Radiographic and clinical characterization of false negative results from CT-guided needle biopsies of lung nodules.
BACKGROUND
Computed tomography-guided transthoracic fine-needle aspiration (FNA) is a highly sensitive technique for diagnosing malignancy in pulmonary nodules; however, there is great uncertainty regarding the reliability of a benign result. The goal of this study was to characterize the clinical, radiologic, and technical variables associated with a false negative result.


METHODS
We performed a consecutive series review of patients who had an initial benign result from an FNA between January 2002 and December 2004. Medical charts were reviewed to identify patients with false negative and true negative results and determine which variables were associated with a missed diagnosis.


RESULTS
One hundred and seventy patients underwent an FNA biopsy yielding an initial benign result and had adequate clinical follow-up. Eighteen of these proved to be false negatives and 152 were true negative. Compared with the patients with true negatives, those with false negative results had significantly larger nodules (mean, 27 mm versus 17 mm, p = 0.04), fewer imaging adjustments per needle pass (4.5 versus 6.4, p = 0.01), a higher proportion in whom the needle tip was not documented within the lesion (24% versus 5%, p =0.04), and a higher pneumothorax rate at any point during the procedure (50% versus 22%, p =0.04). When these variables were considered jointly, pneumothorax (p = 0.006), solitary nodule (p = 0.04), and the radiologist who performed the procedure (p = 0.04) were significant predictors of false negative results.


CONCLUSIONS
Factors that were associated with false negative results include increased size of lesion, fewer adjustments of the needle, lack of positive cultures, and the occurrence of a pneumothorax. A benign FNA biopsy result should have the procedure reviewed to ensure the results are reliable.
Division of Pulmonary and Critical Care Medicine, Weill Cornell Medical College, New York, NY, USA. brg9001@med.cornell.edu
Brian D
BD
Gelbman
Mathew D
MD
Cham
Won
W
Kim
Daniel M
DM
Libby
James P
JP
Smith
Jeffrey L
JL
Port
Nasser K
NK
Altorki
Claudia I
CI
Henschke
David F
DF
Yankelevitz
D000230:Adenocarcinoma / Q000000981:diagnostic imaging / Q000473:pathology; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001707:Biopsy, Needle; D002289:Carcinoma, Non-Small-Cell Lung / Q000000981:diagnostic imaging / Q000473:pathology*; D002294:Carcinoma, Squamous Cell / Q000000981:diagnostic imaging / Q000473:pathology; D005069:Evaluation Studies as Topic; D005188:False Negative Reactions; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008175:Lung Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology*; D008223:Lymphoma / Q000000981:diagnostic imaging / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011030:Pneumothorax / Q000000981:diagnostic imaging / Q000473:pathology; D011379:Prognosis; D015203:Reproducibility of Results; D012189:Retrospective Studies; D003074:Solitary Pulmonary Nodule / Q000000981:diagnostic imaging / Q000473:pathology*; D014057:Tomography, X-Ray Computed; D055815:Young Adult