Persistent Postmolar Gestational Trophoblastic Disease: Use of Transvaginal Sonography and Colour Flow Doppler

Invasive moles have been difficult to diagnose except at hysterectomy. Many patients with persistent gestational trophoblastic disease (GTD) have been treated without ever demonstrating the site of the persistent trophoblastic focus. High resolution transvaginal sonography (TVS) has provided a technique of demonstrating very small uterine lesions, previously unsuspected by transabdominal sonography. The addition of colour flow Doppler further increased diagnostic sensitivity and provides another means of monitoring response to therapy. Three patients with persistent GTD, scanned by TVS and CFD (colour flow Doppler) performed as part of their metastatic work-up are presented. The only abnormalities detected were foci demonstrated within the myometrium that demonstrated increased flow on CFD. Single agent chemotherapy was commenced and the patients were monitored periodically through their course with repeat ultrasonography. After an initial lag period, the lesions decreased in size as the beta-HCG titres fell. An unsuspected adnexal mass was diagnosed on 1 patient, later proving to be a mature ovarian teratoma.