The biological environment of Hodgkin's lymphoma and the role of the chemokine CCL17/TARC

Hodgkin's lymphoma is a lymphoproliferative disease, which differs in its morphology and therapeutic response from other lymphomas. Neoplastic cells represent only a minor cell population of the tumour, while the major part of the tumour is formed by inflammatory cells. It results from the production of cytokines and chemokines both by neoplastic cells and by inflammatory cells. An important prognostic marker in Hodgkin's lymphoma appears to be the chemokine (C-C motif) ligand 17 (CCL17), also known as thymus and activation-related chemokine (TARC). This chemokine is expressed by many cell types and tissues, and in the case of Hodgkin lymphoma, also by Reed-Sternberg cells. CCL17/TARC binds to chemokine receptors CCR4 and CCR8 and displays chemotactic activity for T lymphocytes and some other leukocytes. The understanding of biological pathways in Hodgkin's lymphoma could be important for monitoring of disease activity and for the development of future targeted therapy.

Simultaneous occurrence of metastatic breast cancer, Hodgkin's disease and tuberculous lymphadenitis in homolateral axillary lymph nodes--a case report

We report the case of a 78-year-old woman, presenting with enlarged axillary lymph nodes. Histological analysis of the lymph nodes demonstrated the co-existence of locally advanced breast carcinoma, scleronodular Hodgkin's disease and tuberculous lymphadenitis.The association of the 3 disorders in the same lymphatic region is unreported so far.

Cerebrospinal fluid infiltration in Hodgkin lymphoma: a case report

BACKGROUND

Central nervous system (CNS) involvement by Hodgkin lympboma is a rare event. Involvement of the cerebrospinal fluid (CSF) in such cases is even more uncommon. We report a case of Hodgkin lymphoma in which the patient developed infiltration of the CSF while on chemotherapy.

CASE

A 45-year-old woman was diagnosed with Hodgkin lymphoma by fine needle aspiration and subsequent biopsy of the cervical lymph node. She complained of headache during the course of chemotherapy, for which CSF examination was undertaken. Cytocentrifuge sediment of the CSF revealed marked eosinophilic pleocytosis, accompanied by scattered monocytes, polymorpbs, lymphocytes, plasma cells and histiocytes. An occasional large mononudlear cell with a large, round nucleus and prominent irregular nucleolus with a moderate amount of basophilic cytoplasm conformning to the morphology of Hodgkin's cells was noted. Binucleated Reed-Sternberg cells were not seen. Following intratbecal methotrexate, a reduction in the cellular infiltrate was observed.

CONCLUSION

CSF cytology is important for the diagnosis of CNS involvement by Hodgkin lymphoma and may be positive before lesions can be visualized by magnetic resonance imaging or computed tomograpby scans.

High expression of minichromosome maintenance protein 6 in classic Hodgkin's lymphoma points to a cell cycle arrest in G1 phase

BACKGROUND

Minichromosome maintenance protein 6 (MCM6) is one of the six proteins of minichromosome maintenance family that are involved in the initiation of DNA replication and thus represent a marker for proliferating cells. The aim of this study was to determine the proliferation characteristics of neoplastic cells in patients with classic Hodgkin's lymphoma.

METHODS

Paraffin-embedded blocks of lymph node, mediastinal, subcutaneous chest wall, and lung mass biopsies of 55 patients with classic Hodgkin's lymphoma were immunostained by the proliferation-associated monoclonal antibodies; Ki-S5 (Ki-67 antigen) and Ki-MCM6 (MCM6 antigen).

RESULTS

High MCM6 antigen expression was a striking feature of Hodgkin's and Reed-Sternberg cells (median: 85%, range: 35 - 99%) in comparison with lower Ki-67 expression (median: 63.5%, range: 1 - 98%, P<0.001). This indicates that MCM6 is already expressed in the early G1 phase, a cell cycle fraction that is not covered by antibodies specific to the Ki-67 antigen. The proliferation rates were determined by two markers, independent of histologic subtype, stage, presence of B symptoms, and size.

CONCLUSION

These data show that a subset of Reed-Sternberg and Hodgkin's cells is arrested in the early G1 phase and the MCM6-positive cells do not necessarily represent the real proliferating compartment of Hodgkin's lymphoma. Clinical relevance of this marker in patients with Hodgkin's lymphoma should be investigated.

[Clonality analysis and mutational status of IgVH gene in Hodgkin variant of Richter syndrome]

OBJECTIVE

To detect the clonal relationship, the rearrangement, and the mutational status of IgVH gene; the influence of these molecular characteristics on the clinical outcome in Hodgkin variant of Richter syndrome; and the possible molecular pathogenesis in this transformation.

METHODS

The clonal rearrangements and mutational status of IgVH genes were analyzed in Hodgkin variant of Richter syndrome and B-CLL with Reed-Stemberg (R-S)-like cells by GeneScan analysis and sequencing. Semi-nest PCR based on laser capture microdissection was utilized to compare the clonal relationship between B-CLL and R-S/R-Slike cells. Immunohistochemical staining was used to detect the different expressions of ZAP70, p53, IRF-4 and LMP1 in the two components.

RESULTS

(1) 5/6 B-CLL cases transformed to Hodgkin lymphoma (HL)/R-S-like cells carried the mutated IgVH genes; (2) 2 cases of R-S cells and 1 case of R-S-like cells were clonally distinct from B-CLL clone and express LMP1, whereas 1 case of R-S-like cells was relating to the surrounding B-CLL cells and did not express LMP1; (3) 2/6 B-CLL cases transformed to HL convey VH4-34 and VH3-48 respectively.

CONCLUSIONS

(1) Richter transformation to HL/R-S-like cells evolves from the B-CLL which originates from the germinal center or post germinal center B cells, indicating that different lymphoma cells of different subtypes in Richter syndrome come from different B cell lineage and possibly involve a different pathogenesis and pathway; (2) HL and R-S-like cells evolve from either the B-CLL clone or may develop as a clonally unrelated lymphoma, the independent secondary malignancies are appear to be EBV-positive, possibly as a consequence of the underlying immunodeficiency; (3) The biased usage of IgVH genes suggested a role of antigens involved in the HL variant of Richter syndrome.

