Predictive factors of diagnostic accuracy of CT-guided transthoracic fine-needle aspiration for solid noncalcified, subsolid and mixed pulmonary nodules.

PURPOSE: The aim of this study was to analyse factors predicting the diagnostic accuracy of computed tomography (CT)-guided transthoracic fine-needle aspiration (TTFNA) for solid noncalcified, subsolid and mixed pulmonary nodules, with particular attention to those responsible for false negative results with a view to suggesting a method for their correction. MATERIALS AND METHODS: From January 2007 to March 2010, we retrospectively reviewed the CT images of 198 patients of both sexes (124 males and 74 females; mean age, 70 years; range age, 44-90) used for the guidance of TTFNA of pulmonary nodules. Aspects considered were: lesion size and density, distance from the pleura, and lesion site. Multiplanar reformatted images (MPR) were retrospectively obtained in the sagittal and axial oblique planes relative to needle orientation. RESULTS: The overall diagnostic accuracy of TTFNA CT-guided biopsy was 86% for nodules between 0.7 and 3 cm, 83.3% for those between 0.7 and 1.5 cm, and 92% for those between 2 and 3 cm. Accuracy was 95.1% for solid pulmonary nodules, 84.6% for mixed nodules, and 66.6% for subsolid nodules. The diagnostic accuracy of CT-guided TTFNA in relation to the distance between the nodule and the pleural plane was 95.6% for lesions adhering to the pleura and 83.5% for central ones. The diagnostic accuracy was 84.2% for the pulmonary upper lobe nodules, 85.3% for the lower lobe and 90.9% for those in the lingula and middle lobe. In 75% of false negative and inadequate/insufficient cases the needle was found to lie outside the lesion, after reconstruction of the needle path by MPR. CONCLUSIONS: The positive predictive factors of CT-guided TTFNA are related to the nodule size, density and distance from the pleural plane. The most common negative predictive factor of CT-guided TTFNA is the wrong position of the needle tip, as observed in the sagittal and axial oblique sections of the MPR reconstructions. The diagnostic accuracy of CT-guided TTFNA can therefore be improved by using the MPR technique to plan the needle path during the FNA procedure.

Accuracy of fine needle aspiration cytology in the pathological typing of non-small cell lung cancer.

BACKGROUND: Histological typing of non-small cell lung cancer (NSCLC) has an increasing clinical relevance due to the emerging differences in medical treatment between squamous and nonsquamous tumors. However, most NSCLCs are diagnosed in an advanced stage, and the diagnosis is often obtained exclusively by cytology either exfoliative or following fine needle aspiration. We investigated the accuracy of fine needle aspiration cytology (FNAC) in NSCLC typing as compared with histology. METHODS: Over the period 2000-2009, 1182 transbronchial needle aspirate or transthoracic needle aspirate samples were obtained from patients with suspicious thoracic lesions. In 474 patients, a cytological diagnosis of primary NSCLC was obtained, and 186 (39%) of them (108 transbronchial needle aspirates and 78 transthoracic needle aspirates) received a parallel or subsequent histologic diagnosis on endoscopic biopsy (112) or surgery (74). RESULTS: At cytology, 158 (85%) NSCLC cases were typed (89 adenocarcinoma and 69 squamous cell carcinoma), while 28 (15%) were classified as NSCLC not otherwise specified. At histology, 183 (98%) cases were typed (109 adenocarcinoma, 69 squamous cell carcinoma, 3 adenosquamous carcinoma, and 2 large cell carcinoma), and only 3 (2%) were classified as NSCLC not otherwise specified. Cytological and histological typing was concordant in 137 of 156 (88%) cases (K = 0.755; p < 0.001). The positive predictive value of FNAC in typing NSCLC was 92% for adenocarcinoma and 82% for squamous cell carcinoma. CONCLUSION: FNAC in expert hands is fairly accurate for typing NSCLC and can be regarded as an acceptable procedure for diagnostic and medical treatment planning purposes in most NSCLC cases, especially when more invasive approaches are unfeasible. In poorly differentiated and doubtful cases, the use of ancillary techniques, such as immunocytochemistry, may be required to improve the diagnostic yield.