Non-Hodgkin’s Lymphomas in Asia

Non-Hodgkin’s Lymphoma in Northern India: An Analysis of Clinical Features of 241 Cases

Background: Geographic variations with regard to incidence, clinical presentation, and histological subtypes are known to occur in several cancers. This study was aimed to see if similar differences existed in non-Hodgkin's lymphoma (NHL) also during pre-immunohistochemical era. Materials and Methods: Cases of NHL seen at Institute Rotary Cancer Hospital, All India Institute of Medical Sciences, New Delhi from January 1997 to December 2000, were analyzed for baseline clinical features and histology. Results: Total cases: 241, median age: 47 years (range 2–84 years), male-female ratio: 2.2:1, primary extranodal NHL: 44.2%, the most common histological subtype: Diffuse large cell (6.2% of the cases). Conclusion: Our patients presented at younger median age, had more male to female ratio, had diffuse large cell histology as the most common histological subtype.

Hepatitis C virus-associated non-Hodgkin lymphomas: the endless history

Hepatitis C virus (HCV) is a global population problem due to its high prevalence worldwide. In the prognosis of patients with HCV not only hepatic but increasingly frequent of extrahepatic HCV manifestations, such as mixed cryoglobulinemia (MC) and non-Hodgkin's lymphoma (NHL), are important. The role of the HCV virus in the pathogenesis of lymphoproliferative diseases is confirmed by a large number of epidemiological studies, as well as by the effectiveness of antiviral therapy in patients with non-Hodgkin's lymphoma (NHL). The purpose of the review was to provide an overview of epidemiological and biological data explaining the role of HCV in the development of NHL. The review also discusses HCV-associated NHL treatment by the traditional antiviral therapy (interferon and ribavirin) and by the new direct antiviral agents.

Nasopharyngeal Lymphoma: A 22-Year Review of 35 Cases

Nasopharyngeal (NP) lymphoma is a rare primary malignancy of the head and neck and represents a minority of malignancies originating from the nasopharynx. For this reason, there are limited data regarding epidemiologic and treatment outcomes. This is a retrospective review of patients diagnosed with NP lymphoma from 1995 to 2017 at a tertiary medical center. The patients’ demographic data, clinical presentations, treatment modalities, Epstein–Barr virus (EBV)-encoded small RNA (EBER) staining, and outcomes were investigated. We considered a total of 35 patients, including 20 males and 15 females, diagnosed with NP lymphoma. The age ranged from 17 to 88 years (mean = 59.6). The common presentations were nasal obstruction, epistaxis, and neck mass. In our study, the most common pathological diagnosis of NP lymphoma was diffuse large B cell lymphoma (DLBCL) (n = 17), followed by NK/T cell lymphoma (NKTCL) (n = 9). Other pathologic diagnoses included extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALToma), small lymphocytic lymphoma, mantle cell lymphoma. There were 13 cases showing EBER positivity, including 7 cases of NKTCL, 5 cases of DLBCL, and 1 case of post-transplant lymphoproliferative disorder (PTLD). Most patients received chemotherapy alone, while some patients received both chemotherapy and radiotherapy. Seven patients had local recurrence, and fewer than half of the patients (n = 16) were alive at the time of the study (mean follow-up duration: 54.4 months). The five-year overall survival was 50.4%. NP lymphoma is very rare, and the most common pathologic type is DLBCL. EBER positivity is found in both NKTCL and DLBCL. Identifying more effective therapeutic agents is extremely important to improve patients’ survival.

Adenosine Deaminase Activity in Chronic Lymphocytic Leukemia and Healthy Subjects

Background

B cell chronic lymphocytic leukemia is one of the most frequent hematologic malignancies in the world. Cellular surface CD markers and serum Beta-2-microglobulin may be used as a prognostic tool in CLL patients.

Objectives

In the present study we introduce serum adenosine deaminase as a diagnostic marker in CLL.

Materials and Methods

Blood samples were collected from B-CLL and healthy subjects. White blood cell, red blood cell and platelet count and blood Erythrocyte sedimentation rate was recorded and serum Beta-2-microglobulin, Lactate dehydrogenase and total ADA enzyme activity were determined.