Overexpressed NF-kappaB-inducing kinase contributes to the tumorigenesis of adult T-cell leukemia and Hodgkin Reed-Sternberg cells

The nuclear factor-kappaB (NF-kappaB) transcription factors play important roles in cancer development by preventing apoptosis and facilitating the tumor cell growth. However, the precise mechanisms by which NF-kappaB is constitutively activated in specific cancer cells remain largely unknown. In our current study, we now report that NF-kappaB-inducing kinase (NIK) is overexpressed at the pretranslational level in adult T-cell leukemia (ATL) and Hodgkin Reed-Sternberg cells (H-RS) that do not express viral regulatory proteins. The overexpression of NIK causes cell transformation in rat fibroblasts, which is abolished by a super-repressor form of IkappaBalpha. Notably, depletion of NIK in ATL cells by RNA interference reduces the DNA-binding activity of NF-kappaB and NF-kappaB-dependent transcriptional activity, and efficiently suppresses tumor growth in NOD/SCID/gammac(null) mice. These results indicate that the deregulated expression of NIK plays a critical role in constitutive NF-kappaB activation in ATL and H-RS cells, and suggest also that NIK is an attractive molecular target for cancer therapy.

Loss of expression of LyGDI (ARHGDIB), a rho GDP-dissociation inhibitor, in Hodgkin lymphoma

The guanosine triphosphatase (GTPase) inhibitor LyGDI (ARHGDIB, Ly/D4-GDI, RhoGDIb or RhoGDI 2) is abundantly expressed in haematopoetic cells and possibly plays a role in the onset of apoptosis. Gene expression profiling of Hodgkin cell lines revealed that LyGDI expression was downregulated in these cell lines. The present study evaluated the expression of LyGDI in Hodgkin cells in vivo and studied the function of LyGDI in Hodgkin cell lines in vitro. Our results showed that virtually all Hodgkin and Reed-Sternberg cells in classical Hodgkin lymphoma lacked LyGDI protein expression. On the other hand, almost all non-Hodgkin lymphomas, except for anaplastic large cell lymphomas, expressed LyGDI protein. Transfection of the classical Hodgkin cell line L428 with a vector containing full-length LyGDI-induced apoptosis in a subset of cells. However, the majority of Hodgkin cells with transgenic expression of LyGDI escaped apoptosis. Our data show that lack of LyGDI expression is a frequent feature of cHL but that it is not of vital importance for the growth and survival of these cells.

Pathobiology and molecular profiling of peripheral T-cell lymphomas

Peripheral T-cell lymphomas (PTCLs) are a heterogeneous group of rare diseases, usually manifesting clinical aggressiveness. Although important novel insights into the pathobiology of nodal PTCL have been gained recently from molecular profiling studies and clinico-pathological analyses, the pathogenetic molecular lesions remain to be deciphered for most entities. Angioimmunoblastic T-cell lymphoma (AITL) comprises CD4+ CXCL13+ neoplastic cells displaying overlapping immunophenotypical and molecular features with normal follicular helper T cells. This derivation might account for the presence of a prominent non-neoplastic component in AITL tissues and the clinical manifestations of the disease reflective of an immunological dysfunction. ALK+ anaplastic large cell lymphoma (ALCL), defined by ALK gene translocation with various gene partners, is composed of CD30+ ALK+ cells with a cytotoxic phenotype and usually carries a good prognosis. ALK- ALCL, now considered as a distinct disease entity, is morphologically and immunophenotypically similar to ALK+ ALCL, except for ALK expression, but has distinctive molecular features. PTCL, not otherwise specified (PTCL, NOS), the largest PTCL category, which is derived from activated CD4+ (or CD8+) T cells, is markedly heterogeneous, including at the molecular level. Gene expression profiling approaches have identified novel biomarkers of potential therapeutic interest, and suggest the existence of molecularly distinct PTCL, NOS subgroups.

World Health Organization and beyond: new aspects in the pathology of an old disease

Hodgkin's lymphoma is a highly enigmatic lymphoma disease that still covers most of its secrets up to now. Much effort has been made to successfully wrest at least some of the pathogenetic particularities. The current diagnostic criteria are well established allowing hemato-pathologists to make a clear-cut distinction from other lymphomas in almost all cases. Although classic Hodgkin's lymphoma is curable in the vast majority of cases by treatment with highly aggressive drugs with or without radiotherapy, further molecular studies may lead to the identification of therapeutic targets that enable a more tailored treatment with fewer side effects.

Challenges in array comparative genomic hybridization for the analysis of cancer samples

PURPOSE

To address some of the challenges facing the incorporation of array comparative genomic hybridization technology as a clinical tool, including archived tumor tissue, tumor heterogeneity, DNA quality and quantity, and array comparative genomic hybridization platform selection and performance.

METHODS

Experiments were designed to assess the impact of DNA source (e.g., archival material), quantity, and amplification on array comparative genomic hybridization results. Two microdissection methods were used to isolate tumor cells to minimize heterogeneity. These data and other data sets were used in a further performance comparison of two commonly used array comparative genomic hybridization platforms: bacterial artificial chromosome (Roswell Park Cancer Institute) and oligonucleotide (Agilent Technologies, Santa Clara, CA).

RESULTS

Array comparative genomic hybridization data from as few as 100 formalin-fixed, paraffin-embedded cells isolated by laser capture microdissection and amplified were remarkably similar to array comparative genomic hybridization copy number alterations detected in the bulk (unamplified) population. Manual microdissection from frozen sections provided a rapid and inexpensive means to isolate tumor from adjacent DNA for amplification and array comparative genomic hybridization. Whole genome amplification introduced no appreciable allele bias on array comparative genomic hybridization. The array comparative genomic hybridization results provided by the bacterial artificial chromosome and Agilent platforms were concordant in general, but bacterial artificial chromosome array comparative genomic hybridization showed far fewer outliers and overall less technical noise, which could adversely affect the statistical interpretation of the data.

