title: Utility of polymerase chain reaction for detecting Mycobacterium tuberculosis in specimens from percutaneous transthoracic needle aspiration.
abstract: OBJECTIVE
  To determine the clinical utility of polymerase chain reaction (PCR) for detecting Mycobacterium tuberculosis in specimens from percutaneous transthoracic needle aspiration (PTNA).
  
  
  METHODS
  PCR for M tuberculosis detection in specimens from PTNA was performed prospectively in addition to cytologic and histologic analyses in 45 patients. On computed tomographic (CT) scans, tuberculosis (TB) versus malignant neoplasm or other infection was diagnosed in 28 patients; possible malignancy was diagnosed in 11, but TB was considered clinically because of young patient age or presence of tuberculous lesions in other areas of the lungs. In six of these patients, TB was diagnosed, but bacteriologic results were negative. PTNA was performed with a 21-gauge needle by one chest radiologist by using CT (n = 25), ultrasonographic (n = 5), or fluoroscopic guidance (n = 15). Final diagnoses were malignant neoplasm (n = 19), hamartoma (n = 1), TB (n = 17), and pneumonia (including actinomycosis and aspergillosis) (n = 8). Sensitivity, specificity, and positive predictive values of PCR in PTNA specimens for diagnosis of TB were calculated.
  
  
  RESULTS
  In 17 patients with TB, PCR results were positive in 11 and negative in six. PCR results were negative in all cases of malignant neoplasm, hamartoma, and pneumonia. Cytologic and histologic analysis of PTNA specimens resulted in a specific diagnosis of TB in two (12%) of 17 patients. By adding the PCR results, diagnosis of TB was established in 12 (71%) of 17 patients. Sensitivity, specificity, and positive and negative predictive values of PCR for diagnosis of TB in PTNA specimens were 65% (11 of 17), 100% (28 of 28), 100% (11 of 11), and 82% (28 of 34), respectively.
  
  
  CONCLUSIONS
  PCR for detection of M tuberculosis in PTNA specimens is a useful adjuvant to cytologic and histologic analysis for diagnosis of TB.
mesh_terms: D000328:Adult; D001707:Biopsy, Needle; D005471:Fluoroscopy; D006801:Humans; D008168:Lung / Q000382:microbiology* / Q000473:pathology; D008175:Lung Neoplasms / Q000175:diagnosis; D008297:Male; D009169:Mycobacterium tuberculosis / Q000302:isolation & purification*; D016133:Polymerase Chain Reaction; D011237:Predictive Value of Tests; D015641:Radiography, Interventional; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed; D014397:Tuberculosis, Pulmonary / Q000175:diagnosis* / Q000000981:diagnostic imaging; D018084:Ultrasonography, Interventional