Purpose The RENAL nephrometry scoring system has been validated to predict adult kidney tumor complexity. This study aims to explore the application of RENAL nephrometry scoring system in bilateral Wilms tumor (BWT).
Methods A retrospective review of patients with BWT from January 2010 to June 2022 was performed. Each kidney unit was evaluated independently by 2 blinded reviewers, discrepancies were evaluated by a third reviewer to reach a consensus. Tumor anatomical characteristics were summarized and compared.
Results 29 patients with 53 kidney units were included in the study. 53 kidney units included 12 (22.6%) low-complexity, 9 (17.0%) intermediate-complexity, and 32 (60.4%) high-complexity. 2 kidney units (3.8%) had tumor thrombus, and 14 (26.4%) had multiple lesions. A total of 42 kidney units (79.2%) underwent initial nephron-sparing surgery (NSS) and 11 (20.8%) underwent radical nephrectomy. Less complexity tumors were observed in the NSS group. Of the 42 kidney units undergoing initial NSS, 26 were performed in vivo and 16 ex vivo via autotransplantation. The latter group featured a higher complexity. During follow-up, 22 patients survived and 7 died, no statistically significant tumor complexity was observed between the two groups.
Conclusion The anatomical characteristics of tumors in the BWT population are complex. Despite this study did not indicate that the complexity correlated with prognosis, low-complexity tumors were candidates for NSS, and kidney autotransplantation provided a feasible procedure for high-complexity tumors. Given the presence the multiple lesions and tumor thrombus, a refined system is required.