First-line treatment of Hodgkin's lymphoma

Substantial clinical progress over the last decades has made Hodgkin's lymphoma (HL) into one of the most curable human cancers in adults. About 80% of patients in all stages and of all histological subtypes experience long-term disease-free survival. Modern treatment strategies aim to improve chemotherapy and radiotherapy, while minimizing therapy-related toxicities. Ongoing trials investigate a reduction of chemotherapy doses or cycles and the application of lower-radiation doses and smaller radiation field sizes. For patients with a specific high-risk profile, novel approaches with more intense drug combinations are currently being investigated in clinical trials. Here, we review recent approaches in the first-line treatment of early-favorable, early-unfavorable, and advanced-stage HL.

Comparison of initial characteristics and long-term outcome of patients with lymphocyte-predominant Hodgkin lymphoma and classical Hodgkin lymphoma at clinical stages IA and IIA prospectively treated by brief anthracycline-based chemotherapies plus extended high-dose irradiation

Lymphocyte-predominant Hodgkin lymphoma (LPHL), according to the Revised European-American Lymphoma classification, was considered on a retrospective basis as a specific clinical entity with a large majority of patients at clinical stage (CS) IA or IIA. Of the 500 patients with CS IA/IIA Hodgkin lymphoma (HL) prospectively treated between 1981 and 1996 by one or 3 courses of anthracycline-based chemotherapies combined with high-dose extended irradiation, disease in 42 patients was reclassified as LPHL. These 42 patients, none of whom had mediastinal involvement (MI), were compared with the 458 patients with classical HL (cHL), 144 without MI and 314 with MI. Surprisingly, the male-female ratio, age, first site involved, hemoglobin level, lymphocyte count, and sedimentation rate of patients with LPHL and cHL without MI were identical and significantly different from those of patients with cHL with MI. Moreover, 15-year HL mortality rates were similarly low in patients with LPHL (2.4%) and cHL without MI (0.7%). Overall survival rates were also similar (86% and 82%) and as high as 100% and 95% in patients treated before the age of 40 years. This study demonstrated that LPHL and cHL without MI shared the same presenting characteristics and the same excellent long-term prognosis after a brief anthracycline-based chemotherapy plus high-dose extended irradiation.

Bone marrow biopsy in Hodgkin's lymphoma

In the study of patients with Hodgkin's lymphoma (HL) the evaluation of bone marrow biopsy (BMB) can be difficult. In this review we analyze the main diagnostic features and the clinical risk factors of BM involvement. Although the role of BMB is criticized by some authors, its value is irreplaceable in the staging of HL and in the diagnosis of primary medullary HL. The Ann Arbor staging committee criteria should be revised and updated in the light of the current immunohistochemical studies that give a fundamental help in the diagnostic process. A single BMB should be adequate for diagnosis in most instances. In cases of suspicious involvement a controlateral BMB could be performed.

Molecular profiling provides evidence of primary mediastinal large B-cell lymphoma as a distinct entity related to classic Hodgkin lymphoma: implications for mediastinal gray zone lymphomas as an intermediate form of B-cell lymphoma

Expanding on prior studies that have used molecular profiling to elucidate the heterogeneity of diffuse large B-cell lymphomas (DLBCLs), two recent studies (Rosenwald et al and Savage et al) have characterized a third molecularly distinct subtype of DLBCL, primary mediastinal (thymic) large B-cell lymphoma (PMLBCL). Both groups found distinct gene expression patterns that were able to reliably diagnose PMLBCL and distinguish it from other DLBCLs. Notably, the signature gene expression profile of PMLBCL was more closely related to classic Hodgkin lymphoma (CHL) than other DLBCL subtypes. These studies provide further evidence that PMLBCL and nodular sclerosis CHL may represent related tumors on either ends of a continuum, whose interface includes an intermediate form of disease, mediastinal gray zone (MGZL) lymphoma. MGZLs are tumors that have a transitional morphology and phenotype, combining features of both PMLBCL and nodular sclerosis CHL, and provide a diagnostic challenge to pathologists. These studies provide insights into the biology of PMLBCL and CHL and demonstrate the utility of genomic technologies in defining and diagnosing hematopoietic tumors. The ability to map specific pathologic signal transduction pathways regulating hematopoietic differentiation, proliferation, and apoptosis through genomic or proteomic technologies promises to provide the basis for the development of individualized molecularly targeted therapies for specific tumors.

