Nodular lymphocyte-predominant hodgkin lymphoma or T-cell/histiocyte rich large B-cell lymphoma: the problem in "grey zone" lymphomas.

Nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL) is a rare indolent B-cell lymphoma. However, its morphology can resemble T-cell/histiocyte rich large B-cell lymphoma (T/HRBCL), a subtype of more aggressive diffuse large B-cell lymphoma. More and more studies suggest that these two entities are closely related. In this report, a 59-year-old man with nodal NLPHL and concomitant T/HRBCL in the bone marrow is presented, the current progress in our understanding of these two closely related B-cell lymphomas reviewed and the problems in the diagnosis and differentiation of NLPHL and T/HRBCL discussed.