Phenotypic heterogeneity displayed by T-non Hodgkin's lymphoma (T-NHL) cells dispersed from diagnostic lymph node biopsies

Molecular detection of a B cell clone in a case of PTCL in the absence of T cell clonality

In this paper we document a case of peripheral T cell lymphoma (PTCL) that exhibited variable T cell histology at presentation and follow-up. Southern blot analysis for T cell receptor (TCR) and immunoglobulin (Ig) receptor gene rearrangements failed to reveal clonal T or B cell populations. TCR gamma (TCRG) and beta (TCRB) chain gene polymerase chain reaction (PCR) amplification of DNA isolated from biopsies was also consistent with polyclonal T cell populations, however Ig PCR revealed clonal Ig rearrangements in follow-up biopsies but not in the presentation biopsy. There was no histological evidence for a neoplastic B cell population in these biopsies although occasional EB virus positive blasts were present. The significance of a cryptic B cell clone is unknown but suggests a relationship with the proliferating polyclonal T cells in this case of PTCL. These data reflect the complexity of PTCL with implications for treatment and patient management.

HLA antigen expression in enteropathy associated T cell lymphoma

AIMS

To investigate the occurrence of abnormal patterns of HLA-ABC and HLA-DR expression in enteropathy associated T cell lymphoma and to relate such abnormalities to the Epstein Barr virus (EBV) status of the tumours.

METHODS

Eleven enteropathy associated T cell lymphomas were immunostained with HC10 (HLA-ABC heavy chain) and TAL 1B5 (HLA-DR alpha chain) monoclonal antibodies and polyclonal anti-beta 2 microglobulin (beta 2m, the HLA-ABC light chain) antibodies. In situ hybridisation for EBV using EBER probes was performed on all cases.

RESULTS

Tumour cells of two of 11 patients were EBER positive. One of these showed partial, and the other, complete loss of beta 2m. HLA-DR expression was undetectable in both patients. Of the remaining nine EBER negative tumours, two were HLA-ABC heavy chain negative or showed only occasional positive cells and five of nine showed partial or complete loss of the HLA-ABC light chain, beta 2m. Seven of the nine cases were either negative for HLA-DR or showed weak expression in a proportion of tumour cells.

CONCLUSIONS

These data show that low or absent HLA-ABC and HLA-DR antigen expression occurs commonly in enteropathy associated T cell lymphoma. These abnormal patterns of HLA expression may be associated with escape from immune attack which, in a minority of patients, could be directed against EBV antigens.

Genotypic heterogeneity of node based peripheral T-cell lymphoma

PTCL represents a diverse group of histological entities that defy classification schemes based on normal T cell differentiation, differ in their clinical presentation and behave unpredictably. Genetic analyses of this phenotypically heterogeneous group have clearly shown that histologically defined PTCL may be subdivided on the basis of clonal gene rearrangements. The absence of clonal gene rearrangements in a significant proportion of PTCL cases has increased the complexity of classification. The data presented in this review suggest that a molecular classification would allow true reflection of PTCL aetiology, but carefully coordinated studies are required to evaluate the clinical usefulness of such a classification scheme.

Histologic, immunophenotypic and genotypic analyses of bone marrow trephines from patients with non-Hodgkin's lymphoma

Marrow involvement in 20 patients with non-Hodgkin's lymphoma (NHL) were studied by histology, immunophenotypic and genotypic methods. Eighteen of these trephines were histologically involved with recognizable lymphomatous infiltrates and five of these were the primary disease site. In the remaining two cases (with histologically involved lymph nodes) the trephines were uninvolved with tumour. Three B-cell cases expressing surface immunoglobulin (sIg) and/or CD37 and one case not analysed phenotypically showed Ig gene rearrangements. The two remaining cases with B NHL showed no gene rearrangements, however, in one of these the trephine was histologically uninvolved with tumour. Twelve out of 14 T-cell cases were characterized by variable or absent expression of one or more T-cell antigens from the tumour population, one case was negative for all T-cell antigens and the remaining case was not histologically involved with tumour. All three lymphoblastic lymphomas and only 4/11 peripheral T-cell lymphomas (PTCL) cases revealed T-cell receptor (TcR) gene rearrangements. One of the latter cases also exhibited Ig JH gene rearrangements. This study demonstrates the usefulness of bone marrow trephines (BMT) in histologic, phenotypic and genotypic analyses. However, although genotypic data confirm clonality in B NHL and the lymphoblastic lymphomas there was genotypic heterogeneity within the PTCL group.

