Angioimmunoblastic lymphadenopathy type of T-cell lymphoma and angioimmunoblastic lymphadenopathy: a clinicopathological and molecular biological study of 13 Chinese patients using polymerase chain reaction and paraffin-embedded tissues

Diagnostic Impact of Molecular Lineage Analysis on Paraffin-Embedded Tissue in Hematolymphoid Neoplasia Reclassified by Current WHO Criteria

BACKGROUND AND OBJECTIVE

By current WHO criteria, most - though not all - cases of hematolymphoid neoplasm can be diagnosed immunomorphologically, diminishing the role of molecular tests for lymphoid antigen receptor clonality in lymphoma diagnosis. Hence, our objective was to glean immunomorphological and molecular correlates from hematolymphoid neoplasms that had remained unresolvable without diagnostic molecular input.

METHODS

Thirty-five such cases were reviewed histologically and with standard immunoperoxidases. In situ hybridization for Epstein-Barr virus (EBV)-encoded RNAs (EBER) was performed on selected cases. PCR amplification of genes encoding T-cell receptors (TcR) and immunoglobulin heavy chains (IgH) [TR and IGH genes, respectively] was performed on whole tissue in all cases, and on microdissected cells in two cases.

RESULTS

Twenty-five cases (71%) requiring diagnostic molecular genotyping had some form of peripheral T-cell lymphoma (PTCL). Twenty (80%) of these were complicated by a proliferation of B-lineage cells, either within the same tissue ('syntopic') as large B cells (LBC) or Reed-Sternberg (RS)-like cells (17 cases), florid lymphoid hyperplasia (two cases, one also with syntopic LBC) or monotypic plasma cells (one case), or at a separate ('metatopic') site as a B-cell lymphoma (two cases, one of which also had syntopic LBC) or Hodgkin lymphoma (HL; one case, also showing syntopic LBC). Fifteen (75%) of these 20 PTCLs with B-lineage proliferation yielded monoclonal TR gene rearrangements, and only two (10%) showed IGH monoclonality, which was transient in one case. Three (18%) of the PTCLs with LBC had originally been misinterpreted as some form of HL. Conversely, of the remaining cases, three of four (75%) that had been diagnosed initially as some form of large cell non-HL (NHL), including two of three that were called 'anaplastic', had to be revised to grade II/syncytial nodular sclerosing (NS) HL, yielding polyclonal TcRgamma gene (TRG) rearrangements, with one case, in addition, disclosing a biallelic clonal IGH gene rearrangement that excluded anaplastic large cell lymphoma.

DISCUSSION/CONCLUSION

Paradoxically, monoclonality of TR rather than IGH gene rearrangement may more often be detectable in a predominantly dispersed ('hodgkinoid'), large B-lineage cell proliferation, consistent with release from immune regulation in the milieu of impaired immunosurveillance within a PTCL. This is compounded by the difficulty in ascertaining clonal IGH gene rearrangements resulting from (1) poor consensus primer hybridization due to somatic hypermutations, and (2) 'dilution' in a T-cell-rich milieu. These same difficulties also account for the long-elusive identification of the RS cell lineage. Conversely, anaplastic lymphoma, which is of non-B lineage, may be mimicked by NSHL, which is of B lineage.

The frequency of B- and T-cell gene rearrangements and epstein-barr virus in T-cell lymphomas: a comparison between angioimmunoblastic T-cell lymphoma and peripheral T-cell lymphoma, unspecified with and without associated B-cell proliferations

We report on a series of 58 cases of angioimmunoblastic T-cell lymphoma (AILT) and 59 cases of peripheral T-cell lymphoma, unspecified (PTCL-NOS). Subsets of cases from both diagnostic groups were complicated by associated B-cell proliferations, and we performed B- and T-cell clonality studies and in situ hybridization for Epstein-Barr virus (EBV) to investigate the relationship between B-cell proliferation, B-cell clonality, and EBV. Using multiplex polymerase chain reaction assays based on the BIOMED-2 collaborative study, we detected TCRgamma T-cell clones in 78 and 81% of AILT and PTCL-NOS cases, respectively, and IGH B-cell clones in 34 and 35% of AILT and PTCL-NOS cases, respectively. The majority of cases contained EBV-positive cells, including 50% of AILT and 57% of PTCL-NOS cases, and cases with B-cell proliferations were more often EBV-positive. Although a relatively high rate of B-cell clonality has been shown for AILT, our findings for PTCL-NOS differ from previous reports in that B-cell clonality was relatively frequent. Overall, a positive B-cell clone correlated, in part, with the presence of a B-cell proliferation but not with EBV. Our findings demonstrate that B-cell clonality is a common finding in AILT and PTCL-NOS, and its presence should not negate the diagnosis established by morphologic, immunophenotypic, and clinical findings.

