Introduction
Adnexal masses can be benign or malignant, ranging from simple functional cysts to ovarian carcinomas. The clinical challenge is distinguishing benign from malignant lesions to ensure timely intervention while avoiding unnecessary surgery.
Purpose and Scope
This guideline provides evidence-based information to assist clinicians with the initial assessment and appropriate management of suspected ovarian masses.
Evaluation of Adnexal Mass
Evaluation involves history, physical examination, imaging (especially ultrasound), and tumor markers. Management depends on patient age, menopausal status, clinical presentation, and risk of malignancy. Many ovarian masses in premenopausal women can be managed conservatively. Functional or simple ovarian cysts (<50 mm, thin-walled, without internal structures) usually resolve over 2–3 menstrual cycles without intervention.
Types of Adnexal Masses
Benign Ovarian: Functional cysts, endometriomas, serous cystadenoma, mucinous cystadenoma, mature teratoma
Benign Non-Ovarian: Para-tubal cyst, hydrosalpinges, tubo-ovarian abscess, peritoneal pseudocysts, appendiceal abscess, diverticular abscess, pelvic kidney
Primary Malignant Ovarian: Germ cell tumor, epithelial carcinoma, sex-cord tumor
Secondary Malignant Ovarian: Predominantly breast and gastrointestinal metastases
Clinical Assessment
- Take a thorough medical history including ovarian/breast cancer risk factors and family history.
- Perform abdominal and vaginal examination; assess lymphadenopathy.
- In acute presentations (pain), consider torsion, rupture, or hemorrhage.
- Clinical exam sensitivity for ovarian masses is low (15–51%) but helps assess tenderness, mobility, nodularity, and ascites.
Imaging
Pelvic Ultrasound: Most effective evaluation, with transvaginal preferred over transabdominal.
Risk of Malignancy Index (RMI): Widely used; sensitivity 78%, specificity 87%. Less reliable in premenopausal women due to elevated CA-125 from endometriomas, borderline tumors, or non-epithelial tumors.
IOTA Simple Rules:
- B-rules (benign): B1–B5 features
- M-rules (malignant): M1–M5 features
- Sensitivity 95%, specificity 91%, positive likelihood ratio 10.37, negative likelihood ratio 0.06
IOTA LR1 & LR2: Logistic regression models; LR1 more sensitive, LR2 more specific. Used to calculate malignancy probability.
ADNEX Model: Differentiates benign, borderline, stage 1 invasive, stage 2–4 invasive, and secondary metastatic ovarian cancer using 3 clinical + 6 ultrasound variables.
O-RADS (US & MRI): Risk categorization from 0 (incomplete) to 5 (high risk >50%). Defines lesion type, size, papillary projections, color score, and presence of ascites/peritoneal deposits.
MRI
- Conventional MRI sensitivity 92% (89–94%), specificity 88% (84–92%)
- O-RADS MRI scoring from 1–5 based on lesion type, solid tissue, and uptake curves
Comparison of USG and MRI
| Feature | Ultrasound | MRI |
|---|---|---|
| Primary role | First-line imaging | Problem-solving for indeterminate masses |
| Overall accuracy | Good to moderate | High, superior for difficult cases |
| Strengths | Widely available, low cost, no radiation | Excellent soft tissue contrast, high specificity |
| Weaknesses | Operator dependent, lower specificity for indeterminate lesions | Expensive, less accessible, contrast required |
| Reporting system | IOTA, O-RADS US | ADNEX MRI, O-RADS MRI |
| Decision making | Guides initial management | Confirms benignity or high suspicion for malignancy |
Clinical Implication
- Step 1: Initial US using IOTA-ADNEX or O-RADS US
- Step 2: Referral for MRI if indeterminate or features suggest malignancy
- Step 3: Oncology referral for high-probability malignant cases
Tumor Markers
- CA-125 not needed for simple cysts
- CA-125 >200 units/ml → discuss with gynecologic oncologist
- Serial monitoring: rising levels suggest malignancy more than stable high levels
- LDH, AFP, hCG for women <40 with complex masses (possible germ cell tumors)
- HE4: Higher specificity than CA-125 for epithelial ovarian cancer, distinguishes from benign conditions
ROCA – Risk of Cancer Algorithm
- Low risk: repeat CA-125 after 1 year
- Intermediate risk: repeat CA-125 in 6–8 weeks
- Elevated risk: refer for TVS
ROMA – Risk of Ovarian Malignancy Algorithm
- Uses CA-125, HE4, and menopausal status
- Sensitivity 89%, specificity 75% for epithelial ovarian cancer
Conclusion
Evaluation of ovarian masses emphasizes a multidisciplinary approach using RMI, imaging, and tumor markers for risk stratification and timely referral.
References
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Compiled By:
Dr. Tahera Fatima
Dr. Arunthiya Shoma Saha
Contributors
- Prof Dr Fawzia Hossain
- Prof KH Shahnewaz
- Dr Fahmida Zesmin
- Dr Amena Fardous
- Dr Ananna Zakia
- Dr Sabiha Islam
- Dr Tasrina Akhter
- Dr Jinat Fatema
- Dr Shanjida Kabir
- Dr Aklima Zakaria Zinan
- Dr Anjuman Ara
- Dr Khodeja Parveen
- Dr Maniza Khan