High incidence of EBV genome in CD30-positive non-Hodgkin's lymphomas

Skin-Limited, Methotrexate-Associated Epstein-Barr Virus-Positive Mucocutaneous Ulcer-A Mimicker of High-Grade Lymphoma. A Report of 4 Cases and Review of the Literature

ABSTRACT

Immunodeficiency-associated lymphoproliferative disorders (IA-LPDs) constitute a diverse range of conditions including posttransplant lymphoproliferative disorders, other iatrogenic IA-LPDs, and lymphoproliferative disorders associated with an underlying primary immune disorder or HIV infection. IA-LPDs are clinically and pathologically heterogeneous, and there is a lack of standardization of diagnostic terminology. They can represent a potential serious diagnostic pitfall because the histological features of clinically indolent proliferations may mimic those of high-grade lymphoma. However, correct identification of these entities is essential given that complete remission may occur upon reversal of the underlying cause of immunosuppression without the need for systemic therapy. IA-LPDs presenting in the skin are rare but well documented. One form of iatrogenic IA-LPD, methotrexate-associated lymphoproliferative disorder (MTX-LPD), can present with cutaneous nodules, plaques, or ulcers. Predominantly, MTX-LPD develops in the context of long-term treatment of autoimmune conditions, such as rheumatoid arthritis, dermatomyositis, and Sjögren syndrome, and may be associated with underlying Epstein-Barr virus (EBV) infection. We present 4 cases of cutaneous EBV-positive B-cell MTX-LPD and describe their clinical and morphological findings. Comparison of our histological findings to the diagnostic criteria for EBV-positive mucocutaneous ulcer (EBVMCU) revealed significant overlap, highlighting the intersection between MTX-LPD and EBVMCU. Withdrawal of methotrexate resulted in healing of all lesions at a mean time of 2 months. In summary, close clinicopathological correlation is vital to identify MTX-LPD presenting as cutaneous EBVMCU given that the initial treatment strategy is that of withdrawal of methotrexate without the need for immediate systemic therapy.

Epstein-Barr Positive T-Cell Lymphoma in the Ocular Region

Purpose

To present two cases of rapidly growing tumors in the ocular adnexa. Both tumors were Epstein-Barr virus (EBV) positive peripheral T-cell lymphoma.

Methods

Case 1 was a 60-year-old man with a non-tender ulcerating tumor involving the lateral third of both upper and lower right eyelid. Case 2 was a 55-year-old man with a swelling of the left eyelid expanding cranially and dislocating the left eye, resulting in proptosis and diplopia. Both patients underwent incisional biopsy that did not disclose the malignant nature of the tumors. Clinical evaluation resulted in suspicion of malignancy and surgical excision was performed.

Results

The tumors were found to be consistent with EBV-positive peripheral T-cell lymphoma.

Conclusions

Peripheral T-cell lymphoma is uncommon but a diagnosis to be considered in a patient with a tumorous lesion in the eye region. Furthermore, peripheral T-cell lymphoma may be EBV-positive.

Epstein-Barr virus-positive follicular lymphoma

Epstein-Barr virus (EBV) -associated follicular lymphoma is only rarely reported. Herein, we report the largest series analyzing prevalence and clinicopathologic characteristics of EBV-associated follicular lymphoma occurring in unselected cases. Out of 382 analyzed cases, 10 EBV-positive follicular lymphomas were identified (prevalence=2.6%, 95% confidence interval 1.3-4.0%). All EBV-positive follicular lymphomas showed EBV-encoded small RNA-positive lymphoma cells present in a follicular distribution. Of these, eight also had tissue available for testing of expression of latent membrane protein 1 (LMP1), out of which six (75%) were positive. There was a significant association with grades 3A-3B follicular lymphoma (P<0.0001) and CD30 expression (P=0.0002). EBV-positive follicular lymphomas were otherwise morphologically and immunophenotypically indistinguishable from EBV-negative cases of similar grade. Nine of the EBV-positive follicular lymphomas occurred in patients with no known history of immunosuppression, while one patient had a history of hydroxychloroquine administration for Sjögren's syndrome. The mean age in the EBV-positive and -negative follicular lymphomas was 56 (range 31-83 years) and 49 years (range 25-92 years), respectively, with no statistically significant difference. Seven of the patients with EBV-positive follicular lymphoma had additional biopsies from different time points available for review, all of which showed progression of disease in the form of progression of tumor grade. Five of these progressed to diffuse large B-cell lymphoma, one of which had tissue available for testing and was EBV-positive. Our findings suggest that EBV infection may have a role in lymphomagenesis and/or disease progression in a subset of follicular lymphomas, thereby expanding the spectrum of recognized EBV-associated B-cell lymphomas.

CD30 in systemic mastocytosis

CD30 is a transmembrane receptor, normally not expressed by mast cells, which regulates proliferation/apoptosis and antibody responses. Aberrant expression of CD30 by mastocytosis mast cells and interaction with its ligand CD30L (CD153) appears to play an important role in the pathogenesis and clinical presentation of systemic mastocytosis. This article highlights the expression profile and role of CD30 and CD30L in physiologic and pathologic conditions, the applicability of CD30 as a marker for systemic mastocytosis, the consequences of mast cell-expressed CD30, and the possibility of future anti-CD30 based cytoreductive therapies.

Immunohistochemical and other prognostic factors in B cell non Hodgkin lymphoma patients, Kampala, Uganda

BACKGROUND

Non Hodgkin lymphomas are the most common lymphomas in Uganda. Recent studies from developed countries have shown differences in survival for the different immunophenotypes. Such studies are lacking in Africa where diagnosis is largely dependent on morphology alone. We report immunohistochemical and other prognostic factors in B cell non Hodgkin lymphoma patients in Kampala, Uganda.