Results

Serum ADA activity was significantly higher in patients group than that of controls. ADA had a significant and direct correlation with B2M, WBC, LDH and ESR. However, there was not any relation between ADA and the stages of disease. Diagnostic cut-off, sensitivity and specificity of the serum ADA test were 27.97 U/L, 91% and 94%, respectively.

Conclusions

A higher ADA activity in patients group and its correlation with CLL markers were seen in our study. High diagnostic value of serum ADA in our study suggests that it might be considered as a useful screening tool among the other markers in CLL.

Lymphoproliferative Disease of the Orbit

Lymphoproliferative diseases of the orbit account for majority of orbital tumors. The pathologies range from reactive lymphoid hyperplasia to specific IgG4-related inflammation to malignant lymphomas. This review summarizes current concepts regarding pathology, clinical presentation, diagnosis, staging, and treatment strategies of major orbital lymphoproliferative diseases based on updated and relevant bibliography.

Rituximab in follicular lymphoma: the first chapter of the new era?

SUMMARY 

Follicular lymphoma is the most common indolent B-cell lymphoma. Although there is no current standard of care adopted for all patients, clinical outcomes for patients with follicular lymphoma have significantly improved over the past few decades, which can be largely attributed to the incorporation of immunotherapy. Rituximab, a monoclonal antibody to the CD20 antigen, has been widely adopted in the treatment of B-cell lymphomas, resulting from improvements in remission duration and overall survival. We provide an evidence-based discussion of the clinical success and incorporation of immunotherapy, rituximab in the treatment of follicular lymphoma, the prototypical indolent B-cell lymphoma. This shift in the treatment paradigm has opened the door to novel, nonchemotherapy approaches in the treatment of patients with indolent B-cell lymphoma.

Management of B-cell non-Hodgkin lymphoma in Asia: resource-stratified guidelines

Treatment of B-cell non-Hodgkin lymphomas has undergone substantial developments in the past 10 years. The introduction of rituximab has greatly improved survival outcomes in patients. Clinical practice guidelines based on current evidence have been developed to provide recommendations for standard treatment approaches. However, guidelines do not take into account resource limitations in resource-poor countries. The huge disparities in economy, health-care infrastructure, and access to novel drugs between Asian countries can hinder the delivery of optimum care to patients with lymphoma in Asia. We outline guidelines appropriate to different levels of health-care resources and expertise, aiming to provide advice on diagnosis and treatment, unify interpretation of results, and allow the design of future studies in Asia. In this resource-adapted consensus, we summarise recommendations for diagnosis, staging, risk stratification, and treatment of common B-cell non-Hodgkin lymphomas in Asia.

A collaborative nationwide lymphoma study in Lebanon: incidence of various subtypes and analysis of associations with viruses

Incidence of various Hodgkin (HL) and non-Hodgkin lymphoma (NHL) subtypes and association with viruses in Lebanon are not known. We undertook a nationwide study of 272 patients diagnosed with lymphoma in 2007. HL comprised 32.7 % (n = 89) of cases while NHL represented 67.3 % (n = 183). Consistent with the literature, nodular sclerosis was the most predominant HL subtype (n = 57/89). Among NHL, B-cell NHL represented 88 % (n = 161/183), T-cell NHL 9 % (n = 17/183), whereas in 2.7 % it was not classifiable. The B-cell NHL comprised predominantly diffuse large B-cell lymphoma (46 %) and follicular lymphoma (23 %). 81 cases were reviewed by a panel of pathologists with 87.6 % concordance rate. Serology was negative for hepatitis C in 122 tested cases. HIV was positive in 2 cases. Two adult T-cell leukemia/lymphoma were HTLV-I positive. EBV IgG were positive in 88.5 % of cases. 38 EBV seropositive cases [27 NHL (24 B-cell, 3 T-cell) and 11 HL] were studied for EBV genome expression using EBV-encoded RNA (EBER)-in situ hybridization. EBER expression was positive in 8 (21 %) cases (6 HL, 2 T-cell NHL). The distribution of lymphoma subtypes in Lebanon appears similar to that of Western countries. The high rate of EBV positivity in HL and T-cell lymphoma by EBER deserves further investigation.

