Material and Method: A retrospective analysis was performed of EBUS-TBNA samples obtained at the institution over a total of 36 months. Two periods were examined. Almost all of the aspirated material was smeared onto slides and fixed with 95% alcohol in the first period of the study. Subsequently, to improve diagnostic ability, a pair of slides was prepared from each needle pass: the first was air-dried, and the second was fixed in 95% alcohol. The remainder of the aspirate was kept for cell block analysis.

Results: In total, 462 samples were obtained from 260 patients. The overall sampling adequacy was 74% in the first and 81.1% in the second period (p<0.05). Approximately 14% of the specimens included a sufficient number of cells for immunohistochemical cell block evaluation in the first period and 42% in the second period (p<0.001). Histological subtyping of non-small cell lung carcinoma was determined in 18 (56.3%) and the primary origin of a tumor was determined based on morphological and immunohistochemical properties in 32 (84.2%) of the patients in the first and second periods, respectively.