CONCLUSIONS

This study demonstrates that copy number alterations can be robustly and reproducibly detected by array comparative genomic hybridization in DNA isolated from challenging tumor types and sources, including archival materials, low DNA yield, and heterogeneous tissues. Furthermore, bacterial artificial chromosome array comparative genomic hybridization offers the advantage over the Agilent oligonucleotide platform of presenting fewer outliers, which could affect data interpretation.

[Current views of the histogenesis and pathogenesis of Hodgkin lymphoma]

The diagnosis of Hodgkin lymphoma is based on the identification of Beresovsky-Reed-Sternberg (B-R-S) cells which are surrounded by inflammatory cells. The tumor cells are of B-cell origin and their mutations are sometimes observed. T-cell immunophenotype is recorded in 5% of the observations. Epstein-Barr virus is found in one third of the patients.

Cytotoxic molecule expression is predictive of prognosis in Hodgkin's-like anaplastic large cell lymphoma

AIMS

The Revised European American Lymphoma classification uses the term Hodgkin's-like anaplastic large cell lymphoma (HD-like ALCL) for borderline cases with features of both anaplastic large cell lymphoma (ALCL) and classical Hodgkin's lymphoma (HL). The aim of this study was to clarify the association between cytotoxic molecule (CM) expression and clinical outcome in HD-like ALCL.

METHODS AND RESULTS

Subjects were 59 patients with HD-like ALCL, defined by nodal presentation without mediastinal bulky lesions, T- or null-cell phenotype, CD30+ anaplastic lymphoma kinase (ALK)- phenotype and by confluent sheets or nodules of large cells mimicking classic Hodgkin and Reed-Sternberg cells. We evaluated the presenting features and prognosis of subjects on categorization into two defined groups, namely CM (TIA1 and/or granzyme B)-positive (n = 21) and CM-negative (n = 38). The series consisted of 18 women and 41 men ranging from 16 to 88 years of age (median 59 years). The CM+ group had poorer disease-specific survival than the CM- group (P = 0.02) despite the absence of differences in other clinical characteristics. Multivariate analysis confirmed that CM expression was an independent prognostic factor, in contrast to phenotypic categorization (T-cell vs. null-cell group), which had no prognostic impact on disease-specific survival.

CONCLUSION

CM expression is predictive of prognosis in HD-like ALCL.

Association of Hodgkin's lymphoma with Epstein Barr virus infection

The role of Epstein Barr virus (EBV) in the onset of Hodgkin's lymphoma has been a subject of ongoing research. However, confirmation of EBV oncogenic involvement was not possible due to the small number of neoplastic cells characteristic for this type of tumor. Presence of EBV infection in neoplastic and non-neoplastic cells was analyzed in 81 cases of Hodgkin's lymphoma. In neoplastic cells, using an immunohistochemical method, latent membrane protein 1 (LMP1) was found in 33,3% of cases, while in situ hybridization results demonstrated the presence of EBER RNA in 48,1% of the cases. EBER RNA was found in non-neoplastic lymphocytes in 38,3% of cases. EBV is most frequently associated with Hodgkin's lymphoma in the first and seventh decade of life, specifically the nodular sclerosis subtype. No apparent difference was observed in the association of Hodgkin's lymphoma with EBV between genders, or in relation to clinical stage of the disease and average age of the patient. However, association with childhood age is significantly greater in comparison to adults. EBV associated disease shows a significantly greater prevalence in T lymphocytes. Slightly more abundant are cytotoxic T lymphocytes, which are also more frequently in contact with Reed-Sternberg cells, although there is no difference in number and positioning of histiocytes. Variations between the data on the association of EBV with Hodgkin's lymphoma among studies from different parts of the world suggest that factors of age, gender, ethnic background and social status might present biological modifiers of EBV influence on the pathogenesis of this neoplasm. The differences in non-neoplastic infiltrate EBV+ and EBV- lymphoma indicate the effect of the virus on the immune interaction of tumor and host in this disease.

Follicular dendritic cell hyperplasia in plasma cell variant of Castleman's disease with interfollicular Hodgkin's disease

We report a case of a multicentric plasma cell (PC) variant of Castleman's disease (CD) in association with interfollicular type of classic Hodgkin's disease (HD), both diseases identified in the same lymph node. The histologic features of CD were the classic ones, with hyperplastic and atrophic follicles, some with prominent mantle zones, hyalinzed vessels, and a very rich polyclonal proliferation of PCs in the interfollicular region. The presence of LCA-negative, but CD30- and CD15-positive typical and atypical Reed-Sternberg (RS) cells in the interfollicular region confirmed the presence of HD. In addition, many of the RS cells stained positive for EBV. CD35- and CD21-positive follicular dendritic cell (FDC) hyperplasia was a striking feature, a finding that has not been well documented in the PC variant of CD.

PKCeta expression contributes to the resistance of Hodgkin's lymphoma cell lines to apoptosis

The Hodgkin-Reed-Sternberg (HRS) malignant cells in Hodgkin's lymphoma (HL) originate from germinal center B lymphocytes that did not undergo apoptosis. Protein Kinase C (PKC), a family of serine/threonine kinases, plays a crucial role in signal transduction modulating cell growth, differentiation and apoptosis. Here, we report the expression of PKC isoforms in two HL-derived cell lines, L428 and KMH2 and their correlation with drug resistance to CPT and doxorubicin. Among the PKC isoforms examined, only PKCeta and PKCbetaII were preferentially expressed in the drug resistant L428 cells. We have shown correlation between the response to apoptosis of L428 and KMH2 cells and PKCeta expression in these cell lines. In order to directly demonstrate a role for PKCeta in apoptosis, its expression was knocked-down by siRNA in the resistant L428 cells. Downregulation of PKCeta rendered L428 cells more sensitive to doxorubicin and CPT. Furthermore, PKCeta knocked-down cells showed increased PARP-1 cleavage, cytochrome c release and caspase 7 activation. It appears that PKCeta functions as an anti-apoptotic protein in HL-derived cell lines, and as we show here that it is also expressed in HRS of HL biopsies, it may have therapeutic relevance in HL. Thus, PKCeta could provide a new target aimed to reduce resistance to anti-cancer treatments of HL and other cancer patients.

