Koji Matsumoto

Retroperitoneal ectopic pregnancies are extremely rare; only a few cases having been reported. Here, we report laparoscopic removal of an asymptomatic retroperitoneal ectopic pregnancy from a 29‐year‐old woman who was referred to our hospital for a suspected ectopic pregnancy. Transvaginal ultrasound did not reveal a gestational sac in the uterus or pelvic cavity. However, abdominal contrast‐enhanced computer tomography showed a gestational sac between the abdominal aorta and inferior vena cava. On laparoscopy, the gestational sac was confirmed to be in this retroperitoneal location and successfully removed with minimal bleeding. Histopathologic examination revealed chorionic villi surrounded by lymphatic tissue, suggesting lymphatic spread of the retroperitoneal ectopic pregnancy. In summary, contrast‐enhanced computer tomography is very useful for locating the site of pregnancy in women suspected of having a retroperitoneal ectopic pregnancy. Timely diagnosis of a retroperitoneal ectopic pregnancy before bleeding occurs can enable their safe laparoscopic removal.