Evaluation and Management of a Newly Discovered Ovarian Growth
A newly discovered ovarian growth should be evaluated with transvaginal ultrasound (with color Doppler) and stratified using the O-RADS US risk classification system, which determines management based on specific imaging features, size, and menopausal status 1.
Initial Imaging Evaluation
Transvaginal ultrasound is the primary imaging modality for evaluating any adnexal mass 2, 3. The ultrasound report must include:
- Size and laterality of the mass
- Internal characteristics: simple vs. complex, solid components, septations
- Wall characteristics: smooth vs. irregular inner margins
- Papillary projections: number and height (≥3 mm)
- Vascularity: color score (1-4) using Doppler
- Presence of ascites or peritoneal nodules
Color or power Doppler must be included to assess vascularity of any solid components 2.
Risk Stratification Using O-RADS US System
The O-RADS classification assigns risk categories from 0-5, with specific management for each 1:
O-RADS 1: Physiologic (<1% malignancy risk)
- Premenopausal only: follicles <3 cm, corpus luteum <3 cm
- Management: None required
O-RADS 2: Almost Certainly Benign (<1% malignancy risk)
Simple cysts:
- Premenopausal:
- ≤5 cm: no follow-up needed
5 cm to <10 cm: follow-up ultrasound in 8-12 weeks (during proliferative phase)
- If persists/enlarges: refer to US specialist, gynecologist, or MRI
- Postmenopausal:
- ≤3 cm: no follow-up needed
3 cm to <10 cm: follow-up at 1 year, consider annual follow-up up to 5 years if stable 1
Classic benign lesions (hemorrhagic cysts, dermoids, endometriomas, paraovarian cysts):
- <10 cm with characteristic features: US specialist, gynecologist, or MRI
- Hemorrhagic cysts: follow-up in 8-12 weeks to confirm resolution
- Dermoids: if not removed, annual ultrasound follow-up
- Endometriomas: annual follow-up due to small malignant transformation risk 2, 1
Critical point: Simple cysts of any size, regardless of menopausal status, are not associated with increased cancer risk 2. The 2019 SRU consensus raised thresholds for follow-up based on this evidence.
O-RADS 3: Low Risk (1% to <10% malignancy risk)
Includes:
- Simple or nonsimple unilocular cysts ≥10 cm
- Unilocular cysts with irregular inner wall <3 mm height
- Multilocular cysts <10 cm with smooth walls and color score 1-3
- Avascular solid lesions with smooth contour
Management: Gynecologist consultation 1. US specialist evaluation or MRI recommended to optimize characterization and minimize risk of missing suspicious features.
O-RADS 4: Intermediate Risk (10% to <50% malignancy risk)
Includes:
- Multilocular cysts ≥10 cm or with irregular walls/septations
- Unilocular/multilocular cysts with solid components and color score up to 4
- Smooth solid lesions with color score 2-3
Management: Gynecologic oncology consultation prior to surgery, or direct referral for management 1. If general gynecologist performs surgery, facility must have necessary support services for optimal outcomes.
O-RADS 5: High Risk (≥50% malignancy risk)
Includes:
- Irregular solid lesions
- Multilocular cysts with solid components and high color score (4)
- Unilocular cysts with ≥4 papillary projections
- Ascites and/or peritoneal nodules (except with O-RADS 1-2 lesions)
Management: Direct referral to gynecologic oncologist 1.
Additional Diagnostic Considerations
MRI without contrast can be used when IV contrast is contraindicated, with 85% sensitivity and 96% specificity for detecting malignancy 2. MRI is particularly useful for further characterization of indeterminate lesions.
CA-125 measurement should be considered in perimenopausal/postmenopausal women with adnexal masses 3. However, the O-RADS committee intentionally did not mandate routine tumor marker use, as it should be individualized—elevated CA-125 in premenopausal women with suspected endometriosis may unnecessarily raise concern 1.
Common Pitfalls to Avoid
Mischaracterizing larger cysts: Cysts approaching 10 cm are harder to evaluate completely; transabdominal ultrasound should supplement transvaginal imaging 1
Overlooking endometrioma changes: Older premenopausal women may have atypical endometriomas with multilocular appearance and solid components that overlap with malignancy 2
Assuming all solid lesions are malignant: The most common benign solid adnexal mass is a pedunculated uterine fibroid 2
Over-treating simple cysts: Evidence strongly supports that simple cysts, even >10 cm, have extremely low malignancy risk and can be managed conservatively 2, 1
Special Population Considerations
Adolescents (ages 10-19): Small asymptomatic cysts should be monitored, but larger complex or solid tumors require thorough evaluation to rule out malignancy. Fertility-preserving surgery should be prioritized 4.
Pregnancy: Ultrasound and MRI are safe diagnostic tools. Treatment decisions require multidisciplinary approach and should be individualized based on tumor size, gestational age, and surgical expertise 5.