title: "Hook effect" in complete hydatidiform molar pregnancy: a falsely low level of beta-HCG.
abstract: BACKGROUND
  In some cases of gestational trophoblastic disease, a large amount of serum beta-hCG may lead to the high-dose "hook effect" with falsely low serum levels, creating misdiagnosis or delay in diagnosis and therapeutic hazards to the patient.
  
  
  METHODS
  In two cases of the hook effect in complete hydatidiform mole, ultrasonographic scan showed intrauterine echogenic material, whereas diluted serum specimens gave very high levels of beta-hCG (1,600,000 and 2,225,000 mIU/mL).
  
  
  CONCLUSIONS
  The possibility of a method-dependent hook effect must be considered. Early recognition of falsely low values of beta-hCG can allow correction to the true values by various methods, such as serum dilution before the radioimmunometric method.
authors.affiliation: Department of Obstetrics and Gynecology, Beilinson Medical Center, Petah Tiqva, Sackler Faculty of Medicine, Tel Aviv University, Israel.
authors.forename: H
authors.initials: H
authors.lastname: Levavi
authors.forename: A
authors.initials: A
authors.lastname: Neri
authors.forename: J
authors.initials: J
authors.lastname: Bar
authors.forename: D
authors.initials: D
authors.lastname: Regev
authors.forename: J
authors.initials: J
authors.lastname: Nordenberg
authors.forename: J
authors.initials: J
authors.lastname: Ovadia
mesh_terms: D000328:Adult; D014408:Biomarkers, Tumor / Q000097:blood*; D006063:Chorionic Gonadotropin / Q000097:blood*; D018997:Chorionic Gonadotropin, beta Subunit, Human; D005188:False Negative Reactions; D005260:Female; D006801:Humans; D006828:Hydatidiform Mole / Q000097:blood*; D010446:Peptide Fragments / Q000097:blood*; D011247:Pregnancy; D014594:Uterine Neoplasms / Q000097:blood*
chemical_list: D014408:Biomarkers, Tumor; D006063:Chorionic Gonadotropin; D018997:Chorionic Gonadotropin, beta Subunit, Human; D010446:Peptide Fragments