METHODS

Non Hodgkin lymphoma tissue blocks from the archives of the Department of Pathology, Makerere University College of Health Sciences, Kampala, Uganda, from 1991-2000, were sub typed using haematoxylin and eosin, Giemsa as well as immunohistochemistry. Using tissue micro array, 119 biopsies were subjected to: CD3, CD5, CD10, CD20, CD23, CD30, CD38, CD79a, CD138, Bcl-6, Bcl-2, IRTA-1, MUM1/IRF4, Bcl-1/cyclin D1, TdT, ALKc, and Ki-67/Mib1. Case notes were retrieved for: disease stage, chemotherapy courses received and retrospective follow up was done for survival.

RESULTS

Non Hodgkin B cell lymphomas comprised of Burkitt lymphoma [BL] (95/119) diffuse large B cell lymphoma (19/119), mantle cell lymphoma (4/119) and precursor B lymphoblastic lymphoma (1/119). For Burkitt lymphoma, good prognosis was associated with receiving chemotherapy, female gender and CD30 positivity. Only receiving chemotherapy remained significant after Cox regression analysis. Diffuse large B cell lymphomas with activated germinal centre B cell (GCB) pattern (CD10+/-, BCL-6+/-, MUM+/-, CD138+/-) had better survival (98.4 months; 95% CI 89.5 -107.3) than the others (57.3 months; 95% CI 35.5 - 79.0) p = 0.027 (log rank test).

CONCLUSIONS

Activated GCB diffuse large B cell lymphoma had a better prognosis than the others. For Burkitt lymphoma, not receiving chemotherapy carried a poor prognosis. Availability of chemotherapy in this resource limited setting is critical for survival of lymphoma patients.

Evidence for polyclonal infection of Epstein-Barr virus in a patient with primary cutaneous anaplastic large cell lymphoma

We report a case of CD30 + primary cutaneous anaplastic large cell lymphoma. The lymphoma cells were shown to express the Epstein-Barr virus (EBV)-encoded small RNAs by in situ hybridization and to have EBV genomes by PCR, whereas no monoclonal band was detected by Southern blot analysis using the EBV terminal repeat probe. These data suggested polyclonal infection by EBV, which provides evidence that EBV plays little part in the pathogenesis of this tumour even in the infected cases.

Absence of Epstein-Barr virus in anaplastic large cell lymphoma: a study of 64 cases classified according to World Health Organization criteria

The frequency of Epstein-Barr virus (EBV) in anaplastic large cell lymphoma (ALCL) has been controversial. The interpretation of previous studies is complicated by the use of nonuniform EBV detection methods and the inclusion of cases of CD30-positive diffuse large B-cell lymphoma and so-called "ALCL, Hodgkin-like," as defined in the Revised European-American Lymphoma classification scheme. In the current World Health Organization (WHO) classification system, both of these tumors are excluded from the ALCL category. Also, recently developed antibodies (eg, the antibody specific for PAX-5/B-cell-specific activator protein [BSAP]) provide new, sensitive tools for identifying neoplasms of B-cell lineage that can morphologically resemble ALCL. In this study we evaluated 64 cases of ALCL of T- or null-cell lineage, defined according to the WHO classification system, for the presence of EBV. All tumors were negative for B-cell antigens, including PAX-5/BSAP and CD20 or CD79a. The study group included 27 (42%) anaplastic lymphoma kinase (ALK)-positive (18 T-cell and 9 null-cell) and 37 (58%) ALK-negative (30 T-cell and 7 null-cell) tumors analyzed by in situ hybridization for EBV-encoded RNA (EBER) or immunohistochemistry for EBV-latent membrane protein type 1. All 64 cases were negative for EBV. We conclude, based on the current definition of ALCL in the WHO classification, there is no role for EBV in ALCL arising in Western patients. We suggest that published reports of EBV in a small proportion of ALCL cases in Western patients can be explained by the inclusion of tumors no longer considered to be in the current classification of ALCL, such as CD30-positive anaplastic tumors of B-cell origin.

Transformation in mycosis fungoides: the role of methotrexate

BACKGROUND

Large cell transformation in patients with mycosis fungoides (MF) has been well reported in the literature. Although the risk factors have not been clearly elucidated, advanced stage seems to be associated with a higher incidence of transformation. Because MF is a rare disorder, little is known about the influence of other factors such as immunosuppressive therapy in the occurrence of transformation.

OBJECTIVE

We questioned the role of methotrexate (MTX) in the transformation of MF to large cell lymphoma (LCL).

METHODS

We identified all patients with MF who were registered in our cutaneous lymphoma database. Transformation was defined by the presence of large cells exceeding 25% of the infiltrate in at least one skin biopsy. In one patient, we followed the histologic, immunophenotypic, and genotypic changes taking place as transformation occurred.

RESULTS

A total of 134 patients with MF were identified. Of 21 patients who received MTX, 3 transformed, and of the 113 patients in the non-MTX group, only 2 transformed. The incidence of transformation in the patients who received MTX was significantly higher than in those who did not receive the drug (14.3% vs. 1.8%; p = 0.03). This significance was maintained, even after controlling for stage and sex. For one patient who transformed, we demonstrated an identical dominant T-cell clone in all skin specimens, including the large cell lymphoma.

CONCLUSION

Our results demonstrate a significant association between MTX exposure and transformation to LCL in patients with MF. In light of the small sample size, short followup of patients, and the inherent tendency of mycosis fungoides to transform, the role for MTX in transformation is unproven and needs to be confirmed in a multicenter study.

