Table 2.

Modified eighth TNM descriptors for staging malignant pleural mesothelioma. Adapted from Berzenji et al., 2018

Category	Definition
	T
Tx	Primary tumour not assessable
T0	No evidence of a primary tumour
T1	Tumour involving the ipsilateral parietal pleura (including mediastinal and diaphragmatic pleura) with or without involvement of the visceral pleura
T2	Tumour involving each of the ipsilateral pleural surfaces (parietal, mediastinal, diaphragmatic and visceral) with at least one of the following: Confluent visceral pleural tumour—including the fissures Involvement of the diaphragmatic muscle Invasion of the lung parenchyma
T3	Tumour involving all of the ipsilateral pleural surfaces (parietal, mediastinal, diaphragmatic and visceral) with at least one of the following features: Invasion of the endothoracic fascia Extension into the mediastinal fat Solitary, completely resectable focus invading soft tissues of the chest wall Non-transmural involvement of the pericardium
T4	Tumour involving all of the ipsilateral pleural surfaces with at least one of the following features: Diffuse or multifocal soft tissue invasion of the chest wall Any rib involvement Invasion of the peritoneum through the diaphragm Invasion of any mediastinal organ Direct extension to the contralateral pleura Invasion of the spine or brachial plexus Transmural invasion of the pericardium (with or without a pericardial effusion) Myocardium invasion
	N
Nx	Regional lymph nodes not assessable
N0	No regional lymph nodes metastases
N1	Metastases in ipsilateral bronchopulmonary, hilar or mediastinal lymph nodes (including the internal mammary, peridiaphragmatic, pericardial fat pad or intercostal lymph nodes)
N2	Metastases in the contralateral bronchopulmonary, hilar or mediastinal lymph nodes or ipsilateral or contralateral supraclavicular lymph nodes
	M
Mx	Presence of distant metastases not assessable
M0	No evidence of distant metastases
M1	Evidence of distant metastases