Reported sensitivity of US detection is higher for complete mole, with its more pronounced hydropic changes of chorionic villi and absence of a gestational sac, than for partial mole [9,28]. Features suspicious for partial mole include an enlarged placenta or cystic changes within the decidual reaction in association with either an empty sac (>20 mm in diameter) or a delayed miscarriage (fetal pole with crown-rump length >6 mm but no cardiac activity) [22]. Differential diagnosis in partial molar pregnancy may include missed abortion [29] and retained products of conception. There is no substantial evidence to support a role for grayscale US features in risk stratification for future development of GTN [30,31]. Enlarged ovaries with multiple theca lutein cysts may be a helpful secondary finding in suspected GTD but are noted in <50% of patients [29,30]. Gestational Trophoblastic Disease US Pelvis Transabdominal Transvaginal US has superior sensitivity and specificity in the diagnosis of uterine masses when compared with transabdominal US, although given the rarity of GTD, literature comparing both modalities is lacking [32]. US Duplex Doppler Pelvis There is some support for a role for Doppler US in the initial diagnosis and postevacuation follow-up of patients with GTD. A lower uterine artery resistive index before molar evacuation is associated with the development of trophoblastic tumors, a potentially useful means to prospectively recognize patients who are at high risk for progression and warrant closer follow-up [33,34]. In a prospective analysis of 246 women with complete mole, Doppler pulsatility index showed potential as a predictor of subsequent development of GTN [35]. In a retrospective analysis of 189 patients with hydatidiform mole, US evidence of nodules and hypervascularization within the myometrium or endometrium 3 weeks following initial molar evacuation had a high specificity (95.5%) but low sensitivity (53.9%) for later development of GTN [33,34].
Gestational Trophoblastic Disease. Reported sensitivity of US detection is higher for complete mole, with its more pronounced hydropic changes of chorionic villi and absence of a gestational sac, than for partial mole [9,28]. Features suspicious for partial mole include an enlarged placenta or cystic changes within the decidual reaction in association with either an empty sac (>20 mm in diameter) or a delayed miscarriage (fetal pole with crown-rump length >6 mm but no cardiac activity) [22]. Differential diagnosis in partial molar pregnancy may include missed abortion [29] and retained products of conception. There is no substantial evidence to support a role for grayscale US features in risk stratification for future development of GTN [30,31]. Enlarged ovaries with multiple theca lutein cysts may be a helpful secondary finding in suspected GTD but are noted in <50% of patients [29,30]. Gestational Trophoblastic Disease US Pelvis Transabdominal Transvaginal US has superior sensitivity and specificity in the diagnosis of uterine masses when compared with transabdominal US, although given the rarity of GTD, literature comparing both modalities is lacking [32]. US Duplex Doppler Pelvis There is some support for a role for Doppler US in the initial diagnosis and postevacuation follow-up of patients with GTD. A lower uterine artery resistive index before molar evacuation is associated with the development of trophoblastic tumors, a potentially useful means to prospectively recognize patients who are at high risk for progression and warrant closer follow-up [33,34]. In a prospective analysis of 246 women with complete mole, Doppler pulsatility index showed potential as a predictor of subsequent development of GTN [35]. In a retrospective analysis of 189 patients with hydatidiform mole, US evidence of nodules and hypervascularization within the myometrium or endometrium 3 weeks following initial molar evacuation had a high specificity (95.5%) but low sensitivity (53.9%) for later development of GTN [33,34].