title: Diagnostic value of open and needle biopsies in tumors of the sacrum.
abstract: METHODS
  A retrospective study with statistical analysis of 25 percutaneous needle biopsies and 54 open biopsies performed on 60 patients with tumors located in the sacrococcygeal region.
  
  
  OBJECTIVE
  To analyze the diagnostic value of open and needle biopsies in tumors of the sacrum as well as to determine factors leading to a false or equivocal result.
  
  
  BACKGROUND
  Although percutaneous needle biopsies of the spine are valuable for thoracolumbar levels, the benefit in the sacrococcygeal region, specifically, has not previously been shown. This region is unique because of anatomic and oncologic factors.
  
  
  METHODS
  Medical charts, imaging studies, and operative and pathologic records of patients with tumors diagnosed between 1965 and 1996 in the sacrococcygeal region reviewed were analyzed. Accuracy and effective accuracy of each procedure were then calculated.
  
  
  RESULTS
  There were 54 primary lesions (17 benign, 37 malignant) and 6 metastatic tumors. The accuracy and effective accuracy of open biopsies was 87% and 81% but in percutaneous needle biopsies was only 44% and 12%, respectively. An unclear diagnosis resulted in the need for another biopsy in 12 of 21 primary percutaneous needle biopsies but only in 2 of 39 open biopsies (P < 0.0001, chi2). The average number of biopsies required to obtain a definitive diagnosis was significantly less if an open biopsy were performed first instead of a percutaneous needle biopsy, 1.1 versus 1.8, respectively (P = 0.0004, two-sample t test). There was a significant delay in treatment if the initial biopsy was a percutaneous needle biopsy compared with an open biopsy, mean 46 versus 4 days, respectively (P = 0.004, two-sample t test).
  
  
  CONCLUSIONS
  We conclude that for sacral tumors, open biopsies have a higher effective accuracy, whereas needle biopsies are associated with a longer delay in treatment.
authors.affiliation: Department of Orthopaedic Surgery, Suleyman Demirel University, Isparta, Turkey.
authors.forename: Remzi A
authors.initials: RA
authors.lastname: Ozerdemoglu
authors.forename: Roby C
authors.initials: RC
authors.lastname: Thompson
authors.forename: Ensor E
authors.initials: EE
authors.lastname: Transfeldt
authors.forename: Edward Y
authors.initials: EY
authors.lastname: Cheng
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001706:Biopsy / Q000009:adverse effects / Q000379:methods / Q000706:statistics & numerical data*; D001707:Biopsy, Needle / Q000706:statistics & numerical data; D002648:Child; D002675:Child, Preschool; D005188:False Negative Reactions; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D012445:Sacrococcygeal Region; D012447:Sacrum / Q000473:pathology* / Q000601:surgery; D012680:Sensitivity and Specificity; D013125:Spinal Neoplasms / Q000473:pathology* / Q000601:surgery; D013997:Time Factors