This term is used when a complete mole or very rarely a partial mole invades the myometrium. microscopically, villi of hydatidiform mole are present within the myometrium or the myometrial vessels. patients have persistent or rising hcg levels. check for "https://www.cancer.gov/about-cancer/treatment/clinical-trials/intervention/c6985" active clinical trials using this agent. ("http://ncit.nci.nih.gov/ncitbrowser/conceptreport.jsp?dictionary=nci%20thesaurus&code=c6985" nci thesaurus)