Increased incidence of Hodgkin's disease after allogeneic bone marrow transplantation

Chronic graft-versus-host disease in pediatric patients: Differences and challenges

Despite the use of high-resolution molecular techniques for tissue typing, chronic graft-versus-host disease (cGVHD) remains a major complication following allogeneic hematopoietic stem cell transplant. cGVHD adversely affects the life-expectancy and quality of life. The latter is particularly important and functionally relevant in pediatric patients who have a longer life-expectancy than adults. Current laboratory evidence suggests that there is not any difference in the pathophysiology of cGVHD between adults and pediatric patients. However, there are some clinical features and complications of the disease that are different in pediatric patients. There are also challenges in the development of new therapeutics for this group of patients. In this review, we will discuss the epidemiology, pathophysiology, clinical features and consequences of the disease, and highlight the differences between pediatric and adult patients. We will examine the current treatment options for pediatric patients with moderate to severe cGVHD and discuss the challenges facing therapeutic development for cGVHD in the pediatric population.

Cytodiagnostic Sensitivity of Fine Needle Aspiration Biopsy for Hodgkin's Lymphoma Is Decreased in Patients with Human Immunodeficiency Virus Infection

OBJECTIVE

We aimed to evaluate the sensitivity of fine needle aspiration (FNA) for the diagnosis of Hodgkin's lymphoma (HL) in HIV-infected patients.

STUDY DESIGN

An electronic search was conducted to retrospectively identify patients diagnosed with HL who underwent FNA followed by confirmatory biopsy. FNAs were categorized as negative, atypical/suspicious/positive, or nondiagnostic. Diagnostic sensitivity in HIV+ and HIV- patients was statistically compared via Fisher's exact test, with a p value <0.05 considered significant.

RESULTS

Thirty-six patients meeting inclusion criteria were identified (24 HIV- and 12 HIV+). Average age was 36.0 ± 11.5 and 36.5 ± 7.4 years (means ± SD) in HIV- and HIV+ patients, respectively. The male-to-female ratio was 1.4:1 in HIV- patients versus 3:1 in HIV+ patients. Among these 36 patients, a total of 42 FNAs were performed. Overall sensitivity of FNA was 66.7% (95% confidence interval: 52.4-80.9%). When stratified by HIV status, a statistically significant difference in FNA sensitivity was detected, as sen-sitivity was 84.6% (70.8-98.4%) in HIV- patients versus only 37.5% (13.8-61.2%) in HIV+ patients (p =0.003).

CONCLUSION

The diagnostic sensitivity of FNA biopsy was significantly attenuated in the HIV+ cohort. In HIV-infected patients presenting with lymphadenopathy, increased clinical suspicion of HL is critical to avoid misdiagnosis.

Co-Expression of the Epstein-Barr Virus-Encoded Latent Membrane Proteins and the Pathogenesis of Classic Hodgkin Lymphoma

The Epstein-Barr virus (EBV) is present in the tumour cells of a subset of patients with classic Hodgkin lymphoma (cHL), yet the contribution of the virus to the pathogenesis of these tumours remains only poorly understood. The EBV genome in virus-associated cHL expresses a limited subset of genes, restricted to the non-coding Epstein-Barr virus-encoded RNAs (EBERs) and viral miRNA, as well as only three virus proteins; the Epstein-Barr virus nuclear antigen-1 (EBNA1), and the two latent membrane proteins, known as LMP1 and LMP2, the latter of which has two isoforms, LMP2A and LMP2B. LMP1 and LMP2A are of particular interest because they are co-expressed in tumour cells and can activate cellular signalling pathways, driving aberrant cellular transcription in infected B cells to promote lymphomagenesis. This article seeks to bring together the results of recent studies of the latent membrane proteins in different B cell systems, including experiments in animal models as well as a re-analysis of our own transcriptional data. In doing so, we summarise the potentially co-operative and antagonistic effects of the LMPs that are relevant to B cell lymphomagenesis.

Second Malignancies after Hematopoietic Stem Cell Transplantation

OPINION STATEMENT

Second malignancies are a rare but well-defined late complication after autologous and allogeneic hematopoietic stem-cell transplantation (SCT). Solid malignancies occur in up to 15% of patients 15 years after SCT with myeloablative conditioning, with no plateau in the incidence rates. They are responsible for 5-10% of late deaths after SCT. The incidence is increased with advanced age at SCT. The major risk factors are the use of total body irradiation, which is associated with adenocarcinomas and with chronic graft-versus-host disease which is associated with squamous cell cancers. There is less data on the incidence of second malignancies after reduced-intensity conditioning, but it may not be lower. The types of solid tumors reported in excess include melanoma and other skin cancers; cancers of the oral cavity and head and neck, brain, liver, uterine cervix, thyroid, breast, lung; and possibly gastrointestinal cancers. Therapy-related myeloid neoplasms (t-MN) are more common after autologous SCT and may be related mostly to pre-transplant therapies. Post-transplant lymphoproliferative disease is donor-cell-derived lymphoma that is more common after allogeneic SCT with T-cell depletion or intensive immune-suppression state. Second malignancies are most often treated similarly to the standard therapy for similar malignancies. Lifelong cancer screening and prevention interventions are required for all transplantation survivors.

