Differentiation of small adnexal masses based on morphologic characteristics of transvaginal sonographic imaging: a multicenter study

Objective. The purpose of this study was to assess the diagnostic accuracy of transvaginal sonographic examination of small adnexal masses by simple descriptive sonographic scoring. Methods. In a prospective multicenter study, 4 teaching hospitals and 2 regional hospitals with homogeneous standard sonographic equipment and operator experience recruited 677 consecutive patients with small adnexal masses of less than 5 cm. Morphologic scoring was obtained for each mass and recorded. The management of the mass was based on local protocols. The minimal requirement was that surgery had to be performed for complex masses scoring 8 or higher, and follow-up of at least 12 months had to be performed and recorded for patients not admitted to surgery. Sonographic results were compared with pathologic reports and follow-up findings. Results. Fifty-two malignant tumors (19 borderline, 15 stage I-II, 15 stage III-IV, 2 tubal carcinomas, and 1 ovarian lymphoma), 243 benign tumors at pathologic examination, and 382 masses defined as benign according to follow-up findings were observed. Malignant tumors had a significantly higher mean ± SD morphologic score (11.2 ± 2.7) than benign masses (6.2 ± 2.5) (P = .001). No difference was observed in the scoring assignment of malignant masses in different centers (P = .56). With a score of 8 or higher, the likelihood ratio was 3.61 (95% confidence interval, 3.09-4.21); sensitivity, 92%; specificity, 76.9%; and positive predictive value, 25.6%. Conclusions. Our results provide evidence that descriptive morphologic scoring may overcome the subjectivity of interpretation of morphologic characteristics in small masses, and, at the same time, it can incorporate criteria to avoid simplistic description of a complex mass.