Management of O-RADS 2 Lesions
Definition and Risk Assessment
- O-RADS 2 represents the "almost certainly benign" category with less than 1% risk of malignancy, comprising the majority of unilocular cysts less than 10 cm, including simple cysts, nonsimple unilocular cysts with smooth walls, and classic benign lesions 1, 2
Management Based on Lesion Type and Size
- For premenopausal women with simple cysts ≤3 cm, no follow-up is needed, while those with simple cysts >3 cm to ≤5 cm require no additional management, and those with simple cysts >5 cm but <10 cm should have follow-up ultrasound in 8-12 weeks 1, 2, 4
- For postmenopausal women with simple cysts ≤3 cm, no follow-up is needed, while those with simple cysts >3 cm but <10 cm should have follow-up in 1 year, with consideration of annual follow-up for up to 5 years if stable 2, 3, 4
- Typical hemorrhagic cysts <5 cm should be referred to a US specialist, gynecologist, or MRI, while those >5 cm but <10 cm should have follow-up in 8-12 weeks, with referral if persistent or enlarged 1, 5
- Typical dermoid cysts <10 cm should be referred to a US specialist, gynecologist, or MRI, with annual US follow-up considered if not surgically removed 5, 6
- Typical endometriomas <10 cm should have US specialist or MRI evaluation if there is enlargement, changing morphology, or a developing vascular component 5
- Simple paraovarian cysts require no follow-up, with optional single follow-up study in a year 4, 5
- Typical peritoneal inclusion cysts should be referred to a gynecologist 1, 5
- Typical hydrosalpinx (any size) should be referred to a gynecologist 1, 5
Important Considerations
- Transvaginal ultrasound is preferred for evaluation, with size measurement by largest diameter, and each lesion should be separately characterized in cases of multiple lesions 7
Common Pitfalls to Avoid
- Failing to perform adequate follow-up for cysts >5 cm, as larger cysts may be more challenging to evaluate completely 3
- Not distinguishing between simple cysts and other cyst types which have different management protocols 4
- Overlooking the possibility of functional cysts in premenopausal women, which typically resolve within 8-12 weeks 3