PLEURAL MESOTHELIOMA

Malignant Mesothelioma of the Pleura

Pleural mesothelioma is a rare type of cancer where malignant cells are found in the pleura (the thin layer of tissue that lines the chest cavity and covers the lungs). Exposure to airborne asbestos particles increases one's risk of developing malignant mesothelioma. Although reported incidence rates have increased in the past 20 years, pleural mesothelioma is still a relatively rare cancer. About 2,000 new cases of pleural mesothelioma are diagnosed in the United States each year. Pleural mesothelioma occurs more often in men than in women and risk increases with age, but this disease can appear in either men or women at any age. Working with asbestos is the major risk factor for mesothelioma. A history of asbestos exposure at work is reported in about 70% to 80% of all cases. However, mesothelioma has been reported in some individuals without any known exposure to asbestos.

Diagnostic testing: Diagnosing pleural mesothelioma is often difficult, because the symptoms are similar to those of a number of other conditions. Diagnosis begins with a review of the patient's medical history, including any history of asbestos exposure. A complete physical examination may be performed, including x-rays of the chest or abdomen and lung functioning tests. A computed tomography (CT) scan or an magnetic resonance imaging (MRI) may also be useful. A biopsy is needed to confirm a diagnosis of pleural mesothelioma. If the cancer is in the chest, the doctor may perform a thoracoscopy. In this procedure, the doctor makes a small cut through the chest wall and puts a thin, lighted tube called a thoracoscope into the chest between two ribs. Thoracoscopy allows the doctor to look inside the chest and obtain tissue samples. If the procedure does not yield enough tissue, more extensive diagnostic surgery may be necessary.

Physical findings: Symptoms of mesothelioma may not appear until 30 to 50 years after exposure to asbestos. Shortness of breath and pain in the chest due to an accumulation of fluid in the pleura are often symptoms of pleural mesothelioma.

ICD-9: 501; 511.8; 511.81

ICD-10: C45.0

Advanced malignant mesothelioma includes stages II, III, and IV. In stage II, cancer is found in the lining of the chest wall and the lymph nodes on the same side of the chest. Cancer may also be found in the lining of the lung, the lining of the diaphragm, or the lining of the sac that covers the heart on the same side of the chest. In stage III, cancer has spread to any of the following areas: the chest wall, the mediastinum, the heart, beyond the diaphragm and the peritoneum. Cancer may have also spread to lymph nodes on the other side of the chest or outside the chest. In stage IV, cancer has spread to distant organs or tissues. The prognosis is poor with a limited survival time of less than two years.

Treatment for pleural mesothelioma depends on the location of the cancer, the size of the tumor, the amount of fluid in the chest, the stage of the disease, and the individual's age and general health. Standard treatment options include surgery, radiation therapy, and chemotherapy. Surgery is associated with a median survival time of 15-24 months; chemotherapy has an average response rate of 10-20%.

Suggested MER for Evaluation:

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  Biopsy; and

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  Pathology report confirming diagnosis.

Suggested Listings for Evaluation:

REMARKS

Only pathology is required for adjudication.