distinguished between WT and non-WT cases in 94% of cases. Thus, IFS could help in “real time” by analyzing the NSS resection specimen after excision to determine if a small tumor is WT or other RN-appropriate histology.…”