Transformation in Mycosis Fungoides: The Role of Methotrexate

Background:

Large cell transformation in patients with mycosis fungoides (MF) has been well reported in the literature. Although the risk factors have not been clearly elucidated, advanced stage seems to be associated with a higher incidence of transformation. Because MF is a rare disorder, little is known about the influence of other factors such as immunosuppressive therapy in the occurrence of transformation.

Objective:

We questioned the role of methotrexate (MTX) in the transformation of MF to large cell lymphoma (LCL).

Methods:

We identified all patients with MF who were registered in our cutaneous lymphoma database. Transformation was defined by the presence of large cells exceeding 25% of the infiltrate in at least one skin biopsy. In one patient, we followed the histologic, immunophenotypic, and genotypic changes taking place as transformation occurred.

Results:

A total of 134 patients with MF were identified. Of 21 patients who received MTX, 3 transformed, and of the 113 patients in the non-MTX group, only 2 transformed. The incidence of transformation in the patients who received MTX was significantly higher than in those who did not receive the drug (14.3% vs. 1.8%; p = 0.03). This significance was maintained, even after controlling for stage and sex. For one patient who transformed, we demonstrated an identical dominant T-cell clone in all skin specimens, including the large cell lymphoma.

Conclusion:

Our results demonstrate a significant association between MTX exposure and transformation to LCL in patients with MF. In light of the small sample size, short followup of patients, and the inherent tendency of mycosis fungoides to transform, the role for MTX in transformation is unproven and needs to be confirmed in a multicenter study.

Epstein-Barr virus association and ALK gene expression in anaplastic large-cell lymphoma

Anaplastic large cell lymphoma of T/null-cell type (ALCL) is associated with a characteristic genetic abnormality t(2;5) that results in the NPM-ALK chimeric gene and the protein product derived thereof. In 10% to 20% of ALCLs, the translocation partners of the ALK gene are genes other than NPM (variant translocations). ALK gene expression limited to the cytoplasm implies a variant translocation. In this study, we have investigated 46 cases of ALCL for expression and localization of ALK protein and its association with Epstein-Barr virus (EBV) (by hybridization to EBV-encoded nuclear RNA-1 [EBER-1] and immunostaining for LMP-1). ALCL patients with a null cell phenotype were significantly younger as compared with those of T-cell phenotype (mean age: 28 years v 42 years; P =.018). Sixteen of 46 ALCL cases (34%) were ALK positive. ALK-positive patients were significantly younger (mean age: 25 years for those with both cytoplasmic and nuclear staining; 22 years for those with exclusive cytoplasmic staining; and 41 years for those negative for the ALK gene; P =.023). EBER-1 was detected in 9 of 46 cases (20%), and LMP-1 expression was noted in 5 of them. By polymerase chain reaction analysis, all EBV-associated cases that were investigated showed type I EBV. Whereas 2 of 23 T-cell ALCLs (9%) were EBER-1+, and 7 of 23 null-cell ALCLs (30%) showed EBV association (P =.057). EBV association was seen in 20% of ALK-negative cases, in 0% of cases with ALK gene expression in both nucleus and cytoplasm, and in 60% of cases with ALK gene expression exclusively in the cytoplasm (P =.02). Further, although ALK-positive-EBER-1+ cases were LMP-1 negative, ALK-negative-EBER-1+ cases were LMP-1 positive. Our study raises the question whether EBV might have an etiological role in the evolution of ALCLs that lack classical t(2;5).

Percentage of activated cytotoxic T-lymphocytes in anaplastic large cell lymphoma and Hodgkin's disease: an independent biological prognostic marker

Recently, we demonstrated that the presence of high percentages of activated cytotoxic T-lymphocytes (CTLs) in biopsy specimens of both Hodgkin's disease (HD) and ALK negative anaplastic large cell lymphoma (ALCL) is associated with a poor prognosis. To test whether this biological prognostic factor is more important in predicting clinical outcome than histological diagnosis or clinical factors, we compared the prognostic value of these parameters in an expanded group of classical HD and ALK negative ALCL. Tumor biopsies of classical HD (n = 83) and ALK negative systemic nodal ALCL (n = 43) were investigated for the presence of activated CTLs by immunohistochemistry, using a monoclonal antibody directed against granzyme B. Percentages of activated CTLs were quantified using Q-PRODIT, and their prognostic value was compared to that of histological diagnosis and clinical parameters, including age and stage. Both in classical HD and ALK negative ALCL, a high percentage of activated CTLs (ie > or = 15%) identified a group of patients with poor overall and progression-free survival time, even when adjusted for stage. In multivariate analysis, percentage of activated CTLs remained a strong independent prognostic marker, and was more sensitive than histological diagnosis or clinical factors in predicting overall survival time. We conclude that a high percentage of activated CTLs in the reactive infiltrate of ALK negative ALCL and classical HD is a strong indicator for an unfavorable clinical outcome, regardless of histological diagnosis or clinical parameters. As such, this biological parameter may be an especially helpful tool to determine therapeutic strategies in cases in which the differentiation between ALK negative ALCL and HD remains difficult.

