[Radiological features of thoracic localizations of lymphomas]

This retrospective work aims to analyse the incidence and the radiologic features of initial thoracic involvement of lymphomas, observed in 320 patients selected among 1,153 lymphomas (640 Hodgkin's diseases and 513 non-Hodgkin's lymphomas). Thoracic involvement was not observed in 833 (72%) patients with lymphoma. In Hodgkin's disease (HD) (n = 200) thoracic involvement was observed in 31% (200/640). The mediastinal lymph nodes were noted in 99.5% and predominated in the superior and mid mediastinum in 84.5%. Mediastino-thoracic ratio was superior to 0.33 in 33.5%. Unilateral paratracheal nodes were involved in 26% and the hilar groups in 39.5%. The lung involvement was present in 26.5%, such as nodules in 11% and alveolar infiltration in 6.5%. In the cases with lung involvement, there were concomitant mediastinal lymph nodes. Pleural and pericardial effusions were seen in 23.5% and 4%. Parietal involvement was noted in 1%. In non-Hodgkin's lymphomas (NHL) (n = 120) thoracic involvement was observed in 23% (120/513). The mediastinal lymph nodes were seen in 82.5%, located in superior and mid mediastinum in 60%. Mediastino-thoracic ratio was superior to 0.33 in 47%. Lymph nodes were unilateral paratracheal in 7.5% and hilar in 18%. The posterior mediastinal lymph nodes group was involved in 2%. Lung involvement was noted in 24%, pleural effusion in 48%, pericardial effusion in 4% and parietal involvement in 2.5%. In the cases of thoracic involvement in HD, mediastinal lymph nodes involvement is constant, affecting commonly the anterior mediastinal, paratracheal and hilar groups. Involvement of the posterior mediastinum and paracardiac groups is more common in NHL. Thoracic computed tomography is helpful in the detection of the abnormalities misdiagnosed on the chest X-ray. Computed tomography is valuable in the initial stages of HD because it can modify the treatment in 15%.