Dysgerminoma in 45,X Turner syndrome: report of a case.

Here we report the fourth case of dysgerminoma in a patient with the syndrome of gonadal dysgenesis and 45,X karyotype. Typical Turner's syndrome features were unusually associated with breast development, menarche and secondary amenorrhoea. Exaggerated basal and GnRH stimulated gonadotrophin and low oestradiol levels were typical of post-pubertal Turner's syndrome. Detailed (standard) chromosome and banding analysis excluded the presence of Y chromosome material. This case suggests that the presence of a Y chromosome is not necessary for abnormal differentiation of germ cells and the occurrence of a gonadoblastoma.