Synopsis
Describe adnexal masses with standard ultrasound morphology, apply validated benign and malignant features correctly, and direct indeterminate or suspicious findings to the appropriate specialist and cancer pathway.
- Confirm that a reported adnexal mass is ovarian: paraovarian cyst, hydrosalpinx, pedunculated fibroid, pelvic kidney, bowel or an inflammatory collection can imitate ovarian disease.
- Transvaginal ultrasound provides the highest-resolution initial morphological assessment; add transabdominal views for a large lesion or disease beyond its field of view.
- Document maximum dimensions, laterality, unilocular or multilocular architecture, wall and septal regularity, internal echoes, acoustic shadows, papillary projections, solid tissue, colour score, ascites and peritoneal findings.
- IOTA benign features are a unilocular cyst, solid components smaller than 7 mm, acoustic shadows, a smooth multilocular tumour smaller than 100 mm and no detectable blood flow.
- IOTA malignant features are an irregular solid tumour, ascites, at least four papillary structures, an irregular multilocular-solid tumour at least 100 mm and very strong blood flow.
- When one or more malignant features occur without a benign feature, classify as malignant; benign features without a malignant feature classify as benign; both sets or neither set is indeterminate and needs expert ultrasound.
- CA125 is contextual, not diagnostic. It is nonspecific before menopause and can be normal in early epithelial cancer; do not use it to overrule morphology.
- RMI I equals ultrasound score multiplied by menopausal score and CA125. NICE uses 250 for specialist MDT referral, whereas RCOG's postmenopausal cyst pathway uses 200; follow the applicable national or local cancer pathway deliberately.