International Mesothelioma Interest Group, Pleural Mesothelioma

A number of staging systems have been described for staging of malignant pleural mesothelioma. Below is the International Mesothelioma Interest Group TNM staging system.
TNM
T - Tumour

    * Tx : primary tumour cannot be assessed
    * T0 : no evidence of primary tumour
    * T1a
          o potentially resectable
          o only parietal pleura
          o no mediastinal pleural involvement
    * T1b
          o potentially resectable
          o parietal pleura AND
          o scattered foci of mediastinal pleural involvement
    * T2
          o potentially resectable
          o parietal and visceral pleural involvement, and / or
          o pulmonary parenchymal involvement and/or
          o diaphragmatic muscle involvement
    * T3
          o potentially resectable
          o localised tumour mesothelioma extension into endothoracic fascia and / or
          o localised non-transmural involvement of pericardium and / or
          o localised extension into mediastinal fat
    * T4
          o unresectable
          o multiple foci of extension into chest wall +/- rib destruction and/or
          o extension through diaphragm into peritoneum and / or
          o extension into contralateral pleura mesothelioma and / or
          o extension into mediastinal organs and / or
          o extension through pericardium +/- direct extension into hea
N - Nodes

    * Nx : nodes cannot be assessed
    * N0 : no evidence of nodal involvement
    * N1 : ipsilateral bronchopulmonary or hilar nodal involvement
    * N2 : subcarinal or ipsilateral mesothelioma mediastinal / internal mammary nodes
    * N3 : contralateral mediastinal / internal mammary nodes

M - Metastases

    * Mx : presence of metastases cannot be assessed
    * M0 : no evidence of metastases
    * M1 : distant metastases present