Adequacy of Cytologic Samples by Ultrasound-Guided Percutaneous Transthoracic Fine-Needle Aspiration Cytology of Peripheral Pulmonary Nodules for Morphologic Diagnosis and Molecular Evaluations: Comparison With Computed Tomography--Guided Percutaneous Transthoracic Fine-Needle Aspiration Cytology.

Context.--Fine-needle aspiration cytology (FNAC) of pulmonary nodules is usually guided by computed tomography (CT), whereas ultrasonography (US) is generally considered not applicable for such purposes. Objective.--To evaluate the clinical applicability and diagnostic utility of US-guided transthoracic FNAC of peripheral pulmonary nodules. Design.--Ultrasonography-guided transthoracic FNAC was obtained from 40 selected patients with peripheral, subpleural, and paravertebral pulmonary nodules. Airdried and Diff-Quik--stained smears were used for rapid on-site evaluation; additional smears were alcohol fixed for Papanicolaou staining. Cell blocks were set up for immunocytochemical and molecular studies; in 2 cases, a flow cytometry evaluation was also performed. The series was compared to 40 CT-guided pulmonary FNAC samples from patients with pleural, peripheral, and paravertebral pulmonary nodules, to evaluate differences in terms of diagnostic rate, time of execution, safety, and cost. Results.--The US-guided FNAC samples had results that were adequate and representative in 95% of cases. No significant differences were observed between the 2 groups in terms of diagnostic rate, number of passes, and cellularity of both smears and cell blocks. The mean time needed for the execution of US-guided FNAC was 13.1 minutes, whereas the mean time for CT-guided FNAC was 23.6 minutes. Thus, US-guided FNAC was significantly more rapid than CT-guided pulmonary FNAC. Because pneumothorax occurred in 1 individual who underwent US-guided FNAC and in 9 who underwent CT-guided FNAC, we might conclude that US-guided FNAC is a significantly safer procedure. Finally, comparing the costs of both procedures, US-guided FNAC is less expensive. Conclusions.--Our experience showed an elevated clinical applicability and diagnostic utility of US-guided transthoracic FNAC for selected pulmonary nodules. [ABSTRACT FROM AUTHOR]