title: Endometriosis of the appendix.
abstract: OBJECTIVE
  Endometriosis is defined as functioning endometrial tissue outside of the uterus. Endometriosis of the appendix is uncommon. Its clinical presentation varies from asymptomatic to acute abdominal pain. The aims of this study were to describe our experience of managing patients with appendiceal endometriosis and to review the clinical characteristics of this medical condition.
  
  
  METHODS
  Five cases of appendiceal endometriosis diagnosed between January 2007 and December 2012 were retrospectively reviewed. Patients treated for intra-abdominal endometriosis were excluded.
  
  
  RESULTS
  The mean age at diagnosis was 33.8 years old. One patient was in the second trimester of pregnancy. Two patients were asymptomatic. Three patients had clinical symptoms including two with acute pain in the right lower quadrant and one with abdominal discomfort. Four patients showed appendiceal abnormalities in imaging studies including two cases of suspected mucocele and two cases of appendiceal infection. There were no suspicions of endometriosis of the appendix based on preoperative imaging studies. Three patients underwent appendectomy due to clinical symptoms, and two underwent incidental appendectomy combined with another operation. None of the patients received adjuvant therapy.
  
  
  CONCLUSIONS
  Appendiceal endometriosis should be included in the differential diagnosis for acute abdominal pain, especially when women of childbearing age present with clinical symptoms of acute appendicitis.
authors.affiliation: Department of Surgery, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Jiho
authors.initials: J
authors.lastname: Yoon
authors.affiliation: Department of Surgery, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Yong Sang
authors.initials: YS
authors.lastname: Lee
authors.affiliation: Department of Surgery, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Hang-Seok
authors.initials: HS
authors.lastname: Chang
authors.affiliation: Department of Surgery, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Cheong Soo
authors.initials: CS
authors.lastname: Park
keywords: Abdominal pain; Acute abdomen; Appendicitis; Appendix; Endometriosis