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

Abstract

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.

Keywords: Nodular lymphocyte-predominant Hodgkin lymphoma; T-cell/histiocyte rich large B-cell lymphoma; “grey zone” lymphoma.

Figure 1

Nodular lymphocyte-predominant Hodgkin lymphoma. A. Vague nodules with mottled areas (H&E, 100×). B. Large atypical lymphocytic and histiocytic (L&H) cells in a background of reactive small lymphocytes (H&E, 1000×).

Figure 2

T-cell/histiocyte rich large B-cell lymphoma of the bone marrow. A. Singly distributed large atypical cells in a background of small lymphocytes (H&E, original magnification: 1000×). B. The large atypical cell is CD20+, whereas the background small lymphocytes are CD3+ (not shown) (immunoperoxidase, original magnification: 1000×). C. The large atypical cell is also positive for cytoplasmic CD79a (immunoperoxidase stain, 1000×).

Figure 3

Natural course of progressively transformed germinal centers (PTGC), nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL) and T-cell/histiocyte rich large B-cell lymphoma (T/HRBCL). PTGC occurs in response to aberrant antigen stimulation or cytokine secretion, which, if persists, could lead to dominance of one particular clone of germinal center B-cells. The clonal B-cells reside in the meshwork of follicular dendritic cells surrounded by reactive mantle zone B-cells and CD4+/CD57+ T-cells (NLPHL). These clonal B-cells could remain indolent for many years until additional genetic “hits” transform them into aggressive neoplastic B-cells (T/HRBCL).