MESOTHELIOMA DIAGNOSIS
How is mesothelioma diagnosed?
A diagnosis of mesothelioma is most often obtained with careful assessment of clinical and radiological findings in addition to a confirming tissue biopsy. (Learn about typical mesothelioma symptoms.) A review of the patient's medical history, including history of asbestos exposure is taken, followed by a complete physical examination, x-rays of the chest or abdomen, and lung function tests. A CT scan or MRI may also be done at this time. If any of these preliminary tests prove suspicious for mesothelioma; a biopsy is necessary to confirm this diagnosis.
Imaging Techniques and Their Value in Diagnosing and Assessing Mesothelioma
There are several imaging techniques which may prove useful when malignant mesothelioma is suspected due to the presence of pleural effusion combined with a history of occupational or secondary asbestos exposure. While these imaging techniques can be valuable in assessing the possibility of the cancer, definitive diagnosis is still most often established through fluid diagnosis or tissue biopsy.
Some of the most commonly used imaging methods include:
• X-ray
A chest x-ray can reveal pleural effusion (fluid build-up) which is confined to either the right (60%) or left (40%) lung. On occasion, a mass may be seen. Signs of prior non-cancerous asbestos disease, such as pleural plaques or pleural calcification, or scarring due to asbestosis may also be noted.
• Computed Tomography (CT)
CT scans are also able to define pleural effusion, as well as pleural thickening, pleural calcification, thickening of interlobular fissures, or possible chest wall invasion. CT, however, is not able to differentiate between changes associated with benign asbestos disease (pleural disease), or differentiate between adenocarcinoma of the lung which may have spread to the pleura verses mesothelioma. CT scans may also be valuable in guiding fine needle aspiration of pleural masses for tissue diagnosis.
• Magnetic Resonance Imaging (MRI)
MRI scans are most often used to determine the extent of tumor prior to aggressive treatment. Because they provide images in multiple planes, they are better able to identify tumors as opposed to normal structures. They are also more accurate than CT scans in assessing enlargement of the mediastinal lymph nodes (those lymph nodes which lie between the two lungs), as well as a clear diaphragmatic surface, both of which play an important role in surgical candidacy.
