Significant Cytologic Findings in Non-Malignant Pulmonary Disease

¹ The Cancer Research Institute, the Department of Medicine, University of California School of Medicine, and the San Francisco Department of Public Health, San Francisco Hospital, San Francisco, California.
² The Cancer Research Institute, the Department of Medicine, University of California School of Medicine, and the San Francisco Department of Public Health, San Francisco Hospital, San Francisco, California., Department of Pathology, University of Nancy, Nancy, France.

While the cytologic examination of sputum, in the hands of experienced pathologists and their co-workers, can be an accurate and useful method, it must be pointed out that the morphologic identification of cells is often difficult. This problem is more frequently associated with examination of sputum than cytologic examination of other body secretions, since sputum, in sufficient volume for study, generally indicates some type of pulmonary disease and consequent alteration of morphology.

Although the cellular changes observed in most non-malignant pulmonary diseases are minimal, some non-malignant pulmonary diseases produce cellular alterations which closely resemble those of malignancy, while still others result in cytologic findings indicative of a specific disease. Among the chest diseases and pathologic entities in the latter category are asthma, pulmonary infarction, lipid pneumonia, bronchial metaplasia, pneumoconiosis, coccidioidomycosis and bronchial adenoma.

It is hoped that greater attention to the cytologic findings in sputum smears from non-malignant pulmonary diseases will add ultimately a new dimension to the usefulness of exfoliative cytology. Acquaintance with the cytologic patterns attendant thereto should contribute materially to improvement in accuracy of diagnosis by providing a better basis of distinction between malignant cells and benign cellular abnormalities. In addition, the result of such a comparative study is of equal value as an aid toward definitive diagnosis of a number of non-malignant pulmonary diseases which clinically may be confused with cancer. The significance of employing rigid nuclear criteria for identifying malignant cells is emphasized, since similarities in cellular grouping rather than in nuclear features are the most common source of cytologic error.