title: Malignant ovarian tumor composed of endometrioid adenocarcinoma, clear cell adenocarcinoma, squamous cell carcinoma, yolk sac tumor and immature teratoma with prominent neuroectodermal and rhabdomyosarcomatous differentiation: a case study.
abstract: BACKGROUND
  Cases of malignant ovarian tumor composed of müllerian-type epithelial tumor and malignant germ cell tumor are extremely rare.
  
  
  METHODS
  We herein report the case of a 34-year-old woman with an ovarian tumor which was composed of endometrioid adenocarcinoma (EAC), clear cell adenocarcinoma (CCC), squamous cell carcinoma, yolk sac tumor (YST) and immature teratoma with prominent neuroectodermal and rhabdomyosarcomatous differentiation. Even after systemic chemotherapy, this intriguing tumor recurred again and again, which is in contrast to pure germ cell tumor which is known to be sensitive to chemotherapy.
  
  
  CONCLUSIONS
  No previous cases with an identical composition have been found in the literature. Correct diagnosis of this complex and aggressive tumor is paramount.
authors.affiliation: Department of Anatomic Pathology, Graduate School of Medical Sciences, Kyushu University, and Department of Obstetrics and Gynecology, Kyushu University Hospital, Fukuoka 812-8582, Japan. yohishi@surgpath.med.kyushu-u.ac.jp
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Ohishi
authors.forename: Tsunehisa
authors.initials: T
authors.lastname: Kaku
authors.forename: Eisuke
authors.initials: E
authors.lastname: Kaneki
authors.forename: Norio
authors.initials: N
authors.lastname: Wake
authors.forename: Masazumi
authors.initials: M
authors.lastname: Tsuneyoshi
mesh_terms: D018262:Adenocarcinoma, Clear Cell / Q000473:pathology; D000328:Adult; D018269:Carcinoma, Endometrioid / Q000473:pathology; D002294:Carcinoma, Squamous Cell / Q000473:pathology; D018240:Endodermal Sinus Tumor / Q000473:pathology; D005260:Female; D006801:Humans; D017599:Neuroectodermal Tumors / Q000473:pathology; D010051:Ovarian Neoplasms / Q000473:pathology*; D012208:Rhabdomyosarcoma / Q000473:pathology; D013724:Teratoma / Q000473:pathology