A 55-year-old postmenopausal woman is found to have a 12 cm complex ovarian mass with solid components, bilateral involvement, and ascites. CA-125 is 480 U/mL. According to the IOTA (International Ovarian Tumour Analysis) classification system, which ultrasound feature most strongly predicts malignancy?

• A Multilocularity with >10 loculi
• B Presence of solid components with irregular internal echogenicity
• C Acoustic shadowing from mural nodules
• D Color score 3–4 (moderate to very strong vascularity) with solid papillary projections >3 mm ✓

Explanation

The IOTA Simple Rules classify ovarian masses as M (malignant) features or B (benign) features. The most predictive M-feature combination is solid papillary projections >3 mm associated with high internal vascularity (color score 3–4 on Doppler). The IOTA system M-features include: irregular solid tumor, ascites, at least 4 papillary structures, irregular multilocular solid tumor ≥10 cm, and very strong vascularity. Solid components with vascularity consistently outperform other individual features in ROC analysis (sensitivity ~76%, specificity ~76%). Multilocularity alone (A) is also an M-feature but lower specificity alone. Acoustic shadowing (C) is actually a B-feature. The combination in option D is the highest-yield predictor.

Reference: Shaw's Textbook of Gynaecology, 17th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.