Currently in the USA intra-abdominal neoplasia involving or originating in the ovary is responsible for the death of 11,000 women per yr, or 1 every 50 min. Historically, as well as can be documented, although benign ovarian cysts were common, malignant neoplasia was rare. Similar lesions arising in or adjacent to the testes are essentially unknown. The uniqueness of the tumors is appreciated by the recognition of the common cell of origin, but there are many different histologic varieties of neoplasia that may arise therefrom. The differences in incidence between the sexes and the apparent significance of irritants to which the female pelvic cavity may be exposed suggest that such proliferating agents may ascend from the vagina through the patent fallopian tube and into the pelvic and/or the general abdominal cavities. Since little improvement has been made in the overall 5 yr survival rate during the past 25 yr (in spite of the widespread use of chemotherapeutic and other treatment modalities), efforts should be directed at defining carcinogenic processes and thus preventing the development of such lethal disease.