Pericardial Mesothelioma

Pericardial mesothelioma is extremely rare, although it is the most common primary malignant pericardial tumour. Its incidence was < 0.0022% among 500 000 cases in a large necropsy study. Approximately 200 cases have been reported so far and only 25% of these were antemortem diagnoses. Pericardial mesothelioma lung can present as a localised or as a diffuse mass. Three histological types have been described: epithelial, spindle cell, and mixed. There is a possible relation to asbestos exposure but this is seen only in cases with coexistent asbestos related pleural disease.

Pericardial Symptoms

The onset of symptoms is usually insidious. Common clinical manifestations of pericardial mesothelioma are constrictive pericarditis, pericardial effusion, cardiac tamponade, and heart failure caused by myocardial infiltration. Further symptoms may arise due to compression of coronary arteries and local spread into the surrounding great vessels. Primary mesothelioma can also mimic tuberculous pericarditis or intra-atrial myxomas. Distant metastasis, conduction block due to myocardial infiltration, and tumour embolism causing neurological deficits have also been reported.

Diagnostic Tests

Pericardial fluid in pericardial mesothelioma can be difficult to aspirate. Echocardiography is the most commonly used initial investigative tool. Magnetic resonance imaging and CT are useful in showing the extent of involvement of contiguous structures and the degree of constriction. Other investigations such as immunohistochemistry, cytological examination, and high pericardial hyaluronic acid content of the pericardial aspirate can be diagnostic. The abnormal pericardium has also been known to take up gallium 67 extensively at scintigraphy.

Pericardial Treatment Options

Pericardial mesothelioma responds poorly to radiotherapy. Cyclical combination chemotherapy with doxorubicin, vincristine, and cyclophosphamide may reduce the tumour mass. Surgical resection can be curative in localised cases. Palliative treatment includes pericardiectomy, which prevents cardiac tamponade and relieves constriction. Alternatively, a pericardial window can be formed to introduce chemotherapeutic agents. Areas of ongoing research include intracavitary chemotherapy and irradiation. Photodynamic treatment, inhibition of growth factors, vaccines, and adenoviral molecular chemotherapy are also being explored.