Pleural mesothelioma (ICD10 C38.4)

Introduction

This is the data sheet for TNM 9th edition staging of the pleural mesothelioma (ICD10 C38.4)

For more detailed information regarding TNM staging, please see pages 114-117 of the UICC TNM 9 book.

Stage groupings

Stage Group	T stage	N stage	M stage
Stage I	T1	N0	M0
Stage II	T1	N1	M0
	T2	N0	M0
Stage IIIA	T1	N2	M0
	T2	N1, N2	M0
	T3	Any N	M0
Stage IIIB	T4	Any N	M0
Stage IV	Any T	Any N	M1

TNM clinical classification

T - primary tumour

T value	Description
cTX	Primary tumour cannot be assessed
cT0	No evidence of primary tumour
cT1	Tumour limited to the ipsilateral pleura and no involvement of the fissure: Psum ≤12 mm* and Fmax ≤5 mm**
cT2	Tumour limited to the ipsilateral pleura: Psum ≤12 mm* With involvement of any of the following: • Fissure – Fmax >5 mm • Mediastinal fat invasion • Solitary area of chest wall soft tissue invasion Or Tumour limited to the ipsilateral pleura, with Psum >12 mm ≤30 mm* With or without involvement of the following: • Fissure – Fmax >5 mm • Mediastinal fat invasion • Solitary area of chest wall soft tissue invasion
cT3	Tumour limited to the ipsilateral pleura: with Psum >30 mm* With or without involvement of the following: • Fissure – Fmax >5 mm • Mediastinal fat invasion • Solitary area of chest wall soft tissue invasion
cT4	Tumour involves any of the following: • Diffuse chest wall soft tissue involvement • Chest wall with rib involvement • Mediastinal organs (oesophagus, trachea, heart, great vessels, spine) • Direct extension through the diaphragm or pericardium • Direct extension to contralateral pleura • Malignant pericardial effusion

Notes

*As measured on CT scan

Psum = sum of maximal pleural thickness. Measurements are made on axial images perpendicular to the chest wall or mediastinum in the area of estimated maximal pleural thickness in each third of the hemithorax (pmax1, pmax2 and pmax3) and combined to estimate the total pleural thickness (Psum = pmax1+pmax2+pmax3).

Fmax = maximal pleural thickness along the fissures

N - regional lymph nodes

N value	Description
cNX	Regional lymph nodes cannot be assessed
cN0	No regional lymph node metastasis
cN1	Metastases to ipsilateral intrathoracic lymph nodes (includes ipsilateral bronchopulmonary, hilar, subcarinal, paratracheal, aortopulmonary, paraesophageal, peridiaphragmatic, pericardial fat pad or intercostal and internal mammary nodes)
cN2	Metastases to contralateral intrathoracic lymph nodes. Metastases to ipsilateral or contralateral supraclavicular lymph nodes

M - distant metastasis

M value	Description
cM0	No distant metastasis
cM1	Distant Metastasis

pTNM pathological classification

pT - Primary tumour

pT value	Description
pT1	Tumour limited to the ipsilateral pleura and no involvement of the fissure:
pT2	Tumour limited to the ipsilateral pleura with any of the following: • the fissure • ipsilateral lung parenchyma • non-transmural diaphragm involvement
pT3	Tumour limited to ipsilateral pleura with or without fissure involvement and with invasion of any of the following: • mediastinal fat • surface of the pericardium • endothoracic fascia • solitary area of chest wall soft tissue involvement
pT4	Tumour involves any of the following: • diffuse chest wall soft tissue involvement • chest wall with rib involvement • mediastinal organs (oesophagus, trachea, heart, great vessels, spine) • direct extension through the diaphragm or pericardium • direct extension to contralateral pleura • malignant pericardial effusion

pN - Regional lymph nodes

The pN category corresponds to the cN category

Last edited: 16 January 2026 3:47 pm