Analysis of T-cell subpopulations in T-cell non-Hodgkin's lymphoma of angioimmunoblastic lymphadenopathy with dysproteinemia type by single target gene amplification of T cell receptor- beta gene rearrangements

Angioimmunoblastic lymphadenopathy with dysproteinemia (AILD) is defined in the current lymphoma classifications as a T-cell non-Hodgkin's lymphoma. However, in approximately one third of the cases of this lymphoproliferative disease rearrangements of T-cell receptor (TCR) genes indicating clonal expansion of T cells are not detectable. It is currently believed that these cases may represent early stages of a lymphoma with a minor oligoclonal T-cell population. In the present study, 18 lymph nodes with the characteristic histology of AILD were investigated for clonal T-cell receptor gene rearrangements by analysis of DNA extracted from whole tissue sections. Dominant T-cell clones were detected in 12 of these cases. Single CD4(+) and CD8(+) T cells and proliferating Ki67(+) cells of seven cases were micromanipulated from frozen tissue sections. TCRbeta gene rearrangements were amplified from these cells by polymerase chain reaction and sequenced. In all informative cases, the clonal gene rearrangements were only detected among CD4(+), and not among CD8(+) T cells, indicating that the tumor clones in AILD usually derive from CD4(+) T cells. Minor clonal T-cell populations in those cases in which no clone was found by whole-tissue DNA analysis were not detectable even at single cell resolution. T-cell clones in 4 of 10 cases were found to express similar TCRbeta chains, indicating a potential role of (super) antigen triggering in at least some cases of AILD.

Epstein-Barr virus-associated intravascular lymphomatosis within Kaposi's sarcoma in an AIDS patient

Intravascular lymphomatosis (IL) is an unusual neoplasm characterized by multifocal proliferation of lymphoma cells exclusively within the blood vessels. We report here a patient with acquired immunodeficiency syndrome (AIDS) and disseminated Kaposi's sarcoma. A 233-bp amplification product of HHV-8 was detected in the DNA extracted from specimens of Kaposi's sarcoma at different sites by polymerase chain reaction (PCR). At autopsy, the vessels within the Kaposi's sarcoma were dilated and filled with atypical large mononuclear cells. No such feature was seen in the vessels of non-Kaposi's sarcomatous regions. Immunohistochemically, the spindle cells of Kaposi's sarcoma were positive for CD31 (endothelial cell marker). The intravascular tumor cells were positive for CD45 (leukocyte common antigen) but negative for others, including chloroacetate esterase, CD45-RO (UCHL-1, Pan-T), CD3, CD43, CD20 (L26, Pan-B), CD30 (Ki-1), immunoglobulin heavy chains and light chains, CD56 (natural killer cell antigen), and CD31. Monoclonal rearrangement of immunoglobulin heavy chain gene was detected in the DNA extracts from fresh tissue of Kaposi's sarcoma by PCR, which indicated that the lymphoma cells within the Kaposi's sarcoma were of monoclonal B cell origin. In situ hybridization revealed that EBER-1 transcripts were present in the lymphoma cells of IL but not in the spindle cells of Kaposi's sarcoma. To the authors' best knowledge, this is the first instance of IL in an AIDS patient with direct evidence of EBV association.

Nasal T/NK cell lymphoma: a clinico pathologic study of 30 west Chinese patients with special reference to proliferation and apoptosis

Midfacial T-cell lymphomas are more prevalent in Asia than in Europe or North America. Clinically, these lymphomas are noted as one major differential diagnosis in the malignant midline granuloma syndrome. During the past years, the group of nasal T/NK cell lymphomas has been recognized that is frequently associated with EBV-infection. The aim of the current publication was to describe the clinical presentation and course of 30 patients attending the West China University of Medical Sciences, Chengdu, P.R. China, between 1991 and 1994. Clinical records were assessed and the patients were followed for 6 to 29 (mean 12.4) months. Several microscopic features thought to be associated with this entity were carefully evaluated together with immunohistochemical data. The proliferation of the tumour cells was assessed by determining the mitotic index and the ratio of MIB-1 labelled cells. In addition, the incidence of apoptotic cells was investigated by means of the in-situ end labelling (ISEL) technique. Our data confirm the expression of T-cell markers by T/NK cell lymphomas as determined by the immunohistochemistry. The apoptotic index was found to correlate with the ratio of MIB-1 labelled cells. Expression of the bcl-2 oncoprotein was not associated with increased or diminished proliferation or cell death, respectively. Eight of the thirty patients succumbed to their disease during the follow-up period. Kaplan-Meier cumulative survivals and log-rank tests revealed a significant impact of MIB-1 labelling on mean survival times.