title: The new WHO classification of ovarian, fallopian tube, and primary peritoneal cancer and its clinical implications.
abstract: BACKGROUND
  Molecular pathological research has contributed to improving the knowledge of different subtypes of ovarian cancer. In parallel with the implementation of the new FIGO staging classification, the WHO classification was revised. The latter is mainly based on the histopathological findings and defines the actual type of tumor. It has, therefore, also an important impact on prognosis and therapy of the patient.
  
  
  METHODS
  The new WHO Classification of Ovarian Cancer published 2014 by Robert Kurman and co-authors is summarized. The major changes compared to the hitherto existing classification are presented.
  
  
  RESULTS
  The new classification eliminates the previous focus of mesothelial origin of ovarian cancer. Instead, it features a discussion of tubal carcinogenesis of hereditary and some other high-grade serous carcinomas. The previously assumed pathogenesis pathway may be correct for some, but not for all, serous cancers. The new classification was established to classify ovarian cancer in a more consistent way. The earlier transitional cell type of ovarian cancer has been removed while seromucinous tumors have been added as a new entity. The role of some borderline tumors as one possible step in the progression from benign to invasive lesions is incorporated. The article summarizes the essential updates concerning serous, mucinous, seromucinous, endometrioid, clear-cell, and Brenner tumors.
  
  
  CONCLUSIONS
  The new WHO classification takes into account the recent findings on the origin, pathogenesis, and prognosis of different ovarian cancer subtypes. The tubal origin of hereditary and some non-hereditary high-grade serous cancers is mentioned in contrast to the hitherto theory of mesothelial origin of tumors. Seromucinous tumors represent a new entity.
authors.affiliation: Klinik für Gynäkologie und Geburtsmedizin, Uniklinik RWTH Aachen, Pauwelsstr. 30, 52074, Aachen, Germany. imeinhold@ukaachen.de.
authors.forename: Ivo
authors.initials: I
authors.lastname: Meinhold-Heerlein
authors.affiliation: Klinik für Gynäkologie und Geburtsmedizin, Uniklinik RWTH Aachen, Pauwelsstr. 30, 52074, Aachen, Germany.
authors.forename: Christina
authors.initials: C
authors.lastname: Fotopoulou
authors.affiliation: Klinik für Gynäkologie und Geburtsmedizin, Uniklinik RWTH Aachen, Pauwelsstr. 30, 52074, Aachen, Germany.
authors.forename: Philipp
authors.initials: P
authors.lastname: Harter
authors.affiliation: Klinik für Gynäkologie und Geburtsmedizin, Uniklinik RWTH Aachen, Pauwelsstr. 30, 52074, Aachen, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Kurzeder
authors.affiliation: Klinik für Gynäkologie und Geburtsmedizin, Uniklinik RWTH Aachen, Pauwelsstr. 30, 52074, Aachen, Germany.
authors.forename: Alexander
authors.initials: A
authors.lastname: Mustea
authors.affiliation: Klinik für Gynäkologie und Geburtsmedizin, Uniklinik RWTH Aachen, Pauwelsstr. 30, 52074, Aachen, Germany.
authors.forename: Pauline
authors.initials: P
authors.lastname: Wimberger
authors.affiliation: Klinik für Gynäkologie und Geburtsmedizin, Uniklinik RWTH Aachen, Pauwelsstr. 30, 52074, Aachen, Germany.
authors.forename: Steffen
authors.initials: S
authors.lastname: Hauptmann
authors.affiliation: Klinik für Gynäkologie und Geburtsmedizin, Uniklinik RWTH Aachen, Pauwelsstr. 30, 52074, Aachen, Germany.
authors.forename: Jalid
authors.initials: J
authors.lastname: Sehouli
mesh_terms: D018262:Adenocarcinoma, Clear Cell / Q000145:classification* / Q000473:pathology; D002288:Adenocarcinoma, Mucinous / Q000145:classification* / Q000473:pathology; D000328:Adult; D000818:Animals; D001948:Brenner Tumor / Q000473:pathology; D063646:Carcinogenesis; D018284:Cystadenocarcinoma, Serous / Q000145:classification* / Q000473:pathology; D004717:Endometrium / Q000473:pathology; D004847:Epithelial Cells / Q000378:metabolism; D005185:Fallopian Tube Neoplasms / Q000145:classification* / Q000473:pathology; D005260:Female; D006801:Humans; D009367:Neoplasm Staging / Q000379:methods*; D010051:Ovarian Neoplasms / Q000145:classification* / Q000473:pathology; D010534:Peritoneal Neoplasms / Q000145:classification* / Q000473:pathology / Q000601:surgery; D011230:Precancerous Conditions / Q000473:pathology; D011379:Prognosis; D012186:Retroperitoneal Neoplasms / Q000473:pathology; D012509:Sarcoma / Q000473:pathology; D014944:World Health Organization
keywords: Clear cell; Endometrioid; High-grade serous; Low-grade serous; Mucinous