Distinct Hodgkin lymphoma subtypes defined by noninvasive genomic profiling

The scarcity of malignant Hodgkin and Reed-Sternberg cells hampers tissue-based comprehensive genomic profiling of classic Hodgkin lymphoma (cHL). By contrast, liquid biopsies show promise for molecular profiling of cHL due to relatively high circulating tumour DNA (ctDNA) levels1-4. Here we show that the plasma representation of mutations exceeds the bulk tumour representation in most cases, making cHL particularly amenable to noninvasive profiling. Leveraging single-cell transcriptional profiles of cHL tumours, we demonstrate Hodgkin and Reed-Sternberg ctDNA shedding to be shaped by DNASE1L3, whose increased tumour microenvironment-derived expression drives high ctDNA concentrations. Using this insight, we comprehensively profile 366 patients, revealing two distinct cHL genomic subtypes with characteristic clinical and prognostic correlates, as well as distinct transcriptional and immunological profiles. Furthermore, we identify a novel class of truncating IL4R mutations that are dependent on IL-13 signalling and therapeutically targetable with IL-4Rα-blocking antibodies. Finally, using PhasED-seq5, we demonstrate the clinical value of pretreatment and on-treatment ctDNA levels for longitudinally refining cHL risk prediction and for detection of radiographically occult minimal residual disease. Collectively, these results support the utility of noninvasive strategies for genotyping and dynamic monitoring of cHL, as well as capturing molecularly distinct subtypes with diagnostic, prognostic and therapeutic potential.

Hodgkin Lymphoma in Adults

BACKGROUND

Hodgkin lymphoma is the most common neoplasm in young adults, with an incidence of 2 to 3 cases per 100 000 persons per year. Risk-adapted chemotherapy and radiotherapy usually lead to cure. Finding ways to lessen the treatment- associated morbidity and mortality is a major goal of current research.

METHODS

For the creation of an updated guideline (DKH grant number 111778), a systematic literature search was carried out in medical databases (MEDLINE, CENTRAL) and guideline databases (GIN) (search dates: January 2012 to June 2017).

RESULTS

Results from 10 meta-analyses, 89 randomized and controlled trials, and 81 prospective or retrospective trials were evaluated. The use of positron emission tomography (PET) is strongly recommended in the initial diagnostic evaluation, as well as for the guidance of treatment in advanced stages. In early stages, two cycles of ABVD (doxorubicin, bleomycin, vinblastine, and dacarbazine) and involved-site radiotherapy (IS-RT) at a dose of 20 Gy are recommended. For the treatment of intermedi- ate stages, two cycles of escalated BEACOPP (bleomycin, etoposide, doxorubicin, cyclophosphamide, vincristine, procarbazine, and prednisone) + two cycles of ABVD and 30 Gy IS-RT are recommended. In advanced stages, two cycles of escalated BEACOPP are administered, and then PET is performed for the guidance of further treatment: two further cycles of escalated BEACOPP are recommended if the PET is negative and four further cycles if it is positive, followed by radiotherapy of PET- positive residual tumor tissue. The five-year survival of patients with Hodgkin lymphoma is 95%. In case of disease recurrence, high-dose chemotherapy followed by autologous stem-cell transplantation is performed, and targeted drugs including brentuxi- mab vedotin, nivolumab, and pembrolizuab are used.

CONCLUSION

The highly favorable long-term prognosis of HL necessitates careful consideration of the intensity of treatment as well as thorough follow-up to enable the detection of late sequelae, such as second tumors or organ damage.

Hodgkin's Disease in Children. Pathologic Study of 87 Cases

From 1963 to 1977 at the Istituto Nazionale Tumori at Milan, 112 patients below the age of 16 years with Hodgkin's disease (HD) were observed, representing 13.2 % of all the cases of this disease seen during the stated time interval. Eighty-seven of these cases are the subject of the present study. Fifty-nine patients were males and 28 females (2.1:1 ratio). The age range varied from 2 years 10 months to 15 years 10 months (median 10 years). Forty-three (49.4%) children, of whom 35 were males and 8 females, were below the age of 10 years at the onset of their disease. The clinical staging resulted in 34 patients as stage I, 33 as stage II, 13 as stage III and 7 as stage IV. The histologic type was nodular sclerosis (NS) in 49 cases (56.3 %), lymphocytic predominance (LP) in 15 cases (17.2 %), mixed cellularity (MC) type in 9 cases (10.3 %) and lymphocytic depletion (LD) in 8 cases (9.2 %). In the remaining 6 cases the histologic classification was not applicable. LP type in 15/15 (100 %) patients was associated with stages I and II, and NS in 38/49 (77 %) patients was related to stage I and stage II. The latter was also the istologic type most often encountered in patients with stage II disease (23/33 or 70 %). Eleven patients have died, and their survival varied from 6 to 47 months (median 30 months). The histologic type was LD in 4 cases, NS in 3 cases, MC in 1 case, and LP in 1 case. In the other 2 nonsurvivors, the histologic type was not identifiable. Of the 23 patients with more than a 5-year survival, 14 (60.8 %) had NS HD. As in adults, LP and NS were associated with early stages of the disease and with long survival.