Clonality of T cell and phenotypically undefined lymphoid neoplasms: the value of genotypic analyses

The value of genotypic analysis for routine assessment of leukaemia and lymphoma was shown by the findings in a selected series of 30 cases. T cell receptor (TcR) gene rearrangements were observed in six out of nine cases of CD3+ CD8+ lymphocytoses and provided clear evidence for clonality in this group. The T cell proliferations in two of the remaining cases masked B cell lymphocytic leukaemia and hairy cell leukaemia, while in the third case no cause was found for the polyclonal proliferation. Heterogeneity of phenotype and genotype were observed in peripheral T cell lymphomas: one out of six cases showed TcR gene rearrangement, one case retained its germline configuration, a further case masked B cell lymphoma and the remainder were polyclonal. Genotypic analysis was helpful in the analysis of a tumour of mixed T cell and myeloid phenotype which was shown to be germline for TcR and immunoglobulin genes, consistent with a myeloid origin. Two histiocytic tumours were found to have clonal rearrangement of TcR genes. Nine out of 11 B cell tumours showed immunoglobulin gene rearrangement. It is concluded that genetic analyses are useful in the analysis of T cell, histiocytic, and B cell tumours in which an immunoglobulin phenotype cannot be defined.

What's new in the lymphocyte phenotype?

It is a relatively short period of time since the demonstration of surface immunoglobulin by immunofluorescence and the technique of cell surface rosetting first enabled in the identification of lymphocyte subsets. When we now examine the range of monoclonal antibodies which are available to lineage specific and lineage related epitopes the early methods used for the characterisation of normal or abnormal lymphocyte populations seem amazingly crude. The initial development by Kohler and Millstein of techniques for hybridising antibody producing cells to establish continuous lines and their development by large numbers of workers worldwide have provided a vast array of reagents available for cell phenotyping, ranging from the simplest diagnostic determinations to the sophisticated analysis of lymphocyte subsets in development. Indeed, so great is the array of monoclonal antibodies available that the nomenclature has been standardised at four international workshops. The basic aim of these workshops has been to establish a standardised system for the identification of the different monoclonal antibodies available for staining lymphocytes and also to officially allocate antibodies to these groups. A wide range of techniques are employed by the many groups who contribute to these workshops in order to achieve these results. Despite these basic aims, it is also clear that a considerable amount of functional and molecular biological information has come from these large group studies. At the Oxford Workshop, held in 1986, the number of identified "Clusters of Differentiation" (CD) reached the figure 45.(ABSTRACT TRUNCATED AT 250 WORDS)

Clinical implications of the histopathologic diagnosis of pulmonary lymphomatoid granulomatosis

We reviewed the epidemiologic, laboratory, roentgenographic, pulmonary function, and survival data from 28 patients who had a histologic diagnosis of lymphomatoid granulomatosis (LG) with involvement of the lungs. The mean age at the time of diagnosis was 51 years, and the male-to-female ratio was 3:2. Ten patients had other underlying diseases before LG was diagnosed. The most prominent symptoms were cough, dyspnea, fever, and rash, which were usually present for several months before diagnosis of LG. Multiple nodules were detected on a chest roentgenogram in 68% of the patients. Immunoglobulin concentrations were abnormal in 8 of 12 patients studied. Although bronchoscopy established the diagnosis in approximately a third of the patients who underwent this procedure, open-lung biopsy was uniformly diagnostic. The median survival was 72 months, with follow-up through 12 years. In 11 patients, the original diagnosis of LG was eventually changed to lymphoma. In five of these patients, the change in diagnosis was based on immunohistologic data obtained shortly after LG was discovered. Lymphoma diagnosed in this way was associated with a better prognosis than lymphoma diagnosed on the basis of conventional histopathologic findings. In three patients, solid tumors eventually developed. The diversity of clinical outcomes and frequent revisions of the diagnosis led us to consider the possibility that LG may also represent a histopathologic finding that occurs transiently in several disease processes.