Leukocyte-specific phosphoprotein-1 and PU.1: two useful markers for distinguishing T-cell-rich B-cell lymphoma from lymphocyte-predominant Hodgkin's disease

BACKGROUND AND OBJECTIVES

T-cell-rich B-cell lymphoma is a rare variant of diffuse large B-cell lymphoma. It shows morphologic, phenotypic and molecular similarities to lymphocyte predominant Hodgkin's disease, and in consequence the two diseases may sometimes be difficult to distinguish. In this paper, we have evaluated the usefulness of the pan-leukocyte marker LSP1 and the transcription factor PU.1 for resolving such diagnostic problems.

DESIGN AND METHODS

Immunohistochemical techniques were used to investigate the expression of LSP1 and PU.1 in 34 tumors, comprising typical examples of T-cell-rich B-cell lymphoma (15 cases), lymphocyte-predominant Hodgkin's disease (13 cases), and lymphocyte-rich classical Hodgkin's disease (6 cases).

RESULTS

The neoplastic cells of T-cell-rich B-cell lymphoma were LSP1-positive and PU.1-negative, whereas the lymphocytic and/or histiocytic (L&H) cells of lymphocyte-predominant Hodgkin's disease were mostly LSP1-negative, with variable PU.1 expression. The two markers did not discriminate between T-cell-rich B-cell lymphoma and lymphocyte-rich classical Hodgkin's disease, whilst they concurred to the distinction between lymphocyte-predominant and lymphocyte-rich classical Hodgkin's disease by integrating the already available tools.

INTERPRETATION AND CONCLUSIONS

Antibodies to LSP1 and PU.1 may represent useful reagents for the differential diagnosis between T-cell-rich B-cell lymphoma and lymphocyte-predominant Hodgkin's disease.

Expression of c-FLIP in Classic and Nodular Lymphocyte-Predominant Hodgkin Lymphoma

Different molecular pathways are believed to be involved in the pathogenesis of classic Hodgkin lymphoma as opposed to non-Hodgkin lymphoma. Antiapoptotic mechanisms have been proposed for classic Hodgkin lymphoma, including expression of the cellular Fas-associated death domain-like interleukin-1beta-converting enzyme inhibitory protein (c-FLIP), which plays a critical role in resistance to CD95/Fas-mediated apoptosis. In this study, we compare the expression of c-FLIP in the neoplastic cells of classic Hodgkin lymphoma and nodular lymphocyte-predominant Hodgkin lymphoma cases. Sixteen cases of classic Hodgkin lymphoma and 19 cases of nodular lymphocyte-predominant Hodgkin lymphoma were reviewed. Of 16 classic Hodgkin lymphoma cases, 13 cases (81%) were c-FLIP-positive, compared with 6 of 19 (32%) nodular lymphocyte-predominant Hodgkin lymphoma cases. Strong cytoplasmic staining was seen in 7 of 13 c-FLIP-positive classic Hodgkin lymphoma cases, in contrast with only 2 of 6 c-FLIP-positive nodular lymphocyte-predominant Hodgkin lymphoma cases. The 2 cases of nodular lymphocyte-predominant Hodgkin lymphoma with strong c-FLIP expression were associated with transformation to large B-cell lymphoma. An additional 15 cases of diffuse large B-cell lymphoma were studied for c-FLIP expression. All but 1 were c-FLIP-positive. In conclusion, we detected c-FLIP in a significantly lower proportion of nodular lymphocyte-predominant Hodgkin lymphoma cases compared with classic Hodgkin lymphoma cases. Therefore, c-FLIP expression may not be the major mechanism of pathogenesis in nodular lymphocyte-predominant Hodgkin lymphoma. However, strong c-FLIP expression in nodular lymphocyte-predominant Hodgkin lymphoma was associated with transformation to large B-cell lymphoma in 2 cases. c-FLIP expression is not limited to Hodgkin lymphoma, because the majority of diffuse large B-cell lymphoma cases tested were strongly c-FLIP-positive.

