CD3- and CD4-positive plasmablastic lymphoma: a literature review of Japanese plasmablastic lymphoma cases.

Plasmablastic lymphoma (PBL) is a very rare and recently-described subtype of diffuse large B-cell lymphoma. A maxillary tumor in an 84-year-old HIV-negative Japanese-man was referred. The biopsied specimen showed a diffuse proliferation of mature plasma cells, expressing CD3 (+), CD4 (+), CD20 (-), CD138 (+) and EBER (+) by immunohistochemistry. He was diagnosed as a plasmablastic lymphoma; radiation therapy (RT) was started, but the response to the RT was only a partial response. To our knowledge, this is the first report of a patient with PBL expressing CD3 and CD4.