PLEURAL CHANGES IN MALIGNANT PLEURAL EFFUSIONS - APPEARANCE ON COMPUTED-TOMOGRAPHY

BACKGROUND Tumors metastatic to the pleura are a leading cause of pleural effusions. The computed tomographic (CT) appearance of malignant pleural effusions varies from uniformly low attenuation without pleural abnormalities to thickened, irregular, contrast-enhanced pleura with or without discrete masses. There may be associated changes in the subcostal tissues. OBJECTIVE To determine the prevalence of abnormalities observed with CT scanning in patients with malignant pleural effusion. METHODS We analyzed the CT appearance of the pleura in 86 patients with documented malignant pleural effusions. Patients with primary malignancy of the pleura (mesothelioma) were excluded. RESULTS In 98% of the malignant effusions the fluid was homogeneous. Focal tumor masses were identified within the effusion in 10%. CT evidence of fluid loculation was seen in 40%. Pleural thickening, either smooth or irregular, was identified in 62%. CONCLUSIONS The transaxial anatomic display afforded by CT scanning facilitates demonstration of several features that should arouse the suspicion of the radiologist and the clinician to the possibility of malignancy involving the pleura.