Paediatric lymphoma in China: a clinicopathological study of 213 cases

AIM

This retrospective study was conducted to evaluate information on paediatric lymphoma in China.

METHODS

We reviewed the pathological files of patients less than 12 years of age with lymphoma in Shanghai Xinhua Hospital from January 1982 to June 2009. SPSS version 11.0 was used to analyse the results.

RESULTS

Of the 213 subjects, 176 (82.6%) had non-Hodgkin's lymphoma (NHL) and 37 (17.4%) had Hodgkin's lymphoma (HL). All NHL cases had diffuse and high grade tumours, and 33.5% of these tumours primarily involved extra-nodal sites. Of the NHL cases, 56.6%, 43.3%, and 1.7% were derived from T, B, and null cells, respectively. Lymphoblastic lymphoma (LL, 50.6%), Burkitt's lymphoma (BL, 28.4%), and anaplastic large cell lymphoma (ALCL, 12.5%) comprised the majority of the NHL cases. A significant difference was found in the frequency of stage I/II cases between LL and ALCL. Paediatric HL resembled the disease in adults.

CONCLUSIONS

Paediatric lymphoma in China is different from that in Western countries with respect to the incidence rate of HL and BL. The distribution pattern of NHL histological subtypes is more similar to that in Japan than that in Pakistan. These features suggest ethnic or geographic variations.

Clinicopathological Features and Outcomes of T- and NK-Cell Lymphomas in European Russia

With the introduction of the revised World Health Organization Classification of Tumors of Hematopoietic and Lymphoid Tissues in 2001, many patients had to be re-evaluated for the correct diagnosis of T- and NK-cell lymphomas. Because some T-cell malignancies are associated with poor outcome, it is important to identify subsets of patients that may benefit from novel or more intensive therapies. The purpose of this study was to determine, for the first time, the relative frequencies, pathological features and outcomes of patients with T- and NK-cell lymphomas in a predominantly Russian Slavic population. We identified 291 patients with a diagnosis of T- and NK-cell malignancies treated at our Center between 2000-2008. In applying the revised WHO classification, we confirmed the diagnosis and had complete clinical follow up and pathological information on 264 cases that were included in the analysis. We found some differences in frequency of several subsets as compared with previously published reports, including younger age of onset and relatively higher incidence of T-LGL in our patients. We also confirm that intensive treatment regimens of advanced stage PTCL and ALK—ALCL led to considerable improvement in response rates, but not in the overall survival.

A novel prognostic model for extranodal natural killer/T-cell lymphoma

Natural killer (NK)/T-cell lymphoma is a rare neoplasm with heterogeneous clinical behaviors. This study aimed to devise a prognostic model specifically for extranodal NK/T-cell lymphoma, providing risk stratification in affected patients. A total of 146 patients newly diagnosed with extranodal NK/T-cell lymphoma were retrospectively analyzed. Independent predictors of survival were determined by Cox regression analysis. The estimated 5-year overall survival rate for all patients was 41.9%. Both the International Prognostic Index and Korean NK/T-cell lymphoma Prognostic Index were prognostic in univariate analysis. The majority of our patients were in the low-risk International Prognostic Index and Korean NK/T-cell lymphoma Prognostic Index category (with no or one adverse factor), but both of these two prognostic models had no discriminating power within the subgroup of these patients. Absolute lymphocyte count at diagnosis, B symptoms, and advanced stage were independently predicted poorer survival. Cox analysis yielded a novel prognostic model based on these three parameters that categorized patients into one of three risk groups: Group 1 (57 cases, 39.0%), no adverse factors; Group 2 (43 cases, 29.5%), one adverse factor; and Group 3 (46 cases, 31.5%), two or three adverse factors. Five-year overall survival was 71.6% for Group 1, 55.5% for Group 2, and 0% for Group 3 (P < 0.0001). The novel prognostic model balanced the distribution of patients into different risk groups with better predictive discrimination. It may be useful to stratify patients with extranodal NK/T-cell lymphoma into different risk groups and provide more information for treatment selection.

