title: Prevalence of ovarian endometriosis in epithelial ovarian cancer.
abstract: OBJECTIVE
  The objective of this study was to examine the occurrence of ovarian endometriosis in epithelial ovarian cancer in Japan.
  
  
  METHODS
  The presence of ovarian endometriosis was determined by reviewing the sections of resected specimens in 172 epithelial ovarian cancers.
  
  
  RESULTS
  The incidence of ovarian endometriosis in ovarian cancer (14.5%) was higher than that in Western countries. The rank order of incidence of endometriosis in each histologic type was clear cell (40.6%)>endometrioid (23.1%)>serous (8.7%)>mucinous (2.9%). The incidence in serous type was higher when compared with that reported in Western countries. The higher incidence of endometriosis in Japan can be explained by a greater proportion of clear cell type, comprising 18.6% of all the cases and a higher incidence of endometriosis in the serous type.
  
  
  CONCLUSIONS
  The association of ovarian endometriosis with epithelial ovarian cancer was more frequently found in Japan.
authors.affiliation: Department of Obstetrics and Gynecology, Faculty of Medicine, University of Tokyo, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Jimbo
authors.forename: H
authors.initials: H
authors.lastname: Yoshikawa
authors.forename: T
authors.initials: T
authors.lastname: Onda
authors.forename: T
authors.initials: T
authors.lastname: Yasugi
authors.forename: A
authors.initials: A
authors.lastname: Sakamoto
authors.forename: Y
authors.initials: Y
authors.lastname: Taketani
mesh_terms: D018262:Adenocarcinoma, Clear Cell / Q000453:epidemiology; D000367:Age Factors; D018269:Carcinoma, Endometrioid / Q000453:epidemiology; D018282:Cystadenocarcinoma, Mucinous / Q000453:epidemiology; D018284:Cystadenocarcinoma, Serous / Q000453:epidemiology; D004715:Endometriosis / Q000453:epidemiology*; D005260:Female; D006801:Humans; D015994:Incidence; D007564:Japan / Q000453:epidemiology; D008593:Menopause; D008875:Middle Aged; D010049:Ovarian Diseases / Q000453:epidemiology*; D010051:Ovarian Neoplasms / Q000453:epidemiology*; D010298:Parity; D015995:Prevalence