IOTA Simple Rules

International Ovarian Tumor Analysis

Benign Features (B-Rules)

Malignant Features (M-Rules)

IOTA Conclusion

INCONCLUSIVE / UNCLASSIFIED

Simple Rules can classify ~75% of masses. Masses that don't fit (neither or both types) should be analyzed using IOTA ADNEX / Specialist assessment.

Guidelines & Evidence

Verified

Last Review: 2026-07-17

When to Use

Primary Clinical Uses

Sonographic characterization of adnexal/ovarian masses

Triaging surgical referrals (general gynecology vs. gynecologic oncology)

Standardizing global ultrasound terminology regarding ovarian cysts

Why it Exists

Prior to IOTA, radiologists used highly subjective terminology ("complex", "worrisome", "thickened") that caused massive over-operation by oncologists for universally benign cysts, and accidental rupture of malignant cysts by generalists.

Last Comprehensive Review: 2026-07-17

Recent Journal Updates

WHO NewsJul 20, 2026

Road deaths fall by 21% globally but stronger action is needed to save lives

Clinical Context

We think this might be relevant to the clinical guidance for IOTA Simple Rules.

WHO NewsJul 15, 2026

Global childhood immunization coverage inches forward despite conflict and hesitancy – UNICEF, WHO

Clinical Context

We think this might be relevant to the clinical guidance for IOTA Simple Rules.

WHO NewsJun 15, 2026

Open letter to leaders of G7, G20, BRICS and all nations on finalizing the WHO Pandemic Agreement’s Pathogen Access and Benefit Sharing annex

Clinical Context

We think this might be relevant to the clinical guidance for IOTA Simple Rules.

IOTA Simple Rules