The size and quality of the histology specimens obtained with transbronchial needle aspiration

Although several studies have demonstrated that the size of the transbronchial biopsy specimen contributes to increase the diagnostic yield, no data has been available as to the size of the transbronchial needle aspiration (TBNA) specimen. The purpose of this study was to investigate the association between the quality and the size of the histologic TBNA specimen, which might thus contribute to predict specimen adequacy at the time of the procedure. We retrospectively studied clinical records and histopathologic slides of 67 patients who underwent histologic TBNA of mediastinal and/or hilar lesions. Each of the 182 specimens retrieved from 83 lesions was categorized by size and pathologic findings. At least 1 specimen could be prepared on a glass slide for histologic examination in 78 of 83 lesions (94%). In the 182 specimens submitted to pathology, 38 specimens were interpreted as malignant, 42 specimens as benign, 78 specimens as nonspecific, and 24 specimens as disappearance. Tracheal or bronchial wall tissue elements such as epithelium, smooth muscle, tracheobronchial glands, cartilage, and connective tissue were the frequent pathologic findings (n = 30) in the specimens with nonspecific diagnoses. Smaller specimens >0 and <1 mm² in size were more likely to contain nonspecific tissue, and larger specimens ≥2 mm² in size were more likely to contain diagnostic tissue to the contrary (chi square = 16.3, df = 4, P < 0.005). In conclusion, our study suggests that the size of the retrieved specimen could be a simple predictor for determining the adequacy of TBNA specimens at the time of the procedure.