Risk of Malignancy Index (RMI, Adnexal Mass) — free guideline decision tool
Estimate malignancy risk of an adnexal mass with the Risk of Malignancy Index (RMI).
Open guideline tool →Guideline-based
Implements the decision logic from published clinical guidelines.
Runs in your browser
No installation. Enter the patient's values and get a guideline recommendation instantly.
Data stays local
Nothing is uploaded. Results are for licensed clinicians only.
Worked calculation
The values below come from this tool's own example placeholders and are computed server-side with the formula shown on this page, so the arithmetic can be checked quickly. It demonstrates how to substitute values only — it is not clinical advice and not a real case.
| RMI version | RMI 1 (U = 0/1/3, M = 1/3) |
|---|---|
| Number of ultrasound features (multilocular/solid/bilateral/ascites/intra-abdominal metastases) | 0 features |
| Menopausal status | Premenopausal |
| Serum CA-125 | 80 U/mL |
→RMI0
- Calculation：U = 0 × M = 1 × CA-125 = 80 = 0 (RMI 1)
- Interpretation：RMI < 200: lower malignancy risk → correlate with imaging (e.g. O-RADS); follow up as needed
- Tip：Complementary to O-RADS imaging: RMI uses CA-125 + menopause + US features, O-RADS focuses on lesion morphology
| RMI version | RMI 2 (U = 1/1/4, M = 1/4) |
|---|---|
| Number of ultrasound features (multilocular/solid/bilateral/ascites/intra-abdominal metastases) | ≥ 2 features |
| Menopausal status | Postmenopausal |
| Serum CA-125 | 80 U/mL |
→RMI1280
- Calculation：U = 4 × M = 4 × CA-125 = 80 = 1280 (RMI 2)
- Interpretation：RMI ≥ 200: elevated malignancy risk → refer to gynecologic oncology for surgical staging by a specialist
- Tip：Complementary to O-RADS imaging: RMI uses CA-125 + menopause + US features, O-RADS focuses on lesion morphology
Common questions
What is Risk of Malignancy Index (RMI, Adnexal Mass)?
Estimate malignancy risk of an adnexal mass with the Risk of Malignancy Index (RMI).
How is Risk of Malignancy Index (RMI, Adnexal Mass) calculated? What is the core formula?
RMI = ultrasound score U × menopausal status M × CA-125. RMI 1: U = 0/1/3, M = 1/3; RMI 2: U = 1/1/4, M = 1/4. ≥ 200 = elevated risk.
When is Risk of Malignancy Index (RMI, Adnexal Mass) used?
Triage adnexal masses and decide on gynecologic-oncology referral.
What are the key clinical points for Risk of Malignancy Index (RMI, Adnexal Mass)?
≥ 200 warrants gynecologic-oncology referral. Complementary to O-RADS imaging. RMI 1 is more specific, RMI 2 more sensitive.
What are the limits and cautions when using Risk of Malignancy Index (RMI, Adnexal Mass)?
For licensed clinicians and clinical researchers. Interpret results with history, investigations and local protocols; not a diagnosis or prescription, and not a substitute for multidisciplinary decision-making or local guidelines.
How is Risk of Malignancy Index (RMI, Adnexal Mass) calculated in practice? Can you show a worked example?
Inputs: RMI version RMI 1 (U = 0/1/3, M = 1/3), Number of ultrasound features (multilocular/solid/bilateral/ascites/intra-abdominal metastases) 0 features, Menopausal status Premenopausal, Serum CA-125 80 U/mL → Result: RMI 0（Calculation: U = 0 × M = 1 × CA-125 = 80 = 0 (RMI 1), Interpretation: RMI < 200: lower malignancy risk → correlate with imaging (e.g. O-RADS); follow up as needed, Tip: Complementary to O-RADS imaging: RMI uses CA-125 + menopause + US features, O-RADS focuses on lesion morphology） Inputs: RMI version RMI 2 (U = 1/1/4, M = 1/4), Number of ultrasound features (multilocular/solid/bilateral/ascites/intra-abdominal metastases) ≥ 2 features, Menopausal status Postmenopausal, Serum CA-125 80 U/mL → Result: RMI 1280（Calculation: U = 4 × M = 4 × CA-125 = 80 = 1280 (RMI 2), Interpretation: RMI ≥ 200: elevated malignancy risk → refer to gynecologic oncology for surgical staging by a specialist, Tip: Complementary to O-RADS imaging: RMI uses CA-125 + menopause + US features, O-RADS focuses on lesion morphology）
Run Risk of Malignancy Index (RMI, Adnexal Mass) now
Estimate malignancy risk of an adnexal mass with the Risk of Malignancy Index (RMI).
Open guideline tool →For licensed clinicians. Not a substitute for clinical judgement.
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