Table 2 TNM (IMIG) and (AJCC/UICC) staging system for diffuse MPM

T stage

T1a

Tumour limited to parietal pleura

T1b

Tumour involving parietal pleura, with foci in visceral pleura

T2

Tumour involving pleura with one of the following: involvement of diaphragmatic muscle confluent visceral pleural tumour (including fissures) or extension of tumour from visceral pleura into underlying pulmonary parenchyma

T3

Locally advanced, but potentially resectable tumour. Tumour involving all pleural surfaces with at least one of the following: involvement of endothoracic fascia; exension into mediastinal fat; solitary, completely respectable focus of tumour extending into soft tissues of chest wall; non-transmural involvement of pericardium

T4

Locally advanced, but technically unresectable. Tumour involving all pleural surfaces with at least one of the following: Diffuse extension or multifocal masses of tumour in chest wall, with or without associated rib destruction; direct transdiaphragmatic extension of tumour to peritoneum; direct extension of tumour to contralateral pleura; direct extension to one or more mediastinal organs, e.g. direct extension of tumour into spine; extension through internal surface of pericardium, with or without pericardial effusion, or involvement of myocardium

N stage

NX

Not assessable

N0

No regional nodal metastases

N1

Ipsilateral bronchopulmonary or hilar metastases

N2

Ipsilateral mediastinal or subcarinal metastases

N3

Contralateral mediastinal, contralateral internal mammary, or ipsilateral or contralateral supraclavicular metastases

M stage

MX

Not assessable

M0

No distant metastases

M1

Distant metastases

Stage grouping

TNM equivalent

Ia

TlaN0 M0

Ib

T1b N0 M0

II

T2 N0M0

III

Any T3 M0

Any N1 M0

Any N2 M0

IV

Any T4

Any N3

Any M1