title: Low-grade endometrial stromal sarcoma with retroperitoneal metastases: an unusual case report.
abstract: BACKGROUND
  Endometrial stromal sarcoma (ESS) is an uncommon malign neoplasm, and its occurrence outside the uterus is extremely rare in the absence of metastasis or extension of a primary uterine neoplasm. When arising in the pelvis or abdominal cavity, ESS is associated with uterine adnexa or serosal surface of various organs.
  
  
  METHODS
  We present the case of a 46-year-old woman with lower abdominal pain and regular menstruation who underwent laparotomy after a diagnosis of pelvic mass mimicking a right adnexial tumor. Exploration of the pelvis revealed a retroperitoneal mass of 15 cm in diameter in the right illiac fossa without accompanying pelvic or paraaortic lymphadenopathy. Uterus and ovaries were bilaterally normal in size. The pathology showed low-grade ESS of the uterus with direct spread to retroperitoneum without serosal metastases.
  
  
  CONCLUSIONS
  This case shows that despite its well-known good prognostic nature, low-grade ESS may behave as an aggressive malignancy.
authors.affiliation: Department of Obstetrics and Gynecology, Dr. Lutfi Kirdar Kartal Education and Research Hospital, Istanbul, Turkey. kguzelmeric@yahoo.com
authors.forename: Kadir
authors.initials: K
authors.lastname: Guzelmeric
authors.forename: Bahar
authors.initials: B
authors.lastname: Ergen
authors.forename: Zehra Meltem
authors.initials: ZM
authors.lastname: Pirimoglu
authors.forename: Melin Ozgun
authors.initials: MO
authors.lastname: Gecer
authors.forename: Orhan
authors.initials: O
authors.lastname: Unal
authors.forename: Cem
authors.initials: C
authors.lastname: Turan
mesh_terms: D016889:Endometrial Neoplasms / Q000473:pathology*; D005187:Fallopian Tubes / Q000601:surgery; D005260:Female; D006801:Humans; D007044:Hysterectomy; D008197:Lymph Node Excision; D008875:Middle Aged; D010052:Ovariectomy; D012186:Retroperitoneal Neoplasms / Q000556:secondary*; D018203:Sarcoma, Endometrial Stromal / Q000473:pathology* / Q000556:secondary*