Workup/Staging Flashcards
What are the common initial presenting Sx of MPM?
Dyspnea and nonpleuritic chest pain. Other common Sx include cough, pleural effusion, CW mass, weight loss, fever, and sweating.
What is the initial workup of a pleural-based mass seen on CXR?
Pleural-based mass initial workup: H&P, CBC, CMP, serum mesothelin-related protein (SRMP) and osteopontin levels (optional), CT chest + contrast, thoracentesis for cytology, and pleural Bx (thoracoscopic Bx [preferred], open Bx, or CT-guided core Bx). Consider talc pleurodesis or a pleural catheter for management of effusion.
What additional workup should be done with a Dx of MPM?
MPM workup: CT C/A/P + contrast, PET/CT, and MRI chest to determine if there is CW or diaphragmatic invasion. Consider mediastinoscopy or EBUS with FNA for suspicious nodes. Consider laparoscopy to r/o transdiaphragmatic extension if suggested by imaging. Use video-assisted thoracoscopic Sg to r/o contralat Dz, if necessary. Use PFTs to assess lung function.
How does MPM appear on chest imaging (CXR, CT)?
Large unilat pleural effusion and/or pleural thickening may be found on CXR. On CT of the thoracic chest, malignant MPM appears as pleural thickening with involvement of interlobar fissures/atelectasis, with possible pleural plaques and calcification. Effusions and contracted ipsi hemithorax are also commonly seen.
What is the DDx of tumors of the pleura?
Primary tumors (benign [empyema] or malignant), thymoma, sarcoma, or more commonly, metastatic Dz (i.e., adenocarcinoma).
What is the diagnostic yield of MPM from the fluid cytology of the pleural effusion?
Fairly poor, only ∼23%. Often, cytology finds atypical mesothelial cells only.
With a needle Bx, what entity is often confused with MPM? What additional procedures may be needed for definitive pathologic Dx of MPM?
Adenocarcinoma (metastatic) is often confused with MPM. Surgical intervention using video-assisted thorascopic surgery (VATS) biopsy or open thoracotomy may be needed for definitive pathologic Dx.
What pathologic features distinguish MPM from adenocarcinoma?
MPM is negative for periodic acid-Schiff stain, carcinoembryonic antigen, and Leu-M1. It is positive for calretinin, vimentin, WT1, and cytokeratin 5/6. In MPM, EM reveals that cells have long microvilli, in contrast to adenocarcinomas, which have short microvilli.
What biomarker is elevated in MPM?
SRMP could be elevated in 80% of pts, but has limited accuracy since it is not elevated in sarcomatoid lesions, and could be elevated in other cancers. The sensitivity of SRMPs range from 19%–68% (Hollevoet K et al., J Clin Oncol 2012). Other markers under evaluation include osteopontin and fibulin-3.
What is the AJCC 8th edition (2017) T staging of MPM?
Tx: Primary tumor cannot be assessed
T0: No evidence of primary tumor
T1: limited to ipsi parietal pleura, with or without visceral, mediastinal, and diaphragmatic pleural involvement
T2: involves each of the ipsi pleural surfaces (parietal, mediastinal, diaphragmatic, and visceral) with a pleural tumor, and at last (a) invasion of diaphragmatic muscle, or (b) invasion of lung parenchyma
T3: locally advanced but potentially resectable Dz and involves all ipsi pleural surfaces with at least 1 of the following: (a) involving endothoracic fascia, (b) invasion into mediastinal fat, (c) solitary focus of tumor invading soft tissues of CW, and (d) nontransmural involvement of pericardium
T4: locally advanced but technically unresectable Dz, with involvement of any ipsi pleural surfaces and at least 1 of the following: (a) diffuse or multifocal invasion of soft tissues of CW, with or without rib destruction, (b) direct transdiaphragmatic extension to peritoneum, (c) direction invasion of any mediastinal organs, (d) direct extension to contralat pleura, (e) invasion into spine, (f) extension to internal surface of pericardium, with cytology + or without pericardial effusion or invasion of myocardium
Describe the N staging of MPM according to the AJCC 8th edition (2017).
Nx: Regional LNs cannot be assessed
N0: No regional LN mets
N1: mets involving ipsi bronchopulmonary, hilar, or MNs (including IM, peridiaphragmatic, pericardial fat pad, or intercostal)
N2: mets to contralat mediastinal, ipsi or contra SCV nodes
Note: N3 is no longer part of the AJCC staging
Describe the overall stage groupings for MPM according to the AJCC 8th edition (2017).
Stage IA: T1N0
Stage IB: T2–3N0
Stage II: T1–2N1
Stage IIIA: T3N1
Stage IIIB: T1–3N2 or T4Nx
Stage IV: TxNxM1 (any distant metastasis)
Which histologic subtype of MPM has a worse prognosis?
The sarcomatoid type has the worse prognosis.
Name the 4 EORTC prognostic factors that generated the EORTC index for MPM.
EORTC poor prognostic factors for MPM that formed the EORTC index:
WBC >8.3 × 109/dL
PS 1–2
Sarcomatoid histology
Male gender
The CALGB has also evaluated a series of pts to identify 6 prognostic factors which have been validated in other series. These include pleural (vs. peritoneal or pericardial), serum LDH >500 IU/L, poor PS, chest pain, platelet count >400 K/ul, nonepithelial histology, and age >75.
What are the estimated 1- and 2-yr OS rates for EORTC low- and high-risk MPM?
Low risk: 1-yr OS 40%; 2-yr OS 14%
High risk: 1-yr OS 12%; 2-yr OS 0%
