title: Partial and hemi-nephrectomy for renal malignancy in patients with horseshoe kidney.
abstract: BACKGROUND
  Horseshoe kidney is the most common congenital renal fusion anomaly, with an estimated incidence of 1.7 to 2.5 cases per 1000 live births. In these patients, nephron-sparing surgical management of renal tumors may be complicated by abnormal renal location, aberrant vasculature, and the presence of a renal isthmus. We present the largest known series of patients with renal malignancy in horseshoe kidneys managed by partial or hemi-nephrectomy with associated outcomes.
  
  
  METHODS
  A retrospective review of our institution's electronic medical record was conducted to identify consecutive cases over an 11 year period. Pediatric patients and those who underwent surgery for benign indications were excluded from analysis.
  
  
  RESULTS
  Eight patients with horseshoe kidney who underwent partial or hemi-nephrectomy for renal malignancy were identified. Median tumor size was 6.0 cm (IQR 3.7 cm-9.5 cm). Six patients had clear cell renal cell carcinoma (RCC), 1 patient had papillary RCC, and 1 patient had a renal carcinoid tumor with concurrent adenocarcinoma. Median length of stay was 4 days (IQR 2-.5.5 days). Median perioperative change in eGFR was -6 mL/min/1.73² (IQR -2.6-8.6 mL/min/1.73m²). One patient developed postoperative urine leak requiring percutaneous drainage and ureteral stent placement. Median follow up was 38.5 months, with a cancer-specific survival of 87.5% and an overall survival of 62.5%.
  
  
  CONCLUSIONS
  Partial and hemi-nephrectomy for renal malignancy can safely be performed in patients with horseshoe kidney with acceptable operative and oncologic outcomes.
authors.affiliation: Department of Urology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.
authors.forename: Todd
authors.initials: T
authors.lastname: Yecies
authors.forename: Robert M
authors.initials: RM
authors.lastname: Turner Іi
authors.forename: Matthew C
authors.initials: MC
authors.lastname: Ferroni
authors.forename: Bruce L
authors.initials: BL
authors.lastname: Jacobs
authors.forename: Benjamin J
authors.initials: BJ
authors.lastname: Davies
mesh_terms: D000069337:Fused Kidney / Q000150:complications / Q000601:surgery*; D006801:Humans; D007680:Kidney Neoplasms / Q000150:complications / Q000473:pathology / Q000601:surgery*; D009392:Nephrectomy; D012189:Retrospective Studies