title: Evaluation of pregnancy-related cells in endometrial cytology.
abstract: OBJECTIVE
  To determine the significance of pregnancy-related cells in endometrial smears.
  
  
  METHODS
  Pregnancy-related cells in 4429 endometrial smear samples were retrospectively analyzed and evaluated for clinicopathologic and cytomorphologic features.
  
  
  RESULTS
  Of the 4429 endometrial smears taken for cancer screening, pregnancy-related cells were detected in 12 cases (0.3%). They were estimated cytologically as negative or suspicious and confirmed as cases ofspontaneous abortion (8 cases), placental site nodule (3 cases), and partial hydatidiform mole (1 case). Decidual cells were observed in all cases, and some of these showed atypia. Trophoblasts were observed in 5 (41.7%) of the 12 cases. Syncytiotrophoblasts were observed in 1 case (8.3%) and nonsyncytiotrophoblasts in 5 (41.7%) of the 12 cases. Pregnancy-related cells were observed in an endometrial smear in 7 cases; other cases were missed during cytologic examination and were retrospectively identified.
  
  
  CONCLUSIONS
  Pregnancy-related cells are likely to be missed because they are difficult to identify or are surrounded by a cluster of endometrial cells. The decidual cell is a key cell for the cytologic diagnosis of pregnancy-related cells. Determining the existence of pregnancy-related cells in endometrial smears is important for the further assessment of patients and the differential diagnosis of several endometrial lesions.
authors.affiliation: Department of Gynecology, Shinnai Medical Corporation, Tenjin Clinic, Fukuoka, Japan. DZB06614@niefty.ne.jp
authors.forename: Yoshiko
authors.initials: Y
authors.lastname: Kashimura
authors.forename: Junko
authors.initials: J
authors.lastname: Fukuda
authors.forename: Naoyuki
authors.initials: N
authors.lastname: Toki
authors.forename: Wakaho
authors.initials: W
authors.lastname: Doki
authors.forename: Masamichi
authors.initials: M
authors.lastname: Kashimura
mesh_terms: D000022:Abortion, Spontaneous / Q000175:diagnosis / Q000473:pathology*; D000328:Adult; D003937:Diagnosis, Differential; D004717:Endometrium / Q000473:pathology*; D005260:Female; D006801:Humans; D006828:Hydatidiform Mole / Q000175:diagnosis / Q000473:pathology*; D008875:Middle Aged; D011247:Pregnancy; D012189:Retrospective Studies; D014327:Trophoblasts / Q000473:pathology*; D014594:Uterine Neoplasms / Q000175:diagnosis / Q000473:pathology*; D014626:Vaginal Smears