Table 1.

N & M category of MPM ¹³

Regional lymph nodes (N) :
Nx	Regional lymph nodes cannot be assessed.
N0	No regional lymph node metastases.
N1	Metastases in the ipsilateral bronchopulmonary/hilar lymph nodes or in the subcarinal or the ipsilateral mediastinal lymph nodes including the ipsilateral internal mammary and peridiaphragmatic nodes.
N2	Metastases in the contralateral mediastinal, contralateral internal mammary, ipsilateral or contralateral supraclavicular lymph nodes.
Distant metastases (M):
M0	No distant metastases
M1	Distant metastases present

MPM, malignant pleural mesothelioma.

From AJCC Cancer Staging Manual 8th edition.¹³