title: A case of cystic leiomyoma mimicking an ovarian malignancy.
abstract: BACKGROUND
  We report an unusual case of a large cystic, pedunculated uterine leiomyoma mimicking a primary malignant ovarian tumour on sonography and computed tomography (CT).
  
  
  METHODS
  A 56-year-old post-menopausal woman presented with a right pelviabdominal mass. Sonography and CT examination showed a large extrauterine mass arising from the right adnexa and extending into the abdomen. The mass was predominantly cystic with a solid component at the periphery. A preoperative diagnosis of a primary malignant ovarian tumour was made.
  
  
  METHODS
  The patient underwent laparotomy. The large mass was found to arise from the uterine fundus; the ovary was not involved. The mass was resected, followed by total hysterectomy and bilateral salpingo-oophorectomy. Histology was that of a leiomyoma with extensive cystic degeneration.
  
  
  RESULTS
  The patient made an uneventful recovery.
  
  
  CONCLUSIONS
  A pedunculated, subserosal uterine leiomyoma with extensive cystic degeneration can mimic an ovarian tumour on imaging and should be considered in the differential diagnosis of an adnexal mass.
authors.affiliation: Department of Diagnostic Imaging, KK Women's and Children's Hospital, Singapore.
authors.forename: S C A
authors.initials: SC
authors.lastname: Low
authors.forename: C L
authors.initials: CL
authors.lastname: Chong
mesh_terms: D003560:Cysts / Q000175:diagnosis; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007889:Leiomyoma / Q000175:diagnosis* / Q000000981:diagnostic imaging; D008875:Middle Aged; D010051:Ovarian Neoplasms / Q000175:diagnosis* / Q000000981:diagnostic imaging; D011859:Radiography; D014463:Ultrasonography; D014594:Uterine Neoplasms / Q000175:diagnosis* / Q000000981:diagnostic imaging