title: Ectopic production of HCG by a benign ovarian mature cystic teratoma simulating an extra-uterine pregnancy: a case report.
abstract: Physicians should consider a benign mature cystic teratoma in their differential diagnosis of a patient with an elevated serum human chorionic gonadotropin concentration.
  
  
  BACKGROUND
  Following tubal ligation, a woman with amenorrhea and elevated serum human chorionic gonadotropin (HCG) concentrations may be experiencing either an ectopic or an intrauterine pregnancy. Other sources of HCG production can include ovarian germ cell tumors or gestational trophoblastic disease such as a complete or partial molar pregnancy. A rare source of HCG production is a benign mature ovarian teratoma.
  
  
  METHODS
  A 31-year old Gravida 2 para 2 presented with a positive home pregnancy test three years after she had experienced a Pomeroy tubal ligation. Her serum HCG was 57,914 mlU/mL but a transvaginal ultrasound did not find an intrauterine pregnancy. Laparoscopy was performed due to a suspicion of an ectopic pregnancy and an 11-cm benign mature cystic teratoma (dermoid cyst) within the right ovary was removed. An ectopic pregnancy was not visualized. Post-operatively, her serum HCG levels decreased and were negative within four weeks.
  
  
  CONCLUSIONS
  Mature ovarian cystic teratomas have rarely been reported to secrete HCG. They can be an infrequent source of HCG production and may lead to emergency surgery to treat a suspected extra-uterine pregnancy.
authors.forename: Brenda
authors.initials: B
authors.lastname: Dawley
authors.forename: Andreia
authors.initials: A
authors.lastname: Acuna
authors.forename: Beatrice
authors.initials: B
authors.lastname: Grasu
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000097:blood; D006063:Chorionic Gonadotropin / Q000097:blood*; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D010051:Ovarian Neoplasms / Q000097:blood* / Q000175:diagnosis* / Q000601:surgery; D010052:Ovariectomy; D011247:Pregnancy; D011271:Pregnancy, Ectopic / Q000175:diagnosis; D013724:Teratoma / Q000097:blood* / Q000175:diagnosis* / Q000601:surgery; D016896:Treatment Outcome
chemical_list: D015415:Biomarkers; D006063:Chorionic Gonadotropin