Histologic Subclassification of Nodular Sclerosis Hodgkin's Disease

Nodular sclerosis (NS) Hodgkin's disease was pathologically subdivided by cellular composition and degree of fibrosis in a series of 49 children admitted to the Istituto Nazionale Tumori of Milan between 1967 and 1977. NS showed lymphocytic predominance (LP) in 26 cases, mixed cellularity (MC) in 16 cases, and lymphocytic depletion (LD) in 7 cases. « Early fibrosis » (EF) and « advanced fibrosis » (AF) subgroups in 28 and 21 cases, respectively, were observed. Of the cases with LP 76.9 % (20/26) presented with stages I and II disease, compared with 37.5 % (6/16) and 28.6 % (2/7) of the MC and LD subgroups, respectively. LP and EF subgroups coexisted in 12 of 28 (42.9 %) patients at stages I and II. Predominance of lymphocytes, rarity of lacunar cells, and a mild degree of fibrosis were associated with early stages of disease. This data confirms that subclassification of NS is feasible.

Clinical and Morphological Correlation of Hodgkin's Disease in Children

Clinical and morphological characteristics of Hodgkin's disease were studied in 62 children. The classification by histological type and staging were based on international recommendations. The morphological investigation included repeated biopsies and the study of several lymph nodes and serial sections. Lymphocyte predominance type appeared to be the most frequent histological type, being diagnosed in 47% of the children.

Clinical and morphological observations allowed us to distinguish an additional histological type, « incipient» Hodgkin's disease, in which the structure of the lymph nodes is conserved, but there is a small quantity of pathological cells. Clinical manifestations were minimal in this type of Hodgkin's disease. Lymphocyte predominance type was often associated with Stage I and II and was often met in infants; lymphocyte depletion was correlated with Stage III and IV and with general symptoms; nodular sclerosis and Stage II were observed in older children.

Reclassifying patients with early-stage Hodgkin lymphoma based on functional radiographic markers at presentation

The presence of bulky disease in Hodgkin lymphoma (HL), traditionally defined with a 1-dimensional measurement, can change a patient's risk grouping and thus the treatment approach. We hypothesized that 3-dimensional measurements of disease burden obtained from baseline 18F-fluorodeoxyglucose positron emission tomography-computed tomography (PET-CT) scans, such as metabolic tumor volume (MTV) and total lesion glycolysis (TLG), would more accurately risk-stratify patients. To test this hypothesis, we reviewed pretreatment PET-CT scans of patients with stage I-II HL treated at our institution between 2003 and 2013. Disease was delineated on prechemotherapy PET-CT scans by 2 methods: (1) manual contouring and (2) subthresholding of these contours to give the tumor volume with standardized uptake value ≥2.5. MTV and TLG were extracted from the threshold volumes (MTVt, TLGt) and from the manually contoured soft-tissue volumes. At a median follow-up of 4.96 years for the 267 patients evaluated, 27 patients were diagnosed with relapsed or refractory disease and 12 died. Both MTVt and TLGt were highly correlated with freedom from progression and were dichotomized with 80th percentile cutoff values of 268 and 1703, respectively. Consideration of MTV and TLG enabled restratification of early unfavorable HL patients as having low- and high-risk disease. We conclude that MTV and TLG provide a potential measure of tumor burden to aid in risk stratification of early unfavorable HL patients.

Predominance of CD4+ T Cells in T-Cell/Histiocyte-Rich Large B-Cell Lymphoma and Identification of a Subset of Patients With Peripheral B-Cell Lymphopenia

OBJECTIVES

T-cell/histiocyte-rich large B-cell lymphoma (THRLBCL) is a morphologic variant of large B-cell lymphoma whose flow cytometry findings are not well characterized.

METHODS

Nineteen cases with flow cytometric immunophenotyping were identified from the case records of four institutions between 2001 and 2016.

RESULTS

In most cases, neoplastic B cells were not detected by flow cytometry. Overall, cases showed a predominance of CD4+ T cells, which in some cases was marked. Significant coexpression of CD57 was seen on CD4+ T cells where this marker was analyzed, which correlated with PD-1 expression. Two cases also showed a profound systemic B-cell lymphopenia, which was associated in one case with hypogammaglobulinemia.

CONCLUSIONS

Overall, our work challenges previous findings that cases of THRLBCL are rich in CD8+ T cells and highlights parallels between THRLBCL and nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL). Also, an association of THRLBCL with systemic B-cell lymphopenia has not been previously reported but may represent an underrecognized manifestation.

[Update on nodular lymphocyte predominant Hodgkin's lymphoma and related lesions]

The present article gives an overview of novel developments in the diagnosis of nodular lymphocyte predominant Hodgkin's lymphoma with reference to the revised WHO classification from 2016. Differential diagnoses that are discussed are progressively transformed germinal centers, T cell/histiocyte-rich large B cell lymphoma as well as transformation into a diffuse large B cell lymphoma.

