CT in differential diagnosis of benign and malignant pleural disease

Background. CT plays a valuable role in assessment of patients with a wide variety of diseases of the pleura, and pulmonologists should be aware of the significance of different CT findings for the differential diagnosis of benign and malignant pleural diseases. Methods. 155 patients with pleural disease who had undergone CT scans of the lungs and thorax before treatment were enrolled. We retrospectively reviewed CT findings in 146 patients with proven pleural disease. Results. Fifty-nine of the cases were malignant, 87 of them had benign pleural diseases. CT findings that were helpful in distinguishing malignant from benign pleural disease were: 1) pleural nodularity; 2) rind; 3) mediastinal pleural involvement; and 4) pleural thickening greater than 1 cm. The sensitivities and specificities were 37%/97%, 22%/97%, 31%/85%, 35%/87%, respectively. CT findings differentiating malignant pleural mesothelioma from metastatic pleural disease were identified. Findings for malignant mesothelioma were as follows: 1) involvement of interlobar fissure (sensitivity 30%, specificity 92%), 2) pleural thickening greater than 1 cm (sensitivity 60%, specificity 77%). Whereas, findings for metastatic pleural disease were mediastinal/hilar lymph node enlargement and lung parenchymal involvement (P<.05). Conclusion. CT is helpful in the differential diagnosis of pleural diseases, particularly in differentiating malignant from benign conditions and metastatic pleural disease from malignant mesothelioma.