How should I manage a patient with an incidental ovarian cyst found on imaging during routine screening?

Management of an incidental ovarian cyst discovered on imaging during routine screening depends on the patient's age, symptoms, cyst characteristics, and risk factors for malignancy. First, a thorough clinical assessment including abdominal and pelvic examination should be performed to check for ascites or palpable masses; if these are present and not explained by benign causes such as uterine fibroids, urgent referral to a gynaecological cancer service within 2 weeks is recommended NICE CKS,NICE CG122.

If the examination is normal, serum CA125 measurement should be considered, especially in women aged 50 years or over, as elevated CA125 (≥35 IU/mL) warrants further evaluation with an ultrasound scan of the abdomen and pelvis NICE CKS,NICE CG122.

For incidental cysts detected on imaging without symptoms or clinical signs suggestive of malignancy, the cyst’s size, morphology, and complexity guide management. Simple cysts less than 5 cm in premenopausal women are often benign and may be managed conservatively with observation and follow-up imaging, as many resolve spontaneously [Mansour et al., 2023]. Complex cysts, cysts larger than 5 cm, or those with solid components require further assessment, including repeat ultrasound and possibly referral to secondary care for specialist evaluation NICE CKS[Mansour et al., 2023].

In women under 40 years, additional tumour markers such as alpha fetoprotein (AFP) and beta human chorionic gonadotrophin (beta-hCG) may be measured to exclude germ cell tumours NICE CG122.

If ultrasound and CA125 suggest malignancy, referral via the suspected cancer pathway is mandatory NICE CKS,NICE CG122,NICE CKS. If CA125 is normal but the cyst is complex or persistent, clinical judgment should guide referral or continued monitoring NICE CKS,NICE CG122.

For cysts suspected to be endometriomas, referral to a specialist endometriosis service is advised, especially if the cyst is larger than 3 cm or if there is deep endometriosis involvement NICE NG73,NICE CKS.

In pregnancy, management of incidental ovarian cysts requires careful consideration; most simple cysts are monitored expectantly, but complex or large cysts may require specialist input [Goh et al., 2014; Senarath et al., 2021].

Overall, incidental ovarian cysts without suspicious features can often be managed conservatively with clinical and ultrasound follow-up, while those with concerning features or elevated tumour markers require prompt referral and further investigation NICE CKS,NICE CG122[Mansour et al., 2023].