Positron emission tomography in patients with Hodgkin's disease: correlation to histopathologic subtypes

The aim of this study was to evaluate the initial staging and restaging of Hodgkin's disease (HD) according to histopathologic subtype (HST) using fluorine-18-deoxyglucose-positron emission tomography (PET). Special attention was paid to the accuracy of PET for detection of bone marrow infiltration (BMI). 44 patients with HD (m:f = 28:16, mean age 36 +/- 15 years) underwent PET; 16 were primary stagings and 28 restaging examinations. PET results were compared with methods of conventional staging including computed tomography (CT) and bone marrow biopsy. Viable tumor tissue was detected by PET in 25/44 cases, 16 nodular sclerosis (NS), 4 mixed cellularity (MC), 3 lymphocyte predominance (LP) and 2 cases with a nonclassified subtype (NC). FDG tumor uptake, measured as standard uptake value (SUV), ranged from 1.7 to 13. Maximum SUV in NS was 5.2 +/- 1.5 (2.5-7.3), 3.2 +/- 2.4 for MC, 2.6 +/- 0.7 for LP, and 9.1 +/- 3.8 for NC, respectively. In 7% of all patients (3/44) bone marrow infiltrations were detected by PET. PET is known for its superior detection of viable tissue in HD. In this study it was shown that HST does not influence the intensity of glucose metabolism, although 2 patients with NC showed the highest SUVs. In addition PET accurately detected focal BMI and may thus be applied before BMB to guide its optimal use.

Hodgkin and non-Hodgkin lymphoma involving bone marrow

The role of bone marrow examination in diagnosis and staging of patients with Hodgkin lymphoma, B-non-Hodgkin lymphoma, and T-non-Hodgkin lymphoma is reviewed. Optimal routine and specialized bone marrow examination techniques are discussed. The salient morphologic, immunophenotypic, and genetic features of mature and immature B, T neoplasms and classic Hodgkin lymphoma in bone marrow are delineated, along with recommendations to distinguish these overt neoplasms from non-neoplastic processes.

La maladie de Hodgkin nodulaire à prédominance lymphocytaire et ses diagnostics différentiels

Nodular lymphocyte predominance Hodgkin's disease (NLPHD), previously called nodular paragranuloma, is a rare entity recognized as a clinico-pathological entity distinct from classic Hodgkin's lymphoma. It is an indolent B cell lymphoma derived from a germinal center cell. NLPHD may closely resemble lymphocyte-rich classic Hodgkin's disease (LR-CHD) or T-cell or histiocyte-rich large B-cell lymphoma (TCRLBCL). A reproducible distinction between these entities is difficult but the classification is prognostically relevant. NLPHD is characterized by neoplastic "popcorn" cells CD20+ CD30- CD15- EMA+ Bcl6+ scattered within a nodular background predominantly composed of small B lymphocytes. LR-CHD neoplastic proliferation is composed of CD20+/- CD30+ CD15+/- EMA- Bcl6+/- Reed Sternberg or Hodgkin's cells, scattered within numerous CD3+ T cells. TCRLBCL is an agressive lymphoma composed of CD20+ CD30- CD15- EMA+/- Bcl6+/- polymorphic neoplastic cells, scattered within a mixture of CD3+ T cells and histiocytes. Epstein Barr virus is detectable within half cases of LR-CHD, but never in NLPHD and rarely in TCRLBCL. The transcription factors BOB1, PU-1, BSAP and IRF4 are new markers that could be useful for differential diagnosis.

Expression of CCL28 by Reed-Sternberg cells defines a major subtype of classical Hodgkin's disease with frequent infiltration of eosinophils and/or plasma cells

Classical Hodgkin's disease (HD) is characterized by rare neoplastic Hodgkin and Reed-Sternberg (H-RS) cells within abundant reactive cellular backgrounds. In most cases, H-RS cells originate from the B-cell lineage, but their immunophenotypes are unusual. Here we newly found frequent expression of chemokine receptors CXCR6 and CCR10 and their respective ligands CXCL16 and CCL28 in HD-derived cell lines. CCR10 is known to be selectively expressed by plasma cells, whereas CCL28 attracts eosinophils via CCR3 and plasma cells via CCR10 and CCR3. Therefore, we examined their expression in HD tissues by immunohistochemistry. We found that H-RS cells in 15 of 19 cases were positive for CCL28. Among them, seven cases were also positive for CCR10, suggesting a potential autocrine effect. In situ hybridization confirmed the expression of CCL28 mRNA in H-RS cells. The CCL28 positivity in H-RS cells did not significantly correlate with that of LMP-1, CCL17, CCL22, or CCL11. However, it significantly correlated with the background accumulation of eosinophils, plasma cells, and CCR10+ cells. Thus, the production of CCL28 by H-RS cells may play a major role in tissue accumulation of eosinophils and/or plasma cells in classical HD. The frequent expression of CCR10 in H-RS cells themselves also supports their close relationship to plasma cells.

