What are the implications of an ovarian cyst in a postmenopausal woman?

From the Guidelines

Ovarian cysts in postmenopausal women should be managed based on their size and characteristics, with simple cysts up to 10 cm in diameter being likely benign and manageable with repeat imaging, as recommended by the American College of Obstetricians and Gynecologists Committee on Practice Bulletins—Gynecology 1.

Key Considerations

• Simple cysts smaller than 3 cm in postmenopausal women generally require no further management, according to the O-RADS US risk stratification and management system 1.
• For cysts greater than 3 cm but less than 10 cm, at least 1-year follow-up showing stability or decrease in size is recommended, with consideration of annual follow-up for up to 5 years if stable 1.
• The risk of malignancy in simple cysts is low, with a recent meta-analysis suggesting a risk of approximately 1.5% in postmenopausal women 1.

Management Approach

• Transvaginal ultrasound and CA-125 blood testing should be used to assess ovarian cysts in postmenopausal women.
• Simple cysts with thin-walled, unilocular, and no solid components typically require follow-up imaging in 3-6 months to ensure stability.
• Complex cysts or those with CA-125 elevation warrant gynecologic oncology referral due to higher cancer risk.
• Management options include observation with serial imaging for low-risk cysts or surgical intervention for persistent, enlarging, symptomatic, or suspicious cysts.

Recent Guidelines

• The ACR Appropriateness Criteria for clinically suspected adnexal mass, no acute symptoms, recommends that unilocular simple cysts, regardless of size and menopausal status, are not associated with an increased risk of cancer 1.
• The SRU consensus update in 2019 reflects the benignity of simple ovarian cysts, with a higher threshold for follow-up of simple cysts in postmenopausal patients 1.

From the Research

Ovarian Cyst Incidence in Postmenopausal Women

• The incidence of ovarian cysts in postmenopausal women is approximately 18% over a 15-year period in the USA 2.
• A large screening trial in Europe revealed a 21.2% incidence of ovarian cysts among healthy postmenopausal women 2.
• Worldwide, about 7% of women have an ovarian cyst at some point in their lives 2.

Management of Ovarian Cysts in Postmenopausal Women

• Simple cysts found on ultrasound may be safely followed without intervention, even in postmenopausal women, as they are not likely cancer precursors or markers of increased risk 2.
• The American College of Obstetricians and Gynecologists (ACOG) recommends conservative management of simple ovarian cysts in postmenopausal women 2.
• Ovarian cancer screening and follow-up include a CA-125 blood test and transvaginal ultrasonography (TVU) at baseline, an annual TVU for three additional years, and annual CA-125 tests for five years beyond baseline 2.

Natural History of Simple Ovarian Cysts

• Simple ovarian cysts in postmenopausal women can be followed conservatively because their risk for malignant transformation is low 3.
• The majority of simple ovarian cysts either resolve spontaneously or persist unaltered on follow-up 3, 4, 5.
• One study found that 46.30% of simple ovarian cysts resolved spontaneously, and 43.91% persisted unchanged over the follow-up period 3.

Size Threshold for Follow-up

• A 3 cm size threshold is appropriate for simple cyst follow-up in postmenopausal women 4.
• Cysts ≤ 1 cm are unlikely to require follow-up, while cysts ≥ 7 cm may require more frequent monitoring 4.

Malignancy Rate

• The malignancy rate of simple ovarian cysts in postmenopausal women is approximately 1 in 10,000 5.
• The risk of malignant transformation is low, and simple ovarian cysts are most likely to remain unchanged or disappear during follow-up 5.

Surveillance and Life Expectancy

• Surveillance of postmenopausal women with simple ovarian cysts affords limited benefits, particularly in women with advanced age and comorbidities 6.
• Projected life expectancy gains from follow-up are limited, ranging from 3.7 to 5.1 days for women with no comorbidities, and 2.1 to 3.5 days for women with severe comorbidities 6.