Iatrogenic Fibroepithelial Polyps in Children With Hydronephrosis.

OBJECTIVE: To discover the possible factor of the iatrogenic fibroepithelial polyps (FEPs).

MATERIALS AND 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.

CONCLUSION: 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.