What is the management approach for a complex adnexal mass identified on computed tomography (CT) scan?

Management of Complex Adnexal Mass Identified on CT Scan

The initial management of a complex adnexal mass identified on CT scan should include transvaginal ultrasound (US) for further characterization, followed by appropriate triage based on imaging features, patient age, and risk factors for malignancy. 1

Initial Diagnostic Approach

Step 1: Transvaginal and Transabdominal Ultrasound

• Transvaginal US is the essential first-line imaging modality for characterization of adnexal masses initially detected on CT 1
• Transabdominal US should complement transvaginal US, especially for large masses or those not optimally visualized with transvaginal approach 1
• Color or power Doppler should be included to evaluate vascularity of solid components 1

Step 2: Assessment of Imaging Features

Classify the mass based on ultrasound characteristics:

1. Benign features:

   • Simple cyst (no or minimal risk of malignancy <0.4%) 1
   • Single thin septation <3mm 1
   • Specific features of:
     • Endometrioma (low-level internal echoes, mural echogenic foci)
     • Dermoid/teratoma (echogenic attenuating component)
     • Hydrosalpinx (tubular cystic mass with/without folds)
     • Pedunculated fibroid (blood supply from uterine vessels)

2. Suspicious features:

   • Solid components with irregular contour (93% PPV for malignancy) 1
   • Multiple thick septations (>3mm) 1
   • Papillary projections or excrescences 1
   • Increased vascularity in solid components 1
   • Presence of ascites 1
   • Bilateral masses 1

Management Algorithm

For Masses with Benign Features:

1. Premenopausal women:

   • Simple cysts <5cm: No follow-up needed
   • Simple cysts 5-7cm: Follow-up US in 8-12 weeks
   • Masses with specific benign features (endometrioma, dermoid): Consider surgical management if symptomatic

2. Postmenopausal women:

   • Simple cysts <1cm: No follow-up needed
   • Simple cysts 1-7cm: Follow-up US in 8-12 weeks
   • Note: In postmenopausal women, 53% of simple adnexal cysts disappear completely, 28% remain constant in size 1

For Indeterminate Masses:

1. MRI with contrast (if not contraindicated)

   • MRI significantly improves characterization of indeterminate adnexal masses 1
   • Contrast-enhanced MRI performs better than both US and non-contrast MRI in confirming enhancing tissue components 1
   • Enhancement pattern analysis helps differentiate benign from malignant lesions 1

2. Follow-up based on MRI findings:

   • If benign features confirmed: Follow-up US in 8-12 weeks
   • If still indeterminate: Consider gynecologic consultation

For Masses with Suspicious Features:

1. Immediate referral to gynecologic oncologist for:

   • Any solid mass with irregular contours
   • Masses with >4 papillary structures 1
   • Presence of ascites
   • Masses >10cm
   • Any mass with solid components and increased vascularity 1

2. CT abdomen and pelvis with IV contrast for staging if malignancy is suspected 1

   • CT is the modality of choice for staging and follow-up post-treatment
   • FDG-PET/CT may be useful to identify other sites of disease 1

Special Considerations

Age-Related Factors

• Postmenopausal women: Higher risk of malignancy (up to 50% in women >60 years with solid components and blood flow) 1
• Premenopausal women: Lower risk of malignancy, more likely to have functional cysts

Size Considerations

• Complex masses <5cm in postmenopausal women have a low risk of malignancy (1.3%) 1
• Early-stage high-grade serous cancers are rarely <5cm 1
• Masses >10cm warrant referral regardless of other features 2

Persistence

• Any mass that persists longer than 12 weeks should be referred for gynecologic evaluation 2
• Complex masses that show growth during observation period require prompt evaluation 1

Common Pitfalls to Avoid

1. Relying solely on CT findings - CT has poor soft-tissue discrimination in the adnexal region 1
2. Misdiagnosing pedunculated fibroids as ovarian masses - Careful identification of normal ovaries and blood supply from uterine vessels helps avoid this error 1
3. Delaying referral for suspicious masses - After stage, the second most important prognostic factor in ovarian cancer is initial management by a gynecologic oncologist 1
4. Over-reliance on CA-125 alone - Should be used in conjunction with imaging findings, not as a standalone test
5. Failure to recognize that small, complex masses can be malignant - Though less common, malignancy can occur in smaller masses

By following this systematic approach to evaluation and management of complex adnexal masses, clinicians can appropriately triage patients to conservative management or specialist referral, optimizing outcomes and reducing unnecessary procedures.