Expression of carbohydrate antigens, p80NPM/ALK, cytotoxic cell-associated antigens, and Epstein-Barr virus gene products in anaplastic large cell lymphomas

The expression of carbohydrate antigens, including sialyl Lewis X (SLEX) and BNH9 antigen, the nucleophosmin (NPM)-anaplastic lymphoma kinase (ALK) fusion protein (p80NPM/ALK), cytotoxic cell-associated antigens, and Epstein-Barr virus (EBV) gene products in CD30+ anaplastic large cell lymphoma (ALCL) was investigated by immunohistochemistry and in situ hybridization (ISH) methods. The expression of SLEX and BNH9 antigen in ALCL was examined using CSLEX1 and BNH9, which specifically react with SLEX and oligosaccharides (H and Y haptens), respectively. SLEX was expressed in seven of 12 ALCL and BNH9 was positive for five of 12 ALCL. With respect to the relationship between SLEX and BNH9 expression in ALCL, some ALCL expressed both antigens, which suggests that they might have an increased or preserved activity of glycosyltransferase that is responsible for the synthesis of the type I or type II core sequences, although other ALCL expressed either SLEX or BNH9. To detect p80NPM/ALK in ALCL, the sections were immunostained with an anti-p80 antibody. Three of 12 ALCL expressed the NPM/ALK-encoded p80 protein. All three ALCL positive for p80NPM/ALK expressed SLEX and two of them were stained with BNH9, which raised the possibility that p80 overexpression may be involved in the aberrant expression of type I or type II chains with varying degrees of fucosylation or sialylation. While the expression of cytotoxic cell-associated antigens such as CD8, CD56 and T cell intercellular antigen 1 (TIA-1) in ALCL was immunohistochemically examined, none of the 12 ALCL expressed CD56 and only one case expressed CD8. TIA-1 was expressed in seven of 12 ALCL. Four of five BNH9-positive cases expressed TIA-1, suggesting that BNH9-positive cases tended to have TIA-1. In situ hybridization studies using an EBV-encoded RNA-1 (EBER-1) probe were performed on 12 ALCL to detect EBV in the lymphoma cells. EBER-1 signals were detected in the small lymphocytes but not in the lymphoma cells of two ALCL. However, latent membrane protein 1 immunoreactivity was found in one case. These results appear to indicate that there is no strong association between EBV and ALCL.

Anaplastic large cell lymphoma: a distinct molecular pathologic entity: a reappraisal with special reference to p80(NPM/ALK) expression

The p80(NPM/ALK) expression activated by the t(2;5) (p23;q35) translocation recently has been shown to play an important role in the pathogenesis of anaplastic large cell lymphoma (ALCL). However, the clinicopathologic significance of identification of p80 among ALCL cases has not been completely resolved. Difficulties also exist in the histologic and immunophenotypic identification of ALCL and Hodgkin's disease (HD) as separate processes, often complicating the clinicopathologic evaluation of and therapeutic approach to these entities. In order to clarify these issues, 67 specimens of ALCL and 63 specimens of HD (31 of the nodular-sclerosing type [NS-HD] and 32 of the mixed-cellularity type [MC-HD]) were immunostained using anti-p80 antibody and other relevant markers on paraffin sections. The clinicopathologic and immunophenotypic features were reviewed on the basis of p80 reactivity. The expression of p80 was detected in 43 of 67 cases of ALCL (64%), but none of HD. The p80+ ALCL cases constituted a very homogeneous group of tumors, characterized by the occurrence in a much younger group and relatively more favorable clinical course than the p80- ALCL, which were in keeping with the data previously reported. They showed virtually the identical immunophenotypic findings of p80+, CD30+, EMA+, CD15-, bcl-2-, and Epstein-Barr virus (EBV) with T- and null-cell phenotype, and showed the distinct morphologic features, including three cases of lymphohistiocytic/small-cell variant, as follows: the indented nuclei, often termed as reniform, embryolike, and horseshoelike; multiple, irregular, but indistinct nucleoli; and few reactive cells of eosinophils and epithelioid cells. Conversely, the 24 p80- ALCL cases, in which epithelial membrane antigen (EMA) and bcl-2 positivities were 33% and 55%, respectively, were heterogeneous and could be subdivided into five different categories, namely (a) 11 cases of HD-like ALCLs, (b) six cases of p80 common ALCL, (c) three cases of secondary ALCL, (d) two cases of primary cutaneous ALCL, and (e) two cases of primary classical ALCL that lacked p80 expression. This study clearly demonstrated that the immunohistochemical detection of p80 is of a crucial importance in delineating the biologically distinct entity of "primary classical ALCL" from various diseases that show morphologic and immunohistologic overlap, including HD and HD-like ALCL.

An immunohistochemical analysis of Reed-Sternberg-like cells in posttransplantation lymphoproliferative disorders: the possible pathogenetic relationship to Reed-Sternberg cells in Hodgkin's disease and Reed-Sternberg-like cells in non-Hodgkin's lymphomas and reactive conditions

The aim of this study was to assess the incidence and immunophenotype of Reed-Sternberg-like (R-S-like) cells in the setting of posttransplantation lymphoproliferative disorders (PTLD). Twenty-eight formalin-fixed, paraffin-embedded cases (17 renal and 11 heart/heart-lung PTLDS) were analyzed for the presence of typical binucleate cells with inclusionlike nucleoli--the Reed-Sternberg phenotype. An immunohistochemical evaluation for the following markers was performed: CD3, CD20, CD79a, CD15, CD30, CD45, EBV-LMP-1, and vimentin. Monoclonality was assessed by staining for light chain restriction. Eleven cases contained R-S-like cells (9 renal and 2 heart/heart-lung PTLD). All 11 cases were positive for CD45 (LCA), EBV-LMP-1, and vimentin. Ten of 11 cases were CD20/CD79a positive, one case being of a null immunophenotype. Nine cases expressed CD30, whereas 0 of 11 were positive for CD15. In nine cases, expression of both kappa and lambda light chains was present; the remaining two cases failed to express either light chain. This study shows that the R-S-like cells encountered in PTLD have an activated B cell immunophenotype, are invariably EBV-LMP-1 positive, are often CD30 positive, and are CD15 negative. This latter immunophenotypic feature separates R-S-like cells from the R-S cells seen in Hodgkin's disease. The strong staining for EBV-LMP-1 in R-S-like cells also indicates a strong association between EBV-LMP and the R-S morphological phenotype in the context of PTLDs.