Peripheral T cell lymphoma: value of bone marrow trephine immunophenotyping

Bone marrow infiltrates taken from 11 patients with peripheral T cell lymphoma were immunophenotyped as T cell lymphoma using monoclonal antibodies on frozen bone marrow trephine biopsy specimens. In nine these were taken at diagnosis and in two after failure of treatment to eradicate lymphoma in the marrow. Patterns of infiltration were as follows: diffuse (n = 4), interstitial (n = 1), nodular (n = 1), focal (n = 5). All cases were CD3 positive and 10 were CD2 positive; five lacked expression of either CD5 or CD7, or both markers. In nine the determination of T cell phenotype depended on analysis of the frozen bone marrow trephine biopsy specimen as there was no other biopsy tissue available for study. In the other two cases there was agreement between the immunophenotypes seen in lymph node and bone marrow infiltrates.

Correlation between histology and immunophenotype in a series of 322 cases of non-Hodgkin's lymphoma

The non-Hodgkin's lymphomas (NHL) are a heterogeneous group of lymphoid neoplasms displaying a wide variation in cell morphology, histological patterns, immunological phenotype and prognosis. In this paper we compare the results of phenotypic investigation of 322 tissue biopsies with the histology based on the Kiel classification. Immunological analysis revealed that 81 per cent of these tumours were of B cell origin, 12 per cent of T cell origin and the remaining 7 per cent could not be characterized as representing either cell lineage. This last group included a number of cases which had received a histological diagnosis of true histiocytic lymphoma. The original morphological diagnosis, based on routine haematoxylin and eosion sections correlated with the immunologically determined phenotype in 86 and 93 per cent of the T- and B-cell cases respectively. The B cell tumours were phenotypically heterogenous with respect to immunoglobulin (Ig) heavy chain and B lymphocyte subset marker expression. IgG was most often found associated with NHL of cb/cc histology and a small subgroup of lymphocytic NHL. IgA expression was uncommon and occurred in combination with IgD and G in three cases and alone in two cases of NHL. The most common immunoglobulin isotype expressed was IgM this isotype occurred with IgD most often in lymphocytic and centrocytic NHL and less often in tumours of cb/cc histology. Whilst greater than 90 per cent of the lymphocytic NHLs expressed the CD5 antigen, between 20 and 75 per cent of B-cell tumours of other histologies also expressed this epitope. The CD10 antigen and the epitope recognized by the monoclonal reagent FMC7 were widely distributed on tumour cells from all histologies. TdT expression commonly regarded as a marker for immature cells was found in one case of follicle centre cell lymphoma. All cases of T cell NHL displayed marked heterogeneity for both pan T and T subset antigens which is significant in terms of the routine diagnosis of T NHL and with regard to the rational classification of node based T NHL. Unlike resting peripheral blood T cells, MHC class II, OKT 10 and CD25 epitopes were expressed reflecting activation of tumour populations.(ABSTRACT TRUNCATED AT 400 WORDS)

Phenotypic and genotypic heterogeneity of peripheral T-cell lymphoma

A series of 21 phenotypically characterised T-cell lymphomas histologically defined as lymphocytic, lymphoblastic, immunoblastic, AILD type, pleomorphic, T-zone and Lennert's T-cell lymphoma, were investigated for T-cell receptor (TcR) and immunoglobulin (Ig) gene rearrangements. Phenotypic analyses of frozen sections and cell suspensions were heterogeneous and in many cases no single T-cell marker recognised all of the malignant cells. Data derived by staining with antibodies reactive with antigens in paraffin embedded tissue were consistent with T NHL in all cases except lymphoblastic lymphoma. TcR gene rearrangements were observed in lymphocytic, lymphoblastic and immunoblastic lymphoma, however, in the remaining 14 phenotypically and histologically defined peripheral T-cell lymphomas, 2 showed rearrangement of TcR gamma and beta genes consistent with T NHL and 2 showed Ig JH rearrangements only, suggestive of either reactive T-cell populations masking cryptic disease or presence of tumour populations with aberrant gene rearrangement and expression of T lineage antigens. No Ig or TcR gene rearrangements were found in the remaining 10 cases, in which morphologically identifiable tumour cells comprised 10-90% of the cell population. In 3/6 cases tested some CD3 positive cells failed to stain with WT31 or beta F1, monoclonal antibodies that recognise determinants on combined TcR gamma beta or TcR beta chains respectively. Whether these cases represent tumours arising from an undetermined cell of origin or polyclonal expansions of T-cells remains to be determined. Our results confirm the phenotypic heterogeneity of histologically defined peripheral T-cell lymphoma and indicate that in these particular histological subtypes gene rearrangement analysis can also yield heterogeneous results which may be unhelpful in determining cell lineage and clonality.

