Stage I malignant pleural mesothelioma

Stage I is divided into stages IA and IB. In stage IA, cancer is found in the inside lining of the chest wall on one side of the chest. On the same side of the chest, cancer may also be found in one or more of the following: the thin layer of tissue that covers the lung; the thin layer of tissue that covers the organs between the lungs; and/or the thin layer of tissue that covers the top of the diaphragm. In stage IB, cancer is found in the inside lining of the chest wall, and in each of the thin layers of tissue that cover the lung, the organs between the lungs, and the top of the diaphragm on one side of the chest. On the same side of the chest, cancer has also spread into one or more of the following: diaphragm; lung tissue; tissue between the ribs and the inside lining of the chest wall; fat in the area between the lungs; soft tissues of the chest wall; and/or sac around the heart.