Abstract
Embryonal adenosarcom which is called as embryonal mixed tumor of kidney, Wilms's tumor etc. was first reported by Eberth in 1872. Reports on this tumor were published, thereafter, by Birsch-Hirschf eld, Lubarsch and numerous other investigators. Its occurrence in Japan, however, has been quite rare.
1. The authors could investigate an embryonal adenosarcoma formed on the left side kidney of a male infant of 3 years and 10 months old.
2. After extirpation of the adenosarcoma, the patient followed a favorable clinical course and discharged from the hospital 2 weeks after operation.
3. On histological examination, the adenosarcoma was found to be the one classifiable as Masson's type 3 (nephrogenic dysembryoma) .
