Contribution of ultrasound-guided fine-needle aspiration cell blocks of metastatic supraclavicular lymph nodes to the diagnosis of lung cancer

Purposes: Routine smears of fine-needle aspiration (FNA) specimens of supraclavicular lymph nodes with ultrasound (US) real-time guidance have proven useful in lung cancer staging, but the clinical value of additional information from cell-block of FNA samples has been little researched. This study mainly focused on the contribution of cell block analysis to the diagnosis and staging in lung cancer. Materials and Methods: Clinical data about 211 lung cancer patients with supraclavicular lymph node enlargement admitted to ultrasonography in the Zhejiang Cancer Hospital and recommended a needle biopsy under US-guided, the adequacy of the specimens for preparing cell blocks was acquireded, and the additional immunohistochemistry or genetic information provided from cell block analysis was examined. Results: In 211 lung cancer patients referred for US-guided FNA (median age 61.8 10.0 years, range 30-88) 279 aspirations were performed. Conventional smears could be obtained from 185 aspirates (66.3%) and contained 176 (95.1%) diagnostic smears. Cell blocks could be obtained from 94 aspirates (33.7%) and contained diagnostic material in 88 (93.6%) aspirates. Above all, cell blocks also made epithelial growth factor receptor gene mutation analysis in 17 patients with FNA samples, and the positive rate was 70.6%. Overall, cell blocks provided clinically significant information for 51 of the 211 patients participating in the study (24.2%). Conclusion: Cell-block samples from US-guided FNA is a promising, relatively noninvasive technique to provide additional information in lung cancer diagnosis. Analysis of cell blocks allows for genetic analysis of the patients with supraclavicular lymph nodes metastasis.