[Testicular feminization with an unusual gonadal tumour (Author's transl)].

A case of a 31-year-old patient showing the typical features of testicular feminization is presented.--Laparotomy was performed, and a large cystic tumour at the place of the right gonad was removed. Microscopically dysgenetic testicular tissue was found. The cyst was lined with cuboid epithelium. Its wall contained smooth muscle fibers.--Probably this cyst was a derivative of the Muellerian ducts.--Today, androgen resistance of the target organs is considered to be the cause of testicular feminization, while the production of hormones of the fetal gonads is normal.--In cases with rudiments of the Muellerian ducts there may be an insufficiency of the oviduct repressor.