Clinicopathological, immunological and genetic studies of CD30+ anaplastic large cell lymphoma of B-cell type; association with Epstein-Barr virus in a Japanese population

The clinicopathological features, the immunophenotype, and the presence of Epstein-Barr virus (EBV)-associated genomes and gene products were examined in 17 cases of CD30+ anaplastic large cell lymphoma (ALCL) of B-cell type. Microscopically, the 17 cases were divided into ten cases of the monomorphic type and seven cases of the pleomorphic type. EBV was detected in 6 of 17 cases (38 per cent) by RNA in situ hybridization (ISH) with EBV-encoded RNA (EBER1). EBER1+ cases consisted of two cases (20 per cent) of the monomorphic type and four cases (57 per cent) of the pleomorphic type. The five EBER1+ cases showed clonality of the EBV genome by Southern blotting, consistent with the presence of EBV in a monoclonal proliferation. The EBV-encoded latent membrane protein 1 (LMP1) was found in all six EBER1+ cases and EBV-encoded nuclear antigen 2 (EBNA2) was present in two cases by immunohistochemistry. No expression of LMP1 or EBNA2 was observed in the EBER1-cases. The EBER1+ cases had a tendency for a more favourable prognosis than the EBER1-cases. It is concluded that EBV has an association with CD30+ ALCL of B-cell type in the Japanese population studied, and especially with the large pleomorphic type. EBV infection may play a pathoaetiological role and may influence clinical behaviour.

Epstein-Barr virus in non-Hodgkin's lymphomas of the upper respiratory tract: association with sinonasal localization and expression of NK and/or T-cell antigens by tumour cells

Fifty-five cases of non-Hodgkin's lymphoma (NHL) of the upper respiratory tract, comprising 27 sinonasal (SN) and 28 Waldeyer's ring (WR) NHL, were investigated for expression of Epstein-Barr virus (EBV)-encoded EBER transcripts and latent membrane protein-1 (LMP-1) by RNA in-situ hybridization (RISH) and immunohistochemistry, respectively. Thirty-two cases were B-cell tumours (10 SNHLs and 22 WRNHLs) and 23 cases expressed natural killer (NK) and/or T-cell antigens (17 SNHLs and 6 WRNHLs). EBER transcripts were detected in tumour cells in 19 lymphomas expressing NK and/or T-cell antigens (16/17 SHNHLs and 3/6 WRNHLs) but in only 2/32 B-NHLs (1/10 SNHLs and 1/22 WRNHLs). LMP-1 expression was found in tumour cells in the 19 EBER-positive tumours expressing NK and/or T-cell antigens but in none of the B-cell lymphomas. All the LMP-1-positive lymphomas expressed the CD30 molecule in tumour cells. These results indicate that in lymphomas of the upper respiratory tract, EBV is strongly associated with sinonasal localization and expression of NK and/or T-cell antigens by tumour cells. EBV can also be detected in some cases of WRNHLs expressing NK and/or T-cell antigens, whereas it is rarely found in B-cell SNHLs and WRNHLs. Furthermore, the detection of the LMP-1 protein in tumour cells in most SNHLs and some WRNHLs expressing NK and/or T-cell antigens, in view of the LMP-1 transforming potential, suggests that EBV may play a role in the pathogenesis of these lymphomas.

The association of the Epstein-Barr virus with malignant lymphoma

The Epstein-Barr virus, a human herpesvirus, has been found in the neoplastic cells of numerous lymphoid malignancies, including Burkitt's lymphoma, immunodeficiency-associated lymphoproliferative disorders, nasal T/NK lymphoma, and Hodgkin's disease. The available data suggest that Epstein-Barr virus contributes to the pathogenesis of many of these neoplasms but is not directly linked to the etiology of any of these lymphomas.

Phenotype of Hodgkin and Sternberg-Reed cells and expression of CD57 (LEU7) antigen

Possible associations between the immunophenotype of Hodgkin (H) and Sternberg-Reed (S-R) cells, the expression of CD57 (Leu 7) antigen, and the presence of Epstein-Barr virus (EBV) were investigated in lymph node specimens from 50 cases of Hodgkin's disease (HD), including 26 cases of mixed cellularity and 24 cases of nodular sclerosis. Tissues were fixed in 10% neutral formalin, or/and B5 solution. H and S-R cells were CD30+, CD15+ (85% of the cases) and LCA (CD45). A proportion of neoplastic cells positive for either T-cell markers (CD3) or B-cell markers (CD20) was observed in 10% and 34% of the cases, respectively. Membrane positivity for CD57 antigen was found in H and S-R cells in 10 cases (8 cases of mixed cellularity, and 2 cases of nodular sclerosis). Such immunopositivity was only observed in B5-fixed sections. No staining for CD57 antigen was identified in H and S-R cells of any case with CD20 positive neoplastic cells. H and S-R cells of both CD57-positive and CD57-negative cases were further studied by immunohistochemistry for LMP1, by in-situ hybridization for EBER and by polymerase chain reaction (PCR) for EBV-DNA. No association was identified between the expression of CD57 antigen and the presence of EBV sequences, transcripts or proteins. Our findings do not support a B-cell origin for H and S-R cells in CD57-positive cases of Hodgkin's disease and suggest that these neoplastic cells may be related to natural killer (NK) or T-cells expressing CD57 antigen.

