Non-Wilms' Renal Tumors In Children:A 139 Cases Series

Background:Pediatric non-Wilms renal tumors (NWRTs) which comprise a small proportion of renal tumors,are a heterogeneous group of neoplasms with variable malignant potential, mortality, and response to treatment.This study aimed to determine the clinical characteristics, management and prognosis of children with non-Wilms' renal tumors(NWRTs). Methods:Medical records of all patients (n = 139) treated for NWRTs over a 12-year period (2008.01–2019.10) at a single center were reviewed retrospectively.Results:The histopathological groups of NWRTs included malignant rhabdoid tumor of the kidney(MRTK)(n: 30, 21.6%), renal cell cancer(RCC)(n: 26,18.7%), clear cell sarcoma of the kidney(CCSK)(n: 24,17.3%), congenital mesoblastic nephroma(CMN)(n: 21,15.1%), cystic nephroma(CN)(n: 16,11.5%),metanephric tumours(n: 12, 8.6%), renal angiomyoliporma(RAML)(n: 3, 2.2%), renal primitive neuroectodermal tumor(rPNET)(n: 2, 1.4%), renal hemangioma(n: 2, 1.4%), inflammatory myofibroblastic tumor(IMT)(n: 2, 1.4%), ossifying renal tumor of infancy(ORTI)(n: 1, 0.7%). 123 children were followed up with an average of 42 months. 16 children were lost to follow-up. Tumor-free survival was observed in 94 children. 28 children(22.8%) were died.Conclusions:Pediatric NWRTs comprises 19.1% of all renal tumors in our single center. Accurate diagnoses along with appropriate management are important factors in improving patients outcome. The mainstay treatment of malignant NWRTs including MRTK,CCSK,RCC and PNET is comprehensive treatment. The mainstay treatment of benign NWRTs including RAML,CN, ORTI, CMN,metanephric tumours, and renal hemangioma is surgical resection alone.