Malignant Pleural Mesothelioma Staging 

Updated: Jan 04, 2016
  • Author: Winston W Tan, MD, FACP; Chief Editor: Jules E Harris, MD, FACP, FRCPC  more...
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TNM Classification for Malignant Pleural Mesothelioma

The TNM classification for malignant pleural mesothelioma staging is provided below. [1, 2]

Table. TNM Classification for Malignant Pleural Mesothelioma (Open Table in a new window)

Primary tumor (T)
TX Primary tumor cannot be assessed
T0 No evidence of primary tumor
T1 Tumor limited to the ipsilateral parietal pleura with or without mediastinal pleura and with or without diaphragmatic pleural involvement
T1a No involvement of the visceral pleura
T1b Tumor also involving the visceral pleura
T2 Tumor involving each of the ipsilateral pleural surfaces (parietal, mediastinal, diaphragmatic, and visceral pleura) with at least 1 of the following:
  • Involvement of the diaphragmatic muscle
  • Extension of tumor from the visceral pleura into the underlying pulmonary parenchyma
T3 Locally advanced but potentially resectable tumor; tumor involving all of the ipsilateral pleural surfaces (parietal, mediastinal, diaphragmatic, and visceral pleura) with at least 1 of the following:
  • Involvement of the endothoracic fascia
  • Extension into the mediastinal fat
  • Solitary, completely resectable focus of tumor extending into the soft tissue of the chest wall
  • Nontransmural involvement of the pericardium
T4 Locally advanced, technically unresectable tumor; tumor involving all of the ipsilateral pleural surfaces (parietal, mediastinal, diaphragmatic, and visceral pleura) with at least 1 of the following:
  • Diffuse extension or multifocal masses of tumor in the chest wall, with or without associated rib destruction
  • Direct diaphragmatic extension of the tumor to the peritoneum
  • Direct extension of the tumor to the contralateral pleura
  • Direct extension of the tumor to a mediastinal organ
  • Direct extension of the tumor into the spine
  • Tumor extending through to the internal surface of the pericardium with or without a pericardial effusion or tumor involving the myocardium
Regional lymph nodes (N)
NX Regional lymph node(s) cannot be assessed
N0 No regional lymph node metastases
N1 Metastases in the ipsilateral bronchopulmonary or hilar lymph node
N2 Metastases in the subcarinal or in the ipsilateral mediastinal lymph node, including the ipsilateral internal mammary and peridiaphragmatic nodes
N3 Metastases in the contralateral mediastinal, contralateral internal mammary, ipsilateral or contralateral supraclavicular lymph nodes
Distant metastases (M)
M0 No distant metastasis
M1 Distant metastasis

Table. Anatomic stage/prognostic groups (Open Table in a new window)

Stage T N M
I T1 N0 M0
IA T1a N0 M0
IB T1b N0 M0
II T2 N0 M0
III T1, T2 N1 M0
T1, T2 N2 M0
T3 N0-2 M0
IV T4 Any N M0
Any T N3 M0
Any T Any N M1

Stage I:

  • Completely resected within the capsule of the parietal pleura without adenopathy (ie, ipsilateral pleura, lung, pericardium, diaphragm, or chest wall disease limited to previous biopsy sites)

Stage II:

  • All stage I characteristics, with positive resection margins, intrapleural adenopathy, or a combination

Stage III:

  • Local extension of disease into the chest wall or mediastinum, into the heart, through the diaphragm or peritoneum, or extrapleurally to involve the lymph nodes

Stage IV:

  • Distant metastatic disease