Detection of Epstein-Barr virus in cutaneous and lymph nodal anaplastic large cell lymphomas (Ki-1+)

Epstein-Barr virus (EBV) is a gamma DNA herpes virus which is thought to play a part in the pathogenesis of some non-Hodgkin's lymphomas in individuals with or without immunodeficiency. We investigated 16 lymph nodal and 12 cutaneous anaplastic large cell lymphomas (ALCLs) (Ki-1+), all of which were in patients without immunodeficiency, for the presence of EBV genomes. The highly sensitive polymerase chain reaction (PCR) technique was employed for detection of viral DNA in extracts from formalin-fixed, paraffin-embedded tissue sections. In addition, we performed radioactive and non-radioactive in situ hybridization (ISH) for localization of EBV at the single cell level. EBV-DNA was demonstrated by PCR in five cases of nodal ALCLs (31%). All cutaneous ALCLs were negative. EBV-encoded small nuclear RNAs (EBERs) could be identified by ISH in the tumour cells of one of the five EBV-DNA-positive patients. Our results further support the concept that EBV may be involved in the development of a proportion of nodal ALCLs, but not in cutaneous ALCLs.

Large-cell anaplastic non-Hodgkin's lymphoma originating in donor cells after allogenic bone marrow transplantation

Second neoplasms after allogenic bone marrow transplantation (BMT) occur in donor cells; however, host origin generally cannot be excluded. Using fluorescence in situ hybridization (FISH) the origin of the malignant population can be proven indisputably. In a female patient with CD30+ large-cell anaplastic non-Hodgkin's lymphoma (LCAL) after BMT with an HLA-identical brother donor, FISH using anti-CD30 immunocytochemistry in combination with anti-Y- and anti-EBV RNA probes was applied. In pathological lymph nodes the majority of cells were of donor type (Y). CD30-positive cells were Y-positive; these cells were also EBV-positive. Using FISH and immunocytochemistry we have demonstrated convincingly that this, possibly EBV-induced, LCAC originated in donor cells.

p53 protein expression in cutaneous T-cell lymphomas

p53 is an oncosuppressor gene located on chromosome 17p. Point mutations of the p53 gene are seen frequently in human malignancies, and are closely associated with malignant transformation under in vitro conditions. Mutated p53 protein shows a slow cell turnover rate, and accumulates in cells at the nuclear and/or cytoplasmic level. As a result, mutated p53 protein can be detected more readily by immunohistology than the wild-type protein. In this study, we used a monoclonal anti-p53 antibody (clone DO7) to examine the expression of p53 protein in 25 cutaneous T-cell lymphomas (CTCL) of low- and high-grade malignancy, i.e. mycosis fungoides (n = 6), Sézary's syndrome (n = 2), and large cell lymphomas of pleomorphic (n = 14) or anaplastic (n = 3) subtype. The results showed that easily detectable p53 protein was present in many of the neoplastic cells in half of the high-grade lymphomas. In contrast, in the low-grade lymphomas no, or only very few, p53-positive neoplastic cells could be detected. These findings suggest that molecular and/or genetic alterations of p53 may be implicated in the pathogenesis of high-grade CTCL, but are unlikely to be of critical importance in low-grade CTCL.

Epstein-Barr virus (EBV) in extranodal T-cell non-Hodgkin's lymphomas (T-NHL). Identification of nasal T-NHL as a distinct clinicopathological entity associated with EBV

T-cell Non-Hodgkin's lymphomas (T-NHL) can be defined as clonal malignant proliferations related phenotypically and functionally to normal T-cell populations of the lymphoid tissue. There is increasing evidence that T-NHL with similar morphology but originating from different sites differ in their clinical behaviour, immunophenotypic features, oncogene expression and relation with oncogenic viruses such as HTLV-I and EBV. Indeed, it has been shown that the prevalence of EBV in T-NHL is related to the site of origin. Thus, EBV was found in nearly all nasal T-NHL but only in a proportion of primary nodal, lung, gastrointestinal and Waldeyer's ring T-NHL while it was undetectable in most primary cutaneous T-NHL. Besides their constant association with EBV, nasal T-NHL display peculiar clinical, histological, immunophenotypic and genotypic features. They present clinically as lethal midline granuloma and histologically as pleomorphic malignant tumours variably associated with angiocentricity, angioinvasion and necrosis. Moreover, they frequently exhibit extensive loss of T-cell antigens, including CD3 and TCR alpha beta and gamma delta proteins, usually express the Natural Killer (NK)-related CD56 antigen and frequently show absence of clonal rearrangements of TCR beta, gamma and delta loci. Therefore, among T-NHL, nasal T-NHL can be regarded as a distinct clinicopathologic entity associated with EBV, which could be derived either from immature T-cells or from NK cells.

Immunohistochemical demonstration of different latent membrane protein-1 epitopes of Epstein-Barr virus in lymphoproliferative diseases

AIM

To compare the immunoreactivity of monoclonal antibodies S12 and CS1-4, which recognise different epitopes of the Epstein-Barr virus (EBV) latent membrane protein-1 (LMP-1), in EBV associated benign and malignant lymphoproliferative disorders and control tissues processed using different methods.

