title: Pseudocapsule of renal cell carcinoma associated with Xp11.2 translocation/TFE3 gene fusion: a clue for tumor enucleation?
abstract: OBJECTIVE
  To evaluate the feasibility and efficacy of tumor enucleation (TE) for patients with small renal cell carcinoma (RCC) associated with Xp11.2 translocation/TFE3 gene fusion (Xp11.2 RCC) by analyzing the pseudocapsule characteristics of Xp11.2 RCCs comparing with that of clear cell renal cell carcinoma (ccRCC).
  
  
  METHODS
  From June 2007 to February 2014, 22 patients with Xp11.2 RCC who were diagnosed by fluorescence in-situ hybridization polyclonal (FISH) assay and 32 patients with ccRCC treated in our institution were comparatively studied. 12 patients with ccRCC underwent radical nephrectomy (RN) and 20 received TE. Among 22 patients with Xp11.2 RCC, 19 were treated by RN and 3 by TE (1 by radiofrequency ablation assisted TE). Pseudocapsule and other clinicopathological characteristics of the two subtypes of RCC were compared. Survival of patients treated with different surgical methods was evaluated and compared.
  
  
  RESULTS
  Pseudocapsule incidence of Xp11.2 RCC (14/22, 63.6%) was lower than that of ccRCC (32/32, 100%, P<0.001). However, pseudocapsule integrity rate of Xp11.2 RCC (10/14, 71.4%) was comparable with that of ccRCC (23/32, 71.9%, P=1.000). The 5-year overall survival of patients with ccRCC treated with RN and TE was 86% and 81%, respectively (P=0.845). Three patients with small Xp11.2 RCC performed well after TE.
  
  
  CONCLUSIONS
  Over half Xp11.2 RCC had pseudocapsules, whose integrity rate was comparable to that of ccRCC. Treatment effectives of TE and RN were comparable in ccRCC. A preliminary attempt to treat small Xp11.2 RCC with intact pseudocapsule by using TE produced a favorable treatment outcome.
authors.affiliation: Department of Urology, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School No. 321 Zhongshan Road, Nanjing, Jiangsu Province, China.
authors.forename: Xiangming
authors.initials: X
authors.lastname: Cheng
authors.affiliation: Department of Radiology, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School No. 321 Zhongshan Road, Nanjing, Jiangsu Province, China.
authors.forename: Jian
authors.initials: J
authors.lastname: He
authors.affiliation: Department of Urology, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School No. 321 Zhongshan Road, Nanjing, Jiangsu Province, China.
authors.forename: Weidong
authors.initials: W
authors.lastname: Gan
authors.affiliation: Department of Pathology, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School No. 321 Zhongshan Road, Nanjing, Jiangsu Province, China.
authors.forename: Xiangshan
authors.initials: X
authors.lastname: Fan
authors.affiliation: Department of Pathology, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School No. 321 Zhongshan Road, Nanjing, Jiangsu Province, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Yang
authors.affiliation: Department of Radiology, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School No. 321 Zhongshan Road, Nanjing, Jiangsu Province, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Zhu
authors.affiliation: Department of Urology, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School No. 321 Zhongshan Road, Nanjing, Jiangsu Province, China.
authors.forename: Hongqian
authors.initials: H
authors.lastname: Guo
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D051778:Basic Helix-Loop-Helix Leucine Zipper Transcription Factors / Q000235:genetics*; D002292:Carcinoma, Renal Cell / Q000235:genetics* / Q000473:pathology; D002648:Child; D002675:Child, Preschool; D041321:Chromosomes, Human, X; D005260:Female; D006801:Humans; D007680:Kidney Neoplasms / Q000235:genetics* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D050596:Oncogene Fusion; D014178:Translocation, Genetic; D055815:Young Adult
chemical_list: D051778:Basic Helix-Loop-Helix Leucine Zipper Transcription Factors; C069203:TFE3 protein, human
keywords: Carcinoma; Xp11.2 translocation; pseudocapsule; renal cell; treatment outcome; tumor enucleation