Subtype distribution of lymphomas in South of Iran, analysis of 1085 cases based on World Health Organization classification

Lymphoma is one of the most common malignancies worldwide. Subtype distribution is different throughout the world. Some reports from the Middle East are in record. This article is trying to report the subtype distribution of lymphoma in Iran and compare it to that of Western, Far East Asian and Middle Eastern countries. A retrospective study was done on all lymphomas diagnosed in a large referral center in the South of Iran during a time period between 2009 and 2014. All diagnoses have been made according to 2008 WHO classification. A total number of 1085 cases with diagnoses of lymphoma retrieved. Twenty-nine cases (2.6 % of all) were precursor lymphoid neoplasm, 608 cases (56 % of all) were mature B cell neoplasm, 115 cases (10.5 % of all) were mature T and NK cell neoplasm, and 333 cases (30.6 % of all) were Hodgkin lymphoma. The six most frequent subtypes of mature B cell neoplasm were diffuse large B cell lymphoma, NOS (57 %), Burkitt lymphoma (7 %), small lymphocytic lymphoma (6.9 %), mantle cell lymphoma (5.7 %), extranodal marginal zone B cell lymphoma (5.2 %) and follicular lymphoma (3.6 %). Among mature T and NK cell neoplasm, mycosis fungoides was the most common type (43.4 %) followed by peripheral T cell lymphoma, NOS (20 %) and angioimmunoblastic T cell lymphoma (9.9 %). Of Hodgkin lymphoma cases, 90.6 % were classical type and 9.3 % were nodular lymphocyte predominant Hodgkin lymphoma. Extranodal involvement was seen in 42.2 % and GI tract was the most common site. Lymphoma frequencies were similar to that of Middle Eastern countries except for lower rate of follicular lymphoma and higher incidence of diffuse large B cell lymphoma, NOS and small lymphocytic lymphoma.

[Lymphomas]

Although malignant lymphoma is split in over 60 distinct entities, four of them, diffuse large B cell lymphoma, follicular-, Hodgkin's- and mantle cell lymphoma constitute more than half of all new cases. A recent major revision of the Ann Arbor staging system restricts the suffix “A” and “B” just to Hodgkin's lymphoma. Bone marrow exams are abandonned in Hodgkin's and restricted in DLBCL. PET exams at different time points are crucial. PET guided therapy will lead to a reduction of the use of chemo- and radiation therapy. Many new targeted drugs have been introduced. Their therapeutic index is impressive as is their price tag. The radiation and chemotherapy free treatment of malignant lymphoma is within reach.

Next-generation surveillance strategies for patients with lymphoma

While remission and cure rates for Hodgkin and non-Hodgkin lymphoma continue to improve, surveillance approaches remain controversial, especially in light of recent reports suggesting limited benefit for routine radiologic assessment. Routine cross-sectional imaging results in considerable patient expense and anxiety, and this approach does not clearly improve patient outcomes. Next-generation approaches including minimal residual disease detection may provide an opportunity to identify relapse early and intervene prior to progression of clinical disease. This review discusses the role of surveillance imaging in Hodgkin and non-Hodgkin lymphoma and provides an introduction to serologic assessment of minimal residual disease. Future studies will need to focus on the clinical application of minimal residual disease surveillance and its ability to predict relapse, treatment response and survival.

A novel immunohistochemical classifier to distinguish Hodgkin lymphoma from ALK anaplastic large cell lymphoma

Classical Hodgkin lymphoma and ALK(-) anaplastic large cell lymphoma share many features like strong CD30 expression and usually loss of B- and T-cell markers. However, their clinical course is dramatically different with curability rates of >90% for classical Hodgkin lymphoma and an unfavorable prognosis for anaplastic large cell lymphoma. Classical Hodgkin lymphoma and ALK(-) anaplastic large cell lymphoma can usually be distinguished by PAX5 expression in the Hodgkin and Reed-Sternberg cells of classical Hodgkin lymphoma and expression of cytotoxic molecules in tumor cells of anaplastic large cell lymphoma. However, in some cases the differential diagnosis is difficult owing to absence of established markers. To be able to better classify these cases, we reevaluated gene expression data of microdissected tumor cells of both lymphomas for differentially expressed genes. A classifier was established, comprising four genes strongly expressed in Hodgkin and Reed-Sternberg cells of classical Hodgkin lymphoma (MDC/CCL22, CD83, STAT3, and TUBB2B). Applying this classifier to a test cohort, Hodgkin lymphoma was successfully distinguished from ALK(-) anaplastic large cell lymphoma with an accuracy of 97% (43/44). MDC/CCL22, CD83, and STAT3 have also been found to be expressed in antigen-presenting cells. Therefore, based on our established classifier, Hodgkin and Reed-Sternberg cells differ from tumor cells of anaplastic large cell lymphoma, which can successfully be applied for practical purposes in histopathologic diagnostics.

EBV may be expressed in the LP cells of nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL) in both children and adults

Nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL) and classical Hodgkin lymphoma (CHL) are classified separately because of their distinct clinical and pathologic features. Whereas Epstein-Barr virus (EBV) is detected in the neoplastic cells of 25% to 70% of CHL, NLPHL is generally considered to be EBV(-). We assessed EBV status in 302 pediatric and adult cases of NLPHL. A total of 145 pediatric (age 18 y or younger) and 157 adult cases of NLPHL were retrieved from 3 North American centers and tested for EBV by in situ hybridization (EBV-encoded small RNA). Clinical and pathologic features were analyzed. Five (3.4%) pediatric and 7 (4.5%) adult NLPHL cases contained EBV(+) lymphocyte-predominant (LP) cells. Although all 12 cases met the criteria for diagnosis of NLPHL, atypical features were present, including capsular fibrosis, atrophic germinal centers, and pleomorphic or atypical LP cells. CD20 and OCT-2 were strongly and diffusely positive in all except 1 case. However, PAX5 and CD79a were weak and/or variable in 7/8 and 6/6 cases tested, respectively. EBV(+) cases were more likely to be CD30(+) (75%) compared with EBV(-) cases (25%) (P=0.0007); CD15 was negative in all cases. Our results show that EBV(+) LP cells may occur in NLPHL. Distinguishing EBV(+) NLPHL from CHL can be challenging, as EBV(+) NLPHL can have partial expression of CD30 and weak PAX5 staining as well as pleomorphic-appearing LP cells. However, the overall appearance and maintenance of B-cell phenotype, with strong and diffuse CD20 and OCT-2 expression, support the diagnosis of NLPHL in these cases.

