18F-fluoro-2-deoxy-d-glucose positron emission tomography/computed tomography fused imaging in malignant mesothelioma patients: looking from outside is not enough.

Malignant mesothelioma (MM) is an uncommon neoplasm with a poor prognosis usually associated with asbestos exposure. 18F-fluoro-2-deoxy-d-glucose (FDG) positron emission tomography (PET)/computed tomography (CT) has become an invaluable tool for the diagnosis, staging, and prognosis of this severe disease as it combines both anatomic and functional information in a single imaging procedure, allowing for improved management of this disease. For many authors, 18F-FDG-PET/CT is the cornerstone of the pre-therapeutic evaluation of mesothelioma patients, particularly when multimodal therapy (including extra-pleural pneumonectomy or omentectomy) is considered. However, while characteristic patterns have been reported as predictive of macroscopic pleural or peritoneal involvement, false negative findings are possible, both for pleural and peritoneal mesothelioma, during the initial diagnosis or during the patient's surveillance as illustrated by this report of three cases of suspected MM with negative PET/CT. This report highlights the limitations of PET/CT in the diagnostic evaluation of MM and the importance of histopathological confirmation by thoracoscopy and/or laparoscopy, which remain the most important diagnostic procedures in MM.