Carcinoma of the lung complicating lipoid pneumonia.

The authors have encountered four cases of oil aspiration pneumonia complicated by carcinoma. Each had a clear-cut history of chronic intake of an oily substance, radiographic changes, and histologically documented oil aspiration pneumonia. Lung cancer later appeared in the involved area. A small number of similar cases also have been reported. The implication is that oil aspiration pneumonitis may induce bronchogenic carcinoma, particularly either the alveolar cell or the squamous cell variety. The radiographic diagnosis of the malignant transformation is difficult, and consequently the prognosis is poor.