Serous cystadenoma and ectopic pregnancy in the fallopian tube.

The coexistence of a cystadenoma with an ectopic pregnancy in the same fallopian tube is extremely rare. A 30-year-old gravid woman exhibited increasing human chorionic gonadotropin concentrations. Intramuscular methotrexate therapy was administered and ectopic precautions were taken. The patient eventually underwent diagnostic laparoscopy. After pathologic review, an ectopic pregnancy and serous cystadenoma were identified in the left fallopian tube.