DIAGNOSTIC FORMULA FOR THE DIFFERENTIATION OF ADNEXAL TUMORS BY TRANSVAGINAL SONOGRAPHY

Objective: To create a strategy for sonographic differentiation of ben ign and malignant adnexal tumors in premenopausal and postmenopausal p atients. Methods: Multiple sonomorphologic criteria were analyzed pros pectively in 754 tumors. Four hundred were found in premenopausal and 354 in postmenopausal women. In a logistic regression model, relevant criteria were selected, and a diagnostic formula for tumor differentia tion was derived. Results: There were 165 malignant tumors, of which 3 7 (9.2%) were found in premenopausal and 128 (36.2%) in postmenopausal women. In both groups, the criteria of solid phase and ascites were t he most significant. Further important diagnostic criteria were struct ure and tumor size in premenopausal women and cyst architecture and tu mor surface in postmenopausal women. These results allowed an estimati on of the probability of malignancy. Using a cutoff point of 10% for t he probability to classify tumors as malignant, the sensitivity and sp ecificity in premenopausal patients were 86.5% and 92.6%, respectively , with an accuracy of 92%. In postmenopausal women, the sensitivity, s pecificity, and accuracy were 93%, 82.7%, and 86.6%, respectively. Ass uming a prevalence as given in the study, the positive and negative pr edictive values were 54.4% and 98.5% in premenopausal and 75.3% and 95 .4% in postmenopausal women. Conclusions: With four binary criteria, a useful diagnostic formula for tumor differentiation was obtained. How ever, estimates for sensitivity, specificity, and accuracy may be too optimistic because they were derived from the same data that were alre ady used for model selection. Copyright (C) 1997 by The American Colle ge of Obstetricians and Gynecologists.