title: Abdominal and pelvic needle aspiration biopsies: can we perform them well when using small needles?
abstract: BACKGROUND
  The aim of this study was to compare abdominal fine-needle aspirations (FNAs) performed with large (>/=20-gauge) or small (</=21-gauge) needles for diagnostic rate, number of samples required for diagnosis, diagnostic accuracy, and complication rates.
  
  
  METHODS
  Abdominal and pelvic FNA procedures were retrospectively reviewed. Needle size, imaging guidance used, number of pathology slides created, complications, and cytologic and final diagnoses were obtained by reviewing radiologic, medical, and cytology records.
  
  
  RESULTS
  Two hundred ninety procedures were included in the study. Two hundred fifty-seven were performed in patients having only one biopsy during the study interval. Of these, 159 had biopsies using small needles and 98 using large needles. Small needle biopsies had as high a diagnostic rate as did large needle biopsies (97.5% vs. 92. 9%, p = 0.11). Small and large needle biopsies showed high diagnostic accuracy (96.1 and 98.9%, respectively; p = 0.27). Incorrect cytologic diagnoses plus nondiagnostic examinations composed 6.3% of biopsies using small needles and 8.2% of biopsies using larger needles (p = 0.62). Complication rates were low. Average number of needle passes tended to be lower when small needles were used.
  
  
  CONCLUSIONS
  Small needles can be successfully used for abdominal and pelvic FNAs. Small needles require the same or fewer needle passes, have low risk, have the same or improved ability to obtain diagnostic material, and achieve correct diagnoses compared with larger needles.
authors.affiliation: Department of Radiology, Indiana University Hospital, 550 North University Boulevard, Indianapolis, IN 46202-5253, USA,
authors.forename: S M
authors.initials: SM
authors.lastname: Stockberger
authors.forename: W T
authors.initials: WT
authors.lastname: Ambrosius
authors.forename: M G
authors.initials: MG
authors.lastname: Khamis
authors.forename: K A
authors.initials: KA
authors.lastname: Bergan
authors.forename: C L
authors.initials: CL
authors.lastname: Younger
authors.forename: D D
authors.initials: DD
authors.lastname: Davidson
mesh_terms: D000005:Abdomen / Q000473:pathology*; D001707:Biopsy, Needle / Q000009:adverse effects / Q000295:instrumentation / Q000592:standards*; D003951:Diagnostic Errors / Q000706:statistics & numerical data; D006801:Humans; D009339:Needles; D010388:Pelvis / Q000473:pathology*; D012189:Retrospective Studies; D018709:Statistics, Nonparametric