Adnexal Lesions: Recommendations for incidental lesions on CT or MRI
Authors: Lauren Roller, MD, Krista Suarez Weiss, MD, Atul Shinagare, MD
Date: February 23, 2021
| Mass Characteristics |
Simple-appearing cyst |
| Size | Largest dimension |
| Technical Considerations |
Limited Assessment on CT/MRI
Fully Characterized by MRI:
|
| Known or presumed menopausal status |
If unknown:
|
- Pre-menarchal women
- Lesions ≤ 1 cm
- Lesions that are unchanged in > 2 years
- Women at high genetic risk for ovarian malignancy
- Women with symptoms potentially related to the mass
- Lesions previously characterized by US or MRI
Features:
- Round or oval
- Smooth, imperceptible or thin walls
- No septations or solid component
- Fluid signal on MRI

| Age | ≤ 3 cm | >3-≤ 5cm | >5 cm |
| Pre-menopausal | No follow up | No follow up | Further imaging** |
| Post-menopausal | No follow up | Further imaging** | |
**Further Imaging:
| If limited assessment | US to characterize | ||
| If adequate assessment but not fully characterized by MRI | US follow up in 6-12 months | ||
| Pre-menopausal: | ≤ 7 cm | No further imaging | |
| > 7 cm | US follow up in 6-12 months | ||
| Post-menopausal: | ≤ 5 cm | No further imaging | |
| > 5 cm | US follow up in 6 -12 months | ||
| Adnexal Mass | Pre-menopausal (or age < 50 yrs if unknown) | Post-menopausal (or age > 50 yrs if unknown) | |
| Hemorrhagic cyst | < 5 cm: no further imaging | > 5 cm: follow up US in 2-3 months | US or MRI to characterize |
| Para-ovarian cyst | Usually further imaging is unnecessary; clinical management | ||
| Peritoneal inclusion cyst | |||
| Simple hydrosalpinx | |||
| Ovarian fibroma | |||
| Uterine leiomyoma | |||
| Endometrioma | Usually gynecologic management; may require follow-up imaging | ||
| Dermoid | |||
| Suspected malignancy | Prompt US or MRI to characterize | ||
Dermoid:
Adnexal masses without simple or characteristic imaging features should be evaluated promptly with US or MRI for further characterization
- US usually first imaging choice
- MRI may be superior for lesions >10 cm

Impression: Incidentally detected <Description of adnexal lesion>.
Recommendation: No further imaging is necessary./Follow-up with pelvic ultrasound at 6-12 months is recommended./Further evaluation with pelvic ultrasound is recommended.
Reference: ACR White Paper on Incidental Adnexal Findings on CT and MRI (Patel et al. JACR 2020;17(2):248-254)