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Incidental simple ovarian cyst in a postmenopausal LNG-IUD user — DFSRH MCQ

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HardOvarian CystsIncidental simple ovarian cyst in a postmenopausal LNG-IUD userDFSRH

A 58-year-old woman attends a specialist sexual and reproductive health service for review of menopausal hormone therapy. Her spontaneous final menstrual period occurred at age 53. For the past 2 years, she has used transdermal estradiol with a 52 mg levonorgestrel intrauterine device for endometrial protection. A pelvic abnormality was incidentally noted during imaging for renal colic. Subsequent expert transvaginal ultrasonography shows a 44 mm unilateral, unilocular, thin-walled, anechoic ovarian cyst with no septations, solid components, papillary projections or ascites. The contralateral ovary is normal. Serum CA125 is 18 units/mL. She has no pelvic pain, abdominal distension, early satiety, urinary symptoms or relevant family history, and examination is unremarkable. Which is the most appropriate management plan?

Educational content. Not a substitute for clinical judgement or local policy.

Reveal the answer and explanation

Correct answer: E — Continue the current hormone therapy and repeat transvaginal ultrasonography and CA125 in 4–6 months

Explanation lettering: E = shown as A · C = shown as B · D = shown as C · A = shown as D · B = shown as E

She is postmenopausal and has completed the recommended initial assessment with expert transvaginal ultrasonography and CA125. The cyst is asymptomatic, unilateral, unilocular and simple, but measures more than 3 cm and no more than 5 cm. RCOG therefore recommends conservative management with repeat ultrasonography and CA125 after 4–6 months. If it remains unchanged or decreases in size with a normal CA125, follow-up may usually cease after 1 year. A is incorrect because the December 2025 RCOG amendment permits immediate discharge without routine follow-up only for simple cysts measuring 3 cm or less. C incorrectly attributes management significance to the LNG-IUD: ovarian cysts may be reported more frequently during LNG-IUD use, but most are transient, and the presence of a benign cyst is not a contraindication to continuing the device. D is incorrect because MRI is a second-line test for an indeterminate lesion when ultrasonography is inconclusive; this cyst has been adequately characterised as simple. E is disproportionate because she is asymptomatic and has low-risk morphology with a normal CA125. Surgical evaluation becomes appropriate if symptoms develop, the lesion becomes complex or persistent in a clinically concerning way, or risk assessment suggests malignancy.

Reference: The Management of Ovarian Cysts in Postmenopausal Women (Green-top Guideline No. 34) (Amended December 2025) — https://www.rcog.org.uk/media/4v3ncfib/gtg_34.pdf Ovarian Cysts in Postmenopausal Women (Green-top Guideline No. 34) (Last reviewed 5 December 2025) — https://www.rcog.org.uk/guidance/browse-all-guidance/green-top-guidelines/ovarian-cysts-in-postmenopausal-women-green-top-guideline-no-34/ FSRH Clinical Guideline: Intrauterine Contraception (March 2023) — https://www.fsrh.org/Common/Uploaded%20files/documents/fsrh-clinical-guideline-intrauterine-contraception-mar-23-amended.pdf