title: Nephron-sparing surgery in the treatment of pediatric renal cell carcinoma associated with Xp11.2 translocation/TFE3 gene fusions.
abstract: OBJECTIVE
  To investigate the safety and efficacy of nephron-sparing surgery (NSS) in the treatment of pediatric Xp11.2 translocation renal cell carcinoma (RCC).
  
  
  METHODS
  Clinical characteristics of 9 RCC children (7 males and 2 females) with Xp11.2 translocation who received NSS between January 1973 and December 2015 were retrospectively analyzed. The mean age was 7.8years (range: 4.5-13.5years). Xp11.2 translocation RCC was found in the left side in 4 patients and right in 5. 3 tumors were located in the upper pole of the kidney, 1 in the middle dorsal, 1 in the middle ventral and 4 in the lower pole. RCC presented with painless gross hematuria in 4 patients, abdominal mass in 1, and as an incidental finding by ultrasound examination in 4 patients. The mean course of hematuria was 3months (range: 1-7months). The mean tumor diameters were 3.7cm (range: 2.2-6.9cm).
  
  
  RESULTS
  All the patients received NSS with open transperitoneal approach. The mean operative time and estimated blood loss were 115min and 40ml, respectively. The time of renal pedicle clamping was 19-25min (mean: 21.5min). No complications (such as leakage of urine, prolonged drainage or secondary bleeding) were noted. No patients experienced local recurrence during the mean of 50.1-month follow-up (range: 13-117months). Intravenous urography (IVU) or contrast-enhanced CT was conducted at 6months after surgery which showed favorable kidney function in all patients.
  
  
  CONCLUSIONS
  Xp11.2 translocation RCC is a predominant pathological but biologically inert type of pediatric RCC. For Xp11.2 translocation RCC sized <4-7cm in diameter and located in one pole, NSS is safe and feasible.
  
  
  METHODS
  Treatment Studies, LEVEL IV.
authors.affiliation: Beijing Children's Hospital Affiliated to Capital Medical University, Beijing 100045, China.
authors.forename: Chao
authors.initials: C
authors.lastname: Liu
authors.affiliation: Beijing Children's Hospital Affiliated to Capital Medical University, Beijing 100045, China. Electronic address: 241551704@qq.com.
authors.forename: Weiping
authors.initials: W
authors.lastname: Zhang
authors.affiliation: Beijing Children's Hospital Affiliated to Capital Medical University, Beijing 100045, China. Electronic address: 602585683@qq.com.
authors.forename: Hongcheng
authors.initials: H
authors.lastname: Song
mesh_terms: D000293:Adolescent; D051778:Basic Helix-Loop-Helix Leucine Zipper Transcription Factors / Q000235:genetics; D002292:Carcinoma, Renal Cell / Q000235:genetics / Q000473:pathology / Q000601:surgery*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007680:Kidney Neoplasms / Q000235:genetics / Q000473:pathology / Q000601:surgery*; D008297:Male; D009392:Nephrectomy / Q000379:methods*; D009399:Nephrons / Q000601:surgery; D061646:Operative Time; D059351:Organ Sparing Treatments / Q000379:methods*
chemical_list: D051778:Basic Helix-Loop-Helix Leucine Zipper Transcription Factors
keywords: Children; Nephron-sparing surgery; Renal cell carcinoma; TFE3 gene fusion; Xp11.2 translocation