Pericardial mesothelioma affects the pericardium which is the membrane made up of mesothelial cells that surrounds and protects the heart. This membrane has two layers: A} an outer layer called parietal pericardium B} an inner layer called the visceral pericardium {epicardium}

Unlike in the case of pleural mesothelioma, there is no clear link between this cancer and exposure to asbestos fibers, but a number of patients with pericardial mesothelioma have a history of exposure to asbestos.

Some schools of thought believe that it is the inhaled asbestos fibers in the lungs that travel via blood from the lungs to the heart, although this theory is not supported by conclusive evidence.

When asbestos fibers get lodged in the pericardium, the body is unable to excrete the asbestos fibers and they remain stuck in the pericardium. These fibers over a long period of time cause the pericardial cells to undergo changes that result into cancerous transformation.

The cancer cells divide without control and they eventually lead to the thickening of the pericardial membranes eventually causing development of the tumors. These changes lead to the accumulation of fluids in between the two layers which combined with the thickening of these layers result in the compression of the heart.

Symptoms

Most of the symptoms are caused by the accumulation of fluids and the thickening of the pericardial layer. The common symptoms are: A) Heart palpitations or irregular pulse (arrhythmias) B) Chest pain C) Murmurs (abnormal heart sounds) D) Cough E) Dyspnoea (shortness of breath) F) Fatigue H) Fever or night sweats I) Orthopnoea (breathlessness on lying down)

These symptoms are not specific for the cancer, making the clinical diagnosis very difficult.

Diagnosis

After getting a clinical diagnosis a series of tests can be done to locate the cancer and identify the cancer cells.

-MRI, Magnetic Resonance Imaging

This is useful in assessing and determining the extent of development of the cancer.

-Biopsy

This involves the removal of pericardium tissue or fluid for laboratory test to confirm the presence of mesothelioma cells.

-Chest x-ray

This helps to identify the tumor, there is a characteristic shape of the heart on the x-ray film when there is a tumor of the pericardium.

-Chest CT scan

This also helps to identify the tumor.

Treatment

Pericardial mesothelioma patients are not usually suitable for surgery, except in rare cases where the cancer is diagnosed very early and surgery may be done to remove small localized tumors.

This type of surgery is very risky because of the proximity of the heart.

Palliative treatment is often the only option for treating pericardial mesothelioma, this type of treatment is aimed at improving the patient's quality of life and reducing the severity of symptoms caused by the accumulation of fluid in the pericardium.

Fine needle aspiration may be done to drain the accumulated fluid surrounding the heart. Radiotherapy could also be used to shrink the tumor to alleviate the symptoms caused by the compression of the heart by the accumulating fluid. The proximity of the heart and lungs however makes this a very risky procedure.

Prognosis

The prognosis of this type of mesothelioma is very poor, about 50 -60% of all cases die within 6 months of diagnosis. Occasionally few patients survive for longer periods following treatment with partial surgical resection and radiotherapy.