High-dose Chemotherapy with Stem Cell Rescue Provided Durable Remission for Classical Hodgkin Lymphoma-type Post-transplant Lymphoproliferative Disorder after Unrelated Cord Blood Transplantation: A Case Report and Review of the Literature

An adult woman developed polymorphic post-transplant lymphoproliferative disorder (PTLD) 58 months after unrelated cord blood transplantation. She was treated successfully with chemotherapy and radiation therapy but presented with lymphadenopathy and splenomegaly 74 months after transplantation. A lymph node biopsy confirmed the diagnosis of nodular sclerosis type Hodgkin lymphoma (classical Hodgkin lymphoma [CHL]-type PTLD). After salvage therapy and hematopoietic stem cell harvesting, she was subsequently treated with consolidative high-dose chemotherapy with melphalan followed by stem cell rescue, which resulted in durable remission. High-dose chemotherapy using stem cell rescue has potential as a therapeutic option for subsequent CHL-type PTLD.

Late Effects Surveillance Recommendations among Survivors of Childhood Hematopoietic Cell Transplantation: A Children's Oncology Group Report

Hematopoietic cell transplantation (HCT) is an important curative treatment for children with high-risk hematologic malignancies, solid tumors, and, increasingly, nonmalignant diseases. Given improvements in care, there are a growing number of long-term survivors of pediatric HCT. Compared with childhood cancer survivors who did not undergo transplantation, HCT survivors have a substantially increased burden of serious chronic conditions and impairments involving virtually every organ system and overall quality of life. This likely reflects the joint contributions of pretransplantation treatment exposures and organ dysfunction, the transplantation conditioning regimen, and any post-transplantation graft-versus-host disease (GVHD). In response, the Children's Oncology Group (COG) has created long-term follow-up guidelines (www.survivorshipguidelines.org) for survivors of childhood, adolescent, and young adult cancer, including those who were treated with HCT. Guideline task forces, consisting of HCT specialists, other pediatric oncologists, radiation oncologists, organ-specific subspecialists, nurses, social workers, other health care professionals, and patient advocates systematically reviewed the literature with regards to late effects after childhood cancer and HCT since 2002, with the most recent review completed in 2013. For the most recent review cycle, over 800 articles from the medical literature relevant to childhood cancer and HCT survivorship were reviewed, including 586 original research articles. Provided herein is an organ system-based overview that emphasizes the most relevant COG recommendations (with accompanying evidence grade) for the long-term follow-up care of childhood HCT survivors (regardless of current age) based on a rigorous review of the available evidence. These recommendations cover both autologous and allogeneic HCT survivors, those who underwent transplantation for nonmalignant diseases, and those with a history of chronic GVHD.

How I treat posttransplant lymphoproliferative disorders

Posttransplant lymphoproliferative disorder (PTLD) is a potentially fatal disorder arising after solid organ transplant (SOT) or hematopoietic stem cell transplant (HSCT). Iatrogenically impaired immune surveillance and Epstein-Barr virus (EBV) primary infection/reactivation are key factors in the pathogenesis. However, current knowledge on all aspects of PTLD is limited due to its rarity, morphologic heterogeneity, and the lack of prospective trials. Furthermore, the broad spectrum of underlying immune disorders and the type of graft represent important confounding factors. Despite these limitations, several reviews have been written aimed at offering a guide for pathologists and clinicians in diagnosing and treating PTLD. Rather than providing another classical review on PTLD, this "How I Treat" article, based on 2 case reports, focuses on specific challenges, different perspectives, and novel insights regarding the pathogenesis, diagnosis, and treatment of PTLD. These challenges include the wide variety of PTLD presentation (making treatment optimization difficult), the impact of EBV on pathogenesis and clinical behavior, and the controversial treatment of Burkitt lymphoma (BL)-PTLD.

Caring for the long-term survivor after allogeneic stem cell transplantation

Survivors of allogeneic hematopoietic cell transplantation (HCT) are at risk of developing long-term complications such as subsequent malignancies and cardiopulmonary compromise. The prevalence of chronic health conditions approaches 75% among allogeneic HCT survivors and that for severe or life-threatening conditions exceeds 20%. This chapter describes the burden of morbidity carried by HCT survivors to help healthcare providers and policy makers understand the scope of the problem and the need for life-long follow-up and proactive care for this vulnerable population.

Non-AIDS-Defining Malignancies in the HIV-Infected Population

With the advent of effective combination antiretroviral therapy, HIV infection has been transformed from a fatal disease to a chronic condition. There is renewed clinical interest in long-term morbidities, including malignancies that occur disproportionately within this population. Non-AIDS-defining cancers (NADCs) are a significant source of morbidity and mortality in the aging HIV-infected population. There are data to suggest that incidence rates are elevated among HIV-infected individuals for many cancer sites, particularly those with a confirmed or suspected infectious etiology. The complex interplay between behavioral risk factors, coexistence of viral infections, immunodeficiency and antiretroviral therapy makes it difficult to analyze why certain cancers develop more frequently in HIV-infected individuals. The challenge to clinicians caring for HIV-infected patients is to develop and implement effective means to screen, treat, and prevent NADCs in the future. This review presents data on whether NADCs are increased in the HIV-Infected population, as well as ongoing research on epidemiology, prevention and pathogenesis of this evolving aspect of the HIV epidemic.