EBV associated lymphomas in 2008 WHO classification

Epstein-Barr virus (EBV) is a ubiquitous γ-herpes virus that asymptomatically infects more than 90% of the world's population. The exact mechanism of EBV in oncogenesis is an area of active debate. However, EBV has been implicated in the pathogenesis of several kinds of lymphomas and lymphoproliferative disorders, including B-, T- and NK-cell derived. Subsequent studies have proven that the EBV gene expression product plays an activating and/or promoting role on lymphomagenesis, and paves the way for novel cellular therapies of EBV-associated lymphomas. This review concentrates on the pathology, morphology, treatment and prognosis of EBV-associated lymphomas in the 2008 WHO classification of tumors of hematopoietic and lymphoma tissues.

Hodgkin lymphoma

Hodgkin lymphoma (HL), a B cell-derived cancer, is one of the most common lymphomas. In HL, the tumor cells--Hodgkin and Reed-Sternberg (HRS) cells--are usually very rare in the tissue. Although HRS cells are derived from mature B cells, they have largely lost their B cell phenotype and show a very unusual co-expression of markers of various hematopoietic cell types. HRS cells show deregulated activation of multiple signaling pathways and transcription factors. The activation of these pathways and factors is partly mediated through interactions of HRS cells with various other types of cells in the microenvironment, but also through genetic lesions. The transforming events involved in the pathogenesis of HL are only partly understood, but mutations affecting the NF-κB and JAK/STAT pathways are frequent. The dependency of HRS cells on microenvironmental interactions and deregulated signaling pathways may offer novel strategies for targeted therapies.

Hodgkin lymphoma in Pakistan: an analysis of subtypes and their correlation with Epstein Barr virus

The epidemiology of Hodgkin lymphoma (HL) shows a wide geographic variation with regard to age, gender, histological subtypes and their association with Epstein-Barr virus. The proportion of EBV positive cases appears higher in developing than in developed countries. EBV is a common infection in Pakistan due to poor socioeconomic conditions, but reports regarding HL subtypes have been rather selective. Our aims were to establish the relative frequencies of the five subtypes of Hodgkin lymphoma, to determine their associations with Epstein-Barr virus, and finally to establish whether such association follows patterns seen in developing or developed countries. Among 100 cases, the male: female ratio was 4.5:1, with an age range of 4-82 years and an average of 26.6 years. Similar to the subtype distribution in developing countries, mixed cellularity was the commonest 57%, followed by nodular sclerosis 35%, lymphocyte rich 6% and nodular lymphocyte predominant 2%. EBV-LMP1 staining was demonstrated in 41/57 (71%) of the mixed cellularity and the 19/35 (54.2%) of nodular sclerosis subtypes. All 6 cases of lymphocyte rich and 2 cases of nodular lymphocyte predominant were negative for EBV-LMP 1. Speculation about prognostic effects of EBV infection on the course of HL are tempting. Thus the EBV-positive HL could in the future prove to be an excellent candidate for targeted cellular immunotherapy.

[Lymphomas associated with human immunodeficiency virus infection: retrospective review of medical records]

BACKGROUND

The incidence of lymphoma increases enormously in patients infected with the human immunodeficiency virus (HIV).

AIM

To describe the incidence, clinical and histological characteristics, treatments and survival of lymphomas associated with HTV infection.

MATERIAL AND METHODS

Retrospective review of medical records of patients with HIV and lymphoma, treated in a public hospital, between January 2001 and June 2009.

RESULTS

Twenty-two male patients were included but 14 had immunohistochemical confirmation of the lymphoma. The accumulated incidence for this period was 2.8%. The median age at lymphoma diagnosis was 39.5 years. Twelve patients (86%) had non-Hodgkin lymphoma (NHI) and two (14%) Hodgkin lymphoma. The main pathological type of non-Hodgkin lymphomas was diffuse large B cell in seven cases (50%). The mean CD4 cell count and viral load were 83 cell/mm³ (33.5-113.5) and 26.000 RNA copies/ml (1210-196500), respectively Twelve patients (86%) had B type symptoms of lymphoma at the moment of diagnosis. Eleven patients (29%) received chemotherapy with or without radiotherapy, one patient (7%) received radiotherapy alone and two patients (14%) received palliative symptomatic treatment. Six cases (43%) received highly active antiretroviral therapy simultaneously with chemotherapy. Global mortality in this series was 57% (8 patients) with a median survival time of 5.8 months (2.6-26.2).

CONCLUSIONS

In this series of patients infected with HIV, a predominance of aggressive histological subtypes of lymphomas and low complete remission rates, were observed.

