🎗️ Risk of Malignancy Index (RMI, Adnexal Mass)
Estimate malignancy risk of an adnexal mass with the Risk of Malignancy Index (RMI).
Clinical takeaway
≥ 200 warrants gynecologic-oncology referral.
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When to use
Triage adnexal masses and decide on gynecologic-oncology referral.
How it works
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.
Key points
- ≥ 200 warrants gynecologic-oncology referral.
- Complementary to O-RADS imaging.
- RMI 1 is more specific, RMI 2 more sensitive.
References
Decision support for licensed clinicians only; not a substitute for clinical judgement, diagnosis or local protocols.
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
Frequently asked 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）