Perinatal and family risk factors for Hodgkin lymphoma in childhood through young adulthood

The incidence of Hodgkin lymphoma has increased among adolescents and young adults in recent decades, but the relevant risk factors in early life are still unknown. A national cohort study was conducted of 3,571,574 individuals born in Sweden in 1973-2008 and followed up for Hodgkin lymphoma incidence through 2009, to examine perinatal and family risk factors for Hodgkin lymphoma in childhood through young adulthood (ages 0-37 years). There were 943 Hodgkin lymphoma cases identified in 66.3 million person-years of follow-up. High fetal growth was associated with an increased risk of Hodgkin lymphoma after adjustment for gestational age at birth and other potential confounders (P(trend) = 0.005). Family history of Hodgkin lymphoma in a sibling or parent also was strongly associated with an increased risk, with adjusted hazard ratios = 8.83 (95% confidence interval: 3.67, 21.30) and 7.19 (95% confidence interval: 3.58, 14.44), respectively. No association was found between gestational age at birth, birth order, twinning, parental age, or parental education and Hodgkin lymphoma. These findings did not vary by age at Hodgkin lymphoma diagnosis. Similar associations were found for nodular sclerosis and mixed cellularity subtypes. These findings suggest that perinatal factors including possible growth factor pathways may contribute to the risk of Hodgkin lymphoma in childhood through young adulthood.

Long-term health impacts of hematopoietic stem cell transplantation inform recommendations for follow-up

Advances in transplantation techniques and supportive care strategies have resulted in a significant improvement in survival of those who have undergone treatment. However, hematopoietic stem cell transplantation (HSCT) survivors are at risk of developing long-term complications, such as endocrinopathies, musculoskeletal disorders, cardiopulmonary compromise and subsequent malignancies. These complications have a direct impact on the morbidity and mortality experienced by HSCT survivors. Two-thirds of HSCT survivors develop at least one chronic health condition; while a fifth develop severe or life-threatening conditions. HSCT patients who have survived for at least 5 years post-transplantation are at a fourfold to ninefold increased risk of late mortality for as long as 30 years from HSCT, producing an estimated 30% lower life expectancy compared with the general population. The high burden of morbidity experienced by HSCT survivors makes it critically important that there is standardized follow-up of HSCT survivors at high risk for post-HSCT complications. The Center for International Blood and Marrow Transplant Research/European Group for Blood and Marrow Transplantation/American Society for Blood and Marrow Transplantation and the Children's Oncology Group long-term follow-up guidelines offer such standardized care. Future steps include wider dissemination and refinement of these guidelines.

Viral hit and run-oncogenesis: genetic and epigenetic scenarios

It is well documented that viral genomes either inserted into the cellular DNA or co-replicating with it in episomal form can be lost from neoplastic cells. Therefore, "hit and run"-mechanisms have been a topic of longstanding interest in tumor virology. The basic idea is that the transient acquisition of a complete or incomplete viral genome may be sufficient to induce malignant conversion of host cells in vivo, resulting in neoplastic development. After eliciting a heritable change in the gene expression pattern of the host cell (initiation), the genomes of tumor viruses may be completely lost, i.e. in a hit and run-scenario they are not necessary for the maintenance of the malignant state. The expression of viral oncoproteins and RNAs may interfere not only with regulators of cell proliferation, but also with DNA repair mechanisms. DNA recombinogenic activities induced by tumor viruses or activated by other mechanisms may contribute to the secondary loss of viral genomes from neoplastic cells. Viral oncoproteins can also cause epigenetic dysregulation, thereby reprogramming cellular gene expression in a heritable manner. Thus, we expect that epigenetic scenarios of viral hit and run-tumorigenesis may facilitate new, innovative experiments and clinical studies in spite of the fact that the regular presence of a suspected human tumor virus in an early phase of neoplastic development and its subsequent regular loss have not been demonstrated yet. We propose that virus-specific "epigenetic signatures", i.e. alterations of the host cell epigenome, especially altered DNA methylation patterns, may help to identify viral hit and run-oncogenic events, even after the complete loss of tumor viruses from neoplastic cells.

Current insight on trends, causes, and mechanisms of Hodgkin's lymphoma

Hodgkin's lymphoma (HL) has a unique and distinct history, epidemiology, treatment, and biology. A viral agent or infectious agent has long been considered as the etiologic agent and Epstein-Barr virus is the main candidate for the infectious agent causing HL; however, Epstein-Barr virus genome is found within the tumor in only about 20% to 40% of HL cases with a prior diagnosis of infectious mononucleosis. Recently, autoimmune and related conditions have drawn attention to a potential role for immune-related and inflammatory conditions in the etiology and pathogenesis of the malignancy. Evidence from multiply-affected families, a twin study, a case-control study, and population-based registry studies implicate genetic factors. Data from Eastern Asia and among Chinese immigrants in North America indicate increasing incidence trends for HL being associated with westernization. These results emphasize an interaction between environmental and genetic risk factors in HL.

Hodgkin lymphoma: an update on its biology with new insights into classification

In the past few years, there has been a greater understanding of the spectrum and biology of Hodgkin lymphoma (HL). In standard texts, HL is classified as 2 distinct entities, namely nodular lymphocyte-predominant HL and classical HL (CHL). However, recent evidence suggests that CHL is not a single disease. Although the mixed cellularity and lymphocyte-depleted subtypes might be part of a biologic continuum, the nodular sclerosis subtype has a distinct epidemiology, clinical presentation, and histology. Nodular sclerosis HL might also be related to primary mediastinal B-cell lymphoma and mediastinal gray-zone lymphomas. We present an update on the pathobiology of HL and discuss these biologic and clinical differences in this review.

