title: Metastases of clinically occult testicular seminoma mimicking primary extragonadal retroperitoneal germ cell tumors.
abstract: BACKGROUND
  Whether extragonadal germ cell tumors develop primarily in the retroperitoneum or whether they are essentially metastases of a primary testicular tumor has long been debated and remains controversial.
  
  
  METHODS
  Three patients presenting with apparent primary extragonadal retroperitoneal germ cell tumors are reported. Ipsilateral testicular evaluation was extended with palpation, ultrasonography and finally histological examination.
  
  
  RESULTS
  The retroperitoneal extragonadal tumors were found during abdominal MSCT. It was a fortuitous finding in the two first patients.The third patient presented with abdominal pain attributed to necrosis of the large mass which was subsequently firstly drained through endoscopic ultrasound-guided transduodenal puncture. The seminomatous nature of the retroperitoneal tumors was obtained through transduodenal echoendoscopic-guided cytopuncture in the first case, celioscopic resection in the second case and delayed percutaneous CT guided biopsy in the third symptomatic case. The first two patients had a history of cryptorchidism with substantial clinical testicular atrophy; ultrasonography showed microlithiasis and a small intratesticular tumor in the first patient and an hypoechoic but rather homogeneous atrophic testis in the other; orchiectomy confirmed small seminomatous intratesticular tumors in the two cases. The third patient had an atypical hypoechoic area on testicular ultrasound and histopatholgy revealed a burn-out primary tumor.
  
  
  CONCLUSIONS
  So-called primary extragonadal retroperitoneal germ cell tumors are extremely rare and should first be considered as metastases of a viable or burned-out testicular cancer until proven otherwise. All ipsilateral testicular abnormalities revealed by the patient's history, clinical examination and mostly by testicular ultrasound must be treated adequately with orchiectomy because they may act as a sanctuary for later tumor growth.
authors.affiliation: Department of Medical Imaging, Clinique St Luc, Bouge, Belgium. bcoulier@skynet.be
authors.forename: B
authors.initials: B
authors.lastname: Coulier
authors.forename: Y
authors.initials: Y
authors.lastname: Lefebvre
authors.forename: L
authors.initials: L
authors.lastname: de Visscher
authors.forename: A
authors.initials: A
authors.lastname: Bourgeois
authors.forename: L
authors.initials: L
authors.lastname: Montfort
authors.forename: M
authors.initials: M
authors.lastname: Clausse
authors.forename: P
authors.initials: P
authors.lastname: Mailleux
authors.forename: I
authors.initials: I
authors.lastname: Gielen
mesh_terms: D000328:Adult; D003937:Diagnosis, Differential; D006801:Humans; D008297:Male; D008875:Middle Aged; D009373:Neoplasms, Germ Cell and Embryonal / Q000175:diagnosis*; D012186:Retroperitoneal Neoplasms / Q000175:diagnosis* / Q000556:secondary*; D018239:Seminoma / Q000175:diagnosis / Q000556:secondary*; D013736:Testicular Neoplasms / Q000473:pathology*; D014057:Tomography, X-Ray Computed