Pleura & peritoneum



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PubMed Search: Mesothelioma staging pleura

Debra L. Zynger, M.D.
Andrey Bychkov, M.D., Ph.D.
Page views in 2022: 550
Page views in 2023 to date: 471
Cite this page: Zynger DL, Bychkov A. Staging. website. Accessed November 28th, 2023.
Definition / general
  • All diffuse malignant pleural mesothelioma are covered by this staging system
  • This staging system does not apply to localized malignant pleural mesothelioma, solitary fibrous tumor, peritoneal mesothelioma, lymphoma or sarcoma
  • Clinical staging relies primarily on imaging, most frequently CT, sometimes FDG PET / CT and MRI
  • Pathological staging is based on surgical resection
  • T category staging is descriptive without a size criterion
  • Other staging systems also exist (Brigham staging, Butchart staging) (Semin Thorac Cardiovasc Surg 1997;9:356)
Essential features
  • AJCC 7th edition staging was sunset on December 31, 2017; as of January 1, 2018, use of the 8th edition is mandatory
  • T, N and M categories predict outcome of patients with malignant pleural mesothelioma
  • Tumor histology (epithelioid versus sarcomatoid) is an important prognostic factor beyond TNM
ICD coding
  • ICD-O: C38.4 - pleura, NOS
  • ICD-10: C38.4 - malignant neoplasm of pleura, NOS
Diagrams / tables

Images hosted on other servers:

Simplified chart

Clinical features
  • The most frequent sites of metastatic disease are the contralateral pleura and lung, peritoneum, extrathoracic lymph nodes, bones and liver
  • Tumor histology is an important prognostic factor: epithelioid tumors have a better prognosis than biphasic or sarcomatoid tumors, while desmoplastic malignant mesothelioma has the worst prognosis (J Thorac Oncol 2012;7:1631)
  • Major variables from the largest international database (J Thorac Oncol 2012;7:1631):
    • Median age: 63 years; 79% men, 62% epithelioid tumor
    • Stage I (11%), stage II, (21%), stage III (48%) and stage IV (20%)
    • Median survival by TNM stage: 21 months (stage I), 19 months (stage II), 16 months (stage III) and 12 months (stage IV)
    • Median survival by histology: epithelioid 19 months, biphasic 13 months and sarcomatoid 8 months
Primary tumor (pT)
  • pTX: cannot be assessed
  • pT0: no evidence of primary tumor
  • pT1: tumor limited to the ipsilateral parietal surface with or without involvement of visceral pleura, mediastinal pleura or diaphragmatic pleura
  • pT2: tumor involves each of the ipsilateral pleural surfaces (parietal, mediastinal, diaphragmatic and visceral pleura) and has at least one of the following
    • Diaphragmatic muscle involvement
    • Extension from visceral pleura into the underlying pulmonary parenchyma
  • pT3: tumor is locally advanced but potentially resectable; tumor involves all the ipsilateral pleural surfaces (parietal, mediastinal, diaphragmatic and visceral pleura) and has at least one of the following
    • Endothoracic fascia involvement
    • Mediastinal fat involvement
    • Solitary completely resectable focus of tumor extending into soft tissue of chest wall
    • Nontransmural involvement of the pericardium
  • pT4: tumor is locally advanced and technically unresectable; tumor involves all the ipsilateral pleural surfaces (parietal, mediastinal, diaphragmatic and visceral pleura) and has at least one of the following
    • Diffuse extension or multifocal masses in chest wall
    • Direct transdiaphragmatic extension to peritoneum
    • Direct extension to the contralateral pleura
    • Direct extension to mediastinal organs
    • Direct extension into spine
    • Extension to internal surface of the pericardium
    • Myocardium involvement
Regional lymph nodes (pN)
  • pNX: cannot be assessed
  • pN0: no regional lymph node metastasis
  • pN1: metastases in the ipsilateral bronchopulmonary hilar or mediastinal (including the internal mammary, peridiaphragmatic, pericardial fat pad or intercostal) lymph nodes
  • pN2: metastases in the contralateral mediastinal, ipsilateral or contralateral supraclavicular lymph nodes
Distant metastasis (pM)
  • pM0: no distant metastasis
  • pM1: distant metastasis
  • y: preoperative radiotherapy or chemotherapy
  • r: recurrent tumor stage
AJCC prognostic stage groups
Stage group IA:  T1   N0   M0
Stage group IB:  T2 - 3   N0   M0
Stage group II:  T1 - 2   N1   M0
Stage group IIIA:  T3   N1   M0
Stage group IIIB:  T1 - 3   N2   M0
 T4   any N   M0
Stage group IV:  any T   any N   M1
Registry data collection variables
  • Histologic type
  • Age, sex
  • Performance status
  • Laboratory parameters (white blood cells, platelet count and hemoglobin)
  • Surgical resection with curative intent (pleurectomy / decortications, extended pleurectomy / decortications or extrapleural pneumonectomy)
  • For patients undergoing multimodality therapy, use of chemotherapy or radiotherapy
  • Comment: these are supplementary factors recommended for clinical care owing to their prognostic significance (J Thorac Oncol 2014;9:856)
Histologic grade (G)
  • GX: cannot be assessed
  • G1: well differentiated
  • G2: moderately differentiated
  • G3: poorly differentiated
  • G4: undifferentiated
Histopathologic type
  • Epithelioid
  • Biphasic (at least 10% of epithelioid and sarcomatoid)
  • Sarcomatoid
  • Desmoplastic
Board review style question #1
A 59 year old man presented with a 2 cm malignant pleural tumor with focal extension to the underlying lung parenchyma. Biopsy revealed well differentiated epithelioid malignant pleural mesothelioma confirmed by BAP1 immunostaining. What is the pT category using the AJCC / TNM 8th edition?

  1. pTX
  2. pT1
  3. pT2
  4. pT3
  5. pT4
Board review style answer #1
C. pT2. Extension of malignant mesothelioma from visceral pleura into the underlying pulmonary parenchyma qualifies as the pT2 category.

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Reference: Pleura - Staging
Board review style question #2
Which of the following is a major prognostic factor of malignant mesothelioma (other than TNM variables)?

  1. Duration of asbestos exposure
  2. Family history
  3. Genetic / mutation signature
  4. PDL1 expression by microenvironment
  5. Tumor histology
Board review style answer #2
E. Tumor histology is the major prognostic factor beyond TNM (epithelioid tumors have better prognosis than sarcomatoid).

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Reference: Pleura - Staging
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