title: Outcomes and complications related to the management of Bosniak cystic renal lesions.
abstract: OBJECTIVE
  The objective of our study was to evaluate outcomes and complications related to the management of Bosniak category IIF, III, and IV renal cysts.
  
  
  METHODS
  For this multiinstitutional retrospective study, a Web-based Research Electronic Data Capture (REDCap) data registry was used to record data of 286 adult patients with 312 prospectively classified Bosniak IIF, III, and IV renal cysts diagnosed between January 2000 and October 2011. Included patients were managed by surgery (n = 86), percutaneous ablation (n = 19), or imaging surveillance of 1 year or more (n = 181). The median number of years of clinical surveillance was 2.4 years (range, 0-11.7 years), 2.6 years (range, 0.4-11.4 years), and 3.2 years (range, 1.1-11.6 years) for patients managed by surgery, ablation, and imaging surveillance, respectively. Pathologic and survival outcomes and complications related to management were evaluated.
  
  
  RESULTS
  The malignancy rate at surgical pathology was 38% (3/8) for Bosniak IIF, 40% (29/72) for Bosniak III, and 90% (18/20) for Bosniak IV renal cysts. There were no metastases or deaths (0/144) directly related to Bosniak IIF renal cysts. There were no deaths (0/113) directly related to Bosniak III renal cysts, although one patient (1/113) developed local progression and lung metastases after thermal ablation. One patient with a Bosniak IV renal cyst (1/29) presented with and died of metastatic disease. Moderate to severe complications occurred in 19% (16/86), 5% (1/19), and 0% (0/181) of patients managed by surgery, ablation, and imaging surveillance, respectively (p < 0.0001). Severe complications occurred in 7% (6/86) of surgical patients and included multiorgan failure (n = 2), acute myocardial infarction (n = 1), acute ischemic stroke (n = 1), conversion to hemodialysis-dependent chronic kidney disease (n = 1), and postoperative severe hemorrhage (n = 1).
  
  
  CONCLUSIONS
  There were no deaths from Bosniak IIF or III renal cysts regardless of management approach. Moderate to severe complications are frequent in patients managed by surgery.
authors.affiliation: 1 Department of Radiology, University of Mississippi Medical Center, 2500 N State St, Jackson, MS 39216.
authors.forename: Andrew Dennis
authors.initials: AD
authors.lastname: Smith
authors.forename: Brian C
authors.initials: BC
authors.lastname: Allen
authors.forename: Rupan
authors.initials: R
authors.lastname: Sanyal
authors.forename: James Daniel
authors.initials: JD
authors.lastname: Carson
authors.forename: Haowei
authors.initials: H
authors.lastname: Zhang
authors.forename: Jason Henry
authors.initials: JH
authors.lastname: Williams
authors.forename: Clinton
authors.initials: C
authors.lastname: Collins
authors.forename: Michael
authors.initials: M
authors.lastname: Griswold
authors.forename: Xu
authors.initials: X
authors.lastname: Zhang
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003952:Diagnostic Imaging; D005260:Female; D006801:Humans; D052177:Kidney Diseases, Cystic / Q000150:complications* / Q000473:pathology / Q000628:therapy*; D007680:Kidney Neoplasms / Q000150:complications* / Q000473:pathology / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D012042:Registries; D012189:Retrospective Studies; D016896:Treatment Outcome; D057832:Watchful Waiting
keywords: Bosniak; cystic renal tumors; renal cysts