Lung cancer. Gross specimen of part of a lung with mesothelioma, a type of lung cancer. The tumour (white) is at bottom, encasing the pulmonary tissue. This cancer affects the pleura, the membrane that lines the lungs and chest cavity, and is usually associated with exposure to asbestos. Although mesothelioma can cause a cough and chest pain, in many cases it is symptomless. This delays diagnosis and therefore treatment. If a diagnosis is made before it has grown too large, treatment may include surgical removal. Otherwise the prognosis is poor.