Diffuse, Nodular Pleural Thickening:
1. Malignant Mesothelioma
2. Metastatic Disease to the Pleura: Especially adenocarcinoma of the lung, breast, and ovary. Pleural extension of a malignant thymic tumor may also produce similar findings.
3. Asbestos related Pleural Fibrosis
4. Fibrothorax following infection/ empyema (tuberculosis)