Ovarian cysts may occur in up to 17 percent of postmenopausal women, but the optimal management is unknown. A significant proportion of such cysts are believed to spontaneously involute. Although the evidence linking ovarian cysts to malignancy is weak, ovarian cancer is increasingly common in older women. Survival rates are poor if the disease spreads beyond the ovary. Ultrasonography and measurement of serum CA 125 levels have not proved suitable as screening tests for ovarian cancer. Nardo and colleagues studied the optimal clinical management of persistent unilocular ovarian cysts smaller than 50 mm in diameter in post-menopausal women who had normal serum CA 125 levels.

The authors retrospectively reviewed the records of 226 postmenopausal women diagnosed with persistent unilocular ovarian cysts. These women had been referred to the gynecology department of an English district hospital for conditions mainly related to menopause. The average age of study participants was 56.2 years (range, 45 to 87 years). After a thorough assessment, those with a personal or family history of breast, endothelial, or ovarian cancer, or use of hormone therapy were excluded from the study. The remaining patients were followed by clinical examination, ultrasonography, and serum CA 125 measurements six months after the initial assessment, and then every 12 months for five years.

Of the 226 women, 172 (76 percent) showed no change in cyst diameter or rise in CA 125 levels during follow-up. In 21 women, cyst diameter increased within 18 months. By 30 months, 33 women had increased cyst diameter. By five years, 54 women had increased cyst diameter, but only six of these women had increased CA 125 levels, and only two developed malignancy. No malignancies developed in women whose cysts did not increase in size.

The authors conclude that in postmenopausal women, most ovarian cysts smaller than 50 mm in diameter are benign and can be managed safely by regular monitoring of cyst size and serum CA 125 level.