title: Differences in peritumoral pseudocapsule characteristics according to clinicopathological factors in clinical T1a renal tumors.
abstract: OBJECTIVE
  To evaluate the status of peritumoral pseudocapsules in renal tumors and the effects of clinicopathological factors on their formation.
  
  
  METHODS
  From January 2011 to December 2012, 258 patients with solitary clinical stage T1a renal tumors who underwent partial nephrectomy were analyzed. Status of pseudocapsule was re-evaluated by a pathologist.
  
  
  RESULTS
  The mean long diameter (± SD) of the tumor and the width of the safety margin were 2.17 (± 0.94) cm and 3.2 (± 2.4) mm, respectively. A complete pseudocapsule was identified in 152 (58.9%) tumors, an incomplete pseudocapsule was identified in 69 (26.7%) tumors, and no pseudocapsule was identified in 37 (14.3%) tumors. Out of 152 tumors with complete pseudocapsules, 45 (29.6%) were confirmed to directly invade the renal parenchyma. In a multivariable analysis, age (odds ratio [OR], 1.045; 95% confidence interval [CI], 1.021-1.070, P < 0.001) and histologic subtype (chromophobe type: OR, 19.455; 95% CI, 4.233-89.471, P < 0.001; oncocytoma: OR, 11.307; 95% CI, 1.357-94.198, P = 0.025) were significant factors for an incomplete or absent pseudocapsule.
  
  
  CONCLUSIONS
  Peritumoral pseudocapsules are absent or incomplete in a significant portion of renal tumors. Old age as well as chromophobe and oncocytoma histologic subtypes were significant risk factors for an incomplete or absent peritumoral pseudocapsule.
authors.affiliation: Department of Urology, Asan Medical Center Seoul, Republic of Korea.
authors.forename: Myong
authors.initials: M
authors.lastname: Kim
authors.affiliation: Department of Urology, Seoul National University Hospital Seoul, Republic of Korea.
authors.forename: Woo Suk
authors.initials: WS
authors.lastname: Choi
authors.affiliation: Department of Urology, Seoul National University Hospital Seoul, Republic of Korea.
authors.forename: Chang Wook
authors.initials: CW
authors.lastname: Jeong
authors.affiliation: Department of Urology, Seoul National University Hospital Seoul, Republic of Korea.
authors.forename: Ja Hyeon
authors.initials: JH
authors.lastname: Ku
authors.affiliation: Department of Urology, Seoul National University Hospital Seoul, Republic of Korea.
authors.forename: Hyeon Hoe
authors.initials: HH
authors.lastname: Kim
authors.affiliation: Department of Pathology, Seoul National University Hospital Seoul, Republic of Korea.
authors.forename: Kyung Chul
authors.initials: KC
authors.lastname: Moon
authors.affiliation: Department of Urology, Seoul National University Hospital Seoul, Republic of Korea.
authors.forename: Cheol
authors.initials: C
authors.lastname: Kwak
mesh_terms: D018249:Adenoma, Oxyphilic / Q000473:pathology* / Q000601:surgery; D000328:Adult; D000367:Age Factors; D000368:Aged; D002292:Carcinoma, Renal Cell / Q000473:pathology* / Q000601:surgery; D016009:Chi-Square Distribution; D005260:Female; D006801:Humans; D007680:Kidney Neoplasms / Q000473:pathology* / Q000601:surgery; D010535:Laparoscopy; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging; D018365:Neoplasm, Residual; D009392:Nephrectomy / Q000379:methods; D016017:Odds Ratio; D012189:Retrospective Studies; D012307:Risk Factors; D047368:Tumor Burden
keywords: Renal tumor; partial nephrectomy; pathologic finding; peritumoral pseudocapsule; surgical margin