Analysis of 1983 cases of malignant lymphoma in Thailand according to the World Health Organization classification

Studying a large series of malignant lymphoma is important to increasing our understanding of this disease. Based on the World Health Organization classification system, 1983 cases of lymphoma at Siriraj Hospital were classified as either non-Hodgkin lymphoma (NHL) (92.1%) or Hodgkin lymphoma (HL) (7.9%). The NHL cases were 75% B cell type and 25% T cell type. Diffuse large B-cell lymphoma, unspecified peripheral T-cell lymphoma, follicular lymphoma, extranodal marginal zone B-cell lymphoma, precursor T lymphoblastic lymphoma, and Burkitt lymphoma accounted for 84.3% of all NHL cases found. Mixed cellularity and nodular sclerosis types constituted 77.7% of the HL cases found. An overall male preponderance was observed, but sex distribution differed among various types of lymphoma, and a female preponderance was observed in the elderly subjects. Changes in the frequency of B-cell NHL by age were characteristic: <50% in the first decade of life, a further decrease in the second decade, >60% in the third decade, and increases thereafter, reaching 90% after the seventh decade. High frequency of follicular lymphoma in Bangkok but low frequency in the Northeastern region and high frequency of HL in the Southern region were significant (P <0.05). Extranodal involvement was observed in 58.7% of NHLs, commonly affecting the upper aerodigestive tract and gastrointestinal tract, with some differences in geographical distribution. Higher frequencies of T-cell NHLs involving extranodal sites and of B-cell NHLs involving lymph nodes were significant (P <0.05). The distribution of various types of lymphoma and comparison with other large series of lymphoma further demonstrates the heterogeneity of this disease.

Clinicopathological correlations of TIMP-1 and TIMP-2 in Hodgkin's lymphoma

OBJECTIVES

The influence of matrix-tumour interactions in Hodgkin's lymphoma is poorly characterised, although a large part of the tumour often consists of reactive tissue. The aim of the present study was to assess the clinicopathological role of two main inhibitors of matrix metalloproteinases, TIMP-1 and TIMP-2, in Hodgkin's lymphoma.

MATERIALS AND METHODS

The TIMP-1 and TIMP-2 protein expressions were studied from paraffin-embedded tumour sections of 68 patients with Hodgkin's lymphoma by using immunostaining with TIMP-1 and TIMP-2-specific antibodies. The results of the stainings were compared with the clinicopathological disease characteristics.

RESULTS

A total of 33.3% of the tumour tissue sections expressed TIMP-1 and 46.8% expressed TIMP-2. The expression of the TIMP-1 protein was found to be strongly associated with the nodular sclerosis subtype (P = 0.015) and the existence of a bulky tumour (P = 0.004) in Hodgkin's lymphoma. The expression of the TIMP-2 protein, on the other hand, correlated with the occurrence of B symptoms (P = 0.032).

CONCLUSIONS

These results provide the first clinical evidence suggesting that TIMP-1 could promote growth of Hodgkin's lymphoma, and may be linked to connective tissue turnover in the nodular sclerosis subtype. However, TIMP-2 is shown to correlate with systemic symptoms.

Hodgkin's lymphoma

Hodgkin's lymphoma is a malignant disease of the lymphatic system. This article gives an overview of the disease process and the classification and staging of Hodgkin's lymphoma. The nursing care and psychological support of these patients during radiotherapy and chemotherapy treatment are also discussed.