Pathologic and clinical features of Hodgkin lymphoma--like posttransplant lymphoproliferative disease

Because of its rarity, pathologic and clinical features of Hodgkin lymphoma-like posttransplant lymphoproliferative disorder (HL-like PTLD) are not well understood, and it is unclear whether its biological behavior is more closely related to classical Hodgkin disease or to monomorphic B-cell PTLD. The authors compared 6 cases of HL-like PTLD with 5 cases of monomorphic B-cell PTLD for differences in histology, immunophenotype, and clinical behavior. Histologically, all cases of HL-like PTLD resembled classical HL with typical Reed-Sternberg (RS) cells and a cellular background mimicking mixed cellularity subtype. CD45 was absent on RS-like cells, but the expression pattern of B-cell-associated markers Oct-2 and BOB.1 resembled monomorphic B-cell PTLD. Whereas Epstein-Barr virus early RNA expression is normally restricted to RS cells of classical HL, it was expressed in both RS-like cells and background lymphocytes in HL-like PTLD. Although all patients diagnosed with monomorphic B-cell PTLD show no evidence of disease following treatment, half of the patients with HL-like PTLD relapsed or died, indicating a more aggressive clinical behavior. The findings suggest that HL-like PTLD represents a distinct clinicopathologic entity with an aggressive clinical course.

New aspects in descriptive, etiologic, and molecular epidemiology of Hodgkin's lymphoma

Epstein-Barr virus (EBV) has remained the main candidate suggested as the infection causing Hodgkin's lymphoma for several years. However, EBV genome has been found only within the tumor in about 20%-40% of Hodgkin's lymphoma cases with a prior diagnosis of infectious mononucleosis. Recently, autoimmune and related conditions have drawn attention to a potential role for immune-related and inflammatory conditions in the etiology and pathogenesis of the malignancy. Evidence from multiple affected families from case series, a twin study, a case-control study, and population-based registry studies implicate a role for genetic factors. Simultaneously, data from Eastern Asia and among Chinese immigrants in North America indicate increasing incidence trends for Hodgkin's lymphoma being associated with westernization. These results emphasize an interaction between environmental and genetic risk factors in Hodgkin's lymphoma.

Cigarette smoking and risk of Hodgkin lymphoma: a population-based case-control study

BACKGROUND

Studies have inconsistently reported an association between tobacco smoking and Hodgkin lymphoma (HL) risk. The conflicting finding may reflect etiologic heterogeneity between HL subtypes, warranting further characterization of the relationship.

METHODS

We collected information on tobacco-smoking habits in 586 classic HL cases and 3,187 population controls in a Danish-Swedish case-control study. HL EBV status was established for 499 cases by standard techniques. Odds ratios (OR) for an association with cigarette smoking were calculated by logistic regression for HL overall and stratified by age, sex, major histology subtypes, and tumor EBV status, adjusting for known confounders.

RESULTS

Compared with never smokers, current cigarette smokers were at an increased overall HL risk [adjusted OR, 1.57; 95% confidence interval (95% CI), 1.22-2.03]. The association was strongest for EBV-positive HL (adjusted OR, 2.36; 95% CI, 1.51-3.71), but also applied to EBV-negative HL (adjusted OR, 1.43; 95% CI, 1.05-1.97; P(homogeneity EBV-pos) versus P(homogeneity EBV-neg) = 0.04). The association did not vary appreciably by age, sex, or histologic subtype, the apparent EBV-related difference present in all strata. There was no evidence of a dose-response pattern, whether by age at smoking initiation, daily cigarette consumption, number of years smoking, or cumulative number of cigarettes smoked. Similar results were obtained in analyses using non-HL patients (n = 3,055) participating in the founding study as comparison group.

CONCLUSION

The observed association between cigarette smoking and HL risk is consistent with previous findings and biologically credible. Although not easily dismissed as an artifact, the limited evidence of a dose-response pattern renders the overall evidence of causality weak.

Immunodeficiency-related Hodgkin lymphoma and its mimics

Classic Hodgkin lymphoma (CHL) in patients with underlying immunodeficiency disorders frequently differs from that in the immune competent population in terms of its clinical behavior and pathologic features. Moreover, differential from Hodgkin-like lymphoid proliferations may be problematic. Topics under review include: (a) CHL posttransplant lymphoproliferative disorders, (b) CHL in HIV/AIDS, (c) Hodgkin variant of Richter syndrome in chronic lymphocytic leukemia in association with fludarabine therapy, (d) CHL in other immunodeficiency states including methotrexate-associated lymphoproliferative disorder in patients with rheumatoid arthritis and primary immune deficiencies, and (e) Hodgkin-like lymphoid proliferations including senile Epstein-Barr virus+ B-cell lymphoproliferative disorder. Also under consideration is the pathogenesis of these disorders with an emphasis on the role of Epstein-Barr virus.

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.

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.

