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Malignant pleural mesothelioma (MPM) is the most common primary malignancy of the pleura and is associated with asbestos exposure in approximately 80% of patients. The patient prognosis is poor, with a median survival of 9-17 months after diagnosis. However, improved survival and decreased morbidity and mortality have been demonstrated when the diagnosis is made in the early stages of disease and specific treatment strategies are implemented. A staging system that focuses on the extent of primary tumor (T), lymph node involvement (N), and metastatic disease (M) has been devised by the International Mesothelioma Interest Group and emphasizes factors related to overall survival. Radiologists should recognize the manifestations of MPM across multiple imaging modalities, translate these findings into the updated staging system, and understand the effects of appropriate staging on treatment and survival. Computed tomography (CT) remains the primary imaging modality used to evaluate MPM and efficiently demonstrates the extent of primary tumor, intrathoracic lymphadenopathy, and extrathoracic spread. However, additional imaging modalities, such as magnetic resonance (MR) imaging of the thorax and positron emission tomography (PET)/CT with fluorodeoxyglucose, have emerged in recent years and are complementary to CT for disease staging and evaluation of patients with MPM. Thoracic MR imaging is particularly useful for identifying invasion of the chest wall, mediastinum, and diaphragm, and PET/CT can accurately demonstrate intrathoracic and extrathoracic lymphadenopathy and metastatic disease.

Lymphoma is the most common hematologic malignancy and represents approximately 5.3% of all cancers. The World Health Organization published a revised classification scheme in 2008 that groups lymphomas by cell type and molecular, cytogenetic, and phenotypic characteristics. Most lymphomas affect the thorax at some stage during the course of the disease. Affected structures within the chest may include the lungs, mediastinum, pleura, and chest wall, and lymphomas may originate from these sites as primary malignancies or secondarily involve these structures after arising from other intrathoracic or extrathoracic sources. Pulmonary lymphomas are classified into one of four types: primary pulmonary lymphoma, secondary pulmonary lymphoma, acquired immunodeficiency syndrome-related lymphoma, and post-transplantation lymphoproliferative disorders. Although pulmonary lymphomas may produce a myriad of diverse findings within the lungs, specific individual features or combinations of features can be used, in combination with secondary manifestations of the disease such as involvement of the mediastinum, pleura, and chest wall, to narrow the differential diagnosis. While findings of thoracic lymphoma may be evident on chest radiography, computed tomography has traditionally been the imaging modality used to evaluate the disease and effectively demonstrates the extent of intrathoracic involvement and the presence and extent of extrathoracic spread. However, additional modalities such as magnetic resonance imaging of the thorax and (18)F-FDG PET/CT have emerged in recent years and are complementary to CT in the evaluation of patients with lymphoma. Thoracic MRI is useful in assessing vascular, cardiac, and chest wall involvement, and PET/CT is more accurate in the overall staging of lymphoma than CT and can be used to evaluate treatment response., (Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.)