An ovarian cyst is a fluid-filled sac that develops on or within an ovary. While common during the reproductive years, the ovaries become less active after menopause, which is defined as 12 consecutive months without a menstrual period. However, the ovaries do not entirely cease function, and the formation of growths remains possible. Understanding the nature of cysts in this post-reproductive phase is important, as their significance changes when the body is no longer ovulating.
Prevalence and Context of Postmenopausal Cysts
Ovarian cysts are found less frequently after menopause compared to the reproductive years, but their presence is not rare. Studies suggest that 5% to 17% of postmenopausal women may have an ovarian cyst, often discovered incidentally during imaging for unrelated issues. Functional cysts, common during the menstrual cycle, are extremely rare after menopause because they are linked to ovulation.
The postmenopausal ovary no longer produces follicles or corpus lutea, which are the source of most benign cysts in younger women. Although the overall frequency of cysts decreases, the medical significance of any mass found tends to increase. This shift is due to the chance that a non-functional cyst or mass may represent a malignancy, which is a greater concern in this age group. Therefore, any ovarian mass identified after menopause warrants a thorough evaluation.
Classifying Postmenopausal Ovarian Masses
Once an ovarian mass is identified, physicians classify it based on physical characteristics observed during imaging. Simple cysts are typically benign, appearing as thin-walled, unilocular structures. These masses rarely pose a cancer risk, and many will spontaneously resolve or remain stable over time.
In contrast, a complex mass exhibits features that raise suspicion for malignancy. These masses may contain solid areas, thick internal walls (septations), or small growths projecting into the cyst cavity (papillary projections). The presence of a mixed solid and cystic component is a defining feature of a complex mass that requires greater vigilance.
Pathological cysts, such as dermoid cysts or cystadenomas, arise from abnormal cell growth and can occur after menopause. The distinction between these benign pathological cysts and malignant growths is often based on size and complexity. Masses exhibiting solid components, being multi-chambered (multilocular), or exceeding 5 centimeters, are considered higher risk and require more aggressive management.
How Ovarian Cysts Are Detected and Monitored
Ovarian cysts are frequently asymptomatic and are discovered during routine screening or imaging for other conditions. As masses enlarge, they can cause vague symptoms such as a dull ache in the pelvis or lower back, abdominal bloating, pressure, or a change in bowel or bladder habits. Acute, severe pain may signal a complication like a cyst rupture or ovarian torsion (a twisting of the ovary).
The primary diagnostic tool used to visualize and characterize an ovarian mass is transvaginal ultrasound (TVUS). This technique uses sound waves to create a detailed picture, allowing the physician to assess the cyst’s size, internal structure, and blood flow. This information is combined with a blood test measuring the protein Cancer Antigen 125 (CA-125).
CA-125 is a serum tumor marker associated with ovarian cancer, though it can be elevated by benign conditions like fibroids or endometriosis. After menopause, a significantly elevated CA-125 level, combined with suspicious ultrasound findings, contributes to a higher calculated risk score. Clinicians use scoring systems, such as the Risk of Malignancy Index (RMI), which integrates menopausal status, CA-125 levels, and ultrasound features to stratify the risk of cancer.
Treatment and Long-Term Management
The management approach for a postmenopausal ovarian mass is dictated by its risk stratification. Small, simple, unilocular cysts, typically less than five centimeters in diameter and with a normal CA-125, are usually managed conservatively. This involves “watchful waiting,” where the mass is monitored with follow-up TVUS examinations, often scheduled every three to six months.
Many simple cysts will remain stable in size or resolve completely over one to two years without intervention. Surgical intervention becomes necessary if the mass is symptomatic, exhibits complex features, is persistently large, or if the CA-125 level is rising. Surgery aims to remove the mass for definitive pathological examination to confirm whether it is benign or malignant.
The surgical approach may be minimally invasive (laparoscopy) for smaller cysts presumed benign, or a traditional open procedure (laparotomy) for larger or highly suspicious masses. In postmenopausal women, surgical removal often includes the entire ovary and fallopian tube, a procedure called salpingo-oophorectomy, to reduce the future risk of malignancy.