Hodgkin lymphoma and immunodeficiency in persons with HIV/AIDS

In persons with HIV/AIDS (PWHAs), Hodgkin lymphoma (HL) risk is increased. However, HL incidence in PWHAs has unexpectedly increased since highly active antiretroviral therapy (HAART) was introduced. We linked nationwide HIV/AIDS and cancer registry data from 1980 through 2002. Immunity was assessed by CD4 T-lymphocyte counts at AIDS onset. Annual HL incidence rates were calculated for 4 through 27 months after AIDS onset. During 477 368 person years (py's) of follow-up in 317 428 persons with AIDS (PWAs), 173 HL cases occurred (36.2 per 10(5) py's). Incidence was significantly higher in 1996 to 2002 than earlier. Incidence in PWAs with 150 to 199 CD4 cells/muL was 53.7 per 10(5) py's, whereas in PWAs with fewer than 50 CD4 cells/muL, it was 20.7 per 10(5) py's (P(trend) = .002). For each HL subtype, incidence decreased with declining CD4 counts, but nodular sclerosing decreased more precipitously than mixed cellularity, thereby increasing the proportion of mixed cellularity HL seen in PWAs. We conclude that HL incidence is lower with severe immunosuppression than with moderate immunosuppression, and HAART-related improvements in CD4 counts likely explain the increasing HL incidence in PWHAS observed since 1996. With more severe immunosuppression, nodular sclerosing HL becomes infrequent, explaining the higher proportion of mixed cellularity HL found in PWAs. Pathogenesis implications are discussed.

Hodgkin lymphoma-like posttransplant lymphoproliferative disorder (HL-like PTLD) simulates monomorphic B-cell PTLD both clinically and pathologically

Although Hodgkin lymphoma-like posttransplantation lymphoproliferative disorder (HL-like PTLD) has been grouped with classic Hodgkin lymphoma type PTLD (HL-PTLD), controversy remains as to whether it is truly a form of HL or whether it should be more appropriately classified as a form of B-cell PTLD. Because only few cases of HL-like PTLD have been reported, their pathologic nature and clinical behavior have not been well defined. This report characterized 5 cases of HL-like PTLD with respect to their immunophenotype, EBV status, clonality, and clinical outcome. All of the patients were male, with ages ranging from 1.5 to 55 years at diagnosis. PTLD developed from 4 months to 6 years following solid organ transplantation (3 hearts, 1 kidney, 1 liver), and involved both nodal and extranodal sites. All were EBV-related (EBER+) with the large neoplastic cells CD20/CD79a positive but CD15 negative. Immunoglobulin gene rearrangements were detected in 3 of 5 tested. All patients were managed by initial reduction/withdrawal of immunosuppression, with 2 also receiving chemotherapy for non-HL. Three patients died of progressive disease within 2 to 3 months after diagnosis, 1 is alive and well 2 years later, and the fifth was disease free but died of unrelated causes (graft coronary disease) 2 years later. We conclude that, although HL-like PTLD morphologically simulates classic HL PTLD, there are important immunophenotypic, molecular genetic, and clinical differences, suggesting it is in fact most often a B-cell PTLD. Distinction between HL and HL-like PTLD may be important for clinical management and prognosis.

Hodgkin lymphoma-like posttransplantation lymphoproliferative disorder

Posttransplantation lymphoproliferative disorders (PTLD) are a heterogeneous group of monoclonal or polyclonal lymphoproliferative lesions that occur in immunosuppressed recipients following solid organ or bone marrow transplantation, including 4 categories: (1) early lesions (reactive plasmacytic hyperplasia, and infectious-mononucleosis-like PTLD), (2) polymorphic PTLD, (3) monomorphic PTLD (including B-cell neoplasms and T-cell neoplasms), and (4) Hodgkin lymphoma (HL) and HL-like PTLD in the current World Health Organization classification. Although HL-like PTLD has been grouped with classic HL PTLD, controversy remains as to whether it is truly a form of HL or whether it should be more appropriately considered as a form of B-cell PTLD. The current available literature data indicate the presence of important immunophenotypic, molecular genetic, and clinical differences between HL PTLD and HL-like PTLD, suggesting that HL-like PTLD is in fact most often a form of B-cell PTLD. Distinction from true HL may be important for clinical management and prognosis.

Occupation and malignant lymphoma: a population based case control study in Germany

AIMS

To identify occupations suspected to be associated with malignant lymphoma and to generate new hypotheses about occupational risks in a multicentre, population based case control study.

METHODS

Male and female patients with malignant lymphoma (n = 710) aged 18-80 years of age were prospectively recruited in six study regions in Germany. For each newly recruited lymphoma case, a sex, region, and age matched control was drawn from the population registers. Odds ratios and 95% confidence intervals for major occupations and industries were calculated using conditional logistic regression analysis, adjusted for smoking (in pack-years) and alcohol consumption. Patients with specific lymphoma subentities were additionally compared with the entire control group using unconditional logistic regression analysis.

RESULTS

The following economic/industrial sectors were positively associated with lymphoma: food products, beverages, tobacco; paper products, publishing and printing; and metals. Chemicals; real estate, renting, and business activities were negatively associated with lymphoma diagnosis. The authors observed an increased overall lymphoma risk among architects; maids; farmers; glass formers; and construction workers. Shoemaking and leather goods making was negatively associated with the lymphoma diagnosis (although based on small numbers). In the occupational group analysis of lymphoma subentities, Hodgkin's lymphoma was significantly associated only with rubber and plastic products making; diffuse large B cell lymphoma risk was considerably increased among metal processors; follicular lymphoma showed highly significant risk increases for several occupational groups (medical, dental, and veterinary workers; sales workers; machinery fitters; and electrical fitters); and multiple myeloma showed a particularly pronounced risk increase for farmers as well as for agriculture and animal husbandry workers.