Hodgkin and non-Hodgkin lymphoma of the head and neck: clinical, pathologic, and imaging evaluation

Lymphomas are subdivided into HL and NHL and are more specifically classified into subtypes of HL or NHL according to the WHO classification. HLs involve the lymph nodes predominantly and only approximately 5% arise in extranodal sites, whereas 30% of NHLs present in extranodal sites. Imaging studies, including CT and MR imaging, cannot distinguish [figure: see text] HL from NHL, and cannot differentiate their various subtypes, necessitating a pathologic diagnosis. Clinical parameters, however, can be helpful in differentiating the two broad categories of lymphomas, and subtypes of lymphomas have predilections for different sites within the head and neck. HL is most commonly located in the lymph nodes of the neck and mediastinum. Marginal-zone lymphoma has an affinity for the ocular adnexa, salivary glands, larynx, and the thyroid gland. Diffuse large B-cell lymphoma is commonly encountered in the paranasal sinuses, mandible, maxilla, and Waldeyer ring. Burkitt lymphoma occurs more frequently in children and young adults and frequently affects the maxilla and mandible, with a greater distribution of involvement at a lower frequency. On imaging studies, the lymph nodes of HL and NHL are homogeneous and variable in size, with an average diameter from 2 to 10 cm. They may enhance slightly to moderately, display necrosis before and after treatment, and display calcification post-treatment. NHL in extranodal sites in the head and neck (nasopharynx, Waldeyer ring, oral cavity, and larynx) manifests frequently as a submucosal mass accompanied [figure: see text] by polypoid, bulky masses with a smooth mucosal surface. Clinically aggressive lymphomas, such as Burkitt lymphoma, diffuse large B-cell lymphoma, and NK-/T-cell lymphomas are characterized by destruction of the maxilla, mandible, and bones around the paranasal sinuses, which is indistinguishable from bony destruction in other malignant tumors, such as SCC. Contrast CT is indicated for evaluation of cervical lymph nodes; the chest, including the mediastinum; the pelvic cavity; paranasal sinuses; and orbits. CT is also useful for detection of bone destruction involving the base of the skull, paranasal sinuses, and the mandible or maxilla. MR imaging is preferred for the assessment of extension of lymphomas to different fascial spaces (parapharyngeal, masticator, infratemporal fossa, tongue, and nasopharynx) and for intracranial extension. Lymphomas are isodense to muscle on CT and circumscribed with distinct margins that occasionally display extranodal extension with less-well-defined margins and areas of necrosis within the tumor matrix. Lymphomas appear low in signal intensity on T1-weighted images and low to high in signal intensity on T2-weighted images, with variable, but usually low, enhancement following introduction of Gadolinium-DTPA (Gd-DTPA) contrast material.

[World Health Organization (WHO) classification of malignant lymphoma--how is the WHO now?]

The WHO classification of malignant lymphoma presents a list of disease entities well defined by clinical, immunologic and genetic features. The disease entities are primarily exemplified by mantle cell lymphoma (the relative incidence, 3%, related with an aberrant expression of cyclin D1 activated by t(11;14) chromosomal translocation), follicular lymphoma (7%, with BCL2 by t(14;18) translocation), marginal zone B-cell lymphoma of MALT type (8%, with MALT1 by t(11;18) or t(14;18) translocation), adult T-cell leukemia/lymphoma (7%, but 20% in Kyushu, with human T-cell leukemia virus type 1 [HTLV1]), extranodal NK/T-cell lymphoma of nasal type (2%, with Epstein-Barr virus [EBV]), and anaplastic large cell lymphoma (2%, with ALK by t(2;5) translocation). The genetic alterations or agents related with their pathogenesis are of great relevance to the diagnoses of these entities. Conversely, the category of diffuse large B-cell lymphoma occupies the largest percentage (33%), and is heterogeneous, including several subtypes. The diagnoses of lymphoma subtypes, except for the main entities described above, largely depends on the phenotypic analysis, in addition to their clinical manifestations and histologic evaluations. Therefore, much attention should be paid to the diagnostic pitfalls in the phenotypic analysis of T-cell lymphomas in regard to incorrect classification of lymphoma, due to lack of awareness or incomplete immunophenotypic evaluation; incorrect interpretation of immunophenotypic data, due to failure to correlate them with the other laboratory data; and suboptimal quality of immunohistochemical stains, leading to a wrong conclusion.

