Abstract

The CT appearences of benign and malign pleural diseases have been well described. However, there have been limited number of reports which assessed features in the differential diagnosis of diffuse pleural disease. Without knowledge of clinical or pathologic data , we reviewed CT findings in 146 consecutive patients with proved diffuse pleural disease. Fiftynine of patients had malign , 87 of them had benign pleural disease. The patients included 95 women and 51 men , 15-76 years old. CT findings that were helpful in distinguishing malignant from benign pleural disease were: 1)pleural nodülarity, 2)rind , 3)bilateral pleural disease, 4)mediastinal pleural involvement, 5)pleural thickening greater than 1 cm ,6) hilar and mediastinal LAP, 7)volume loss. The sensitivities were %37 , 22 , 33 , 30 , 35 , 35 and 27 respectively. The specificities were % 96 , 96 , 88 , 88 , 87 , 86 and 86 respectively. CT findings differentiating malignant mesothelioma from metastatic pleural disease were identified. Findings for malignant mesothelioma were as follows: 1)pleural plaque ( sensitivity % 15 , specificity % 100), 2) interlober fissure involvement ( sensitivity % 30 , specificity % 99), 3)pleural thickening greater than 1cm (sensitivity %60 , specificity % 75). Wherease , findings for metastatic pleural disease were ; 1)lung parenchymal involvement (sensitivity % 50, specificity % 100), 2)mediastinal shift (sensitivity % 19, specificity % 100) , 3) mediastinal and hilar LAP (sensitivity % 44, specificity % 90).

We concluded that CT is helpful in the differential diagnosis of diffuse pleural diseases , particularly in malign from benign conditions and metastatic pleural disease from malignant mesothelioma.