title: Iatrogenic Fibroepithelial Polyps in Children With Hydronephrosis.
abstract: OBJECTIVE
  To discover the possible factor of the iatrogenic fibroepithelial polyps (FEPs).
  
  
  METHODS
  A retrospective chart review of 28 pediatric patients who have undergone pyeloplasties for ureteropelvic junction obstruction with pathologically proven FEPs was performed from January 2009 to June 2016 at our hospital. Among them, 6 patients without apparent FEPs at the time of the first pyeloplasty were found to have FEPs at the time of reoperation. The medical history and clinical, diagnostic, intraoperative, pathologic, and follow-up data of the 6 patients were reviewed.
  
  
  RESULTS
  All iatrogenic FEPs were located proximal to the anastomotic stoma. On pathological examination, the size of the FEPs ranged from 1.5 to 3.5 cm. The FEPs were pink, grayish-white, or tan-gray in color and cauliflower-like in shape. Microscopically, they arose from the submucosa and consisted of a layer of normal transitional epithelium covering a fibrovascular stromal core showing sparse vascularity and prominent edema. The mean follow-up period was 47 months (range, 4-82 months). All patients' symptoms disappeared and the function of the affected kidney was preserved after the second pyeloplasty. No patients developed FEP recurrence.
  
  
  CONCLUSIONS
  Nephrostomy may associate with iatrogenic FEPs in young children. Iatrogenic FEPs are a specific type of polyp that grows rapidly within a very short time. Pathologically, iatrogenic FEPs are the same as other types of FEPs.
authors.affiliation: Department of Pediatric Urology, Shanghai Xinhua Hospital, Shanghai, China.
authors.forename: Houwei
authors.initials: H
authors.lastname: Lin
authors.affiliation: Department of Pediatric Urology, Shanghai Xinhua Hospital, Shanghai, China.
authors.forename: Maosheng
authors.initials: M
authors.lastname: Xu
authors.affiliation: Department of Pediatric Urology, Shanghai Xinhua Hospital, Shanghai, China.
authors.forename: Dapeng
authors.initials: D
authors.lastname: Jiang
authors.affiliation: Department of Pediatric Urology, Shanghai Xinhua Hospital, Shanghai, China.
authors.forename: Guofeng
authors.initials: G
authors.lastname: Xu
authors.affiliation: Department of Pediatric Urology, Shanghai Xinhua Hospital, Shanghai, China.
authors.forename: Xiaoliang
authors.initials: X
authors.lastname: Fang
authors.affiliation: Department of Pediatric Urology, Shanghai Xinhua Hospital, Shanghai, China.
authors.forename: Lei
authors.initials: L
authors.lastname: He
authors.affiliation: Department of Pediatric Urology, Shanghai Xinhua Hospital, Shanghai, China. Electronic address: ghongquan@hotmail.com.
authors.forename: Hongquan
authors.initials: H
authors.lastname: Geng
mesh_terms: D005260:Female; D005500:Follow-Up Studies; D005549:Foreign-Body Reaction; D006801:Humans; D006869:Hydronephrosis / Q000150:complications / Q000175:diagnosis*; D007049:Iatrogenic Disease; D007223:Infant; D007231:Infant, Newborn; D007239:Infections; D007682:Kidney Pelvis / Q000601:surgery; D008297:Male; D000074643:Nephrotomy; D011127:Polyps / Q000150:complications / Q000175:diagnosis*; D012189:Retrospective Studies; D014513:Ureter / Q000601:surgery; D014517:Ureteral Obstruction / Q000601:surgery