[Primary mediastinal large B-cell lymphoma: histopathologic features. A specific tumour].

The diffuse large B-cell lymphomas of the mediastinum were long considered to be a variant of the classic forms of large B-cell lymphomas. However, their clinical and radiological features and especially their histopathological variants point to other lymphoid tumours such as Hodgkin's disease or anaplastic lymphomas, thymic tumours, germ cell tumours or metastatic tumors. The immunohistochemical findings are of prime importance in the diagnosis. This has recently been completed by molecular studies. Currently, they represent a distinct entity among the large B-cell lymphomas, due to their clinical, pathological and molecular features as well as the outcome. The authors report a new case in a young man.