Part II: Hodgkin's lymphoma—diagnosis and treatment

The outcome of patients with all stages of Hodgkin's lymphoma has improved dramatically over the past few decades. This is mainly due to the use of risk-adapted therapies using intensive polychemotherapeutic regimens in combination with other modalities. Patients with early favourable or unfavourable (intermediate) stage disease receive two or four cycles of chemotherapy, respectively, followed by involved-field radiotherapy (20-30Gy). Advanced stage Hodgkin's lymphoma is treated more aggressively using six to eight cycles of chemotherapy but the effectiveness of consolidative radiotherapy for patients who show a complete response after chemotherapy alone is still unknown. The main challenge in the near future will be the development of strategies that decrease late morbidity and mortality but retain the same efficacy of current regimens. In this paper we review current diagnostic techniques and management strategies used to treat Hodgkin's lymphoma, and the range of new modalities being used to improve long-term outcome and patient quality of life.

Part I: Hodgkin's lymphoma—molecular biology of Hodgkin and Reed-Sternberg cells

Classic Hodgkin's lymphoma is characterised by Hodgkin and Reed-Sternberg cells and in most cases are derived from germinal-centre B cells. Despite progress in basic research showing the natural precursor cells of Hodgkin's lymphoma, most key questions still remain unanswered. Among these are the basic transforming events, the involvement of oncogenic viruses, the mechanisms enabling Hodgkin and Reed Sternberg cells to resist apoptosis in the germinal centre, and the molecular causes of their characteristic phenotype. Beyond the disclosure of these issues, the detection of changes in gene expression, gene mutations, and chromosomal imbalances specific of Hodgkin's lymphoma are central to recent research that may allow one a better understanding of the natural history of this type of lymphoma.

Bystander cells and prognosis in Hodgkin lymphoma. Review based on a doctoral thesis

Hodgkin lymphoma (HL) is characterised histologically by a minority of malignant Hodgkin and Reed-Sternberg (HRS) cells surrounded by benign cells, and clinically by a relatively good prognosis. The treatment, however, leads to a risk of serious side effects. Knowledge about the biology of the disease, particularly the interaction between the HRS cells and the surrounding cells, is essential in order to improve diagnosis and treatment. HL patients with abundant eosinophils in the tumours have a poor prognosis, therefore the eosinophil derived protein eosinophil cationic protein (ECP) was studied. Serum-ECP (S-ECP) was elevated in most HL patients. It correlated to number of tumour eosinophils, nodular sclerosis (NS) histology, and the negative prognostic factors high erythrocyte sedimentation rate (ESR) and blood leukocyte count (WBC). A polymorphism in the ECP gene (434(G>C)) was identified and the 434GG genotype correlated to NS histology and high ESR. The poor prognosis in patients with abundant eosinophils in the tumours has been proposed to depend on HRS cell stimulation by the eosinophils via a CD30 ligand (CD30L)-CD30 interaction. However, CD30L mRNA and protein were detected in mast cells and the predominant CD30L expressing cell in HL is the mast cell. Mast cells were shown to stimulate HRS cell lines via CD30L-CD30 interaction. The number of mast cells in HL tumours correlated to worse relapse-free survival, NS histology, high WBC, and low blood haemoglobin. Survival in patients with early and intermediate stage HL, diagnosed between 1985 and 1992, was generally favourable and comparatively limited treatment was sufficient to produce acceptable results for most stages. The majority of relapses could be salvaged. Patients treated with a short course of chemotherapy and radiotherapy had an excellent outcome. In conclusion prognosis is favourable in early and intermediate stages and there are possibilities for further improvements based on the fact that mast cells and eosinophils affect the biology and prognosis of HL.

