title: Practical usefulness of atypical endometrial cell categories within the new classification of endometrial cytology when applied to conventional smears.
abstract: OBJECTIVE
  Endometrial cytology has been widely used as a screening tool in Japan. Traditionally, a three-tier reporting system, consisting of 'negative', 'suspicious' and 'positive' categories, has been used. However, a more descriptive system, the New Terminology in Endometrial Cytology (NTEMC), which is based on the Bethesda System for uterine cervical cytology, was introduced recently. The objective of this study was to validate the NTEMC criteria.
  
  
  METHODS
  Endometrial cytology specimens that had been categorised as 'suspicious' were collected in our hospital between 2003 and 2013, and from these, 106 specimens with corresponding histological results, were re-evaluated according to the NTEMC criteria. Diagnostic categories were assigned based on that chosen by the majority of the examining members.
  
  
  RESULTS
  Negative, atypical endometrial cells, of undetermined significance (ATEC-US), atypical endometrial cells for which atypical endometrial hyperplasia or worse cannot be excluded (ATEC-A), endometrial hyperplasia, atypical endometrial hyperplasia and malignancy were selected as the diagnostic categories for 9 (8.5%), 34 (32.1%), 17 (16%), 34 (32.1%), 5 (4.7%) and 7 (6.6%) specimens, respectively. Corresponding histological categories of benign, endometrial hyperplasia, atypical endometrial hyperplasia and malignancy were established in 28 (82.4%), 1 (2.9%), 2 (5.9%) and 3 (8.8%) ATEC-US specimens, respectively, and in 6 (35.3%), 3 (17.6%), 2 (11.8%) and 6 (35.3%) ATEC-A specimens, respectively. The histological category distribution differed significantly (P = 0.001), and there was a significant correlation between corresponding cytological and histological categories (P = 0.005).
  
  
  CONCLUSIONS
  The ATEC category of NTEMC system works well in a practical setting and resembles the Bethesda reporting system ASC (atypical squamous cells) category for cervical cytology.
authors.affiliation: Department of Pathology, Sakai City Medical Center, Sakai, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Munakata
authors.affiliation: Department of Clinical Laboratory, Sakai City Medical Center, Sakai, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Sasaki
authors.affiliation: Department of Clinical Laboratory, Sakai City Medical Center, Sakai, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Takase
authors.affiliation: Department of Clinical Laboratory, Sakai City Medical Center, Sakai, Japan.
authors.forename: R
authors.initials: R
authors.lastname: Okatake
authors.affiliation: Department of Clinical Laboratory, Sakai City Medical Center, Sakai, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Suzuki
authors.affiliation: Department of Obstetrics and Gynecology, Sakai City Medical Center, Sakai, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Yamamoto
authors.affiliation: Department of Obstetrics and Gynecology, J. A. Suzuka General Hospital, Suzuka, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Yanoh
mesh_terms: D001706:Biopsy; D004714:Endometrial Hyperplasia / Q000175:diagnosis* / Q000473:pathology*; D016889:Endometrial Neoplasms / Q000175:diagnosis / Q000473:pathology*; D004717:Endometrium / Q000473:pathology*; D005260:Female; D006801:Humans; D002583:Uterine Cervical Neoplasms / Q000175:diagnosis / Q000473:pathology*; D014626:Vaginal Smears / Q000379:methods
keywords: Bethesda system; cytology; endometrium; feasibility study; gynaecological pathology