MORPHOIMMUNOLOGIC CHARACTERIZATION OF LARGE-CELL MEDIASTINAL LYMPHOMAS
The purpose of this study was to analyze morphoimmunologic features of large-cell mediastinal lymphomas, i. e. primary mediastinal large B-cell lymphoma and Hodgkins lymphoma with nodular sclerosis. Morphologic and immunohistochemicl analysis of tumor tissue specimens from 31 patients with primary mediastinal large B-cell lymphoma and 20 patients with Hodgkins lymphomawas made. A case of gray zone lymphoma was identified. Immunohistochemical study was done by standard assay using 8 markers such as CD10, CD11c, CD23, MUM1, c-REL, TRAF1, HLA-DR. Nuclear oncoprotein c-REL was found in 24 (77%) and cytoplasmatic reactivity with TRAF1 was seen in 80% of primary mediastinal large B-cell lymphoma cases. In contrast, none of Hodgkins lymphomas presented with nuclear c-REL. The conclusion was made that NF-B signaling activation markers (c-REL and TRAF1) were very useful and might be recommended for differential diagnosis of primary mediastinal large B-cell lymphoma from Hodgkins lymphoma.