Elizabeth Lazarus MD, Presenter: Nothing to Disclose

Ana P. Lourenco MD, Abstract Co-Author: Nothing to Disclose

Deepika Sagaram, Abstract Co-Author: Nothing to Disclose

C. James Sung, Abstract Co-Author: Nothing to Disclose

The sonographic diagnosis of early partial molar pregnancy is less accurate than for complete moles. Diandric partial moles feature normal and enlarged villi with or without an identifiable embryo. These changes can manifest as masses along the gestational sac and decidual thickening on ultrasound. We sought to determine whether these findings could be identified on sonograms performed early in pregnancy as a way to improve early diagnosis.

This study was IRB approved and HIPAA compliant. We retrospectively reviewed all consecutive patients with pathologically confirmed partial molar pregnancy at our institution between 3/1/2001 and 5/30/2011. Two radiologists evaluated all available ultrasound exams performed prior to diagnosis to examine the gestational sac for wall thickening or focal masses. The sac contents, ovaries, and adnexa were also examined for additional findings. When the images were not available, reports were obtained. This data was correlated with gestational age, bHCG levels, and the ultrasound report diagnosis.

166 cases of partial mole were diagnosed, of which 38 underwent ultrasounds within a mean of 10 days (range 1-51) of pathologic diagnosis. A total of 41 ultrasound exams or reports were examined in 38 patients. Gestational age at the time of ultrasound was a mean of 9.7 weeks (range 4-14), and b-HCG levels were a mean of 102,480 mIU/ml (range 7248-445090). A gestational sac was seen on 40 of 41 sonograms (98%). Twenty gestational sacs (50%) demonstrated heterogeneous or cystic decidual thickening (mean 13 mm, range 8-49) or a focal mass along the wall (mean volume 19.6 cc, range 2-61cc). Twenty-eight contained a fetal pole (70%), 26 of which demonstrated no fetal cardiac activity. No theca lutein cysts were seen in the ovaries. No free fluid or additional adnexal abnormalities were seen. The diagnosis of molar pregnancy was made on 10 reports (24%).

The finding of decidual thickening and/ or masses can be found in 50% of ultrasounds performed on early partial molar pregnancies. Assessing for these findings could improve the sensitivity of pre-operative sonography in the diagnosis of partial molar pregnancy from 24 to 50%.

Sonographic diagnosis of partial moles results in histological evaluation. Women diagnosed after uterine evacuation have fewer complications than those presenting later with persistent GTD.

Lazarus, E, Lourenco, A, Sagaram, D, Sung, C, Decidual Thickening and Mass: Sonographic Signs to Improve Early Diagnosis of Partial Molar Pregnancies.  Radiological Society of North America 2012 Scientific Assembly and Annual Meeting, November 25 - November 30, 2012 ,Chicago IL. http://archive.rsna.org/2012/12022585.html