OFP-20-009 Synchronous Angiomyolipoma and renal tumors in patients without Tuberous Sclerosis: Clinico-pathological study of 18 cases F. J. Queipo * , R. A. Carías, Án. F. Panizo, M. L. Gómez-Dorronsoro, F. J. Pardo * Clínica Universidad de Navarra, Pathology, Pamplona, Spain Objective: Simultaneous existence of AML and renal neoplasia is frequent in Tuberous Sclerosis (TS) patients, but uncommon in non-TS cases. Method: A total of 18 cases of coexistent renal neoplasia and AML in non-TS patients were identified. Clinico-pathological features were studied. Results: 18 patients: 10 M/8 F (mean age 62,77 year; range: 35-83) . Mean AML size: 0,82 cm (range: 0,2-3,4). The main size of the renal neoplasms was 5,09 cm (range 1,2-15). AML morphology: 6 leiomyomatous, 4 classic-triphasic, 4 lipomatous, and 4 epithelioid. Three cases had multifocal AML. 15 cases had ipsilateral tumors associated with AML: 6 CCRCC (1 sarcomatoid), 4 ChRCC, 1 RO, 1 TFE3 RCC, 1 hybrid (RO-ChRCC) renal-cell tumor, 1 urothelial carcinoma, and 1 case had 2 tumors: MTSC-RCC and concomitant PRCC. 2 cases had contralateral tumours associated with AML: 1 ChRCC and 1 RO. One patient had bilateral tumors associated with AML: an ipsilateral RO and a contralateral CCRCC. The median follow-up was 36,85 mths (range 0,4-199,8) : all patients were alive without disease. Conclusion: The coexistence of renal tumors with AML is a rare event, usually incidental. If AML is found incidentally together with other renal tumors, it is important to exclude TS retrospectively.