The role of imaging in malignant pleural mesothelioma

The role of imaging in the management of primary pleural malignancies

Malignant pleural mesothelioma is a rare tumour, but its incidence is increasing. Imaging is invariably involved in its diagnosis, staging, and follow-up. Although there are some characteristic radiological signs, none are pathognomonic. Computed tomography (CT) and magnetic resonance (MR) have similar local staging accuracies, but have distinct limitations; MR has marginal superiority in specific areas and should probably be offered to surgical candidates. The capabilities of multidector CT await evaluation. The role of positron emission tomography (PET), and PET-CT is undefined, but will likely have a major contribution. The challenges in imaging are matched by controversies in staging and treatment, which require future close multidisciplinary and multicentre collaboration.

Asbestos: when the dust settles an imaging review of asbestos-related disease

Asbestos-related neoplastic and nonneoplastic diseases of the lungs and pleura range from pleural effusion and pleural plaques to lung cancer and malignant mesothelioma. Pleural effusions are typically hemorrhagic exudates of mixed cellularity but do not typically contain asbestos bodies. The classic distribution of pleural plaques seen on chest radiographs is the posterolateral chest wall between the seventh and tenth ribs, lateral chest wall between the sixth and ninth ribs, the dome of the diaphragm, and the mediastinal pleura. Computed tomographic (CT) findings support this distribution but also show anterior and paravertebral plaques not well shown at chest radiography. Imaging features of diffuse pleural thickening include a continuous sheet, often involving the costophrenic angles and apices, that rarely calcifies. The typical CT features of round atelectasis are of a round or oval mass that abuts the pleura, a "comet tail" of bronchovascular structures going into the mass, and thickening of the adjacent pleura. Features of asbestosis on chest radiographs include ground-glass opacification, small nodular opacities, "shaggy" cardiac silhouette, and ill-defined diaphragmatic contours. CT, however, is more sensitive in their detection. Chest radiography in patients with malignant mesothelioma may show an effusion, pleural thickening, and as the tumor progresses, a more lobulated outline. CT can help identify the disease in its early stages. Asbestos-related cancers can occur anywhere in the lungs. Recognition of the clinical, radiologic, and pathologic features of these diseases will be important for some years to come.