Diagnosis of Hodgkin's disease: an update on histopathological and immunophenotypical features

The Hodgkin lymphoma (HL) is a B-cell lymphoma, as was proved by molecular studies with single-cell PCR. Histologically, it is characterized by a minority of neoplastic cells, Reed-Sternberg cells and its variants, related to a variable non-neoplastic inflammatory background. Nowadays, (WHO classification) the following types of HL are recognized: Nodular Paragranuloma and the Classical Hodgkin Lymphoma, the latter including Nodular Sclerosis, Mixed Cellularity, Lymphocyte-rich Classical Hodgkin Lymphoma and Lymphocyte Depletion. Morphology together with immunohistochemical studies allows to classify the different forms of Hodgkin lymphoma and to make a differential diagnosis with non-Hodgkin lymphomas. All classical Hodgkin lymphomas are treated similarly, and chances for remission and survival are currently good. Molecular parameters should be added to the current classification and patients could benefit from new therapeutic targets.

Metastatic ganglioneuroblastoma in head and neck diagnosed by fine needle aspiration: a case report

BACKGROUND

To describe the cytologic findings of a case of ganglioneuroblastoma metastatic to the jaw and neck.

CASE

A 15-year-old boy with a known case of ganglioneuroblastoma of the kidney for the previous 10 years manifested by right mandibular and neck masses on 2 occasions 1 year apart was diagnosed with metastatic ganglioneuroblastoma by fine needle aspiration (FNA). FNA showed neurofibrillary material, small malignant cells, Homer-Wright rosettes. mononucleated, binucleated and multinucleated ganglion cells and Reed Sternberg-like ganglion cells. Metastatic ganglioneuroblastoma was diagnosed on both occasions, and the patient received appropriate treatment, with resolution of the lesions.

CONCLUSION

This case illustrates the FNA findings of metastatic ganglioneuroblastoma in the head and neck region.

A definitive diagnosis of primary Hodgkin lymphoma on endoscopic biopsy material utilizing in-depth immunohistochemical analysis

The esophagus and stomach can be primary sites for Hodgkin lymphoma (HL). The pathognomonic feature of HL is the Reed-Sternberg cell. Because these cells can be rare in HL tumours, biopsies obtained via endoscopy are usually inadequate for establishing a definitive diagnosis. A case of a gastroesophageal junction primary HL is presented that was diagnosed on endoscopic biopsy material with the assistance of the immunohistochemical stains PAX5 and MUM1 which verified the presence of Reed-Sternberg cells. The patient was effectively treated for HL and avoided traditional laparotomy or thoracotomy procedures to obtain the diagnosis. This advanced immunohistochemical approach should be the standard in the diagnosis of primary gastrointestinal HL. An endoscopy-based approach should obviate more invasive, open biopsy procedures for establishing HL diagnosis.

Pharmacologic activation of p53-dependent and p53-independent apoptotic pathways in Hodgkin/Reed-Sternberg cells

The status of the p53 pathway in classical Hodgkin lymphoma (cHL) remains unclear, and a lack of proven TP53 mutations contrasts with often high expression levels of p53 protein. In this study, we demonstrate that pharmacologic activation of the p53 pathway with the murine double minute 2 (MDM2) antagonist nutlin-3 in Hodgkin lymphoma-derived cell lines leads to effective apoptosis induction and sensitizes the cells to other anticancer drugs. Cells with mutant p53 are resistant to nutlin-3, but sensitive to geldanamycin, a pharmacologic inhibitor of heat shock 90 kDa protein (HSP90), indicating that HSP90 inhibition can induce apoptosis in a p53-independent manner. Conversely, cells with defects in the HSP90/nuclear factor-kappa B pathway expressing wild-type p53 are more resistant to geldanamycin, but still sensitive to nutlin-3. Our results suggest that selective activation of p53 by MDM2 antagonists as a single agent or in combination with conventional chemotherapeutics and/or inhibitors of p53-independent survival pathways may offer effective treatment options for patients with cHL. Importantly, because nutlins and HSP90 inhibitors are non-genotoxic agents, their use might offer a means to reduce the genotoxic burden of current chemotherapeutic regimens.

Posttransplant Hodgkin lymphoma preceded by polymorphic posttransplant lymphoproliferative disorder: report of a pediatric case and review of the literature

Epstein-Barr virus-mediated posttransplant lymphoproliferative disorder (PTLD) is a well-recognized complication of immunosuppression in transplant patients and has broad clinical manifestations and pathologic features ranging from reactive lymphoid proliferation to malignant lymphoma. The category of Hodgkin lymphoma and Hodgkin lymphomalike PTLD is an uncommon variant of PTLD. Development of Hodgkin lymphoma subsequent to other subtypes of PTLD in the same patient is even more unusual, especially in pediatric patients. In this report, we describe a pediatric case of Epstein-Barr virus-associated posttransplant Hodgkin lymphoma developing several years after the patient was diagnosed with polymorphic PTLD and review the literature of the previously reported cases in children to further help characterize the clinical features, histopathologic appearances, biology, and treatment strategies of this uncommon entity.

