The Lifetime risk of ovarian carcinoma for a female American is approximately 1 in 70 with an age-adjusted annual incidence of approximately 13.7 cases per 100,000 women.(2) This results in approximately 21,000 new cases of ovarian cancer and 12,500 deaths per annum.(16) These malignancies can occur at any age, including infancy and childhood; however, the overall age-specific incidence increases dramatically with age. In women 40 years of age there are approximately 10 cases per 100,000, increasing to a peak incidence of approximately 45 cases per 100,000 women between the ages of 60 and 65 years.(50) The incidence of adnexal masses associated with pregnancy has been reported to range from 1 in 81 to 1 in 2500.(4,52) Incidental discovery of such masses during either physical examination or routine obstetric. ultrasound obviously can lead to anxiety on the part of both the patient and the obstetrician. While the use of ultrasound for routine fetal surveillance increases, the detection of previously unrecognized adnexal masses in both early and late gestation is likely to increase.