title: An unusual cause of acute appendicitis: Appendiceal endometriosis.
abstract: BACKGROUND
  While endometriosis is a common disorder in women of reproductive age, appendiceal endometriosis accounts for less than 1% of all pelvic endometriotic lesions. Appendiceal involvement may present as acute appendicitis and definitive diagnosis is made by only postoperative histological examination.
  
  
  METHODS
  In this study, we present two cases of female patients who underwent an appendectomy presumed diagnosis as acute appendicitis, and a histopathological examination of the retrieved specimen revealed appendiceal endometriosis.
  
  
  CONCLUSIONS
  Endometriosis is defined as the presence of ectopic endometrial tissue outside the lining of the uterine cavity. Gastrointestinal endometriosis is observed in 3-37% of all endometriosis cases, whereas appendiceal endometriosis accounts for only about 3% of gastrointestinal endometriosis. Appendiceal endometriosis is usually asymptomatic, although it sometimes causes abdominal cramps, nausea, chronic pelvic pain, lower gastrointestinal hemorrhage, intussusception, perforation, or acute appendicitis.
  
  
  CONCLUSIONS
  Appendiceal endometriosis is an unusual histopathological finding. A preoperative diagnosis is difficult, but this condition should be considered when women of childbearing age present with clinical symptoms of acute appendicitis.
authors.affiliation: Department of Surgery, Malatya State Hospital, 44300 Malatya, Turkey.
authors.forename: Arif
authors.initials: A
authors.lastname: Emre
authors.forename: Sami
authors.initials: S
authors.lastname: Akbulut
authors.forename: Mehmet
authors.initials: M
authors.lastname: Yilmaz
authors.forename: Zehra
authors.initials: Z
authors.lastname: Bozdag