CONCLUSIONS

The results partly confirm previously defined occupational risks. Occupational risk factors for follicular lymphomas might differ from the overall risk factors for malignant lymphoma.

Secondary malignancies after hematopoietic stem cell transplantation

Advances in the field of hematopoietic stem cell transplantation have led to an increasing number of cures of malignant and non-malignant diseases with this therapeutic approach. Long-term survivorship may, however, be associated with secondary malignancies, the result of a complex interaction of treatment-, recipient- and immunosuppression-related factors. Furthermore, the increasing use of donors other than human leukocyte antigen-identical siblings is associated with more intense immunosuppression, delayed immune recovery and higher incidence of B-cell post-transplantation lymphoproliferative disorders. Here, we review the incidence and the risk factors associated with these complications of hematopoietic stem cell transplants.

Hodgkin's disease as unusual presentation of post-transplant lymphoproliferative disorder after autologous hematopoietic cell transplantation for malignant glioma

BACKGROUND

Post-transplant lymphoproliferative disorder (PTLD) is a complication of solid organ and allogeneic hematopoietic stem cell transplantation (HSCT); following autologous HSCT only rare cases of PTLD have been reported. Here, a case of Hodgkin's disease (HD), as unusual presentation of PTLD after autologous HSCT for malignant glioma is described.

CASE PRESENTATION

60-years old man affected by cerebral anaplastic astrocytoma underwent subtotal neurosurgical excision and subsequent high-dose chemotherapy followed by autologous HSCT. During the post HSCT course, cranial irradiation and corticosteroids were administered as completion of therapeutic program. At day +105 after HSCT, the patient developed HD, nodular sclerosis type, with polymorphic HD-like skin infiltration.

CONCLUSION

The clinical and pathological findings were consistent with the diagnosis of PTLD.

Impact of chronic GVHD therapy on the development of squamous-cell cancers after hematopoietic stem-cell transplantation: an international case-control study

Previous studies of recipients of hematopoietic stem-cell transplants suggest that graft-versus-host disease (GVHD) and its therapy may increase the risk for solid cancers, particularly squamous-cell carcinomas (SCCs) of the buccal cavity and skin. However, the importance and magnitude of these associations are not well characterized. We conducted a case-control study of 183 patients with posttransplantation solid cancers (58 SCCs, 125 non-SCCs) and 501 matched control patients within a cohort of 24,011 patients who underwent hematopoietic stem-cell transplantation (HSCT) at 215 centers worldwide. Our results showed that chronic GVHD and its therapy were strongly related to the risk for SCC, whereas no increase in risk was found for non-SCCs. Major risk factors for the development of SCC were long duration of chronic GVHD therapy (P < .001); use of azathioprine, particularly when combined with cyclosporine and steroids (P < .001); and severe chronic GVHD (P = .004). Given that most patients who received prolonged immunosuppressive therapy and those with severe chronic GVHD were also treated with azathioprine, the independent effects of these factors could not be evaluated. Additional analyses determined that prolonged immunosuppressive therapy and azathioprine use were also significant risk factors for SCC of the skin and of the oral mucosa. These data provide further encouragement for strategies to prevent chronic GVHD and for the development of more effective and less carcinogenic treatment regimens for patients with moderate or severe chronic GVHD. Our results also suggest that clinical screening for SCC is appropriate among patients exposed to persistent chronic GVHD, prolonged immunosuppressive therapy, or both.

Second malignant neoplasms following hematopoietic stem cell transplantation

Hematopoietic stem cell transplantation is being successfully used to treat a variety of malignant and nonmalignant disorders. This therapy has resulted in an increasing number of survivors who are at risk for adverse long-term outcomes, including the development of second and subsequent malignant neoplasms. We review the incidence and spectrum of posttransplantation malignancies and discuss risk factors and future directions for research.

Epstein-Barr virus-associated Hodgkin's lymphoma

Survivors of Hodgkin's lymphoma (HL) frequently have many years to experience the long-term toxicities of combined modality therapies. Also, a significant proportion of HL patients will relapse or have refractory disease, and less than half of these patients will respond to current salvage strategies. 30-50% of HL cases are Epstein-Barr virus associated (EBV-positive HL). The virus is localized to the malignant cells and is clonal. EBV-positive HL is more frequent in childhood, in older adults (>45 years) and in mixed cellularity cases. The survival of EBV-positive HL in the elderly and the immunosuppressed is particularly poor. Despite improvements in our understanding of EBV-positive HL, the true contribution of EBV to the pathogenesis of HL remains unknown. Increased knowledge of the virus' role in the basic biology of HL may generate novel therapeutic strategies for EBV-positive HL and the presence of EBV-latent antigens in the malignant HL cells may represent a target for cellular immunotherapy.

