title: [Should frozen section examination be performed systematically as part of conservative surgery for renal cell carcinoma?].
abstract: OBJECTIVE
  To prospectively assess the value of frozen section examination during conservative surgery for renal cell carcinoma (RCC) in exclusively elective indications and to evaluate the reality of safety margins.
  
  
  METHODS
  From 1997 to 2001, 220 conservative procedures for RCC were performed in our department, including 104 elective lumpectomies, 61 of which were studied prospectively. The mean age of these 61 patients was 59.4 years (range: 34.2 to 78.5). The mean tumour diameter was 32 mm (range: 12 to 50). Tumours were peripheral in 51 cases and in a juxtahilar position in 10 cases. Resection margins were evaluated macroscopically by the surgeon, and the specimen was systematically sent for frozen section examination. Incomplete margins, i.e. negative but with no safety margin, were distinguished from positive margins on the final histological examination. The thickness of the safety margins was measured on the cortical and deep extremities of the operative specimen. The mean follow-up was 78.5 months (range: 52 to 101).
  
  
  RESULTS
  Histological types of RCC comprised conventional clear cell (n = 42), tubulopapillary (n = 17) and chromophobe (n = 2), stage pT1 (n = 57) and pT2 (n = 4), and grade 1 (n = 16), 2 (n = 35) and 3 (n = 10). No positive margins were detected. The mean thickness of the safety margin was 7 mm peripherally and 2 mm in depth with no correlation between these two values. Surgeons concluded on the presence of 51 complete margins and 10 incomplete margins versus 53 and 8 on histological examination, respectively. Frozen section examination never modified the course of the operation. All patients were alive and recurrence free at last follow-up.
  
  
  CONCLUSIONS
  Macroscopic evaluation of resection margins by the surgeon is precise and usually avoids the need for frozen section. However when the margins are considered to be incomplete by the surgeon, frozen section examination is mandatory to avoid positive margins, which must remain the main objective of conservative surgery.
authors.affiliation: Service d'Urologie et Transplantation, Hôpital Necker, Paris, France. marc-olivier.timsit@nck.aphp.fr
authors.forename: Marc-Olivier
authors.initials: MO
authors.lastname: Timsit
authors.forename: Arnaud
authors.initials: A
authors.lastname: Méjean
authors.forename: Matthieu
authors.initials: M
authors.lastname: Bordenave
authors.forename: Yves
authors.initials: Y
authors.lastname: Chretien
authors.forename: Stéphane
authors.initials: S
authors.lastname: Leroux
authors.forename: Bertrand
authors.initials: B
authors.lastname: Dufour
authors.forename: Nicolas
authors.initials: N
authors.lastname: Thiounn
mesh_terms: D000328:Adult; D000368:Aged; D002292:Carcinoma, Renal Cell / Q000473:pathology* / Q000601:surgery*; D005629:Frozen Sections; D006801:Humans; D007680:Kidney Neoplasms / Q000473:pathology* / Q000601:surgery*; D008875:Middle Aged; D009392:Nephrectomy; D011446:Prospective Studies