Mesothelioma

Corinne E Sadowski, MD
Kathleen S Lee, MD
Robert D Pugatch, MD

October 5, 1995

Presentation

A 62-year-old man presented with shortness of breath and known history of asbestos exposure.

Imaging Findings

Plain radiographs, PA and lateral

Axial CT

Axial T1-weighted MRI

Posteroanterior (PA) and lateral plain radiographs demonstrate a circumferential irregular lobular opacity involving the right hemithorax with a well defined inner border (PA with arrows) (Lateral with arrows). Mass effect is visible with deviation of the trachea (arrows) and mediastinum to the left. The lateral view demonstrates that the opacity infiltrates the minor (arrow) and major (arrow) fissures. No calcification is present. There is no associated rib destruction.

Axial computed tomography (CT) confirms the pleural-based soft tissue mass (arrow) with involvement of the fissures (arrows).

Axial T1-weighted magnetic resonance imaging (MRI) demonstrates this mass (2.5 cm thick) to abut the mediastinum (first image with arrows) (second image with arrows), encase the right pulmonary artery (RPA) and cross the midline both anteriorly and posteriorly (first image with arrow) (second image with arrow). Lymphadenopathy is present in the right precarinal (arrow) and subcarinal (arrow) regions. On additional imaging, neither effusion, nor diaphragmatic or chest wall invasion is documented.

Differential Diagnosis

A circumferential pleural mass with the imaging characteristics described above is likely to be malignant. Metastases, predominantly adenocarcinoma (especially lung, breast, GI, kidney and ovaries) thyroid or melanoma, often result from peripheral pulmonary tumor emboli with resultant pleural involvement. Diffuse mesothelioma can have this radiographic appearance. Lymphoma, most commonly Hodgkin's disease (both the intrapulmonary and extrapulmonary forms), can have direct pleural involvement. Malignant thymoma can present as an anterior mediastinal mass that contiguously spreads to involve pleura. Less likely considerations include focal post inflammatory thickening; however, there is usually associated parenchymal disease. Splenosis related to prior splenic trauma with diaphragmatic rupture could have similar pleural thickening but should not have lymph node enlargement. Finally, a loculated pleural effusion could have such pleural thickening.

Diagnosis

Diffuse malignant mesothelioma

Discussion

The development of malignant mesothelioma has a strong correlation with asbestos exposure. Five to ten percent of those exposed develop the disease after a 20-40-year latency.

Histologically, epithelial sarcomatous subtypes are apparent. Radiographically, other stigmata of asbestos exposure such as contralateral pleural plaques, focal pleural thickening, pleural calcifications or effusions may be present but are not obligatory. Spread of the disease can either be contiguous with extension through the chest wall and diaphragm, or hematogenous predominantly to lung and lymph nodes. The Burchart staging is as follows:

I. Involvement of the ipsilateral parietal pleura diaphragm or pericardium
II. Invasion into the chest wall or mediastinum, mediastinal lymph nodes
III. Penetration of the diaphragm, contralateral pleural disease, or extrathoracic lymph nodes
IV. Hematogenous metastases

Extrapleural pneumonectomies are reserved for stage I and II disease.

References

1. Freundlich IM, Bragg DB. A radiologic approach to diseases of the chest. Philadelphia: Williams and Wilkins, 1992.

2. Frasier RG, Pare JAP, Pare PD, Frasier RS, Genereux GP. Diagnosis of diseases of the chest. 3rd ed. Philadelphia: WB Saunders, 1991.

Return to the Teaching Case Database search page
Return to Professional Education
About BrighamRAD

Dear Visitors: Nothing on this World Wide Web site should be considered medical advice. Only your own doctor can help you make decisions about your medical care. It is not the policy of the Brigham and Women's Hospital Department of Radiology to provide consultation on the World Wide Web or via e-mail. If you have a specific medical question or are seeking medical care, please call the Brigham and Women's Hospital toll-free physician referral line at 1-800-294-9999.

Is this a mirrored page?
The official homepage of the BrighamRAD Teaching Case Database is http://brighamrad.harvard.edu/education/online/tcd/tcd.html

Contact the BrighamRAD Design Team for additional information about this website.