Expression of bcl2 family proteins and active caspase 3 in classical Hodgkin's lymphomas

The expression of various bcl2 family proteins has been reported in Hodgkin and Reed-Sternberg cells, but the proteins bad, bid, and bim have not been analyzed in classical Hodgkin's lymphomas (HLs). This study aimed to investigate the expression of the proteins bcl2, bcl-xl, mcl1, bax, bak, bad, bid, bim, and active caspase 3, and the TUNEL (terminal deoxynucleotidyl transferase-mediated in situ labeling) index to gain further insight into the apoptosis profile of classical HLs. A high expression of the proteins bcl2, bcl-xl, mcl1, bax, bak, bad, bid, and bim in HRS cells was found in 27 of 101 (27%), 95 of 101 (94%), 27 of 97 (29%), 73 of 95 (77%), 37 of 102 (36%), 85 of 94 (90%), 19 of 109 (17%), and 43 of 91 (47%) cases, respectively. The high expression of bcl-xl, bax, and bad in HRS cells in most classical HLs indicates that these proteins may play predominant roles in the regulation of apoptosis in classical HLs. Active caspase 3-positive and TUNEL-positive Reed-Sternberg cells were detected in 47 of 70 (67%; range, 0%-12%) and 60 of 71 (85%; range, 0%-19%) cases, respectively. Significant positive correlations were found between bax/bcl2 (P = .002), bad/bcl2 (P = .020), bad/bcl-xl (P = .003), and bim/mcl1 (P = .036). Based on these findings, it could be hypothesized that the antiapoptotic proteins bcl2, bcl-xl, and mcl1 may counteract the expression of the proapoptotic proteins bax, bad, and bim, thereby contributing to the survival of Reed-Sternberg cells.

Demonstration of Chimeric DNA of bcl-2 and Immunoglobulin Heavy Chain in Follicular Lymphoma and Subsequent Hodgkin Lymphoma from the Same Patient

We performed single cell polymerase chain reaction (PCR) amplification of the t (14 ; 18) translocation from paraffin embedded sections in a case of follicular lymphoma (FL) with subsequent development of Hodgkin lymphoma (HL). The lymphoma cells of FL were positive for CD20, CD10 and BCL-2, and negative for CD3, CD30 and CD15. Hodgkin and Reed-Sternberg (HRS) cells of HL were positive for CD20, CD30 and CD15, and negative for CD3 and CD10. EBER-1 RNA in situ hybridization failed to stain with both lymphomas. HRS cells manipulated and FL cells micro-shaved from individual neoplastic follicles were subjected to single-cell PCR. The t (14 ; 18) translocation, a chimeric DNA containing portions of the bcl-2 and the immunoglobulin heavy chain (IgH) genes, was amplified from four of 27 isolated HRS cells and two individual FL follicles. All t (14 ; 18) PCRs yielded products of the same size, and an identical nucleotide sequence including the t (14 ; 18) translocation was found in both FL and HRS samples. Thus, the data demonstrate the common clonal origin of FL cells and HRS cells in subsequent HL, and that both FL and HL were derived from germinal center B cells with the t (14 ; 18) translocation.

Absence of measles virus genome and transcripts in Hodgkin-Reed/Sternberg cells of a cohort of Hodgkin lymphoma patients

In the search for viruses in Hodgkin lymphoma (HL), it was reported that the measles virus (MV) can be detected in the Hodgkin-Reed/Sternberg (HRS) cells of a large fraction of cases from Israel by immunohistochemistry or in situ hybridisation, suggesting a potential role of this virus in HL. To extend and validate this report, we studied HL-derived cell lines and HRS cells microdissected from German and Israeli HL cases for the presence of MV RNA genome and transcripts, analysing three MV genes (nucleoprotein, matrix, haemaglutinin). A cell line infected with MV was used as a positive control for MV RNA detection. MV RNA was detectable down to 1 infected cell in a nested RT-PCR. Pools of microdissected HRS cells from 18 German and 7 Israeli classical HL (the latter reported to be positive for MV proteins in the previous study) were analysed for MV genome and transcripts. None of the viral genes was obtained in independent replicate experiments in any of the 25 HL cases. A Southern blot hybridisation performed with the second round PCR products further confirmed the negative results. Whole HL tissue sections were analysed to exclude MV in non-HRS cells, also yielding negative results. We also analysed four HL cell lines and showed that these are MV-negative, too. In this cohort of German and Israeli HL patients--including cases previously typed as MV-positive--and HL-derived cell lines, there was no evidence of MV genome in the HRS cells.

Epidemiology and pathologic features of Hodgkin lymphoma

Hodgkin lymphoma (HL) has unique epidemiologic characteristics. The variation in incidence according to age, sex, race, socioeconomic status, and histologic subtype suggests an etiologic heterogeneity for this tumor. Epidemiologic studies have shown that both genetic and environmental factors play a role in the pathogenesis of HL. HL is one of the Epstein-Barr virus-associated lymphomas, but the oncogenetic mechanism of HL remains to be elucidated. Recent advances in molecular biology have revealed the peculiar nature of the nodular lymphocyte predominant subtype, and as a result this disease is separated from classic types of HL in the new World Health Organization classification. Reed-Sternberg (RS) cells and lymphocytic and/or histiocytic (L&H) cells originate from germinal center B-cells. Loss of the B-cell phenotype due to down-regulation of several B-cell-specific transcription factors is characteristic of RS cells in classic HL.

Gene rearrangement and comparative genomic hybridization studies of classic Hodgkin lymphoma expressing T-cell antigens

CONTEXT

Reed-Sternberg cells in classic Hodgkin lymphoma are enigmatic and difficult to study because they are so sparse. Tissue microdissection allows for the isolation of single Reed-Sternberg cells. Isolated Reed-Sternberg cells show clonal immunoglobulin gene rearrangement indicating a B-cell origin. Rarely, Reed-Sternberg cells in classic Hodgkin lymphoma express T-cell antigens, suggesting a possible T-cell origin.

OBJECTIVE

To determine whether there is a difference in genotype between classic Hodgkin lymphoma and classic Hodgkin lymphoma expressing T-cell antigens and to document T-cell clonality.

DESIGN

We studied 4 cases of Hodgkin lymphoma with a characteristic phenotype and immunoreactivity for CD2 and CD3. Single CD30+ Reed-Sternberg cells from each case were isolated by laser capture microdissection for immunoglobulin heavy chain and T-cell receptor-gamma genes by polymerase chain reaction studies. Comparative genomic hybridization was performed in all cases.

RESULTS

Two of 4 cases showed clonal rearrangement of the T-cell receptor-gamma; none showed immunoglobulin heavy chain rearrangement. Two control cases were negative for T cell receptor-gamma but 1 showed immunoglobulin heavy chain rearrangement. Comparative genomic hybridization analysis revealed significant overlap in genomic alteration in Hodgkin lymphoma cases regardless of genotype or phenotype and several regions of imbalance specific to CD3+ Hodgkin lymphoma cases. All patients are alive with no evidence of disease from 10 to 44 months.

