Stage III Pleural Diffuse Malignant Mesothelioma AJCC v9

**Semantic type:** Neoplastic Process

**Definition:** Stage III includes: IIIA: (T2, N1, M0); (T3, N0-N1, M0); (T1-T3, N2, M0); IIIB: (T4, Any N, M0). cT1: Tumor limited to the ipsilateral parietal pleura with Psum 12 mm or less and no involvement of the fissure (Fmax 5 mm or less). Note: Psum: pmax1+pmax2+pmax3 (sum of 3 measurements of maximal pleural thickness measured on axial images along the chest wall or mediastinum in each of the three divisions of the chest - upper, middle and lower divided by two lines; one at the top of the aortic arch and the second drawn at the top of the left atrium). Fmax: maximal thickness of pleural tumor along the fissures measured on sagittal images. pT1: Tumor limited to the ipsilateral parietal pleura with no involvement of the fissure. cT2: Tumor involving the ipsilateral pleura with Psum 12 mm or less, and with any of the following: involvement of the fissure (Fmax more than 5 mm); mediastinal fat invasion; solitary area of chest wall soft tissue invasion; or tumor involving the ipsilateral pleura with Psum more than 12 mm but equal to or less than 30 mm, with or without: involvement of the fissure (Fmax more than 5 mm); mediastinal fat invasion; solitary area of chest wall soft tissue invasion. pT2: Tumor involving the ipsilateral pleura and with any of the following: involvement of the fissure; ipsilateral lung parenchyma invasion; diaphragm (non-transmural) invasion. cT3: Tumor involving the ipsilateral pleura with Psum more than 30 mm, with or without: involvement of the fissure (Fmax more than 5 mm); mediastinal fat invasion; solitary area of chest wall soft tissue invasion. pT3: Tumor limited to the ipsilateral pleura (with or without fissure involvement) and with invasion of any of the following: mediastinal fat; surface of pericardium; endothoracic fascia; solitary area of chest wall soft tissue. cT4: Tumor invasion of any of the following (any Psum): chest wall bony invasion (rib); mediastinal organs (heart, spine, esophagus, trachea, great vessels); diffuse chest wall invasion; direct tumor extension through the diaphragm or pericardium; direct extension to the contralateral pleura; presence of malignant pericardial effusion. pT4: Tumor invasion of any of the following: chest wall bony invasion (rib); mediastinal organs (heart, spine, esophagus, trachea, great vessels); diffuse chest wall invasion; transmural invasion of the diaphragm or pericardium; direct extension to the contralateral pleura; presence of malignant pericardial effusion. N0: No tumor involvement of regional lymph node(s). N1: Tumor involvement of ipsilateral bronchopulmonary, hilar, or mediastinal (including the internal mammary, peridiaphragmatic, pericardial fat pad, or intercostal lymph nodes) regional lymph nodes. N2: Tumor involvement of contralateral mediastinal, ipsilateral or contralateral supraclavicular lymph nodes. M0: No distant metastasis. (AJCC 9th ed.)