title: Diagnostic accuracy of endometrial biopsy in relation to the amount of tissue.
abstract: OBJECTIVE
  For the diagnostic workup of postmenopausal bleeding, histological examination of the endometrium is frequently performed. Failure of endometrial sampling due to insufficient material is often reported but objective criteria for quality assessment of endometrial biopsies are lacking. The aim of the present study is to evaluate the association between the amount of tissue obtained by endometrial sampling and the diagnostic accuracy, and to establish a cut-off level for a minimal amount of tissue required for a conclusive diagnosis.
  
  
  METHODS
  For this retrospective cohort study, clinicopathological data and Pipelle endometrial sampling slides of 139 patients who were treated with hysterectomy were collected. The surface of evaluable endometrial tissue was measured by means of structured digital assessment. The correlation between the predictive values in relation to the endometrial tissue surface was calculated for different cut-off values.
  
  
  RESULTS
  The median endometrial tissue surface was 4.7 mm2(range 0.4-156.4) for benign endometrium, 27.8 mm2(range 0.0-208.4) for premalignant endometrium and 43.8 mm2(range 0.0-223.6) for malignant endometrium. There was a significant association between the endometrial tissue surface and the correctness of diagnosis. A minimal endometrial tissue surface of 35 mm2could be defined, for positive and negative predictive values of 92.6% and 85.7%, respectively.
  
  
  CONCLUSIONS
  The diagnostic accuracy of Pipelle endometrial sampling is associated with the amount of endometrial tissue surface, with a minimal cut-off value of 35 mm2required to classify an endometrial sample as conclusive. Quantification of endometrial tissue can contribute to standardisation of quality assessment of endometrial samplings.
authors.affiliation: Department of Obstetrics and Gynaecology, Radboud University Medical Center, Nijmegen, The Netherlands.
authors.forename: Casper
authors.initials: C
authors.lastname: Reijnen
authors.affiliation: Department of Pathology, Radboud University Medical Center, Nijmegen, The Netherlands.
authors.forename: Nicole C M
authors.initials: NCM
authors.lastname: Visser
authors.affiliation: Department of Pathology, Radboud University Medical Center, Nijmegen, The Netherlands.
authors.forename: Johan
authors.initials: J
authors.lastname: Bulten
authors.affiliation: Department of Obstetrics and Gynaecology, Radboud University Medical Center, Nijmegen, The Netherlands.
authors.forename: Leon F A G
authors.initials: LFAG
authors.lastname: Massuger
authors.affiliation: Department of Obstetrics and Gynaecology, Radboud University Medical Center, Nijmegen, The Netherlands.
authors.forename: Louis J M
authors.initials: LJM
authors.lastname: van der Putten
authors.affiliation: Department of Obstetrics and Gynaecology, Radboud University Medical Center, Nijmegen, The Netherlands.
authors.forename: Johanna M A
authors.initials: JMA
authors.lastname: Pijnenborg
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy; D004717:Endometrium / Q000473:pathology* / Q000601:surgery; D005260:Female; D006801:Humans; D007044:Hysterectomy; D008875:Middle Aged; D017698:Postmenopause; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D012189:Retrospective Studies; D014591:Uterine Diseases / Q000150:complications / Q000473:pathology* / Q000601:surgery; D014592:Uterine Hemorrhage / Q000209:etiology; D057188:Workflow
keywords: DIAGNOSTICS; ENDOMETRIUM; GYNAECOLOGICAL PATHOLOGY; ONCOLOGY