EUS-guided biopsy for the diagnosis and classification of lymphoma

BACKGROUND

EUS-guided FNA and Tru-cut biopsy (TCB) is highly accurate in the diagnosis of lymphoma. Subclassification, however, may be difficult in low-grade non-Hodgkin lymphoma and Hodgkin lymphoma.

OBJECTIVE

To determine the yield of EUS-guided biopsy to classify lymphoma based on the World Health Organization classification of tumors of hematopoietic lymphoid tissues.

DESIGN

Retrospective study.

SETTING

Tertiary referral center.

PATIENTS

A total of 24 patients referred for EUS-guided biopsy who had a final diagnosis of lymphoma or "highly suspicious for lymphoma."

INTERVENTIONS

EUS-guided FNA and TCB combined with flow cytometry (FC) analysis. MAIN OUTCOMES MEASUREMENT: Lymphoma subclassification accuracy of EUS guided biopsy.

RESULTS

Twenty-four patients were included in this study. Twenty-three patients underwent EUS-FNA, and 1 patient had only TCB. Twenty-two underwent EUS-TCB combined with FNA. EUS correctly diagnosed lymphoma in 19 out of 24 patients (79%), and subclassification was determined in 16 patients (66.6%). Flow cytometry correctly identified B-cell monoclonality in 95% (18 out of 19). In 1 patient diagnosed as having marginal-zone lymphoma by EUS-FNA/FC only, the diagnosis was changed to hairy cell leukemia after a bone marrow biopsy was obtained. EUS had a lower yield in nonlarge B-cell lymphoma (only 9 out of 15 cases [60%]) compared with large B-cell lymphoma (78%; P = .3 [Fisher exact test]).

LIMITATIONS

Retrospective, small number of patients.

CONCLUSION

EUS-guided biopsy has a lower yield to correctly classify Hodgkin lymphoma and low-grade lymphoma compared with high-grade diffuse large B-cell lymphoma.

Hodgkin lymphoma

Hodgkin disease was first described more than 175 years ago. Clinically and histomorphologically, the features of Hodgkin lymphoma are unusual for a lymphoma or for other malignancies. The incidence of Hodgkin lymphoma is estimated to be 7400 new cases per year in the United States, resulting in an age-adjusted yearly rate of 2.7 per 100,000 per year. There have been numerous classifications of non-Hodgkin lymphoma over the years, but the organizational schemes of Hodgkin lymphoma have been stable. This article reviews the diagnosis of the various types of Hodgkin lymphoma classification, diagnosis and differential.

Pitfalls in diagnostic hematopathology -- Part II

The overlapping features of malignant lymphomas create a diagnostic "grey zone" , and lead to the invention of "grey zone lymphomas". There are several major grey zone lymphomas: 1) Lymphomas with overlapping features of Hodgkin lymphoma and large B-cell lymphoma; 2) Lymphomas with overlapping features of Burkitt lymphoma and diffuse large B-cell lymphoma; 3) Lymphomas with overlapping features of nodular lymphocyte predominant Hodgkin lymphoma and T-cell/histiocyte rich large B-cell lymphoma; 4) Lymphomas with overlapping features of Hodgkin lymphoma, anaplastic large cell lymphoma (ALCL) and peripheral T-cell lymphoma (PTCL); 5) T-cell classical Hodgkin lymphoma and ALCL-HL. The second review of this series will be dedicated to discussion of the "grey zone" features of the lymphomas and how to narrow down the "grey zone" between those lymphomas.

Childhood lymphomas in Yemen. Clinicopathological study

OBJECTIVE

To find out the frequency of childhood lymphomas in all ages, and to describe patterns of lymphomas in relation to gender and site in Yemen.

METHODS

This is a descriptive record-based study of 1167 cases of lymphomas diagnosed by 3 pathologists in the Department of Pathology, Sana'a University, Sana'a, Yemen from 1st January 2004 to 30th December 2007. The diagnoses were made on hematoxylin and eosin stained, and categorized non-Hodgkin's lymphoma (NHL) according to the National Cancer Institute Working Formulation classification, and Hodgkin's disease (HD) according to Rye classification.

RESULTS

Out of 1167 lymphomas, 801 (68.6%) were NHL, and 366 (31.4%) were HD, amongst these 347 (29.7%) were patients aged < or = 18 years, and 221 (63.7%) had NHL, and 126 (36.3%) had HD. The NHL found was Burkitt (64.8%), diffuse large cell lymphoma (23%), lymphoblastic lymphoma (6.3%), and other miscellaneous types account for 5.9%. The histological types of HD were mixed cellularity (72.3%), lymphocyte predominance (16.6%), nodular sclerosis (7.9%), lymphocyte depletion (0.8%), and nonclassified cases (2.4%). The female to male ratio was 1:1.7. The nodal site accounts for 205 (59%) cases, and 142 (41%) were extranodal. The HD was totally nodal, whereas NHL showed 37.4% nodal, and 62.6% extranodal.

CONCLUSION

Childhood lymphomas in this study is of high grade NHL, and of less favorable prognostic type in HD. This indicates that childhood lymphomas in Yemen have similar patterns as that found in other international studies.