Characterization of variant patterns of nodular lymphocyte predominant hodgkin lymphoma with immunohistologic and clinical correlation

Nodular lymphocyte predominant Hodgkin lymphoma (NLPHL) has traditionally been recognized as having two morphologic patterns, nodular and diffuse, and the current WHO definition of NLPHL requires at least a partial nodular pattern. Variant patterns have not been well documented. We analyzed retrospectively the morphologic and immunophenotypic patterns of NLPHL from 118 patients (total of 137 biopsy samples). Histology plus antibodies directed against CD20, CD3, and CD21 were used to evaluate the immunoarchitecture. We identified six distinct immunoarchitectural patterns in our cases of NLPHL: "classic" (B-cell-rich) nodular, serpiginous/interconnected nodular, nodular with prominent extranodular L&H cells, T-cell-rich nodular, diffuse with a T-cell-rich background (T-cell-rich B-cell lymphoma [TCRBCL]-like), and a (diffuse) B-cell-rich pattern. Small germinal centers within neoplastic nodules were found in approximately 15% of cases, a finding not previously emphasized in NLPHL. Prominent sclerosis was identified in approximately 20% of cases and was frequently seen in recurrent disease. Clinical follow-up was obtained on 56 patients, including 26 patients who had not had recurrence of disease and 30 patients who had recurrence. The follow-up period was 5 months to 16 years (median 2.5 years). The presence of a diffuse (TCRBCL-like) pattern was significantly more common in patients with recurrent disease than those without recurrence. Furthermore, the presence of a diffuse pattern (TCRBCL-like) was shown to be an independent predictor of recurrent disease (P = 0.00324). In addition, there is a tendency for progression to an increasingly more diffuse pattern over time. Analysis of sequential biopsies from patients with recurrent disease suggests that the presence of prominent extranodular L&H cells might represent early evolution to a diffuse (TCRBCL-like) pattern. We also report three patients who presented initially with diffuse large B-cell lymphoma and later developed NLPHL.

A practical approach to the diagnosis of Hodgkin lymphoma

The diagnosis of Hodgkin lymphoma has become more difficult in recent years, paradoxically because of great strides made in the understanding of the molecular mechanisms driving the lymphomas. Extensive panels of monoclonal antibodies, coupled with flow cytometric analyses and molecular diagnostic studies, have served to define more lymphoma subtypes that cannot be identified based on morphologic evidence alone. This overview is intended to provide useful criteria for the recognition of Hodgkin lymphoma and to recommend tools that will aid in separating Hodgkin lymphoma from a series of common benign and malignant look-alikes. The relationships among Hodgkin lymphoma, the B-cell non-Hodgkin lymphomas, and the T-cell non-Hodgkin lymphomas are discussed, and useful immunohistochemical markers for the routine diagnosis of Hodgkin lymphoma are suggested.

Comparison of Epstein-Barr virus presence in Hodgkin lymphoma in pediatric versus adult Argentine patients

CONTEXT

In developed countries and high socioeconomic groups, Hodgkin lymphoma has an initial peak in young adulthood, whereas in undeveloped countries and low socioeconomic groups, it shows an early childhood peak. In developing countries, 90% of children are infected with the Epstein-Barr virus (EBV) by the age of 6 years, but in developed countries, only 30% to 40% are seropositive by that age. Early childhood EBV infection in 75% of Argentine patients was demonstrated.

OBJECTIVE

To explore the epidemiology of Hodgkin lymphoma and its relationship with EBV in Argentine patients.

METHODS

The presence of EBV was assessed by Epstein-Barr encoded RNA in situ hybridization and latent membrane protein 1 immunohistochemistry. We studied 92 pediatric and 42 adult Hodgkin lymphoma cases from a public center as well as 39 adult cases from a private center.

RESULTS

The mixed cellularity Hodgkin lymphoma had a prevalence of 52% in the pediatric group, while similar frequencies of both nodular sclerosis Hodgkin lymphoma (47%) and mixed cellularity Hodgkin lymphoma (44%) were observed in adults. As for Epstein-Barr encoded RNAs, 55% of the pediatric cases and 31% of the adult cases were positive. Among adult EBV+ cases, 38% were from the public hospital, and 23% were from the private center. EBV was present in 77% of the pediatric mixed cellularity Hodgkin lymphoma cases when compared with the other histologic subtypes of Hodgkin lymphoma. EBV was mainly detected in mixed cellularity cases (39% in the adult group).

CONCLUSION

Our findings strengthen the argument that EBV is involved in the pathogenesis of Hodgkin lymphoma in most children younger than 10 years. Our findings of EBV prevalence, along with both childhood and second-decade peaks as well as comparable frequencies for Hodgkin lymphomas of mixed cellularity and nodular sclerosis, distinguish our population from others in developing countries.