title: A spurious markedly increased serum estradiol level due to an IgA lambda.
abstract: OBJECTIVE
  To alert physicians about the potential for erroneous laboratory determinations of hormone levels and emphasize the need to assess the overall clinical situation as well.
  
  
  METHODS
  We present a case report of a woman with a dramatically increased serum estradiol (E(2)) level on radioimmunoassay and review the studies that led to the conclusion that this laboratory finding did not reflect her true estrogen status.
  
  
  RESULTS
  In a 41-year-old woman, an unnecessary surgical procedure was performed because of a falsely increased serum E(2) level and a unilateral ovarian mass. The markedly increased serum E(2) measured by radioimmunoassay was found to be attributable to an IgA lambda that bound to the 125 I-labeled tracer of the assay.
  
  
  CONCLUSIONS
  When repeatedly abnormal hormone levels and the clinical picture seem discrepant, use of a different assay method should be considered.
authors.affiliation: Division of Endocrinology, Department of Medicine, Loyola University Medical Center, Maywood, Illinois, USA.
authors.forename: D L
authors.initials: DL
authors.lastname: Gordon
authors.forename: E
authors.initials: E
authors.lastname: Holmes
authors.forename: E J
authors.initials: EJ
authors.lastname: Kovacs
authors.forename: M H
authors.initials: MH
authors.lastname: Brooks