EBV-associated neoplasms: alternative pathogenetic pathways

We propose that there are two main classes of Epstein-Barr virus (EBV) associated lymphomas: primarily malignant Burkitt's Lymphoma (BL) and Hodgkin's Disease (HD), on one hand, and primarily benign lymphoproliferations, e.g., post-transplant lymphoproliferative disease (PTLD) on the other hand. PTLD may start as a benign lymphoproliferation which becomes malignant if out of T cell control for too long. Our discovery of a binding site for the oncoprotein c-Myc at a central position of the EBV genome favours a distinction of pathogenetic pathways or scenarios for the proposed lymphoma classes. In the first scenario nuclear maintenance of the EBV genome and activation of viral anti-apoptotic functions with the help of c-Myc are indispensable for the origin of malignant tumours (BL, HD) from the germinal centre B-cell. In the second scenario expression of the main viral transforming protein EBNA2 is essential for immortalisation and non-malignant morphological transformation of any (germinal centre derived or non-germinal centre) B-cell in the absence of T cell control. Although EBNA2 expression is permissible, under specific circumstances, in malignant B-cells, it is not required for oncogenesis.

Posttransplant lymphoproliferative disease: pathogenesis, monitoring, and therapy

The spectrum of transplant-related lymphoproliferative diseases is expanding to include a variety of neoplasias that typically occur late after transplant including Epstein-Barr virus (EBV)-negative B- and T-cell lymphomas, EBV-positive T-cell lymphoma, myeloma, plasmacytoma, and Hodgkin's disease. New approaches to diagnosis and monitoring based on quantitative polymerase chain reaction for EBV DNA are being explored. What exactly is being measured (the source and character of the viral DNA) remains to be determined, as does the compartment that should be assayed (whole blood, serum, plasma, or lymphocytes). These questions not withstanding, there is an emerging consensus that these technologies will facilitate rapid diagnosis and therapeutic monitoring in the future. A myriad of therapeutic interventions are or will become available. Rituximab, alone or in addition to other therapies, promises a profound change in the landscape with regard to the treatment and perhaps the prevention of posttransplant lymphoproliferative disease. New approaches to adoptive cellular immunotherapy, including use of EBV-specific products from unrelated donors, nonspecifically activated autologous products, and genetically engineered T cells, are all being explored.

Epidemiology of Hodgkin's disease and non-Hodgkin's lymphoma

This review considers in detail the descriptive and aetiological epidemiology of Hodgkin's disease and non-Hodgkin's lymphoma (NHL), with attention to histological subcategories when the literature allows. The aetiology of Hodgkin's disease remains only partially understood. There is evidence that Epstein-Barr virus (EBV) may be involved in the causation of some cases, and clinical immune deficiency is a risk factor for a few, but the evidence is not entirely consistent and other factors may also be important in causing the EBV-associated cases of Hodgkin's disease. The cause of EBV-unassociated cases remains obscure. For NHL, although it has been shown that some cases are related to immune deficiency and chronic antigenic stimulation, and especially to EBV in the context of immune deficiency, the causation of the majority of cases remains unknown. The increasing incidence of NHL, other than that related to AIDS, is also essentially unexplained. Epidemiological investigation of the aetiology of NHL and Hodgkin's disease is making steady progress, however, and there remain leads to be followed that may result in a better understanding and hence prevention.

Target cells of Epstein-Barr-virus (EBV)-positive post-transplant lymphoproliferative disease: similarities to EBV-positive Hodgkin's lymphoma

BACKGROUND

Epstein-Barr virus (EBV)-associated post-transplant lymphoproliferative disease (PTLD) encompasses a histologically broad range of lesions, arising from the expanded pool of EBV-infected B cells in the immunocompromised host. Identification of the precise cellular origin of these tumours could clarify their pathogenesis.

METHODS

Of 13 cases of EBV-positive cases of PTLD characterised by histological analysis, pattern of EBV gene expression, and clinical course, 11 had monoclonal or biclonal lesions in which we determined the progenitor B cell by immunoglobulin heavy chain (IgH) genotyping.

RESULTS

Two tumours had a naive B cell genotype and two showed patterns of IgH somatic mutation typical of antigen-selected (post-germinal-centre) memory cells. All four arose early post-transplant and expressed the markers of EBV transformation--Epstein-Barr nuclear antigen (EBNA) 2 and latent membrane protein (LMP) 1. However, seven tumours, either of early or late onset and including some with downregulated EBNA 2 and LMP 1, arose from post-germinal cells with randomly mutated or sterile IgH genotypes usually incompatible with B-cell survival in vivo.

INTERPRETATION

PTLD can arise from a broad range of target B cells and not only from the pool of antigen-selected memory cells that EBV generally colonises in immunocompetent individuals. Tumour development seems frequently associated with the EBV-induced rescue and expansion of B cells that have failed the physiological process of germinal centre selection into memory. This finding shows an unexpected connection between pathogenesis of PTLD and that of EBV-positive Hodgkin's lymphoma, another B-cell malignancy of atypical post-germinal-centre cell origin.

The international bone marrow transplant registry

The first successful transplants of hematopoietic stem cells were done in 1968 in three children with congenital immune deficiency diseases. In each instance, stem cells were collected from the bone marrow of sibling donors who were genotypically HLA identical or closely HLA matched to the recipient. Since then, thousands of patients have received hematopoietic stem cell transplants to treat malignant and non-malignant diseases. Current estimates of annual numbers of stem cell transplants are about 50,000 worldwide, with growth at a rate of 10-15% per year. The reasons for increasing use include proven and potential efficacy in many diseases, better understanding of the appropriate timing of transplantation and patient selection, greater availability of donors and better techniques for determining HLA match, greater ease of stem cell collection, and improved supportive care resulting in less transplant-related morbidity and mortality. About two-thirds of hematopoietic stem cell transplants use autologous cells, generally collected from peripheral blood by leukapheresis. The remainder are allogeneic transplants, most commonly from HLA-identical sibling donors, and most often using cells collected directly from bone marrow.

