Trans-thoracic biopsy of lung lesions: FNAB or CNB? Our experience and review of the literature.

Purpose: This study was performed to determine the type and incidence of complications of fine-needle aspiration biopsy (FNAB) and core biopsy (CNB) performed under computed tomography (CT) guidance to characterise lung lesions, and assess the diagnostic accuracy of the two techniques.

Materials And Methods: In 2009-2011, we performed 124 lung biopsies (66 CNB and 56 FNAB) on 121 patients with a mean age of 72.4 years. Exclusion criteria were pulmonary resection, pleural lesions and/or effusions, and inadequate blood-coagulation profile. All examinations were acquired after contrast-agent administration in a craniocaudal direction from the lung apex to base during a single inspiratory breath-hold, with standardised parameters. Each lesion was scanned with 13-15 slices that could be repeated whenever necessary to document the needle track and for lesion centring, by positioning a metallic marker perpendicular to the centring light to indicate the point of needle access. Unless otherwise clinically indicated, 4 h after the procedure chest radiography was performed.

Results: Age was found to be a factor influencing the complications: pneumothorax in young subjects (31 %) and parenchymal haemorrhage in the elderly (30 %), with CNB but not with FNAB. We had more complications with the right lung: 50 % of pneumothorax cases in the upper lobe with CNB and 40 % of cases of haemorrhage in the lower lobe with FNAB. The anterior approach gave rise to more complications with CNB, while the posterior approach with FNAB. CNB had more complications than FNAB for lesions ≤ 3.5 cm (31 vs. 18 % pneumothorax), and >3.5 cm (34 vs. 9 % haemorrhage). There was no significant correlation with lesion histology, needle calibre or number of passes (probably due to the small number of procedures done with needles other than 18 G in CNB or 22 G in FNAB or involving more than one needle pass). The diagnostic accuracy of FNAB, done with a pathologist's extemporaneous assessment of sample adequacy, was 94.83 % against 81.82. % of CNB.

Conclusions: FNAB under CT guidance is subject to a lower rate of complications and, if performed in the presence of the pathologist, has a greater diagnostic accuracy compared to CNB.