A left pleural effusion with a calcified tumoral mass and left hemithoracic uptake on bone scan.

Diffuse malignant pleural mesothelioma is a rare primary tumor of the pleura with three principal histological types, epithelial; mesenchymal and mixed epithelial and mesenchymal. We report here a case of a mesenchymal mesothelioma with foci of osteosarcomatous degeneration revealed by dense calcifications associated with the pleural effusion on the computed tomography (CT) of the thorax. The bone scan revealed extraosseous uptake corresponding to the left pleura.