Mesothelioma Symptoms often have dyspnea and chest pain; they may also have pleural effusion, fatigue, insomnia, cough, chest wall mass, loss of appetite, and weight loss (see the NCCN Guidelines for Adult Cancer Pain, available at NCCN).
Patients with MPM often have a high Mesothelioma Symptoms burden when compared with patients who have other types of cancer. Patients often present without distant metastases because mesothelioma symptoms such as chest pain and/or dyspnea are associated with local disease; CNS metastases are uncommon. In patients with recurrent pleural effusion and/or pleural thickening, the recommended initial evaluation for suspected MPM includes: 1) CT of the chest with contrast; 2) thoracentesis for cytologic assessment of the effusion; and 3) pleural biopsy (eg, thoracoscopic biopsy [preferred]) (see Initial Evaluation in the NCCN Guidelines for Malignant Pleural Mesothelioma). However, cytologic samples are often negative even when patients have MPM. Fine-needle aspiration (FNA) is not recommended for diagnosis. Talc pleurodesis or pleural catheter may be needed for management of pleural effusion. Soluble mesothelin-related peptide (SMRP) levels may also be assessed, and these levels may correlate with disease status; osteopontin does not appear to be as useful for diagnosis. Other potential diagnostic biomarkers are being assessed.
It can be difficult to distinguish malignant from benign pleural disease and also to distinguish MPM from other malignancies such as metastatic adenocarcinoma, sarcoma, or other metastases to the pleura. On CT, thymoma metastatic to the pleura can mimic MPM; however, pleural effusion does not typically occur with thymoma.
Cytologic samples of pleural fluid are often negative or inconclusive, but diagnosis can sometimes be made using cytology. Calretinin, WT-1, D2-40, and cytokeratin (CK) 5/6 are useful immunohistochemical markers for the diagnosis of MPM, as are markers that typically are positive in pulmonary adenocarcinoma and negative in mesothelioma (eg, thyroid transcription factor 1 [TTF-1], carcinoembryonic antigen [CEA]) (see Protocol for the Examination of Specimens From Patients With Malignant Pleural Mesothelioma from the College of American Pathologists [CAP]).