Evaluation of cultures of percutaneous core needle biopsy specimens in the diagnosis of pulmonary nodules.

The value of cultures of tissue obtained by image-directed core needle biopsy of lung nodules has not been determined. Of the 250 biopsies performed during a 5-year period in an area endemic for coccidioidomycosis, 225 (90%) were diagnostic. Granulomas were identified in 75 specimens, whereas 3 specimens revealed abscess. Ziehl-Neelsen stain was positive for acid-fast bacilli (AFB) in 2 cases. Spherules of Coccidioides immitis were seen in 54 of the biopsy specimens with granulomas. Microbiologic cultures were positive for C immitis in 5 (9.6%) of 52 biopsy specimens. Both of the AFB-positive cases were negative by culture. Organisms were demonstrated in cases with abscess; however, the cultures submitted in 2 cases were negative. Cultures were uniformly negative in cases where special stains failed to reveal organisms. Cultures of core needle biopsy specimens are insensitive in the detection of specific microorganisms and need not be routinely performed.