A high-risk gestational trophoblastic neoplasia derived from a complete hydatidiform mole with coexisting fetus identified by short tandem repeats analysis: A case report

A complete hydatidiform mole coexisting with a fetus (CHMCF) is a rare form of twin pregnancy. High-risk gestational trophoblastic neoplasia (GTN) can occur after a CHMCF pregnancy, although the frequency is low. In cases of GTN, the clinical diagnosis and that based on the International Federation of Gynecology and Obstetrics (FIGO) scoring system can differ. This case report concerns a patient with a choriocarcinoma that was initially diagnosed and treated as a low-risk stage III GTN following a live birth from a CHMCF pregnancy. We used short tandem repeat (STR) analysis to identify the causative pregnancy as the patient's earlier complete hydatidiform mole. Clinicians should anticipate a high-risk GTN when treating persistent trophoblastic disease (PTD) in patients with a non-typical course.