RESULTS

Both monoclonal antibodies gave comparable results on frozen tissue sections and formalin fixed, paraffin wax embedded samples from cases with Hodgkin's disease and infectious mononucleosis. In all cases S12 stained more cells than CS1-4. For EBV associated B and T non-Hodgkin's lymphomas, frozen tissue sections yielded better LMP-1 staining results than formalin fixed material. Again, in all these cases S12 stained more cells and gave stronger results than CS1-4. For EBV negative tissues, both monoclonal antibodies showed cross-reactivity with melanocytic-like cells in the basal cell layer of the skin, synaptophysin-like staining in layers three and four of the cortex of the brain, and myelin-like staining in peripheral nerves and peripheral ganglion cells. Staining with S12 was always much stronger. Moreover, in contrast to CS1-4, S12 stained pancreatic islands in formalin fixed material but not in frozen tissue sections and sporadically stained solitary epithelial cells in the large bowel especially in formalin fixed tissue sections. CS1-4 also cross-reacted with myoepithelial cells around hair follicles and other adnexa of the skin.

CONCLUSION

The results indicate that for optimal detection of LMP-1, S12 yields better results than CS1-4 and that tissue processing is very important especially when B and T non-Hodgkin's lymphomas are examined.

A study of the association of Epstein-Barr virus with Burkitt's lymphoma occurring in a Chinese population

There is a strong association (approximately 95%) of endemic Burkitt's lymphoma with Epstein-Barr virus (EBV), whereas the association is weak for the sporadic form occurring in Western countries (approximately 15%). In the Middle East, North Africa and South America, 60-80% of Burkitt's lymphomas harbour EBV. These epidemiological differences suggest that either the endemicity of EBV or socio-economic conditions, or both, may influence the pathogenetic role of EBV in Burkitt's lymphoma. Since only meagre data are available on Asians, this study was performed to address this issue by studying cases from Hong Kong, where EBV seroconversion occurs in the first few years of life but the socio-economic conditions approach those of Western countries. In situ hybridization for EBV encoded RNAs (EBERs) was performed on paraffin sections of 18 cases of Burkitt's lymphoma. Labelling of the neoplastic cells was detected in five cases (27.7%). In contrast, among 54 cases of B-cell lymphomas of various subtypes studied for comparison, signals for EBER were detected in only one case each of T-cell-rich large B-cell lymphoma, anaplastic large cell lymphoma and Reed-Sternberg-like cells occurring in B-cell chronic lymphocytic leukaemia/small lymphocytic lymphoma. The strong labelling with oligo-dT probe (which hybridized with the polyadenylated ends of mRNA) in all cases suggested that the negative results were genuine and not due to poor preservation of RNA in the tissues. Thus, among B-cell neoplasms occurring in Chinese, Burkitt's lymphoma shows a statistically stronger association (P < 0.01) with EBV than with other types of B-cell lymphoma.(ABSTRACT TRUNCATED AT 250 WORDS)

Frequent detection of Epstein-Barr virus (EBV), EBER transcripts and latent membrane protein-1 (LMP-1) in tumor cells in Hodgkin's disease arising in childhood

Paraffin sections from 22 cases of Hodgkin's disease (HD) and 30 cases of non-Hodgkin's lymphomas (NHL) occurring in childhood (3-15 years old) were examined for the presence of Epstein-Barr Virus (EBV) encoded EBER mRNAS and Latent Membrane Protein-1 (LMP-1) using RNA in situ hybridization (RISH) and immunohistochemistry, respectively. In 12/22 (54%) cases of HD the EBER transcripts were detected in most Reed-Sternberg and Hodgkin (HRS) cells as well as in some scattered smaller lymphoid cells. In all these cases the LMP-1 protein was detected exclusively in HRS cells. Three additional cases of HD were found to be EBER RISH positive only in a few scattered small lymphoid cells, the LMP-1 staining being negative in these cases. The EBER and LMP-1 positivity in HRS cells were present in 0/1 of lymphocyte predominant, 4/10 (40%) of nodular sclerosis and 8/11 (72%) of mixed cellularity of HD. No EBER RISH signal was found in tumor cells of the 30 cases of NHL. In four of them only a few scattered small lymphoid cells were EBER RISH positive. LMP-1 reactivity was not detected in any NHL. These results provide evidence for an association between EBV and a sizeable proportion of childhood Hodgkin's disease and show that this association is more frequent in mixed cellularity subtype. Furthermore, the detection of the LMP-1 protein in HRS cells in view of the LMP-1 transforming potential, suggests that EBV may be involved in the pathogenesis of a substantial proportion of cases of HD occurring in childhood.

Mycosis fungoides: expression of C-myc p62 p53, bcl-2 and PCNA proteins and absence of association with Epstein-Barr virus

The expression of C-myc p62, bcl-2, p53, PCNA and EBV-encoded LMP-1 proteins was studied by immunohistochemistry on paraffin-embedded skin specimens from 14 patients with early stage (premycotic erythema and second stage plaques) mycosis fungoides (MF), 21 patients with advanced stage MF (third stage plaques and tumors), 3 patients with Sezary's syndrome (SS) and 3 patients with pleomorphic medium and large cell cutaneous T-cell lymphomas (PML-CTCL). All 41 cases were also screened for the presence of EBV by using RNA in situ hybridization with EBER 1/2 oligonucleotides. Increased expression of C-myc p62, p53 and PCNA proteins was found in PML-CTCL and advanced stages of MF as compared to early stages of MF. These results suggest a relationship between levels of C-myc p62, p53 and PCNA proteins and aggressiveness of the cutaneous T-cell lymphomas. Furthermore, C-myc p62 and bcl-2 proteins were found to be frequently coexpressed in the present series. In view of the background information from in vitro findings and animal models that cooperation of C-myc and bcl-2 is important for lymphomagenesis, our results suggest that coexpression of these oncogenes may be implicated in the pathogenesis and/or the progression of cutaneous T-cell lymphomas. Neither LMP-1 expression nor EBV EBER l/2 transcripts were detected in our series suggesting that EBV is not involved in the pathogenesis of cutaneous T-cell lymphomas.

