title: [Hyperdense renal cyst].
abstract: OBJECTIVE
  We update the diagnostic criteria for renal cystic masses, emphasising in the clinical entity known as hyperdense renal cyst.
  
  
  METHODS
  We report the case of a male patient who presented with an atypical left renal cyst. Radiological examinations (US and CT) were performed. A description of renal cyst classification is made. We review the diagnostic criteria for hyperdense renal cyst using the iconography from this case and also its therapeutic approach.
  
  
  RESULTS
  An image compatible with left simple renal cyst was found on ultrasound. A CT scan study showed an homogeneous mass with a high attenuation value, non vascular in nature, which complies with all diagnostic criteria for hyperdense renal cyst.
  
  
  CONCLUSIONS
  Hyperdense renal cyst is a simple cyst which has suffered bleeding or infection. Diagnosis is made by CT scan and it does not require treatment.
authors.affiliation: Servicio de Urología, Hospital de Cruces, Vizcaya, España.
authors.forename: Victor
authors.initials: V
authors.lastname: Crespo Atin
authors.forename: Jesús
authors.initials: J
authors.lastname: Padilla Nieva
authors.forename: Jesús
authors.initials: J
authors.lastname: Martín Bazaco
authors.forename: Víctor
authors.initials: V
authors.lastname: Azurmendi Sastre
authors.forename: David
authors.initials: D
authors.lastname: Lekumberri Castaños
authors.forename: Roberto
authors.initials: R
authors.lastname: Llarena Ibarguren
authors.forename: Carlos
authors.initials: C
authors.lastname: Pertusa Peña
mesh_terms: D000328:Adult; D003287:Contrast Media; D006801:Humans; D052177:Kidney Diseases, Cystic / Q000145:classification; D008279:Magnetic Resonance Imaging; D008297:Male; D007690:Polycystic Kidney Diseases / Q000000981:diagnostic imaging / Q000473:pathology*; D011859:Radiography; D014463:Ultrasonography
chemical_list: D003287:Contrast Media