Fact-sheet: Thoracic lymphoma
Updated on 06/30/2020 at 8:44 AM
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Definition
In France, the incidence of Hodgkin lymphoma is approximately 1,500 cases. For non-Hodgkin lymphomas, the incidence exceeds 10,000, making them the sixth most common cancer.
Thoracic involvement in lymphoma can be divided into mediastinal involvement, by far the most common, and parenchymal, pleural, or chest wall involvement.
Radiography
Radiologic workup of Hodgkin lymphoma always includes a frontal chest radiograph, whose sole purpose is prognostic, as it allows measurement of the mediastinal-thoracic ratio.
This ratio is calculated by measuring the maximal width of the mediastinal mass divided by the internal thoracic diameter at the level of T6.
A mediastinal-thoracic ratio greater than 0.35 defines a bulky mediastinum, associated with a worse prognosis.
CT
Primary mediastinal B-cell lymphoma: anterior mediastinal mass infiltrating the thymus, outlining a thymic shape on coronal reconstructions.
Lymphoblastic lymphoma: large compressive mediastinal masses associated with superior vena cava syndrome, as well as pericardial and pleural involvement causing dyspnea.
MALT lymphoma: The most typical presentation is a single mass with ill-defined margins, though lesions may sometimes be multiple and bilateral.
A suggestive sign is the presence of an air bronchogram within the masses, reflecting development of the lymphomatous proliferation from the bronchial wall mucosa.
These masses may be associated with pulmonary nodules
Diffuse large B-cell lymphoma: large pulmonary mass associated with satellite lymphadenopathy or multiple pulmonary nodules with a "cannonball" appearance.
Lymphomatoid granulomatosis: multiple nodules of variable size, predominating in the lower lobes with a peribronchovascular or septal distribution. These nodules sometimes have well-defined margins but may also appear as ground-glass opacities.