title: Tru-cut biopsy as the initial method of tissue diagnosis in bone tumors with soft tissue extension.
abstract: BACKGROUND
  Tru-cut biopsy in suspected bone tumors can be performed even in less specialized centers. Tru-cut biopsy has been proved as safe with more than 90% accuracy. However, its usefulness was not widely studied in general hospitals where Tru-cut biopsy is performed by orthopedic surgeons. This study was conducted to find out the accuracy and adequacy of Tru-cut biopsy performed by an orthopedic surgeon not trained in musculoskeletal oncology, in a general hospital.
  
  
  METHODS
  A study was conducted through a prospectively collected database using a uniform protocol. All patients who had a malignant appearing bone lesion with a palpable soft tissue mass were included in the current study. Fifty such consecutive cases underwent Tru-Cut biopsy by orthopedic residents or registrars who were aware of the principles of Tru-cut biopsy and the recommendations of Musculoskeletal Tumor Society. When an open biopsy or a resection of the tumor was subsequently performed, the histological diagnosis was compared for accuracy with the diagnosis of needle biopsy. We evaluated adequacy of sample obtained and accuracy of diagnosis in terms of sensitivity, specificity, positive predictive value, and negative predictive value.
  
  
  RESULTS
  Seventy seven cases were initially enrolled. Out of which 18 were excluded and 59 patients were biopsied. Out of which 50 were analysed. Only 4 out of 50 biopsied specimens were inadequate resulting in an adequacy rate of 92%. Among 46 cases, which were analyzed for diagnostic accuracy, 84.78% had true-positive result, 8.69% had true negative, and 6.52% had false-negative report. The sensitivity and specificity of Tru-cut biopsy in our series was 92.85% and 100%, respectively, with positive predictive value of 100% and negative predictive value of 57.14%.
  
  
  CONCLUSIONS
  Tru-cut biopsy can be recommended as an initial method of tissue diagnosis in musculoskeletal tumors with soft tissue extension.
authors.affiliation: Department of Orthopedics, Shree Birendra Hospital, Chhauni, Kathmandu, Nepal.
authors.forename: Amit
authors.initials: A
authors.lastname: Joshi
authors.forename: Sushil Rana
authors.initials: SR
authors.lastname: Magar
authors.forename: Pankaj
authors.initials: P
authors.lastname: Chand
authors.forename: Rajesh
authors.initials: R
authors.lastname: Panth
authors.forename: Bachchu Ram
authors.initials: BR
authors.lastname: Khatri Chhetri
keywords: Diagnostic accuracy; musculoskeletal tumors; tru-cut biopsy