[Extrarenal nodular nephrogenic blastema in the inguinal canal: report of two cases]

Two observations of extrarenal nephrogenic nodule in inguinal canal are reported. We underline the difficulties in differential diagnostic with true Wilms' tumor, and in sparing these pediatric cases from more aggressive treatment. The main morphological arguments in favor of non-tumoral nephrogenic nodular remnants are: the size of the lesion, the association with a congenital inguinal hernia suggesting a congenital abnormality, and the organoid organization of blastemic tissue surrounding the cavities lined with "hobnail" epithelium evoking a mesonephrogenic origin.