title: Retroperitoneal laparoscopic partial nephrectomy for treatment of metanephric adenoma (Report of 6 cases).
abstract: OBJECTIVE
  To investigate the clinical and pathological features of metanephric adenoma (MA) and the clinical outcome after retroperitoneal laparoscopic nephron-sparing surgery.
  
  
  METHODS
  Six out of 183 partial nephrectomies performed during January 2009 to August 2014 were confirmed to be MA confirmed by postoperative pathological study. Perioperative parameters of the six patients were then retrospectively collected, analyzed and compared with current literature, including warm ischemia time (WIT), total operation time, estimated blood loss (EBL), positive surgical margin (PSM), and complications. Surgical and oncological outcome of all six patients were evaluated based on a mean follow up of 17 months (5-48 months).
  
  
  RESULTS
  Tumors in all six cases were all successfully removed by partial nephrectomy. Mean WIT was 24.7 min (19-35 min). Mean operation time was 103.6 min (82-147 min). Mean EBL was 53.5 ml (20-85 ml). No conversion, transfusion or other major complication were observed in all six cases. Postoperative pathology confirmed negative surgical margin in all six cases. During a mean of 17 month follow up (5-48 months), no local recurrence or metastasis were found in all six cases.
  
  
  CONCLUSIONS
  MA is a rare benign primary kidney epithelial cancer, which could hardly be differentiated from renal malignancies based on preoperative imaging. Our data suggested that retroperitoneal laparoscopic partial nephrectomy can be used for surgical treatment of MA, in terms of tumor control and preservation of renal function.
authors.affiliation: Institute of Urology, First Affiliated Hospital of Nanchang University, Nanchang, China.
authors.forename: Ju
authors.initials: J
authors.lastname: Guo
authors.affiliation: Institute of Urology, First Affiliated Hospital of Nanchang University, Nanchang, China.
authors.forename: Xiaochen
authors.initials: X
authors.lastname: Zhou
authors.affiliation: Institute of Urology, First Affiliated Hospital of Nanchang University, Nanchang, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Fu
authors.affiliation: Institute of Urology, First Affiliated Hospital of Nanchang University, Nanchang, China.
authors.forename: Runfu
authors.initials: R
authors.lastname: Cao
authors.affiliation: Institute of Urology, First Affiliated Hospital of Nanchang University, Nanchang, China.
authors.forename: Weipeng
authors.initials: W
authors.lastname: Liu
authors.affiliation: Institute of Urology, First Affiliated Hospital of Nanchang University, Nanchang, China.
authors.forename: Gongxian
authors.initials: G
authors.lastname: Wang
keywords: Laparoscopic partial nephrectomy; Metanephric adenoma; Retroperitoneal