title: Evidence based management of polyps of the gall bladder: A systematic review of the risk factors of malignancy.
abstract: BACKGROUND
  There are no evidence-based guidelines to dictate when Gallbladder Polyps (GBPs) of varying sizes should be resected.
  
  
  OBJECTIVE
  To identify factors that accurately predict malignant disease in GBP; to provide an evidence-based algorithm for management.
  
  
  METHODS
  A systematic review following PRISMA guidelines was performed using terms "gallbladder polyps" AND "polypoid lesion of gallbladder", from January 1993 and September 2013. Inclusion criteria required histopathological report or follow-up of 2 years. RTI-IB tool was used for quality analysis. Correlation with GBP size and malignant potential was analysed using Euclidean distance; a logistics mixed effects model was used for assessing independent risk factors for malignancy.
  
  
  RESULTS
  Fifty-three articles were included in review. Data from 21 studies was pooled for analysis. Optimum size cut-off for resection of GBPs was 10 mm. Probability of malignancy is approximately zero at size <4.15 mm. Patient age >50 years, sessile and single polyps were independent risk factors for malignancy. For polyps sized 4 mm-10 mm, a risk assessment model was formulated.
  
  
  CONCLUSIONS
  This review and analysis has provided an evidence-based algorithm for the management of GBPs. Longitudinal studies are needed to better understand the behaviour of polyps <10 mm, that are not at a high risk of malignancy, but may change over time.
authors.affiliation: Department of Surgery, University of Dublin, Trinity College, at the Adelaide and Meath Hospital, Tallaght, Dublin, Ireland.
authors.forename: Nikita R
authors.initials: NR
authors.lastname: Bhatt
authors.affiliation: Department of Surgery, University of Dublin, Trinity College, at the Adelaide and Meath Hospital, Tallaght, Dublin, Ireland.
authors.forename: Amy
authors.initials: A
authors.lastname: Gillis
authors.affiliation: School of Mechanical and Materials Engineering, University College Dublin, Ireland.
authors.forename: Craig O
authors.initials: CO
authors.lastname: Smoothey
authors.affiliation: Department of Hepatobiliary Surgery, St. Vincent's University Hospital, Dublin, Ireland.
authors.forename: Faisal N
authors.initials: FN
authors.lastname: Awan
authors.affiliation: Department of Surgery, University of Dublin, Trinity College, at the Adelaide and Meath Hospital, Tallaght, Dublin, Ireland. Electronic address: ridgwayp@tcd.ie.
authors.forename: Paul F
authors.initials: PF
authors.lastname: Ridgway
mesh_terms: D000367:Age Factors; D000465:Algorithms; D002763:Cholecystectomy; D003937:Diagnosis, Differential; D018450:Disease Progression; D019317:Evidence-Based Medicine; D005705:Gallbladder Diseases / Q000175:diagnosis / Q000601:surgery*; D017408:Guidelines as Topic; D006801:Humans; D011127:Polyps / Q000175:diagnosis / Q000601:surgery*; D011230:Precancerous Conditions; D018570:Risk Assessment; D012307:Risk Factors; D016896:Treatment Outcome
keywords: Gallbladder; Malignant; Polyp(s); Size; Systematic review