CONCLUSIONS

Our findings suggest that a T-cell phenotype classic Hodgkin lymphoma can be supported by genotypic studies and that there may be cytogenetic differences between classic Hodgkin lymphoma and Hodgkin lymphoma expressing T-cell antigens.

NF-κB–independent down-regulation of XIAP by bortezomib sensitizes HL B cells against cytotoxic drugs

The proteasome inhibitor bortezomib has been shown to possess promising antitumor activity and significant efficacy against a variety of malignancies. Different studies demonstrated that bortezomib breaks the chemoresistance in different tumor cells basically by altering nuclear factor–κB (NF-κB) activity. NF-κB has been shown to be constitutively active in most primary Hodgkin-Reed-Sternberg (H-RS) cells in lymph node sections and in Hodgkin lymphoma (HL) cell lines and was suggested to be a central molecular switch in apoptosis resistance in HL. Here we report a bimodal effect of bortezomib in HL cells. Whereas high-dose bortezomib induced direct cytotoxicity that correlated with decreased NF-κB activity, low-dose bortezomib sensitized HL cells against a variety of cytotoxic drugs without altering NF-κB action. Strikingly, bortezomib induced marked XIAP down-regulation at the posttranslational level that was independent of the NF-κB status. Similarly, RNA interference (RNAi)–mediated XIAP down-regulation generated susceptibility to cytostatic agents. The results identify XIAP as an NF-κB–independent target of bortezomib action that controls the chemoresistant phenotype of HL cells.

Expression of cyclooxygenase-2 in Hodgkin's lymphoma: its role in cell proliferation and angiogenesis

Although many studies have revealed the association between cyclooxygenase-2 (COX-2) and carcinogenesis, the association between COX-2 and Hodgkin's lymphoma (HL) remains unknown. We examined the immunohistochemical expression of COX-2, p53, bcl-2, and Ki-67 in 33 patients with HL, and counted microvessels stained with CD34. Hodgkin and Reed - Sternberg (HRS) cells with COX-2 expression were scored as 0 = no staining; 1 = <25% of cells staining; 2 = 25-49%; 3 = 50-75%; and 4 = > or =75%. COX-2 expression was observed in 15 cases of classical HL. Nevertheless, neither accumulation of p53 nor bcl-2 expression was associated with COX-2 expression. The percentage of Ki-67 positive-HRS cells and microvessel density in COX-2 score groups 2-4 were significantly higher than those in score group 0, respectively. We show that COX-2 expression is associated with cell proliferation and angiogenesis in HL. These findings suggest that COX-2 may be a target for therapy in HL.

Identification and purification of classical Hodgkin cells from lymph nodes by flow cytometry and flow cytometric cell sorting

We demonstrate the feasibility of using flow cytometry (FC) to identify the Hodgkin and Reed-Sternberg (HRS) cells of classical Hodgkin lymphoma (CHL). Initial flow cytometric studies of the HRS cell line L1236 demonstrated potentially useful antigens for identifying HRS cells. L1236 cells spontaneously bound normal T cells, analogous to the T-cell rosetting of HRS cells seen in tissue sections of CHL, but these interactions could be blocked by using a cocktail of unlabeled antibodies to 4 adhesion molecules. Among 27 lymph nodes involved by CHL, FC enabled HRS cells to be identified in 89%, whereas none of 29 non-CHL neoplasms or 23 reactive lymph nodes demonstrated HRS populations. Of the CHL cases, 82% demonstrated interactions between HRS cells and T cells that could be disrupted with blocking antibodies. Flow cytometric cell sorting experiments demonstrated typical HRS cytomorphologic features among the purified cells. FC may offer an alternative to immunohistochemical analysis in confirming the diagnosis of CHL in certain cases, and, through cell sorting, it provides a means of rapidly isolating pure HRS cells.

Pathobiology of Classical Hodgkin Lymphoma

The World Health Organization has acknowledged the malignant nature of classical Hodgkin lymphoma (cHL), which encompasses four histological subtypes. The diagnosis of cHL is based on the detection of malignant Hodgkin and Reed-Sternberg cells (HRSC) confirmed by immunophenotyping and the detection of growth patterns specific to each histological subtype. The pathologic HRSC arise from germinal center or immediate postgerminal cells that lack detectable immunoglobulin/B-cell antigen receptor expression, with a consequent loss of B-cell identity; very few cHL cases are of T-cell origin. To escape apoptosis, which normally occurs in B cells with nonfunctioning antigen receptor machinery, HRSC develop concurrent antiapoptotic mechanisms by activation of nuclear factor-kappaB or are rescued by Epstein-Barr virus infection. HRSC are characterized by a variable and inconstant immunophenotype, with a remarkable loss of lineage-specific cell antigens and expression of antigens of other cell lineages. The master plan of B-cell identity in HRSC is disturbed not only at the immunoglobulin expression level, but also at the transcriptional factor level. HRSC are further characterized by profound cell cycle deregulation with futile replication, multinucleation and poly- and aneuploidy. Here, we review pathobiological aspects of cHL with respect to lymphomagenesis and routine diagnostics.

Aberrant FHIT protein expression in classical Hodgkin’s lymphoma: a potential marker

AIMS

The fragile histidine triad (FHIT) gene is frequently inactivated in human cancers; however, the FHIT gene remains unexplored in Hodgkin's lymphoma. The aim of this study was to investigate the role of FHIT expression in classical Hodgkin's lymphoma.

METHODS

Classical Hodgkin's lymphomas were analysed for FHIT gene expression by two-step non-biotin immunohistochemical method and Western blotting.

RESULTS

Thirty of the 33 (91%) cases of Hodgkin's lymphoma tested were positive for FHIT protein by immuohistochemistry. The expression of FHIT was mainly located in cytoplasm of Reed-Sternberg (HRS) cells. The protein expression was also documented by Western blotting. The non-Hodgkin's lymphomas were negative for FHIT protein.