Detection of Epstein-Barr virus small RNAs in routine paraffin sections using non-isotopic RNA/RNA in situ hybridization

The Epstein-Barr virus (EBV) is associated with an increasing range of reactive and neoplastic lesions. There is a need for a sensitive and specific method for detecting latent EBV in routine histological sections. We report the use of a highly sensitive paraffin section RNA/RNA in situ hybridization (ISH) technique using digoxigenin-labelled antisense riboprobes for demonstrating EBV encoded small RNAs (EBERs), EBV gene products that are transcribed in abundance during latent EBV infection. We applied EBER-ISH to 846 paraffin embedded specimens, including cases of reactive lymphoid hyperplasia (n = 28), infectious mononucleosis (16), Burkitt's lymphoma (44), immunodeficiency-associated lymphomas in transplant recipients (9) and AIDS patients (128), Hodgkin's disease (130), CD30 antigen positive lymphomas (106), peripheral T-cell lymphomas (104), sporadic B-cell non-Hodgkin's lymphomas (162), undifferentiated nasopharyngeal carcinoma (86), salivary gland lymphoepithelioma (11), and oral hairy leukoplakia (5). Strong, reproducible EBER staining was seen in EBV latently infected cells in archival surgical biopsy and autopsy specimens. EBER-ISH is specific, has a sensitivity comparable to that of the polymerase chain reaction, and is now the method of choice for the in situ detection of latent EBV infection.

Expression of EBV encoded latent membrane protein 1 (LMP-1) and bcl-2 protein in childhood and adult Hodgkin's disease: application of microwave irradiation for antigen retrieval

Surgical biopsies obtained from 32 children, and 34 adults with Hodgkin's disease (HD) were investigated for the expression of the EBV encoded Latent Membrane Protein 1 (LMP-1), bcl-2 protein, markers for HD; LeuM1 (CD15), BerH2 (CD30) and the new BLA.36, as well as for B (L26) and T lymphocytes (UCHL1). Before immunostaining, sections were subjected to an Antigen Retrieval (AR) procedure based on microwave irradiation in citrate buffer. In 13 cases staining with and without the AR procedure was compared. Immunoreactivity for LMP-1 was found in 44% of the biopsies from adults and 53% from children. We also found reactivity for the bcl-2 protein in Hodgkin's and Reed Sternberg (HRS) cells in 48% of the biopsies from adults and 45% from children. Immunoreactivity with BLA.36 was found in 94% of the biopsies from adults and 100% from children, with LeuM1 in 83% from adults and 93% from children and with BerH2 in 24% from adults and 84% from children. Nuclear PCNA staining was seen in HRS in all cases both adult and childhood. The T cell marker (UCHL1) displayed no reactivity with HRS cells. In 21% of the adult and 9% cases from the childhood cases we observed reactivity with the B cell marker (L26) in HRS cells. We can conclude that antigen retrieval improves immunostaining results of paraffin sections which were previously negative for bcl-2, LeuM1 and BerH2 antibodies. The high percentage of LMP-1 positive cases, both in adults and in children, indicates that the potential pathogenetic effect of EBV may be of similar importance both in childhood and in adult HD. The new MAb BLA.36 gave consistent immunostaining with HRS cells but also with other cell types. In a panel of markers for HRS cells BLA.36 together with LeuM1 (CD15) and BerH2 (CD30) are useful.

Expression of Epstein-Barr virus latent gene products and related cellular activation and adhesion molecules in Hodgkin's disease and non-Hodgkin's lymphomas arising in patients without overt pre-existing immunodeficiency

Epstein-Barr virus (EBV) recently has been associated with Hodgkin's disease (HD) and the EBV genome was found in CD30-positive Reed-Sternberg cells. Therefore, tissue sections from 25 cases of HD, 35 cases of CD30-positive non-Hodgkin's lymphoma (NHL) (seven CD30-positive anaplastic large cell lymphomas [ALCLs] and 28 CD30-positive non-ALCLs), and 12 cases of CD30-negative NHL that previously had been screened for the presence of EBV by polymerase chain reaction and DNA in situ hybridization were studied by immunohistochemistry for the expression of the latent EBV proteins, latent membrane protein (LMP), and Epstein-Barr nuclear antigen-2 (EBNA-2). We also analyzed the expression of the B-cell activation molecule CD23 and the adhesion molecules LFA-1/CD11a and ICAM-1/CD54 because the upregulation of these molecules by LMP and/or EBNA-2 in vitro has been related to the EBV-induced lymphocyte growth. Latent membrane protein expression was found in Reed-Sternberg cells in nine of 25 cases (36%) of HD and in large, occasionally Reed-Sternberg-like tumor cells in six of 47 cases (12%) of NHL; these six tumors were CD30-positive, histologically high-grade NHL (one CD30-positive ALCL and five CD30-positive non-ALCLs). All the LMP-positive cases were also polymerase chain reaction EBV positive while LMP expression was not found in polymerase chain reaction EBV-negative HD and NHL. No staining for EBNA-2 was detected in our series. In view of the transforming potential of the LMP, these findings suggest that EBV may be associated with the development of some cases of HD and CD30-positive NHL. These findings also suggest a correlation between the expression of LMP and the detection of CD30 in tumor cells of HD and NHL. In contrast, no correlation was found between the expression of LMP and the detection of CD23, LFA-1/CD11a, and ICAM-1/CD54 in tumor cells of HD and NHL.