Nephroblastoma with fibroadenomatous‐like structures

Abstract
Review of the histological sections of the tumors of 889 patients from the files of the SIOP [International Society of Pediatric Oncology] nephroblastoma trials and studies has revealed 23 cases with a distinctive growth pattern. Due to the similarity of the histological structures with the architecture of adenofibroma (fibroadenoma) of the ovary this type was called nephroblastoma with fibroadenomatous-like structures. The clinical and histopathological factors were studied and correlated with recurrence-free survival and actuarial survival and compared with the whole series of SIOP nephroblastomas. This subtype appears to be a distinctive clinicopathological entity with favorable prognosis.