T-cell/histiocyte-rich large B cell lymphoma Monirath Hav, MD, PhD fellow Pathology Department Ghent University Hospital.

T-cell/histiocyte-rich large B cell lymphoma

Monirath Hav, MD, PhD fellowPathology Department

Ghent University Hospital

   Diffuse large B-cell lymphoma (DLBCL), NOS 

         T-cell/histiocyte rich large B-cell lymphoma 

         Primary DLBCL of the CNS 

         Primary cutaneous DLBCL, leg type 

         EBV+ DLBCL of the elderly* 

WHO Classification of Tumours of Haematopoietic and Lymphoid Tissues2008 edition

Introduction

- Characterized by a limited number of scatterd, large, atypical B cells

embedded in a background of abundant small T cells and frequently

Histiocytes- Age: mainly middle-aged men (12-61 yo, 75% cases are male)- Refractory to present chemotherapy- Postulated normal counterpart: germinal center B cell

Morphology

• Diffuse or less commonly vaguley nodular growth pattern• Scattered, single, large B cells (<10%) embedded in the

background of small T lymphocytes and variable numbers of histiocytes

• Tumour cells do not form aggregrates or sheets and mimic popcorn cells in NLPHL but usually show a more pronouced variation in size

• Cases in which tumour cells form sheets or nests should be classified as a subtype of DLBCL, NOS

• Eosinophils and plasma cells are not found

Immunophenotype

• The large atypical cells are:– Positive for pan B cell markers, BCL6 & some for BCL2 &

EMA– Negative for CD15, CD30, & CD138

• The background is composed of CD68+ histiocytes and CD3, CD5 & CD8 + T cells

• Unlike in NLPHL, rosettes of T-cells around the tumour cells are not found in THRLBCL

Differential diagnosis

Main DD: NLPHL rosettes of T cells around tumour cells, usually no BM involvement, CD57+, small B cells in the background

Prognosis

• Aggressive lymphoma

• Refractory to presently available therapy

• IPI score is the only parameter of prognostic significance

LHRLBCL Vs NLPHL - similarities

• Predilection for middle-aged men• Both derived from germinal center B cells• Diffuse or vague nodularity growth pattern• Eosinophils and plasma cells are seldom seen• Large atypical tumour cells are (+) for CD20, CD79a, PAX5, CD45,

CBL6, & BCL2 in the background of small CD3 + cells

• Large atypical tumour cells are (–) for CD30* & CD15

• Large atypical tumour cells are usually EBV (–)

LHRLBCL Vs NLPHL - differences

LHRLBCL NLPHL- CD20 + small reactive B cells are rare or absent in the background- CD8 + cells & histiocytes are common

- CD3 + cells do not form rosettes around tumour cells

- CD21+ FDC are absent- BM, spleen or liver involvement is frequent

- Aggressive lymphoma, refractory to current therapy

- CD20 + small reactive B cells are numerous in the background

- CD4 and CD57 + cells are common

- CD3 & CD57 + cells form rosettes around tumour cells

- CD21+ FDC form expanded meshwork

- BM, spleen, or liver involvement is rare

- Non agressive lymphoma, responsive to therapy (10 y OS >80% for stage I & II)

References

1. WHO classification of Tumours of Haematopoietic and Lymphoid Tissues, 2008 edition

2. Frank X. Zhao. Nodular Lymphocyte-Predominant Hodgkin Lymphoma or T

cell/Histiocyte Rich Large B-cell Lymphoma: The Problem in “Grey Zone” Lymphomas.

Int J Clin Exp Pathol (2008) 1, 300-305

3. Ludmila Boudova et al. Nodular lymphocyte–predominant Hodgkin lymphoma with

nodules resembling T-cell/histiocyte-rich B-cell lymphoma: differential diagnosis between

nodular lymphocyte–predominant Hodgkin lymphoma and T-cell/histiocyte-rich B-cell

lymphoma. Blood. 2003;102:3753-3758.

4. Megan S. Lim et al. T-Cell/Histiocyte-Rich Large B-Cell Lymphoma: A Heterogeneous

Entity With Derivation From Germinal Center B Cells. Am J Surg Pathol 26(11): 1458-

1466, 2002.

5. Á. Illés et al. Nodular Lymphocyte Predominant Hodgkin Lymphoma (NLPHL)

Clinicopathological Features Based on the Data of Two Hungarian Lymphoma Centres.

Pathol. Oncol. Res. (2008) 14:411–421