Diagnosis and treatment of retroperitoneal ectopic pregnancy: review of the literature.

Retroperitoneal ectopic pregnancies (REP) are extremely rare, and early diagnosis and treatment is very difficult. We completed an English literature search in MEDLINE through PubMed for articles on REP. We identified 14 articles (all case reports) but selected only 12 because of unavailable data in the other 2 articles. We also report the case of an REP which was misdiagnosed as ectopic choriocarcinoma. The 33-year-old woman was admitted via the outpatient department with a history of 54 days of amenorrhea and persistent elevated serum β-human chorionic gonadotropin (hCG) levels. The presumed diagnosis ectopic choriocarcinoma was made based on imaging findings. Single-drug chemotherapy with methotrexate (MTX; 20-mg intramuscular injection daily for 5 consecutive days) was administered. An upper abdominal mass was noticed by the patient and laparotomy was performed. A retroperitoneal pregnant lesion was found and removed successfully. The diagnosis, treatment and mechanisms of REP are discussed. We believe REP should be considered in patients with elevated serum β-hCG levels when the uterus and adnexa appear to be normal. Systemic administration of MTX in nonruptured REP before operation may prove to be helpful.