What tools are used in the diagnosis of pleural mesothelioma?
Definitive diagnosis of pleural mesothelioma remains difficult. Over half of all patients requiring analysis of pleural effusion will have a malignancy. CT will provide additional benefit in determining the extent of involvement and is usually used to guide biopsy. Recently, PET has emerged as superior to CT or MRI when evaluating pleural thickening as found on CT with a rate of accuracy at 94%. Thoracocentesis is widely performed to obtain cytology but does not often lend insight into the diagnosis, carrying a sensitivity of only 30% in pleural mesothelioma. Work-up is further complicated as tumor invasion occurs in 40% of study sites. Thoracoscopy is considered the gold standard for the evaluation of exudative pleural effusions in those with negative cytology. In mesothelioma, open pleural biopsy is often required but distinction from other pathology is difficult as pleural fluid tends to be both hemorrhagic and exudative.