Asbestos bodies in fine needle aspirates of lung masses. Markers of underlying pathology.

Analysis of 52 transthoracic-mass aspirates that contained asbestos bodies (ABs) showed the mass to be due to pathology other than (or superimposed upon) asbestosis in every case. Malignancy accounted for 30 masses, all of which were carcinomas except for one mesothelioma. The remaining 22 lesions were benign, with tuberculosis or lung abscesses accounting for the majority. Fine needle aspiration (FNA) detection of the pathology (benign or malignant) associated with ABs was diminished, probably due to asbestos-induced fibrosis. Other diagnostic methods, including bronchial studies, mediastinoscopy and even exploratory thoracotomy, were required to document 20% of the neoplasms and 50% of the benign lesions. The results of this series support the view that ABs in FNA specimens from localized or dominant parenchymal lung masses are significant markers of underlying pathology, whether or not cellular evidence of that pathology is observed in the aspirated material.