An improved risk of malignancy index in diagnosis of adnexal mass.

Background: With the advent of color Doppler flow imaging (CDFI) and technological development of detection of serum tumor markers, new opportunities are presented to the improved risk of malignancy index (RMI) based on Jacobs' research for predicting ovarian malignancy in patients with adnexal masses.

Methods: One hundred and eighty women with an adnexal mass admitted for primary laparotomy were studied. Tumor specific growth factor (TSGF) adjusted ultrasound scores and the results of Doppler blood flow analysis were obtained before the operation. Based on the parameters which had been studied in Jacobs' research, TSGF levels and the findings of color Doppler flow imaging, the risk of malignancy model was redesigned using a binary Logistic regression model. The diagnostic efficacy of the improved risk of malignancy index (improved RMI) was compared with the Jacobs' model RMI by receiver operator characteristic (ROC) curve.

Results: The ROC curve showed a higher sensitivity (Mcnamer's test, P < 0.05) in the discrimination between benign and malignant adnexal masses for the improved RMI than the RMI. Compared with the RMI, the improved RMI had an advantage in prediction of ovarian germ cell tumors and granular cell tumor (28.57% vs.71.43%, P < 0.05) and the early stage tumors and borderline tumors (33.33% vs. 66.67%, P < 0.05).

Conclusion: The predictability of the improved RMI is better than the classic Jacobs' model, especially in diagnosis of the ovarian germ cell tumors and granular cell tumor and other early stage adnexal tumors.