Sonographic diagnosis of gestational trophoblastic disease and comparison with retained products of conception

Objective. Gestational trophoblastic disease (GTD) and retained products of conception (RPC) can be difficult to distinguish sonographically. The aim of this study was to determine whether there were any sonographic criteria that could prospectively distinguish one from the other. Methods. Institutional ethics approval was obtained, and acquisition of consent was waived by the Institutional Review Board. A retrospective review of gynecologic oncology and pathology databases identified 17 cases of GTD and 14 cases of RPC. Findings from the pre-evacuation transvaginal sonographic examinations were analyzed. The scans were independently reviewed by 2 senior radiologists with specific expertise in pelvic sonography using several predetermined sonographic features. The reviewers were blinded to the diagnosis. A consensus reading was obtained. Results. The sonographic features that predicted GTD were a myometrial epicenter (P = .0002; odds ratio [OR] = 28), depth of myometrial invasion of more than one third (P = .001; OR = 20), placental venous lakes (P = .04; OR = 9), maximum mass dimensions of more than 3.45 cm (P = .009), and maximum endometrial thickness of less than 12 mm (P = .02). The remaining criteria were not statistically significant and included the characteristics of the mass, ascites, a "snowstorm" appearance, mass vascularity (including resistive index and peak systolic velocity), and the presence of ovarian cysts. Conclusions. There are specific transvaginal sonographic features that can accurately differentiate GTD and RPC.