Thoracic computed tomography in patients with suspected malignant pleural effusions

To assess the role of contrast-enhanced computed tomography (CT) prospectively in patients with suspected malignant pleural effusions.

Forty consecutive patients referred for the investigation of a suspected malignant pleural effusion had contrast-enhanced thoracic CT, thoracoscopy, thoraco-centesis and pleural biopsy, either percutaneously or at thoracoscopy. Final diagnoses were based on histopathological or cytological analysis (n = 30), autopsy findings (n = 3) or clinical follow-up (n = 7). The pleural surfaces were classified at contrast-enhanced CT as normal or abnormal and, if abnormal, as benign or malignant in appearance using previously established CT criteria for malignant pleural thickening by two observers unaware of the pathological diagnosis.

Pleural effusions were malignant in 32 patients and benign in eight patients. Pleural surfaces assessed at CT showed features of malignancy in 27 out of 32 patients with a malignant effusion (sensitivity 84%, specificity 100%). Overall, CT appearances indicated the presence of malignancy in 28 of 32 (87%) patients. All eight patients with benign pleural disease were correctly diagnosed by CT.

Contrast-enhanced CT is of value in patients with suspected malignant pleural effusions. The previously established criteria for malignant pleural thickening of nodularity, irregularity and pleural thickness >1 cm are reliable in the presence of a pleural effusion.