THE classical picture of asbestosis has been divided into several stages.1 At first, there is a latent period of ten or more years during which asbestos bodies are formed around the asbestos fibers. During this time the patient is completely asymptomatic, and results of his chest x-ray are normal. This stage is followed by the gradual appearance of respiratory symptoms in the form of dyspnea, cough, expectoration, and wheezing; the roentgenologist finds bilateral pulmonary fibrosis. As the disease advances, systemic complaints are added, such as fatigue, malaise, weakness, anorexia, and weight loss. Finally, extensive destruction of lung tissue leads to respiratory and cardiac failure.
It is well known that pleural abnormalities are commonly found in asbestosis. Most experts believe that they are associated only with advanced pulmonary disease; others describe them as secondary complications or even as coincidental lesions not directly connected with asbestos inhalation.2
In contrast to