title: Testicular carcinoma in situ in patients with extragonadal germ-cell tumours: the clinical role of pretreatment biopsy.
abstract: BACKGROUND
  The aim of this study was to determine the prevalence of testicular carcinoma in situ (CIS) in patients with a malignant extragonadal germ-cell tumour (EGGCT) and the incidence of metachronous invasive testicular cancer (TC) in relation to the pretreatment demonstration of CIS.
  
  
  METHODS
  Sixty-eight patients with EGGCT (53 retroperitoneal, 15 mediastinal) had pre-chemotherapy histological assessment of one (13) or both (55) testicle(s). A total of 123 testicles were examined for the presence of CIS.
  
  
  RESULTS
  Testicular CIS was found in 21 patients (31%) (18 retroperitoneal EGGCT, three mediastinal EGGCT). Two patients had bilateral CIS. Five patients, four of them with proven pretreatment CIS, developed a metachronous TC. The 10-year invasive-free TC survival rate for all 68 patients was 88%, but only 65% for those with proven pretreatment CIS. The overall 10-year survival rate for all patients was 82%. CIS was demonstrated in seven of 48 trans-scrotal core biopsies, in 10 of 56 trans-scrotal surgical biopsies and in five of 11 orchiectomy specimens.
  
  
  CONCLUSIONS
  Approximately one-third of patients with EGGCT present with testicular CIS, predominantly those with a retroperitoneal tumour. These patients have a considerable risk of metachronous TC development in spite of chemotherapy. The pretreatment demonstration of testicular CIS in patients with EGGCT gives the possibility of individualised counselling and safe follow-up, and is therefore highly recommended. The data are in agreement with a multi-site development of malignant germ-cell tumours, but do not exclude the possibility that the retroperitoneal EGGCTs in particular represent metastases from a burned-out TC.
authors.affiliation: Department of Clinical Research, The Norwegian Radium Hospital, Oslo, Norway. s.d.fossa@klinmed.uio.no
authors.forename: S D
authors.initials: SD
authors.lastname: Fosså
authors.forename: N
authors.initials: N
authors.lastname: Aass
authors.forename: A
authors.initials: A
authors.lastname: Heilo
authors.forename: G
authors.initials: G
authors.lastname: Daugaard
authors.forename: N
authors.initials: N
authors.lastname: E  Skakkebaek
authors.forename: A E
authors.initials: AE
authors.lastname: Stenwig
authors.forename: J M
authors.initials: JM
authors.lastname: Nesland
authors.forename: L H J
authors.initials: LH
authors.lastname: Looijenga
authors.forename: J W
authors.initials: JW
authors.lastname: Oosterhuis
mesh_terms: D000328:Adult; D000368:Aged; D001706:Biopsy; D002278:Carcinoma in Situ / Q000453:epidemiology* / Q000209:etiology / Q000473:pathology; D005500:Follow-Up Studies; D018237:Germinoma / Q000150:complications / Q000473:pathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D013736:Testicular Neoplasms / Q000453:epidemiology* / Q000209:etiology / Q000473:pathology; D013737:Testis / Q000473:pathology*