The value of immunocytochemical staining of lymph node aspirates in diagnostic cytology

This study investigates the applicability of immunocytochemical techniques towards improving the cytological diagnosis of lymph node disorders. Cytocentrifuge preparations of fine needle aspirates were examined using an indirect immunoperoxidase method and the alkaline phosphatase-antialkaline phosphatase method. 36 reactive lymph nodes were evaluated. 23 patients showed T cell predominance as assessed by the presence of CD3+ cells. 13 patients showed an excess of CD24+ cells over CD3+ cells. In all patients the B cell population showed no light chain class restriction. 48 aspirates from patients with B-non-Hodgkin's lymphoma of low malignancy were investigated. The majority of the cells in each of these cases expressed CD24 and 47 cases were monoclonal with respect to their light chain determinants. In 37/48 cases the antibody OKT9 reacted with less than 15% of cells. 18 aspirates were obtained from patients with B-non-Hodgkin's lymphoma of high malignancy. 17 patients showed light chain class restriction and a high percentage of CD24+ (greater than 80%) and OKT9+ (greater than 40%) cells. 8 malignancies were considered to be of T-cell origin. A low percentage (less than 15%) of Ig+CD24+ cells with a high number of CD3+ and/or CD4+ cells suggests a T-cell lymphoma. The majority of neoplastic cells in peripheral T-cell lymphomas (excluding mycosis fungoides) expressed OKT9 and CD3 expression was found to be variable. In 15 cases of Hodgkin's disease, there were 11 correct cytologic diagnoses. A significant number of BerH2 (CD30)+ cells having the morphology of Sternberg-Reed cells supports this diagnosis. 25 aspirates were obtained from patients with metastatic malignant tumours. Marker studies in eight cases helped in distinguishing metastatic malignant tumours from malignant lymphomas. Our findings indicate that the immunocytochemical technique is applicable to cytological material and that the simplicity of the procedure merits application to routine diagnostic cytology.

A simple guide to the terminology and application of leucocyte monoclonal antibodies

This review aims to provide a simple guide and quick reference to the terminology and diagnostic applications of leucocyte monoclonal antibodies. The differentiation cluster terminology, where applicable, is used throughout.

A comparison of three methods for the determination of the growth fraction in non-Hodgkin's lymphoma

The proliferation rate of non-Hodgkin's lymphomas (NHL) was estimated by using 3 different methods. In cell suspension we determined the proportion of cells in cycle with the monoclonal antibody (Mab) Ki-67 and also in S-phase after the incorporation of bromo-deoxyuridine (BrdU) utilizing Mab anti-BrdU. In low grade lymphomas 3.5 +/- 1.6% of the cells were in cycle and 1.2 +/- 0.9% in S-phase, the corresponding values for high grade lymphomas were 22.5 +/- 18.7% and 8.9 +/- 7.8% respectively. Frozen sections of NHL were reacted with an antibody to the transferrin receptor (TR) and Ki67 as markers for proliferative activity. A high number of TR positive cells was found in low grade lymphomas of all histological types, whereas Ki67 positivity correlated closely with grading. With a few exceptions, low grade lymphomas contained less than 25% Ki67 positive cells within the tumour cell population. This observation is relevant to treatment strategies for low grade NHL.

An investigation of Ki-1 positive large cell lymphoma with antibodies reactive with tissue macrophages

The diagnosis of true histiocytic lymphoma (THL) represents one of the most difficult and controversial areas of lymph node pathology. Recently, Stein et al. (1985) have demonstrated that a series of tumours presenting with morphological and immunocytochemical features, previously considered as being indicative of THL, share antigenic markers with Reed-Sternberg and mononuclear Hodgkin's cells and, therefore, may be derived from lymphocytes, rather than histiocytes. In this study we have re-investigated some of these cases with a panel of monoclonal antibodies variously reactive with macrophages. Although all cases contain a heavy infiltrate of reactive histiocytes the tumour populations are negative for histiocyte antigens.