Objective: To compare the ability of transvaginal color and spectral Doppler and that of gray-scale ultrasound examination to discriminate between benign and malignant extrauterine pelvic tumors.
Methods: One hundred forty-nine consecutive women scheduled for laparotomy because of an extrauterine pelvic mass underwent ultrasound examination, including color and spectral Doppler techniques, within 8 days before a planned operation. Based on the gray-scale ultrasound image, each tumor was classified as a unilocular cyst, multilocular cyst, unilocular cyst with solid parts, multilocular cyst with solid parts, or solid tumor. Doppler signals of the maximum blood flow velocity of tumor vessels were evaluated for pulsatility index (PI) and peak systolic and time-average maximum velocity. The results of gray-scale imaging and Doppler velocimetry were related to the final diagnosis, which in most cases was based on histology of the specimen.
Results: None of the 88 unilocular or multilocular cysts without solid parts were malignant, compared to 28 malignancies (46%) among the 61 tumors with solid components. The PI was significantly lower, and the peak systolic and time-average maximum blood flow velocities significantly higher, in the malignant than in the benign tumors. However, this was true only of the multilocular cysts with solid parts; the PI and blood flow velocity results overlapped completely between benign and malignant solid tumors. According to receiver operating characteristic curves, the ultrasound morphology of the tumors was a better discriminator between benign and malignant tumors than any of the Doppler variables. Ultrasound morphology correctly identified all the malignant tumors, with a false-positive rate of 27%. Discrimination was slightly improved if PI and blood flow velocity were used for discriminating between benign and malignant multilocular cysts with solid parts. With this approach, all the malignant tumors were detected with a false-positive rate of 17-23%, depending on which Doppler variable and which cutoff level was used.
Conclusion: The present technique of Doppler velocimetry has a limited contribution to the differential diagnosis of extrauterine pelvic tumors.