Transbronchial needle aspiration in sarcoidosis: yield and predictors of a positive aspirate.

OBJECTIVE: Transbronchial needle aspiration is a useful diagnostic procedure in sarcoidosis, but widely variable yields are reported. This study determined the diagnostic contribution of standard transbronchial needle aspiration in a large series of patients with sarcoidosis and evaluated predictor variables that might influence its results.
METHODS: Sixty-one consecutive patients with suspected sarcoidosis in a 2-year period were prospectively enrolled and underwent standard transbronchial needle aspiration with a 19-gauge needle. The following predictor variables were recorded for each patient: age; sex; sarcoidosis stage; operator; size, location, and number of sampled lymph nodes; number of needle passes per sampled node; and adequacy of both histologic and cytologic transbronchial needle aspiration specimens.
RESULTS: Sarcoidosis was diagnosed in 53 patients. Lymph node aspiration biopsy was successfully achieved in 50 of 53 cases (94%). Nonnecrotizing epithelioid granulomas were observed in 42 of 53 patients (79%), with similar results for stage I (27/33, 82%) and stage II (15/20, 75%) disease. Sampling of two lymph node stations was the only variable significantly associated with a likelihood of a sarcoidosis-positive aspirate or biopsy sample in both univariate (odds ratio 0.15, 95% confidence interval 0.02-0.79) and multivariate (odds ratio 0.12, 95% confidence interval 0.02-0.70) analyses.
CONCLUSION: Standard transbronchial needle aspiration allows successful lymph node sampling in nearly all patients with sarcoidosis and is associated with high diagnostic yield regardless of disease stage. Whenever possible, sampling of more than one nodal station is advised to increase diagnostic yield. Mediastinoscopy should be reserved for patients with negative transbronchial needle aspiration findings.