title: Retroperitoneal cystic mature teratoma as the presenting clinical scenario of testicular carcinoma.
abstract: OBJECTIVE
  To describe a case of retroperitoneal mature teratoma presenting as metastasis of a testicular mixed germ cell tumor in a thirty year old man who had lumbar and abdominal pain and mass sensation in the left hemiabdomen.
  
  
  METHODS
  Abdominal ultrasound and thoracic-abdominal-pelvic CT multidetector scan were performed, and then after a Doppler ultrasound study of the testicles. Surgical treatment was performed: orchiectomy and retroperitoneal lesion resection.
  
  
  RESULTS
  Imaging studies showed a big cystic lesion in the left retroperitoneal space, 13 × 12 × 11 cm, well defined, with thin septa, displacing the kidney; and a solid-cystic 4 cm left testicular tumor, with multiple septa, solid poles and arterial flows with low resistances. Thoracic extension study did not show any finding. The histopathologic results of the orchiectomy and retroperitoneal resection pieces were, respectively, testicular mixed germ cell tumor (seminoma, with intratubular seminoma foci and teratoma) and mature cystic teratoma.
  
  
  CONCLUSIONS
  Germ cell tumors derive from multipotencial cells with a large capacity of differentiation, and the nodal paraaortic chains are a natural way of dissemination of these neoplasms. Because of that, in the presence of a retroperitoneal lesion in a young patient we have to rule out testicular tumor metastasis. The retroperitoneal mature cystic teratoma must be considered as a lesion with malignant potential.
authors: Radiology, Hospital Clinico de Malaga, Spain.
authors: C
authors: C
authors: Gómez-Rebollo
authors: A J
authors: AJ
authors: Márquez-Moreno
authors: L E
authors: LE
authors: Rojo-Carmona
authors: E
authors: E
authors: Castillo-Gallardo
authors: Nieves
authors: N
authors: Alegre-Bayo
authors: B
authors: B
authors: Cabra-De Luna
authors: I
authors: I
authors: García-Muñoz
authors: J J
authors: JJ
authors: Sánchez-Carrillo