Management of Ovarian Cysts

Classification and Risk Stratification

The Ovarian-Adnexal Reporting and Data System (O-RADS) provides a standardized risk stratification framework, where O-RADS 1 indicates a 0% likelihood of malignancy 3
O-RADS 2 indicates a <1% risk of malignancy, characterized by simple cysts or classic benign lesions with typical features 4
O-RADS 3 indicates a 1-<10% risk of malignancy, requiring gynecologist management but no oncology consultation 4, 5
O-RADS 4 indicates a 10-<50% risk of malignancy, warranting consultation with gynecologic oncology prior to removal 4, 5
O-RADS 5 indicates a ≥50% risk of malignancy, requiring direct referral to gynecologic oncologist for management 4, 5

Simple cysts ≤5 cm require no additional management 1, 2
Simple cysts >5 cm but <10 cm should be followed up in 8-12 weeks, with management by gynecologist suggested if they persist or enlarge 1, 2
Hemorrhagic cysts <10 cm should be followed up in 8-12 weeks to confirm resolution 6, 7
Dermoid cysts and endometriomas <10 cm may have optional initial follow-up at 8-12 weeks, with annual US surveillance considered if not surgically excised 7

Simple cysts ≤3 cm require no further management 1, 2
Simple cysts >3 cm but <10 cm should have at least 1-year follow-up showing stability or decrease in size, with consideration of annual follow-up for up to 5 years if stable 1
Hemorrhagic cysts <10 cm require further evaluation by US specialist, referral to gynecologist, or MRI study 7
Dermoid cysts and endometriomas require consideration of annual US follow-up if not surgically excised, with higher risk of malignancy and malignant transformation in postmenopausal endometriomas 7

Extraovarian cysts generally require no further follow-up, but optional follow-up at 1 year in postmenopausal women may be considered based on diagnostic confidence 5
Fine-needle aspiration is contraindicated for all ovarian masses, with controversy surrounding its use in premenopausal women with fluid cysts 8
Large cysts approaching 10 cm may be incompletely evaluated by transvaginal US alone, requiring transabdominal examination 1, 6

Mischaracterization of larger cysts is possible due to technical limitations of transvaginal ultrasound, emphasizing the importance of transabdominal examination for larger cysts 6
Endometriomas may change in appearance with age, losing classic features and potentially overlapping with malignancy, requiring yearly follow-up due to small risk of malignant transformation 6
The risk of malignancy in benign-appearing lesions managed conservatively with 2-year follow-up is very low (0.3-0.4%), with similarly low risk of acute complications such as torsion or cyst rupture 6
Unilocular cysts in premenopausal women have approximately 0.6% risk of malignancy when surgically removed, likely overestimating risk in the general population due to selection bias 6