Multicentre phase II study of the baseline BEACOPP regimen for patients with advanced-stage Hodgkin's lymphoma

A German Hodgkin's lymphoma (HL) study group designed the BEACOPP (bleomycin, etoposide, doxorubicin, cyclophosphamide, vincristine, procarbazine, prednisolone) regimen. In the BEACOPP regimen, treatment intervals were shortened and the dose-intensity was increased compared with those in the ABVD regimen (doxorubicin, bleomycin, vinblastine and darcarbacine), resulting in a long-term disease-free survival rate of approximately 75-80%. In the present study, we evaluated the safety and efficacy of the BEACOPP regimen. Between April 2001 and February 2004, 20 patients with HL of stage IIB or higher who had received no previous treatment were enrolled. The patients were aged 17-69 years (median 22 years). The histologic types were mixed cellularity in four cases and nodular sclerosis in 16 cases. The stages were stage IIB in four cases, stage III in 12 cases, and stage IV in four cases. Nineteen (95%) of the 20 patients achieved complete remission. The 3-year survival rate was 100% and the 3-year progression-free survival rate was 89.7%. Adverse drug reactions were grade 4 neutropenia in 12 patients, grade 3-4 thrombocytopenia in seven patients, and grade 3 or higher non-hematologic toxicities in two patients (stomatitis in one patient and ALT/AST elevation in one patient). The BEACOPP regimen for advanced-stage HL showed an excellent complete remission rate and high efficacy even in stage III/IV patients. However, a long-term risk of the BEACOPP regimen is the development of secondary leukemia or myelodysplastic syndrome. Therefore, long-term follow-up of these patients, including monitoring for toxicities, is necessary.

Classical Hodgkin's lymphoma in adults: guidelines of the Italian Society of Hematology, the Italian Society of Experimental Hematology, and the Italian Group for Bone Marrow Transplantation on initial work-up, management, and follow-up

The Italian Society of Hematology (SIE), the Italian Society of Experimental Haematology (SIES) and the Italian Group for Bone Marrow Transplantation (GITMO) commissioned a project to develop practice guidelines for the initial work-up, therapy and follow-up of classical Hodgkin's lymphoma. Key questions to the clinical evaluation and treatment of this disease were formulated by an Advisory Committee, discussed and approved by an Expert Panel (EP) composed of senior hematologists and one radiotherapist. After a comprehensive and systematic literature review, the EP recommendations were graded according to their supporting evidence. An explicit approach to consensus methodologies was used for evidence interpretation and for producing recommendations in the absence of a strong evidence. The EP decided that the target domain of the guidelines should include only classical Hodgkin's lymphoma, as defined by the WHO classification, and exclude lymphocyte predominant histology. Distinct recommendations were produced for initial work-up, first-line therapy of early and advanced stage disease, monitoring procedures and salvage therapy, including hemopoietic stem cell transplant. Separate recommendations were formulated for elderly patients. Pre-treatment volumetric CT scan of the neck, thorax, abdomen, and pelvis is mandatory, while FDG-PET is recommended. As to the therapy of early stage disease, a combined modality approach is still recommended with ABVD followed by involved-field radiotherapy; the number of courses of ABVD will depend on the patient risk category (favorable or unfavorable). Full-term chemotherapy with ABVD is recommended in advanced stage disease; adjuvant radiotherapy in patients without initial bulk who achieved a complete remission is not recommended. In the elderly, chemotherapy regimens more intensive than ABVD are not recommended. Early evaluation of response with FDG-PET scan is suggested. Relapsed or refractory patients should receive high-dose chemotherapy and autologous hemopoietic stem cells transplant. Allogeneic transplant is recommended in patients relapsing after autologous transplant. All fertile patients should be informed of the possible effects of therapy on gonadal function and fertility preservation measures should be taken before the initiation of therapy.

[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.

Smoking and lymphoma risk in the European prospective investigation into cancer and nutrition

Lymphomas are one of the few cancers that have been increasing in incidence over the past decades. So far, only a few established risk factors have been identified, including immunosuppression and viral infections. Recent evidence suggests etiologic heterogeneity of different lymphoma subtypes. Smoking may affect risk differently, depending on the lymphoma entity. The European Prospective Investigation into Cancer and Nutrition was used to study the role of smoking in the etiology of lymphomas and individual subtypes within a prospective study. Information on baseline and lifetime tobacco smoking by 478,590 participants was collected between 1992 and 2000. Cox proportional hazards regression was used to calculate multivariate-adjusted hazard ratios and 95% confidence intervals. During 3,567,410 person-years of follow-up, 1,371 lymphoma cases (1,304 non-Hodgkin's lymphomas and 67 Hodgkin's lymphomas) were identified. Relative risk for smokers at recruitment was more than twofold higher for Hodgkin's lymphoma (hazard ratio = 2.14, 95% confidence interval: 1.18, 3.87) but was not elevated for non-Hodgkin's lymphoma (hazard ratio = 1.06, 95% confidence interval: 0.94, 1.19) and individual B-cell non-Hodgkin's lymphoma subtypes. In this prospective study, smoking appeared to increase Hodgkin's lymphoma risk consistently in both genders, whereas B-cell non-Hodgkin's lymphoma risk was not associated. Future analysis should involve viral biomarkers and genetic susceptibility markers to elucidate potential mechanisms of smoking-induced carcinogenesis, particularly for Hodgkin's lymphoma.