Second malignancies after allogeneic hematopoietic stem cell transplantation: new insight and current problems

With increased number of patients surviving on the long term, late effect after allogeneic hematopoietic stem cell transplantation have become of major clinical importance. Among these late effect, second malignancies have increasingly been recognized in the recent years. It has been usual to divide the problem of secondary malignancies following hematopoietic stem cell transplantation into three groups, i.e. leukemia, lymphoma and solid tumors. Recent clinical and biological data on these three types of malignancies, occurring after allogeneic stem cell transplantation, are summarized in this review. We will focus here only on second malignancies after allogeneic stem cell transplantation with particular emphasis on recent development on the pathogenesis, and early diagnosis, and treatment of these transplant-related complications.

Clonally unrelated Hodgkin's disease following autologous stem cell transplant for B-cell lymphoma

Lymphoproliferative disorders after autologous stem cell transplantation (SCT) are rare. We describe two cases of Hodgkin's disease (HD) as a late secondary neoplasia following autologous SCT for mantle cell lymphoma and B-cell chronic lymphocytic leukaemia respectively. Both HD cases were of mixed cellularity type, showed Epstein-Barr virus (EBV) positivity and followed an aggressive course. Clonal analysis of rearranged immunoglobulin genes from the primary B-cell neoplasm and the secondary HD provided evidence of separate clonal origins of the two tumours in both patients, thus excluding secondary transformation of the original B-cell clone through EBV as the causative event for development of HD.

Stem cell transplantation: supportive care and long-term complications

With increasing hematopoietic stem cell transplant (HSCT) activity and improvement in outcomes, there are many thousands of HSCT survivors currently being followed by non-transplant clinicians for their healthcare. Several types of late sequelae from HSCT have been noted, and awareness of these complications is important in minimizing late morbidity and mortality. Late effects can include toxicities from the treatment regimen, infections from immunodeficiency, endocrine disturbances, growth impairment, psychosocial adjustment disorders, second malignancies, and chronic graft-versus-host disease (GVHD). A variety of risk factors for these complications have been noted. The clinician should be alert to the potential for these health issues. Preventive and treatment strategies can minimize morbidity from these problems and optimize outcomes.

Pathogenetic and histogenetic features of HIV-associated Hodgkin's disease

Compared with the cases in the general population, Hodgkin's disease (HD) arising in the HIV setting shows distinctive features in terms of epidemiology, aetiopathogenesis, histopathology and clinical behaviour. Although HD does not represent an AIDS-defining condition, recent evidence consistently indicates that HIV-infected individuals have a significantly increased risk of developing HD. HIV-related HD is characterised by the preponderance of aggressive histological subtypes, advanced stage at presentation, and highly malignant clinical course. Moreover, unlike HD in the general population, the large majority of HIV-related HD cases are pathogenetically linked to Epstein-Barr virus (EBV), with rates of EBV positivity ranging from 80 to 100%. Hodgkin and Reed-Sternberg cells of these cases invariably show a strong expression of the EBV-encoded latent membrane protein-1 (LMP-1), which functions as a constitutively activated tumour necrosis factor (TNF) receptor-like molecule. Usurpation of physiologically relevant pathways by LMP-1 may lead to the simultaneous or sequential activation of signalling pathways involved in the promotion of cell activation, growth, and survival, contributing thus to most of the features of HIV-related HD.

The diverse pathology of post-transplant lymphoproliferative disorders: the importance of a standardized approach

Post-transplant lymphoproliferative disorders (PTLD) are a diverse group of abnormal lymphoid growths that include both hyperplasias and neoplasias. They have been divided into several general pathologic categories that have prognostic significance. These include early or hyperplastic PTLD, polymorphic PTLD, and lymphomatous or monomorphic PTLD. The majority of PTLDs are of B-cell origin and contain Epstein-Barr virus (EBV). However, PTLDs of T- or NK-cell origin have been described, and late-arising EBV-negative lymphoid tumors are becoming more frequently reported in this population. Other lymphoid neoplasms, such as those arising from mucosal-associated lymphoid tissue (MALTomas), have recently been recognized in transplant patients, and their relationship to PTLD is uncertain. Multicentric PTLD may represent either advanced-stage disease or multiple independent primary tumors. Likewise, recurrent PTLD may represent true recurrence or the emergence of a second primary tumor. Transplant patients are also at risk for other opportunistic neoplasms, including EBV-associated leiomyosarcomas that may be seen alone or in conjunction with PTLD. This underscores the necessity for pathologic diagnosis of mass lesions in this patient population. The pathologist should strive to categorize the form of post-transplant lymphoproliferation in accordance with currently accepted criteria. The diagnosis should incorporate the histopathologic appearance, cell phenotype, clonal status, and EB viral status. The pathologist may play a special role in guiding therapy by ascertaining the presence of such markers as CD20 on tumor cells. Specialized techniques, such as molecular analysis of oncogenes/tumor suppressor genes and evaluation of host:donor status of PTLD, may play important roles in diagnostic evaluation in the future.