Do liquid-based preparations of pulmonary bronchial brushing specimens perform differently from classically prepared cases for the diagnosis of malignancies?: Observations from the college of American pathologists interlaboratory comparison program in nongynecologic cytology

Abstract

Context: Pulmonary bronchial brushing specimens can be processed by liquid-based or conventional methods. The ability to accurately diagnose a pulmonary malignancy with a liquid-based preparation (LBP) versus a conventional preparation may differ. Objective: To compare the performance of LBPs of malignant pulmonary bronchial brushing specimens with the performance of conventional preparations. Design: Participant responses from 553 malignant pulmonary bronchial brushing samples were evaluated for concordance with the general diagnosis. The performance of LBPs was compared with that of classic preparations. A nonlinear mixed model was used to analyze the performance by reference diagnosis, preparation type, program years, participant type, and the interaction terms between these 4 factors. Results: Concordance with the general category of malignant disease was observed in 95.2% of conventional Papanicolaou-stained, 90.9% of modified Giemsa-stained, and 96.9% of LBP (P<001) samples. The results were significantly different between individual reference diagnoses (P <001), and metastatic carcinoma not otherwise specified (P