Objective: To describe ultrasound characteristics of adnexal malignancies, i.e., borderline ovarian tumors, primary invasive ovarian epithelial cancer stage 1, primary invasive ovarian epithelial cancer stages 2-4, rare types of malignancy, and metastatic tumors.
Methods: In a prospective international study involving nine European ultrasound centers, 1,066 women with a pelvic mass judged to be of adnexal origin underwent transvaginal gray scale and color Doppler ultrasound examination by a skilled examiner before surgery. A standardized examination technique and predefined definitions of ultrasound characteristics were used.
Results: Of 1,066 masses, 266 were malignant and are included: 55 ovarian borderline tumors, 144 primary invasive epithelial ovarian cancers (42 stage 1, 102 stages 2-4), 25 rare malignancies, and 42 metastatic tumors. Most (56%) metastatic tumors and most (60%) rare types of tumor were solid and richly vascularized at color Doppler ultrasound examination (on a scale ranging from 1 to 4, color score based on subjective evaluation was 3 or 4 in 88% and 86%, respectively). Borderline ovarian tumors and stage 1 primary invasive ovarian epithelial cancers differed from stages 2-4 primary invasive ovarian epithelial cancers: they were larger (median volume 375 ml and 695 ml vs. 209 ml; P = 0.0213 and 0.0001), a larger proportion contained papillary projections (64% and 67% vs. 41%; P = 0.0072 and 0.0054), they were more often multilocular cysts without solid components (18% and 14% vs. 2%; P < 0.0017 and 0.0204), but they were less often purely solid (5% and 7% vs. 38%; P <or= 0.0001 and 0.0005). With increasing degree of invasiveness - from borderline epithelial ovarian tumors via stage 1 invasive epithelial ovarian tumors to stages 2-4 invasive epithelial ovarian tumors - ascites became more common (9% vs. 31% vs. 61%; P = 0.0082, <0.0001, and 0.0017), and, among tumors with solid components (n = 179), the proportion of tumor consisting of solid tissue increased (median 2%-10%-34%; P = 0.0212, <0.0001, and 0.0003).
Conclusion: Papillary projections are characteristic of borderline tumors and stage 1 primary invasive epithelial ovarian cancer. A small proportion of solid tissue at ultrasound examination makes a malignant mass more likely to be a borderline tumor or a stage 1 epithelial ovarian cancer than an advanced ovarian cancer, a metastasis, or a rare type of tumor.