Background: Previous studies have shown that needle gauge size has no significant impact on diagnostic yield during endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA). Our objective was to determine whether cell blocks obtained via the new Flex 19G EBUS-TBNA needle would contain more cellular material based on cell area compared with those obtained from a 21G needle.
Methods: A prospective analysis of patients undergoing EBUS-TBNA at our institutions was performed. Sampling of the same lesion(s) with both the Flex 19G and 21G needles was performed in an alternating manner. In total, 47 patients with suspected lung cancer or mediastinal/hilar lymphadenopathy were included with a total of 83 lesions biopsied. Cell block area was calculated using the Aperio ImageScope software.
Results: Mean cell area in the Flex 19G group was 7.34±12.46 mm compared with 5.23±10.73 mm in the 21G group (P=0.02). In the malignant subgroup, the average cell area was 16.16±16.30 mm in the Flex 19G group versus 11.09±15.55 mm in the 21G group (P=0.02). No significant difference was noted in the mean cell area within the nonmalignant subgroup, 1.80±3.01 mm in the 19G group versus 1.56±1.79 mm in the 21G group (P=0.60).
Conclusion: The cell area obtained via the 19G needle was significantly larger than that obtained with the 21G needle. Further multicenter randomized studies are needed to identify the utility of the Flex 19G needle in diagnosing/subtyping lymphoproliferative disorders and adequacy for molecular testing in non-small cell lung cancer.