When a Pleural Effusion Becomes an Unexpected Diagnosis

Mesothelioma is a neoplasm originating from the serous membranes, most often pleura. We present 72-year-old man with hypoxemic respiratory failure associated unilateral pleural effusion. The computed tomography (CT) of chest didn’t show other alterations besides Thoracoscopy showed thickening described as reactive mesothelial hyperplasia. Repeated contrast- enhanced CT mass in posterior mediastinum. Bronchoscopy and bronchoalveolar lavage cytology atypical inflammatory cells. Finally, mediastinoscopy biopsy revealed an epithelioid mesothelioma locally invasive disease distant dissemination later exposed on F18-fluorodeoxyglucose positron emission (F-18FDG PET-CT). He started palliative treatment but suffered progression death two years. low cytological histological sensitivity diagnosis add more complexity invasiveness to clinical case. To overcome these limitations, less immunohistochemistry molecular techniques have emerged definition mesothelioma.