How many surgically-treated angiomyolipomas are related to tuberous sclerosis complex? Insights from a retrospective multicenter study.

BACKGROUND: Patients with TSC - related renal angiomyolipoma (AML) are eligible for targeted therapy with mTOR inhibitors, avoiding the morbidity of interventional management. Despite clinical criteria for TSC diagnosis have been defined, their use in routine clinical practice is likely suboptimal, leading to potential misclassification of TSC-related AML. The study aims to assess the proportion and characteristics of surgically-treated patients with putative sporadic AML that would have been re-classified as TSC-related. METHODS: We retrospectively reviewed a prospectively collected multi-institutional database to select patients with suspected TSC-related AML among those undergoing surgery at three referral Centers over 11-years (2005-2015). Possible diagnosis of TSC was defined according to the 2012 International Tuberous Sclerosis Complex Consensus (ITSCC) criteria. The proportion and characteristics of patients with possible TSC-related AML (as compared to those of patients with sporadic AML) were considered the main study endpoints. RESULTS: Overall, 132 patients were included. Of these, 10 (7.6%) were considered TSC-related. Most patients (84%) were female. Patients with TSC-related AML were likely to be younger (median age 53 vs. 56 years, P=0.29), symptomatic at diagnosis (70% vs. 21%, P=0.002), with slightly worse preoperative physical status (median ASA score 2 vs. 1, P=0.001) and bilateral disease (30% vs. 7.4%, P=0.04) as compared to patients with sporadic AML. Anatomic complexity and tumor size were also higher among TSC-related AMLs. CONCLUSIONS: A non-negligible proportion of surgically-treated, putative sporadic AMLs were reclassified as potentially hereditary (TSC-related). As TSC patients may be treated with targeted therapies, our findings may increase urologists' awareness of TSC-related AML and prompt the design of future studies evaluating targeted diagnostic pathways for these patients.