Size threshold for follow-up of postmenopausal adnexal cysts: 1 cm versus 3 cm

To assess 3 cm size threshold for follow-up of simple cysts in postmenopausal women.

Radiology information system was retrospectively queried for “US pelvis complete” over 8 years in women > 50 years, with keywords ovarian cyst, adnexal cyst, ovarian mass, cystic mass, cystic neoplasm, ovarian neoplasm, and ovarian mass. Premenopausal women were excluded. Cysts, were classified as ≤ 1 cm, 1–3 cm, 3–5 cm, and ≥ 7 cm. Largest cysts on each ovary was recorded. EMR and imaging archives were reviewed for assessing size, stability duration, and surgical records. Descriptive statistics and confidence interval were performed.

4388 patients met the initial search criteria. 919 cysts in 896 women (age: 50–91 years, mean: 61.5 years) were identified. We found 162 cysts ≤ 1 cm, 352 1–3 cm, 296 3–7 cm , and 51 ≥ 7 cm cysts. 127 patients with 1–3 cm cysts had no follow-up. Final analysis of 225 1–3 cm cysts included 203 ovarian and 22 paraovarian cysts (average size = 1.95 cm (1.1–3.0 cm)). 103 ovarian cysts had less than 2 years, and 100 cysts had more than 2 years follow-up. All except one ovarian cyst were stable for the entire duration of their follow-up (Mean duration of follow-up 5.4 years) (0.3%, 95% CI 0.0–0.05). 40 cysts resolved. One simple cyst increased in size (followed over 3.25 years) without suspicious imaging features and benign on surgery.

1–3 cm cysts represented the most common size range (> 40%) in postmenopausal women, majority of which are stable over follow-up with benign outcome. 3 cm size threshold is appropriate for simple cyst follow-up in postmenopausal women.