Transvaginal ultrasonographic characterization of ovarian masses with an improved, weighted scoring system.
The aim of the study was to modify a previously devised morphologic scoring system with the use of transvaginal ultrasonography in the hope of improving discrimination of benign from malignant ovarian and adnexal masses. Transvaginal ultrasonographic images of 312 patients for a total of 350 ovarian and adnexal masses were obtained over a 3-year period. The derived morphologic data were analyzed by multiple linear regression analysis to select the best performance of the previously described scoring system by Sassone et al. in 1991. This system was thus modified in several ways including weighted point value assignments, fewer point values per variable studied, the deletion of one variable found not to be significant (wall thickness), and the inclusion of a new variable called shadowing. At surgery, 308 benign masses, 31 malignant masses, and 11 tumors of low malignant potential were found. The mean point value obtained was 1.8 for the benign masses, 3.9 for the tumors of low malignant potential, and 5.6 for the malignant tumors (p < 0.0005). With a cutoff of > or = 3 used as the best discriminator, the sensitivity was 96.8% and the specificity 77%. The positive and negative predictive values were 29.4% and 99.6%, respectively. Limitations of the previously devised scoring system included the arbitrary point assignments of each variable, the multiple (4 or 5) point choices for each variable, and the poor positive predictive value. This new scoring system performs well in the differentiation of benign from malignant masses, while assigning scientifically derived, therefore more valid, point values and simplifying the system overall. That the positive predictive value was not improved proves that ultrasonographically, to date we are still hampered by complex and malignant-appearing benign ovarian masses.