Cytology of nonneoplastic occupational and environmental diseases of the lung and pleura.

CONTEXT Cytologic examination of the respiratory tract has been a useful diagnostic tool when evaluating neoplastic lesions of the respiratory tract. However, we have limited experience in the application of this technique in the management of nonneoplastic occupational and environmental diseases of the lung and pleura. This review focuses on the cytologic characteristics of a variety of occupational lung diseases, grouping them into 2 broad diagnostic categories: reactive cellular changes and noncellular elements. The former includes entities such as reactive mesothelial proliferation, goblet cell metaplasia, Creola bodies, and reserve cell hyperplasia, and the latter encompasses Curschmann spirals, Charcot-Leyden crystals, and asbestos bodies. OBJECTIVE To illustrate the cytologic features of several nonneoplastic occupational and environmental diseases and correlate the cytology with various etiologic agents. DATA SOURCES Case-derived material and literature review. CONCLUSIONS The role of cytology in the diagnosis of nonneoplastic occupational and environmental lung diseases is limited. This may be because more than one agent can elicit a similar host reaction and/or the offending agent can be associated with more than one pathologic process. However, in the appropriate clinical and radiographic setting, the cytology can render valuable diagnostic information. Examples include pulmonary alveolar proteinosis in patients with acute silicoproteinosis and asbestos bodies in bronchoalveolar lavage samples of patients with asbestos exposure.