title: A prospective, multicenter analysis of pseudocapsule characteristics: Do all stages of renal cell carcinoma have complete pseudocapsules?
abstract: To assess the characteristics of pseudocapsule (PC) in localized renal cell carcinoma (RCC) by analyzing the rates of completeness of PC and pseudocapsular invasion and clinical and pathological risk factors of it.
  
  
  
  Between February 2013 and September 2015, data were gathered prospectively from 180 consecutive patients who underwent partial nephrectomy or radical nephrectomy at 3 institutions, and 161 were enrolled. Evaluated factors included age and sex; histologic factors such as tumor diameter, stage, tumor subtype, necrosis, and Fuhrman grade; and clinical factors such as RENAL score; and completeness of PC.
  
  
  
  Only 94 tumors (58.4%) were surrounded by a continuous PC completely, 62 (38.5%) were partially surrounded, and 5 (3.1%) had no PC. Overall, 56 PCs (34.8%) were free from invasion, 58 PCs (36.0%) had partial invasion of PC without parenchymal invasion, and 47 PCs (29.2%) had parenchymal invasion. Defining parenchymal invasion as true pseudocapsular invasion, histologic diameter, RCC subtype, and completeness of PC were significant predictors for parenchymal invasion on multivariate analysis (P = 0.006, 0.046, and 0.002, respectively).
  
  
  
  Rate of complete PC in RCC is relatively low in this study. The risk factors for pseudocapsular invasion were a histologic diameter greater than 4cm, non-clear cell histology, and an incomplete PC. Surgeons must prepare for the possibility of a positive surgical margin if a tumor has at least one of these risk factors.
authors.affiliation: Department of Urology, Korea University School of Medicine, Seoul, Republic of Korea.
authors.forename: Seok
authors.initials: S
authors.lastname: Cho
authors.affiliation: Department of Pathology, Korea University School of Medicine, Seoul, Republic of Korea.
authors.forename: Jeong Hyeon
authors.initials: JH
authors.lastname: Lee
authors.affiliation: Department of Urology, Kyung Hee University School of Medicine, Seoul, Republic of Korea.
authors.forename: Seung Hyun
authors.initials: SH
authors.lastname: Jeon
authors.affiliation: Department of Urology, Eulji University Hospital, Eulji University School of Medicine, Daejeon, Republic of Korea.
authors.forename: Jinsung
authors.initials: J
authors.lastname: Park
authors.affiliation: Department of Urology, Kyung Hee University School of Medicine, Seoul, Republic of Korea.
authors.forename: Sang Hyub
authors.initials: SH
authors.lastname: Lee
authors.affiliation: Department of Pathology, Korea University School of Medicine, Seoul, Republic of Korea.
authors.forename: Chul Hwan
authors.initials: CH
authors.lastname: Kim
authors.affiliation: Department of Pathology, Kyung Hee University School of Medicine, Seoul, Republic of Korea.
authors.forename: Ji-Youn
authors.initials: JY
authors.lastname: Sung
authors.affiliation: Department of Pathology, Eulji University Hospital, Eulji University School of Medicine, Daejeon, Republic of Korea.
authors.forename: Joo Heon
authors.initials: JH
authors.lastname: Kim
authors.affiliation: Department of Urology, Korea University School of Medicine, Seoul, Republic of Korea.
authors.forename: Jong Hyun
authors.initials: JH
authors.lastname: Pyun
authors.affiliation: Department of Urology, Korea University School of Medicine, Seoul, Republic of Korea.
authors.forename: Jeong Gu
authors.initials: JG
authors.lastname: Lee
authors.affiliation: Department of Urology, Korea University School of Medicine, Seoul, Republic of Korea.
authors.forename: Je Jong
authors.initials: JJ
authors.lastname: Kim
authors.affiliation: Department of Urology, Korea University School of Medicine, Seoul, Republic of Korea.
authors.forename: Jun
authors.initials: J
authors.lastname: Cheon
authors.affiliation: Department of Urology, Korea University School of Medicine, Seoul, Republic of Korea.
authors.forename: Sung Gu
authors.initials: SG
authors.lastname: Kang
authors.affiliation: Department of Urology, Korea University School of Medicine, Seoul, Republic of Korea. Electronic address: mdksh@korea.ac.kr.
authors.forename: Seok Ho
authors.initials: SH
authors.lastname: Kang
mesh_terms: D000368:Aged; D002292:Carcinoma, Renal Cell / Q000473:pathology*; D005260:Female; D006801:Humans; D007680:Kidney Neoplasms / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D009392:Nephrectomy / Q000379:methods*; D011446:Prospective Studies
keywords: Kidney neoplasms; Partial nephrectomy; Pseudocapsule