IS Case 296: Mesothelioma
Imaging Sciences URMC 2009
Publication Date: 2009-08-05
A 67-year old male, with no significant past medical history (PMH), presented with significant shortness of breath (SOB) and dyspnea on exertion (DOE) five months ago. Initial chest x-ray at an outside hospital was significant for large pleural effusion with compressive atelectasis. Thoracentesis was performed and pleural fluid was suspicious for mesothelioma. He is being managed at our hospital and has regular chest x-rays to evaluate left effusion.
Large left pleural effusion. A significant amount of pleural fluid is compressing the left lung, which is almost totally collapsed. The mediastinum is shifted to the right, and there is a small right pleural effusion as well. There are left pleural plaques (fibrosis/scarring), which are seen more clearly following thoracentesis.
Mesothelioma is a neoplastic process that is almost always caused by exposure to asbestos. Malignant cells develop in the mesothelium, a protective covering, that is found in many organs of the body. A common site is the pleura of the lungs, as exposure is frequently secondary to inhalation.
Patients with pulmonary mesothelioma usually present with SOB and chest wall pain, with or without weight loss. Initial imaging is generally positive for large effusions, and further evaluation with diagnostic thoracentesis, or thorascopy with biopsy gives a diagnosis of mesothelioma.
Mesothelioma can cause pleural fibrosis or nodular scarring, leading to the imaging finding of pleural plaques (as can be seen with this patient). The presence of unilateral pleural plaques is highly specific for mesothelioma if no other primary malignancy is identified. (Pleural plaques can be metastatic lesions, but are generally bilateral.) Pleural thickening caused by mesothelioma affects the parietal pleura along the lateral chest walls and diaphragm, with relative sparing of the visceral pleura.
- Reed JC. Chest Radiology: Plain Film Patterns and Differential Diagnoses. 5th ed., Mosby, 2003