There is no such thing as a standard treatment for diffuse malignant mesothelioma of the pleura (DMM). Surgery, radiotherapy or chemotherapy do not appear to modify the course of the disease, and there seems to be little chance of DDM of the pleural being cured, except for those rare cases of stage I tumour detected early on and curable by surgery or by intrapleural interferon. Biological response modifiers, such as interferon or interleukin, might well be the future therapeutic approach of a tumour known for its resistance to chemotherapy. Surgery remains effective in localized benign (fibroma) or malignant (fibrosarcoma) tumours, although fibrosarcoma has a tendency to local recurrence. Metastatic pleuritis has no other treatment than that of the primary cancer.