Transvaginal ultrasound in a 45-year-old woman shows a complex adnexal mass: unilocular cyst 9 cm, a solid 2 cm papillary projection, no ascites, and bilateral involvement. Using the IOTA (International Ovarian Tumour Analysis) simple rules, features suggesting malignancy include:
- A Solid papillary projection ≥3 mm height AND bilateral lesions ✓
- B Unilocular cyst only
- C Smooth walls and no internal flow on Doppler
- D Purely anechoic content
Correct answer: A. Solid papillary projection ≥3 mm height AND bilateral lesions
Explanation
IOTA simple rules classify adnexal masses using M-features (malignant) and B-features (benign). M-features include: irregular solid tumour, ascites, at least 4 papillary projections, irregular multilocular-solid tumour ≥10 cm, and very strong blood flow (colour score 4). Key malignancy indicators include solid papillary projections ≥3 mm and bilateral involvement. B-features include: unilocular cyst, solid components with largest <7 mm, acoustic shadowing, smooth multilocular tumour <10 cm, and no blood flow. A purely anechoic unilocular cyst is a benign feature.
Reference: Grainger & Allison's Diagnostic Radiology, 7th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.