title: Mucinous cystadenoma of the appendix misdiagnosed as cystic hydatid disease of the liver: a case report.
abstract: BACKGROUND
  Primary neoplastic lesions presenting with a mucocele of the appendix are very rare and can be divided into benign variants of mucinous adenomas or cystadenomas, mucinous tumours of uncertain malignant potential or mucinous cystadenocarcinomas. Most of these tumourous mucoceles are asymptomatic and are found incidentally. The major complication of neoplastic mucinous appendiceal tumours is the development of a pseudomyxoma peritonei due to spreading of mucin-producing cells within the abdominal cavity.
  
  
  METHODS
  A 44-year-old man presented with a history of non-specific symptoms of right upper abdominal pain. Abdominal ultrasound and computed tomography scan identified a cystic mass consistent with the morphological characteristics of an echinococcal hydatid cyst. After completing systemic albendazole therapy, an explorative laparotomy revealed a cystic tumour of the appendix. Ileocaecal resection was performed and pathology reports confirmed the diagnosis of a mucinous cystadenoma of the appendix. The postoperative course was uneventful.
  
  
  CONCLUSIONS
  Here we present the case of a man with a mucinous cystadenoma of the appendix mimicking cystic hydatid disease. We discuss the importance of re-evaluation and differential diagnostic reflections in cases of appendiceal mucocele.
authors.affiliation: Department of General and Visceral Surgery, Heinrich Heine-University, Duesseldorf, Germany. andreas.krieg@med.uni.duesseldorf.de
authors.forename: Andreas
authors.initials: A
authors.lastname: Krieg
authors.forename: Jan Schulte am
authors.initials: JS
authors.lastname: Esch
authors.forename: Ludger W
authors.initials: LW
authors.lastname: Poll
authors.forename: Stefan
authors.initials: S
authors.lastname: Braunstein
authors.forename: Wolfram T
authors.initials: WT
authors.lastname: Knoefel