Malignant lymphomas in Pakistan according to the WHO classification of lymphoid neoplasms

OBJECTIVE

To determine the spectrum of malignant lymphomas in our set up, according to the WHO classification.

METHODS

All the cases diagnosed as malignant lymphoma, during the year 2005, were retrieved from the institution based tumour registry record and classified according to WHO criteria depending on the immunohistochemical results of a panel of lymphoma markers.

RESULTS

The male to female ratio was 2.5:1 for almost all types of malignant lymphomas. The age range was 3 to 80 years. The frequency of Hodgkin's lymphoma, Burkitt's lymphoma and lymphoblastic lymphoma were higher amongst the children, whereas follicular lymphomas, mantle cell lymphoma and CLL/SLL were more frequently reported in 5th, 6th and 7th decades. Of the total cases 62% were nodal and 38% extranodal (majority in the GI tract). Non Hodgkin's lymphoma was more (73%) frequent than Hodgkin's disease. Mixed cellularity and nodular sclerosis were the main histological variants of Hodgkin's disease.

CONCLUSIONS

Immunohistochemistry is not very frequently used in our set up and also at very few other centres. Therefore, its application should be encouraged to raise the quality of data on lymphoid neoplasms and contribute to their control.

Allogeneic transplantation with reduced-intensity conditioning for Hodgkin and non-Hodgkin lymphoma: importance of histology for outcome

Allogeneic stem cell transplantation (SCT) with reduced-intensity conditioning (RIC) has the potential to lead to long-term remissions for patients with lymphoma. However, the role of RIC SCT in the treatment of lymphoma is still unclear. Specifically, the relative benefit of RIC SCT across lymphoma histologies and the prognostic factors in this population are incompletely defined. We retrospectively analyzed the outcomes of 87 patients with advanced lymphoma who underwent RIC SCT at the Dana-Farber Cancer Institute over a 6-year period with a homogeneous conditioning regimen consisting of fludarabine and low-dose busulfan. Thirty-six patients had Hodgkin disease (HD) and 51 had non-Hodgkin lymphoma (NHL). Sixty-eight percent had undergone prior autologous transplantation. The 1-year cumulative incidence of nonrelapse mortality was 13%, and the 3-year cumulative incidence of progression was 49%. The incidence of grade 3-4 acute GVHD was 11%. The 2-year cumulative incidence of chronic GVHD was 68%, and its development was associated with a decreased risk of progression and an improved progression-free survival (PFS). Three-year overall survival (OS) was 56% for patients with HD, 81% for indolent NHL, 42% for aggressive NHL, and 40% for mantle cell lymphoma. The corresponding figures for 3-year PFS were 22%, 59%, 22%, and 30%, respectively. Multivariate analysis identified elevated pretransplantation lactate dehydrogenase (LDH) as an adverse factor for PFS, while indolent NHL histology was favorable. For OS, advanced age and elevated pretransplantation LDH were adverse factors, whereas indolent NHL histology was favorable. Low early donor chimerism was not predictive of poor outcome in univariate or multivariate analyses. Moreover, progression was not associated with loss of chimerism. These results emphasize the importance of lymphoma histology for patients undergoing RIC SCT, as well as the lack of relevance of donor chimerism for outcome in this patient population.

Nodular lymphocyte predominant Hodgkin lymphoma at atypical locations may be associated with increased numbers of large cells and a diffuse histologic component

Nodular lymphocyte predominant Hodgkin lymphoma (NLPHL) typically affects predictable lymph node groups with excellent treatment outcomes, but cases with a diffuse histologic pattern are associated with recurrence and rarely, cases will transform to diffuse large B-cell lymphoma. Although increased numbers of large cells has not been associated with poor prognosis, transformation is thought to histologically progress through a stage distinguished by increasing numbers of large atypical B-cells. From 55 cases of NLPHL, we describe a possible subset of NLPHL occurring in older individuals at atypical sites, associated with increased numbers of large cells, a diffuse histologic component, and expression of Bcl-2.

Lymphomas in Iran

BACKGROUND

The present study aimed at examining the lymphomas in Iran.

METHODS

This study was conducted in 1994 on patients' specimens who were referred to our centers during 1981-1994. Using the histochemical methods, the immunohistochemical markers were used to examine the biopsied specimens of 434 patients with non-Hodgkin's and Hodgkin's lymphomas. The patients were classified according to the updated Kiel and Rye classifications, respectively.

RESULTS

Out of the 385 cases that were diagnosed as lymphoma, 277 had non-Hodgkin's and 108 had Hodgkin's lymphomas. Sixty-four point five percent of those with non-Hodgkin's lymphoma had the B type disease; 7.5% had the T-type; and the remaining 28% had Hodgkin's lymphoma. In the present study, most (48%) patients with Hodgkin's lymphoma had mixed cellularity whereas in western countries the most common type is reported to be nodular sclerosis (69.4%).

CONCLUSION

The comparison made between the findings of this study and those of western countries indicates that high-grade non-Hodgkin's lymphomas are more prevalent in Iran.

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.

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.

