title: Migrating and herniating hydatid cysts.
abstract: OBJECTIVE
  To present the prevalence and imaging findings of patients with hydatid disease (HD) showing features of migration or herniation of the hydatid cysts (HCs) and underline the clinical significance of this condition.
  
  
  METHODS
  Between May 2003 and June 2006, 212 patients with HD were diagnosed by abdomen and/or thorax CT, searched for migrating or herniating HC. Imaging findings of 7 patients (5 women, 2 men with an age range of 19-63 years; mean+/-S.D., 44+/-19 years) with HD showing transdiaphragmatic migration (6 subjects) or femoral herniation (1 subject) were evaluated. Diagnosis of all the patients were established by pathologic examination and migration or herniation was confirmed by surgery in all patients.
  
  
  RESULTS
  Liver HD were identified in 169 (79.7%) of 212 patients with HD. Transdiaphragmatic migration of HCs were identified in 6 (3.5%) of the 169 patients with liver HD. In one patient, femoral herniation of the retroperitoneal HC into the proximal anterior thigh was identified. All of these seven patients exhibiting migration or herniation of HCs had active HCs including 'daughter cysts'. Two patients had previous surgery because of liver HD and any supradiaphragmatic lesion was not noted before operation. Findings of migration or herniation were confirmed by surgery.
  
  
  CONCLUSIONS
  Active HCs may show migration or herniation due to pressure difference between the anatomic cavities, and in some of the patients, by contribution of gravity. Previous surgery may be a complementary factor for migration as seen in two of our patients. The possibility of migration or herniation in patients with HD should be considered before surgery.
authors: Başkent University, Faculty of Medicine, Department of Radiology, Adana, Turkey. koczafer@gmail.com
authors: Zafer
authors: Z
authors: Koc
authors: Ali
authors: A
authors: Ezer
mesh_terms: D000328:Adult; D003287:Contrast Media; D003937:Diagnosis, Differential; D004443:Echinococcosis / Q000175:diagnosis* / Q000473:pathology; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D014057:Tomography, X-Ray Computed / Q000379:methods
chemical_list: D003287:Contrast Media