[A case of diffuse pleural mesothelioma disclosed by a 7 mm tumor shadow on chest X-ray film during a regular physical checkup].

We encountered a patient with diffuse pleural mesothelioma pointed out by a tumor shadow 7 mm in diameter on a chest X-ray film obtained during a regular physical checkup. Computed tomography (CT) scans disclosed several small tumors, slightly thickened pleura, and a small amount of pleural effusion. A cytological examination of the effusion, as well as a bronchoscopic examination, were both unable to detect any evidence of malignancy. The patient was referred to the respiratory medicine department of our hospital, where further bronchoscopic examinations were performed but no conclusive diagnosis was obtained. The patient was therefore referred to our department. CT scans revealed enlarged tumors, markedly thickened pleura, and an increase in pleural effusion. This time a cytological analysis of effusion samples was positive for malignant mesothelioma cells. A pleuropneumonectomy was performed, but tumor cells were partially exposed on the dissected surface. Recurrent tumors were disclosed by CT scans 15 months later. Our conclusion was that a thoracoscopic examination should have been performed for diagnostic purposes at an earlier stage.