High expression of several tyrosine kinases and activation of the PI3K/AKT pathway in mediastinal large B cell lymphoma reveals further similarities to Hodgkin lymphoma

Mediastinal large B-cell (MBL) and classical Hodgkin lymphoma (HL) have several pathogenic mechanisms in common. As we recently observed aberrant tyrosine kinase (TK) activities in HL, we now analysed also MBL for such activities. Indeed, MBL and HL were the only B-cell lymphomas where elevated cellular phospho-tyrosine contents were typical features. Three TKs, JAK2, RON and TIE1, not expressed in normal B cells, were each expressed in about 30% of MBL cases, and 75% of cases expressed at least one of the TKs. Among the intracellular pathways frequently triggered by TKs, the PI3K/AKT pathway was activated in about 40% of MBLs and essential for survival of MBL cell lines, whereas the RAF/mitogen-activated protein kinase pathway seemed to be inhibited. No activating mutations were detected in the three TKs in MBL cell lines and primary cases. RON and TIE1 were each also expressed in about 35% and JAK2 in about 53% of HL cases. JAK2 genomic gains are frequent in MBL and HL but we observed no strict correlation of JAK2 genomic status with JAK2 protein expression. In conclusion, aberrant TK activities are a further shared pathogenic mechanism of MBL and HL and may be interesting targets for therapeutic intervention.

Nodular lymphocyte-predominant hodgkin lymphoma

Nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL), a distinct subtype of Hodgkin lymphoma, is a rare disease with a generally favorable prognosis. The hallmark of NLPHL is the presence of the lymphocytic and histiocytic cell, which, in contrast to the classic Reed-Sternberg cell, is CD20+, CD15-, and CD30-. NLPHL tends to have an indolent natural history, a long time to disease progression, a delayed time to relapse, and a high likelihood of presenting as early-stage disease. The evidence to guide the management of patients with NLPHL is limited by the rarity of this disease, but the available data support the use of involved-field radiation therapy alone for localized disease. Treatment-related late effects contribute significantly to the causes of death in patients treated for NLPHL.

Clinical perspectives in lymphoma

The classification of both Hodgkin's and non-Hodgkin's lymphomas continues to evolve. The current World Health Organization classification incorporates data derived from advances in our understanding of the pathogenesis of these disorders together with their distinguishing immunophenotypic, genotypic, clinical and histopathological characteristics. As outcomes have improved, the main emphasis of treatment has been to incorporate a risk-adapted approach to reduce long-term toxicity without sacrificing efficacy through the use of varying combinations of chemotherapy, radiotherapy and immunotherapy.

Haematopathology practice: the commonest problems encountered in a consultation practice

Although not specifically recognized as a subspecialty of histopathology, haematopathology has a long history of specialist practice in the UK, with a few centres attracting large numbers of referred cases. The specialist nature of haematopathology has been enhanced by the advent of immunohistochemistry and, more recently, molecular genetics, which now play a major role in the diagnosis of haematopoietic and lymphoid neoplasms. Problems encountered by non-specialist pathologists, and reflected in those cases submitted for consultation, include difficulties in the differential diagnosis of certain benign lymphoproliferative disorders from lymphoma and the precise classification of lymphomas which may have an impact on therapeutic decisions. Lymphomas that frequently pose problems include common lesions such as follicular lymphoma and more esoteric disorders such as T-cell/histiocyte-rich large B-cell lymphoma. This review is an attempt to clarify a logical approach to the differential diagnosis of these lesions.

MMA monoclonal antibody is a superior anti-CD15 reagent for the diagnosis of classical Hodgkin's lymphoma

CD15 is a useful immunohistochemical marker to identify Reed-Sternberg cells in classical Hodgkin's lymphoma (HL) and to distinguish it from HD-like neoplasms, but data from the literature concerning its expression in HL are quite variable. Using immunohistochemistry we compared the reactivity of three different anti-CD15 clones (MMA, C3D1 and BY87) and found that anti-CD15 MMA clone is a superior reagent in identifying atypical cells, detecting more numerous cells in 28.2%, and being the only positive marker in 12.8% of cases. We conclude that it is advisable to include this reagent in diagnostic immunohistochemical panels.

Proposed classification of lymphoid neoplasms for epidemiologic research from the Pathology Working Group of the International Lymphoma Epidemiology Consortium (InterLymph)

Recent evidence suggests that there is etiologic heterogeneity among the various subtypes of lymphoid neoplasms. However, epidemiologic analyses by disease subtype have proven challenging due to the numerous clinical and pathologic schemes used to classify lymphomas and lymphoid leukemias over the last several decades. On behalf of the International Lymphoma Epidemiology Consortium (InterLymph) Pathology Working Group, we present a proposed nested classification of lymphoid neoplasms to facilitate the analysis of lymphoid neoplasm subtypes in epidemiologic research. The proposed classification is based on the World Health Organization classification of lymphoid neoplasms and the International Classification of Diseases-Oncology, Third Edition (ICD-O-3). We also provide a translation into the proposed classification from previous classifications, including the Working Formulation, Revised European-American Lymphoma (REAL) classification, and ICD-O-2. We recommend that epidemiologic studies include analyses by lymphoma subtype to the most detailed extent allowable by sample size. The standardization of groupings for epidemiologic research of lymphoma subtypes is essential for comparing subtype-specific reports in the literature, harmonizing cases within a single study diagnosed using different systems, as well as combining data from multiple studies for the purpose of pooled analysis or meta-analysis, and will probably prove to be critical for elucidating etiologies of the various lymphoid neoplasms.