Endobronchial ultrasound-guided transbronchial fine-needle aspiration: the University of Minnesota experience, with emphasis on usefulness, adequacy assessment, and diagnostic difficulties.

Endobronchial ultrasound-guided transbronchial fine-needle aspiration (EBUS-TBNA) is a new technique that facilitates cytologic sampling of mediastinal lymph nodes. We describe our initial experience with this method, including adequacy assessment, impact on cytopathologists' work, and diagnostic pitfalls. There were 229 EBUS-TBNA samples obtained from 100 patients; a mean of 22 minutes was spent with an average of 3 passes performed and 6 slides prepared per site. Of 193 aspirates, 5 were categorized as atypical, 54 as positive, and 134 as negative for malignancy; 36 (15.7%) aspirates were nondiagnostic. We found EBUS-TBNA to have a high specificity (100%) and good sensitivity (86%) in our institution, in which a cytopathologist is available on-site to ensure sample adequacy. Most true-negative samples had moderate to abundant lymphocytes, confirming lymphocyte numbers as a marker of adequacy. For pathologists, this was a relatively time-consuming procedure. Recognizing bronchial contamination, especially with metaplastic or dysplastic cells, is important for avoiding diagnostic pitfalls.