CONCLUSIONS

The results indicate that abnormal FHIT expression is noted frequently in classical Hodgkin's lymphoma and the expression can give insight into the pathogenesis of the disease. The protein may serve as a marker to localise HRS cells in classical Hodgkin's lymphoma.

Primary Cutaneous Lymphoproliferative Disorders With Dual Lineage Rearrangement

We present a series of 15 cases of cutaneous lymphoma and pseudolymphoma with dual lineage rearrangement identified among approximately 1200 cases of cutaneous lymphoproliferative disorders assessed in our 4 institutions during the last 8 years in which the results of both T-cell receptor and immunoglobulin heavy chain rearrangement investigations were available. On the basis of the clinicopathologic information, the cases were retrospectively subdivided into 2 categories: (1) cases with definite features of cutaneous lymphoma or pseudolymphoma (n = 11) and (2) cases with unclassifiable disease (n = 4). The detection of dual genotype in the first group did not influence the final diagnosis; 7 cases represented cutaneous B-cell lymphomas, 3 pseudolymphomas, and 1 case lymphomatoid papulosis. The presence of monoclonal T-cell receptor-gene rearrangements in these cases may be explained either by monoclonal or oligoclonal expansion of exuberant T cells (or B cells in case of lymphomatoid papulosis) or by lineage infidelity. Three patients with unclassifiable disease had several clinical and histopathologic features in common. They were elderly, presented with solitary lesions, were in good general health and histopathologically demonstrated a dense multinodular infiltrate containing approximately an equal number of T and B cells and a high number of histiocytes forming granulomas, with prominent granulomatous features in 2 cases. B cells were either scattered with the infiltrate or formed collections vaguely resembling follicles; Reed-Sternberg-like cells were seen in 2 cases. B cells showed expression neither of immunoglobulin light chain. The T-cell component was represented mainly by small, well-differentiated lymphocytes or slightly pleomorphic cells, with some medium-sized convoluted cells. Epstein-Barr virus was not detected by polymerase chain reaction. The exact classification of these cases is unknown; they differ histopathologically from previously published cases of bigenotypic cutaneous lymphomas. They may merely represent a growth or reactive pattern, but, on the other hand, may be low-grade lymphomas. If so, they may be histopathologically related to cutaneous Hodgkin disease, T-cell/histiocyte-rich large B-cell lymphoma, or composite lymphomas. Further reports are needed to identify these lesions to clarify their nature and biologic potential.

Aberrant expression of ID2, a suppressor of B-cell-specific gene expression, in Hodgkin's lymphoma

The global loss of B-cell-specific gene expression is a distinctive feature of the Hodgkin-Reed/Sternberg (HRS) cells of classical Hodgkin's lymphoma (HL). The reasons for this loss remained largely unknown as transcription factors with pleiotropic effects on B-cell-specific gene expression, namely E2A, EBF, and PAX5, are present in primary HRS cells. We show here that ID2, which can inactivate E2A and perhaps PAX5, is not detectable in normal B cells but is strongly and uniformly expressed in HRS cells of all cases of classical HL. Recurrent chromosomal gains of the ID2 gene might contribute to this aberrant expression. Co-immunoprecipitation of E2A with ID2 from HRS-derived cell lines together with the high amount of ID2 relative to the B-cell transcription factors E2A and PAX5 in HRS-derived cell lines and primary HRS cells indicated that aberrant ID2 expression contributes significantly to the loss of the B-cell-specific gene expression in HRS cells. ID2 was also expressed in lymphocyte-predominance HL, mediastinal large B-cell, diffuse large B-cell, and Burkitt's lymphoma, where lower amounts of ID2 relative to E2A and PAX5 compared with HRS cells might prevent a global down-regulation of B-cell-specific genes and ID2 may contribute to lymphomagenesis in other ways.

Composite recurrent hodgkin lymphoma and diffuse large B-cell lymphoma: one clone, two faces

We describe a composite lymphoma with recurrent Hodgkin lymphoma and diffuse large B-cell lymphoma components manifesting as a single, perforated small intestinal tumor in a 56-year-old man with a history of classical Hodgkin lymphoma and recent relapse in the bone marrow. The resected mass had 2 morphologically and immunophenotypically distinct components; 1 showed a pleomorphic cellular infiltrate with fibrosis and contained numerous, large Hodgkin/Reed-Sternberg-like cells and variants. The tumor cells were CD30+ and focally positive for CD15 but CD20-, CD79a-, and PAX-5-. In situ hybridization for Epstein-Barr virus (EBV) was strongly positive in the large pleomorphic tumor cells. The adjacent component displayed sheets of relatively uniform, large lymphoid cells with typical morphologic features of diffuse large cell lymphoma. The tumor cells showed uniform expression of tested B-cell antigens, absence of CD30 or CD15, and complete absence of EBV-encoded RNA. Separate molecular studies with immunoglobulin heavy and k light chain gene rearrangements clearly demonstrated an identical rearrangement pattern, indicating derivation from the same clone, which was confirmed by direct DNA sequencing analysis. Such distinctly different morphology, immunophenotype, and EBV status in different components within a clonally related single tumor mass is striking.

Molecular Pathogenesis of Hodgkin Lymphoma

Hodgkin lymphoma (HL) is a distinctive lymphoma subtype that accounts for approximately 30% of all lymphomas in the Western world and approximately 5% in Japan. HL is characterized by the giant multinucleated tumor cells called Hodgkin/Reed-Sternberg (H/RS) cells, but the cellular origin had long been unknown. Recent investigations have clarified that H/RS cells have a clonally rearranged immunoglobulin gene in most cases, but it still seems appropriate to differentiate HL from other B-cell neoplasms, because the transforming event rather than its cellular origin is more likely to influence the nature of H/RS cells. Many questions remain to be answered for comprehensive understanding of the pathogenesis of HL. The presence of H/RS cells alone is probably not enough for disease onset, but the immune reaction against these cells appears to be inevitable for generation of HL. Most HL patients are cured with current treatment strategies, but some of them have refractory or recurrent disease, and intensified treatment occasionally induces therapy-related secondary malignancies. Because the growth and survival of H/RS cells are supported by various external stimuli and constitutive intracellular signals, management of HL is expected to be one of the best applications of molecule-targeted therapy.

