Background: Ovarian ectopic pregnancies are uncommon, and a hydatidiform mole in this location is extremely rare but may later develop into a choriocarcinoma.
Case: A 49-year-old woman with a history of an ectopic pregnancy, lost to follow-up in spite of rising human chorionic gonadotropin (hCG) levels, presented three years later at the emergency ward with hemoptysis, vaginal bleeding and elevated serum hCG. Pulmonary and vaginal metastasis was found, and the diagnosis of a choriocarcinoma was confirmed. She received chemotherapy during a 6-month period and recovered successfully. Seven years later she is free of disease. Reevaluation of the histological specimen from the previous ectopic pregnancy confirmed an ovarian hydatidiform mole and the later development of choriocarcinoma which probably originated from this mole.
Conclusion: The diagnosis of hydatidiform mole can be difficult, however, it may be crucial to the patient. Whenever a histopathologic examination of products of conception is performed, it is important that a hydatidiform mole can be ruled out, and that may require additional analysis such as immunohistochemistry and DNA ploidy. In cases in which a gestational trophoblastic disease is suspected, it is necessary to monitor serum hCG until values are negative.