Natural History of Sonographically Detected Simple Unilocular Adnexal Cysts in Asymptomatic Postmenopausal Women

Abstract

At the authors' institution, transvaginal ultrasonography was offered to postmenopausal women as part of routine gynecologic examination from January 1995 to June 2002. When the ultrasound showed the presence of a simple, unilocular adnexal cyst less than 10 cm in size, the patient was given the choice of surgical treatment or conservative management with transvaginal ultrasonography every 6 months. Women with a cyst size of 10 cm or greater or with a CA-125 level of 53 IU/mL or greater were recommended for surgery. Of the 8794 women who underwent transvaginal ultrasonography, 215 (2.5%) were found to have at least one simple, unilocular adnexal cyst. Sixty-six subjects were lost to follow up, leaving 149 patients who were available for analysis. Forty-five women, including all 4 patients who were found to have more than 1 cyst, had surgical treatment (34 after initial diagnosis and 11 during follow up). One hundred four were managed conservatively. Most clinical and demographic characteristics were similar in both groups. The average age of the patients was 59 years (range, 45-84 years), and the average time since menopause was 10.2 years (range, 1-35 years), which was distributed fairly equally across the age range (over 10 years, 39%; 6-10 years, 26.5%; and less than 6 years, 34.5%). Thirteen percent of the patients had CA-125 levels above normal. Seventeen women were receiving hormone replacement therapy and 8 were taking prophylactic tamoxifen. There was a significant difference in the size of cysts in women who underwent surgery compared with those with conservative management. The median cyst volume was 24.3 cm 3 in the surgery group compared with 7.2 cm 3 in the conservative management group, and the median cyst size was 5.4 cm compared with 3.0 cm (P = 0.001 for both). Color Doppler flow was present in 21.5% of all cysts with mean pulsatility index, resistive index, and peak systolic velocity values of 1.94, 0.71, and 16.5 cm/s, respectively. Of the 49 ovarian cysts removed, 41 were serous cystadenoma, 3 each were mucinous cystadenoma and cystadenofibroma, and 1 was a paraovarian cyst. One patient was found to have an ovarian cancer, which was a stage IA squamous carcinoma 0.5 cm 2 in area arising from a cystic teratoma. This 82-year-old woman had a small cyst, 3 cm in size, with no Doppler flow detected. Her serum CA-125 level was 45 IU/mL. There was a 3-mm micropapillary area in the inner wall surface of the cyst, which was not seen with vaginal ultrasonography. In the 104 women managed conservatively, 46 cysts (44%) resolved spontaneously, most (74%) within the first 2 years (median time to resolution 15 months). Thirteen women developed a new cyst and 1 woman developed bilateral cysts within median of 15 months from the resolution of the first cyst. Ten of the new cysts resolved, 2 decreased in size, and 3 remained stable. After a median follow up of 48 months, the cyst persisted in 56 of the 104 women in the conservative management group. Thirty-eight (65.5%) of these were unchanged, 10 (17.3%) increased in size, and 10 decreased in size. Fifty-four percent of cysts in women with less than 10 years since menopause resolved spontaneously compared with 29% of those in women 10 years or more away from menopause (P = 0.02).