Epstein-Barr virus, cytokines, and inflammation: a cocktail for the pathogenesis of Hodgkin's lymphoma?

The association between chronic inflammation and cancer has been known for well over a century. However, direct evidence detailing the role of inflammation in carcinogenesis has been slow in forthcoming. A number of recent studies suggest that the gaps in our understanding of the molecular pathways bridging the link between inflammation and cancer are slowly beginning to close and that this relationship is more deep-rooted than had been previously believed. This review addresses the link between inflammation and Hodgkin's lymphoma (HL), a malignancy which has many features reminiscent of chronic inflammation. The role of Epstein-Barr virus (EBV) in the pathogenesis of HL is discussed, along with an outline of our current understanding of the cellular nature and development of Reed-Sternberg cells, the malignant cells of HL. The involvement of cytokines and chemokines as orchestrators of inflammation and vehicles for chemical cross-talk between the malignant cells and the reactive inflammatory infiltrate forms a major part of the review. It is suggested that chronic inflammation, triggered by factors such as EBV, is likely to contribute to tumor cell proliferation, progression, and inhibition of apoptosis. Furthermore, it is proposed that the pro-inflammatory transcription factor NF-kappaB plays a central role in many of these processes.

Reprogramming of B lymphoid cells in human lymphoma pathogenesis

Previous hypotheses have stated that differentiated cells lose the ability to change their fate. Using lymphoid development as a model system, recent data have challenged this rigid view of cellular differentiation. It has been shown in mouse models that, under certain conditions, even mature lymphoid cells can display a broad developmental potential, and might even transdifferentiate into other cell types. The relevance of these observations for the physiological ontogenesis of lymphoid cells or their malignant transformation is currently unclear. Recent data from our laboratory have demonstrated that similar processes can be observed in the malignant Hodgkin/Reed-Sternberg (HRS) cells of classical Hodgkin lymphoma (cHL), a common B cell-derived lymphoma. In HRS cells, the B cell-specific homodimer activity of the transcription factor E2A is functionally disrupted by overexpression of the E2A antagonists activated B cell factor 1 (ABF-1) and inhibitor of differentiation 2 (Id2). In consequence, the expression of B cell-specific genes is lost, and B lineage-inappropriate genes are upregulated. These data have demonstrated the plasticity of human lymphoid cells and offer an explanation for the unique phenotype of cHL. We first summarize data showing the plasticity of lymphoid cells in mouse models, second describe our observations regarding the altered B cell-specific transcription factor network in HRS cells, and third discuss the possible implications of these findings for human lymphoma pathogenesis.

Simultaneous occurrence of Hodgkin's lymphoma and Kaposi's sarcoma within the same lymph nodes of a non-AIDS patient

We report a case of simultaneous occurrence of Hodgkin's lymphoma and Kaposi's sarcoma within the same lymph nodes of a 61-year-old woman without human immunodeficiency virus (HIV) infection. Epstein-Barr virus (EBV) was detected in the Hodgkin cells and Reed-Sternberg cells by EBV LMP-1 immunostaining and Epstein-Barr virus encoded early RNA (EBER) in situ hybridization. In contrast, Kaposi's sarcoma cells were positive for human herpes virus 8. This case is documented because the occurrence of 2 independent tumors infected by 2 unrelated viruses within the same lymph nodes of a patient without HIV infection has rarely been observed.

Immunophenotyping of Hodgkin's disease--an aid to its classification

Based on morphological, phenotypic, genotypic and clinical findings, Hodgkin's disease has recently been classified into two subtypes: Nodular lymphocyte predominant and classical Hodgkin's disease. Forty-two cases of Hodgkin's disease were subjected to detailed morphological assessment and immunophenotyping. The commonest subtype was Nodular Sclerosis seen in 27 cases. The panel of antibodies used was CD 15, CD 30, CD 3, CD 20, CD 45 and Epithelial Membrane Antigen. Immunophenotyping was done by Streptavidin Biotin Peroxidase complex technique. CD 30 was expressed in 86% and CD 15 in 76% cases. Immunophenotype helped reclassify two cases, according to the WHO classification scheme. Although morphology remains the gold standard in the diagnosis of Hodgkin's disease, immunophenotype is a useful adjunct in differentiating prognostically distinct subtypes.

Interfollicular Hodgkin's disease: an uncommon pattern that may cause diagnostic difficulty

Interfollicular Hodgkin's Disease is characterised by reactive follicular hyperplasia with involvement of the interfollicular area of lymph node by Hodgkin's lymphoma. It represents a peculiar pattern of focal involvement of lymph node and does not constitute a classical subtype. Its importance rests in the fact that it can be misinterpreted as one of the many causes of reactive hyperplasia of lymph node and not as Hodgkin's disease. Eleven cases of interfollicular Hodgkin's disease were diagnosed in a period of five years. Majority of the patients were less than twenty years and all had localised lymphadenopathy. Lymph node biopsy showed follicular hyperplasia with expanded interfollicular area. Careful search of the interfollicular area showed infiltration by inflammatory cells and scattered Reed-Sternberg and Hodgkin's cells. Immunohistochemistry with CD 15 and CD 30 highlighted the atypical cells. This report emphasises on the problems in diagnosis of interfollicular Hodgkin's disease.

Lymphoma mimicking a thyroglossal duct cyst in an adolescent

Mass lesions of the head and neck in infants and children can be either developmental, inflammatory or neoplastic. Lymphomas (Hodgkin’s or Non-Hodgkin’s) commonly present as neck lumps in children. Although malignancy is not the commonest aetiology of paediatric cervical lumps, a high index of suspicion is critical to facilitate early diagnosis and treatment of cervical lesions. We present the case of a 15-year-old boy who presented with a solitary midline cervical lesion, which simulated a thyroglossal cyst on clinical examination. However, histopathological examination revealed it to be a Hodgkin’s lymphoma. Related literature is also reviewed.