A variety of techniques and technologies may be used to diagnose malignant mesothelioma. The aggressive nature of the disease demands an early diagnosis to maximize treatment options, but its unique behavior pattern and relative rarity among the general population often works against such early identification. In its earliest stages, the cancer typically presents in non-specific ways and is often misdiagnosed because of this non-specific presentation. The majority of patients only receive a diagnosis after the disease has progressed to Stage III or Stage IV. Because of this tragic situation, improvements in our ability to definitively determine a diagnosis are among the most important goals in contemporary research with a large number of studies actively investigating novel diagnostic techniques.
Pleural mesothelioma is the most common form of the disease, so an initial evaluation of symptoms will likely be due to pulmonary-related issues. It’s important for a physician to learn about any prior asbestos exposures that the patient is aware of so he or she can complete as full a medical history and workup as possible. This type of communication between the patient and doctor is important so that the earliest possible diagnosis can be made: if the doctor does not suspect an asbestos-related disease initially, he or she may not be able to diagnose the disease early enough to maximize prognosis.
In addition to constructing this medical profile and detailed history, a complete physical examination will be performed. During a physical exam your doctor may look for the following:
- Breath Sounds: By listening to the chest cavity as the patient inhales and exhales, the doctor may note differences in the sounds of a patient’s breath from normal breath sounds. This could indicate the presence of a pleural effusion, or another restriction of lung capacity.
- Vocal Sounds: The doctor may listen to the chest cavity while having the patient make vowel sounds – comparing the sound resonance in the right and left chest cavities. Muted, or dull, sounds between the cavities could also be indicative of effusions or another restriction of the lungs.
- By tapping on the chest area a doctor may notice a dull, solid thumping sound, rather than a hollow resonance. This may also indicate the presence of fluid, or a mass, in the chest cavity.
On the basis of patient symptoms, medical history, the presence of specific risk factors—such as work environment and known asbestos exposure—and the results of a complete physical examination, the doctor is likely to schedule one or more of the methods described below to make a mesothelioma diagnosis.
There are many available technologies that allow doctors to view organs and tissue that might show the presence of fluid or tumors. Imaging technologies are important techniques not only to make a mesothelioma diagnosis, but also for determining a treatment plan and for tracking the patient’s response to the treatments.
- X-Ray Imaging
Due to the ubiquity of the machines and their relative low lost, x-rays are usually the first test given to many patients. X-rays do not have enough resolution to identify the cancer, but they may indicate the presence of a pleural effusion or hint at the existence of a pleural or lung malignancy.
- Computed Tomography (CT)
A computed tomography (CT) scan uses x-rays and computers to give more sophisticated and detailed pictures of the insides of the body than conventional x-rays. CT is considered the gold-standard imaging test for a diagnosis.
- Magnetic Resonance Imaging (MRI)
Magnetic Resonance Imaging (MRI) uses a strong magnetic field and radiowaves to scan the body. MRI provides much better imaging of soft-tissue contrast than does CT and is often used for staging and surgical planning.
- Positron Emission Tomography (PET)
Positron Emission Tomography (PET) scans measure functional and metabolic activity in the body, and are most commonly used to identify the presence of distant metastases.
- PET-CT (Integrated Positron Emission Tomography – Computed Tomography)
PET-CT is a cutting-edge imaging technique that combines PET scans and CT scans in one machine. This allows the physician to precisely register the functional imaging of PET with the anatomical imaging of CT to provide a more complete understanding of a patient’s individual disease status.
A tissue sample of a pleural or pericardial tumor can be obtained during a thoracoscopy. A thoracoscope, a telescope-like instrument connected to a video camera, is inserted through a small incision into the chest, along with small surgical tools. The doctor can see the tumor through the thoracoscope and can use special tools to take a tissue biopsy.
A laparoscopy can be used to see and obtain a biopsy of a peritoneal tumor. In this procedure, a flexible tube is attached to a video camera that is inserted into the abdominal cavity via small incisions.
A bronchoscopy may be performed. In this process, the doctor inserts a flexible lighted tube down the trachea, and into the bronchi to check for masses in the airway. At that time, small samples of abnormal-appearing tissue may also be removed for testing.
During a mediastinoscopy, a patient has a lighted tube inserted under the sternum (chest bone) at the neck level and then moved down into the chest. The surgeon can see the lymph nodes and take tissue samples to check for cancer.