Butchart Staging System

The staging system most often used for mesothelioma is the Butchart system. This system is based mainly on the extent of the primary tumor mass, and has the following stages.

Stage I : Mesothelioma is present within the right or left pleura, and may also involve the lung, pericardium, or diaphragm on the same side.

Stage II : Mesothelioma invades the chest wall or involves the oesophagus, heart, or pleura on both sides. The lymph nodes in the chest may also be involved.

Stage III : Mesothelioma has penetrated through the diaphragm into the peritoneum). Lymph nodes beyond those in the chest may also be involved.

Stage IV : There is evidence of distant metastases.