Malignant pleural mesothelioma

Malignant pleural mesothelioma (MPM) is an uncommon neoplasm that arises from the pleura ,or rarely the pericardium or peritoneum. The relationship between exposure to asbestos, chrysotile or amphiboles (amosite, crocidolite) and other fibers such as erionite (only in parts of Turkey) is well proven [1-3]. Three types of MPM are described histopathologically: epithelioid (45%), sarcomatoid (24%) and biphasic (31%). Patients frequently present with dyspnea, chest pain, cough, and weight loss. The prognosis is poor, with a median survival time of 12 months after diagnosis. CT is the most widely used initial imaging modality for the diagnosis and staging of MPM. Key CT findings include unilateral pleural effusion, nodular pleural thickening, and interlobar fissure thickening. Calcified pleural plaques are found at CT in approximately 20% of patients. MPM is locally aggressive, with frequent invasion of the chest wall, mediastinum, and diaphragm. Pulmonary metastases manifests as nodules and masses and, rarely, diffuse miliary nodules. Direct extension of the tumor into vascular structures and mediastinal organs including the heart, esophagus, and trachea may occur. Also transdiaphragmatic extension of MPM to adjacent abdominal organs can easily been detected on CT scans. Especially in surgical candidates MR imaging and, more recently, PET have proved to be helpful in detecting the extent of disease [4]. Diagnosis of distant organ metastasis during the patient’s lifetime is rare. However, on autopsy series silent metastasis can be found up to 50%. The invasion of the spinal medulla is exceptional [5-7].