title: Clinical use of immunoperoxidase markers in excluding ectopic gestation.
abstract: Ectopic pregnancy is suspected when a pregnancy test is positive and an Arias-Stella phenomenon with decidua is seen on endometrial curettings in the absence of chorionic villi and trophoblast. We performed immunoperoxidase stains for beta-hCG, hPL, placental alkaline phosphatase, and keratin (AE1/AE3) on endometrial curettings of 72 patients with first-trimester bleeding in whom ectopic pregnancy was suspected based on routine hematoxylin and eosin (H&E) stain. Negative immunoperoxidase stains correlated with a retrospective patient chart review identified only ten patients with extrauterine pregnancy, a prevalence of 14%. The sensitivity of hCG, hPL, placental alkaline phosphatase, and keratin markers in detecting trophoblastic cells in the curettings was 42, 48, 24, and 69%, respectively. Each marker had a specificity of 100%. When both keratin and hPL were used, the sensitivity improved to 73%; however, there was no advantage in using three or more markers. We conclude that 73% of patients suspected to have ectopic pregnancy would be spared additional diagnostic techniques when immunoperoxidase markers for keratin and hPL are used on endometrial curettings without trophoblast on routine H&E stain. The procedure requires only 3 hours of laboratory time.
authors.affiliation: Department of Pathology, University of Texas Medical Branch, Galveston.
authors.forename: H G
authors.initials: HG
authors.lastname: Kaspar
authors.forename: T
authors.initials: T
authors.lastname: To
authors.forename: T V
authors.initials: TV
authors.lastname: Dinh
mesh_terms: D003656:Decidua / Q000737:chemistry; D004107:Dilatation and Curettage; D004717:Endometrium / Q000737:chemistry*; D005260:Female; D006801:Humans; D007124:Immunoenzyme Techniques; D011237:Predictive Value of Tests; D011247:Pregnancy; D011271:Pregnancy, Ectopic / Q000175:diagnosis* / Q000453:epidemiology; D015995:Prevalence; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014327:Trophoblasts / Q000737:chemistry