RÉSUMÉ
This study presents the differential diagnosis of metastatic tumors of the pleura vs. primary pleural malignancies in a male patient whose diagnosis was multiple myeloma with pleural involvement and confirmed by bone marrow aspiration and pleural biopsy. Computed tomography [CT] manifestations of this case were retrospectively analyzed, and compared with those of primary pleural malignancies. The CT manifestations of this case mainly involved bilateral multiple pleural nodules with irregular thickening. These nodules were also associated with rib damage and lung metastases, manifestations characteristic of metastatic tumors. The presence of a primary pleural malignancy correlated with patients' clinical history and imaging data, and involved unilateral pleural involvement, and to a lesser extent, mediastinal pleural involvement and pleural effusions. A pleural biopsy can establish a definitive diagnosis. Therefore, multiple myeloma with pleural involvement can be differentiated from primary pleural malignancies by using a combination of imaging data and clinical laboratory tests