| Abstract: | A nephroblastoma is a tumor arising from metanephric blastema occurring in childhood.
Among laboratory rodents, nephroblastoma has been frequently reported in rats, but it
remains exceedingly rare in mice. The present work describes a nephroblastoma in a young
mouse homozygous for the specific Trp53 R172H point mutation coupled with targeted
deletion of the Pin1 gene. The affected kidney was effaced by a biphasic
tumor with an epithelial component arranged in tubules surrounded by nests of blastemal
cells. Immunohistochemically, the neoplasm was diffusely positive for Wilms’ tumor
antigen. The epithelial component expressed markers of renal tubular differentiation
including wide-spectrum cytokeratin, E-cadherin and folate-binding protein. Furthermore,
the neoplasm exhibited a high proliferative index and diffuse nucleocytoplasmic β-catenin
expression. Based on histological and immunohistochemical features, a diagnosis of
nephroblastoma potentially associated with Trp53 loss and oncogenic
β-catenin activation has been proposed. |