Addition of rituximab to the CHOP regimen has no benefit in patients with primary extranodal diffuse large B-cell lymphoma

BACKGROUND

The addition of rituximab to cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) chemotherapy (R-CHOP) has significantly improved clinical outcomes for patients with diffuse large B-cell lymphoma (DLBCL). However, new predictors of patient response to R-CHOP have not been established. We aimed to evaluate the impact of R-CHOP compared with CHOP in patients with DLBCL and to establish clinical predictors of better outcomes in these patients.

METHODS

We retrospectively identified 177 patients diagnosed with CD20-positive DLBCL and treated with CHOP (N=82) or R-CHOP (N=95). The response rate, event-free survival (EFS), and overall survival (OS) rates were compared between the 2 treatment groups. All patients were classified into primary extranodal lymphoma (PENL) or nodal lymphoma (NL) subgroups, and the clinical parameters of each subgroup were analyzed.

RESULTS

The overall response rate was higher in R-CHOP group (95% vs. 84%, P=0.07). The 3-year EFS rate was significantly higher in R-CHOP group (71% vs. 52%, P=0.013), but the OS rate was comparable between the 2 groups (79% vs. 69%, P=0.23). A significant survival benefit was seen with R-CHOP compared to CHOP therapy in NL patients (P=0.002 for EFS and 0.04 for OS). Multivariate analyses confirmed that R-CHOP therapy is an independent prognostic factor for EFS (hazard ratio of 0.32 [0.17-0.62], P=0.001) and OS (hazard ratio of 0.4 [0.18-0.87], P=0.02) in NL patients.

CONCLUSION

Patients in the PENL group did not benefit from R-CHOP chemotherapy.

Distributions of major sub-types of lymphoid malignancies among adults in Mashhad, Iran

BACKGROUND

Global variations in the frequency of the major sub-types of lymphoma have been reported. However, studies on different sub-types of adult malignant lymphoma had never been conducted in Mashhad, Iran. In this paper, we aimed to identify the major sub-types of malignant lymphoma in our area and compare the distribution with other published studies.

METHODS

During a retrospective study we evaluate 391 adult patients with lymphoid malignancy from "Omid Hospital" - a cancer research center and an outpatient hematologic clinic in Mashhad - were evaluated from 2000 to 2009. Patients were reclassified using the World Health Organization (WHO) classification.

RESULTS

The frequency of non-Hodgkin lymphomas (NHL) was 92% (n=359) and Hodgkin lymphoma (HL) was 8% (n=32). The most frequent NHL sub-type using WHO classification was diffuse large B cell lymphoma (DLBCL) and the second most common NHL was chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL). The most common sub-type of HL was mixed cellularity. In this study the frequency of primary extranodal NHL in our study was 11.5%, which slightly less common than other eastern countries.

CONCLUSION

Our findings add to the body of knowledge concerning geographic variations in the descriptive epidemiology of the major lymphoma sub-types. Such observations are extremely important since they potentially point to underling etiological variations.

Clinical features and treatment outcomes of adult B- and T-lymphoblastic lymphoma: results of multicentre analysis in Korea

We performed a retrospective multicentre analysis to study the clinical features and treatment outcomes of B-lymphoblastic lymphoma (B-LBL) and T-lymphoblastic lymphoma (T-LBL) in Asian adult patients, and identify risk factors that predict relapse and poor prognosis. Fifty-five newly diagnosed patients (45 T-LBL and 10 B-LBL) were analysed. All patients were treated with intensive chemotherapy regimens including VPDL (vincristine, prednisolone, daunorubicin, L-asparaginase), CALGB (Cancer and leukemia group B), and Stanford/Northern California Oncology Group (NCOG). There was no difference of clinical features between B- and T-LBL except the frequent site of involvement. The overall response rate including complete response (28/55, 50.9%) and partial response (18/55, 32.7%) was 83.6%. Among 46 responders, 22 patients relapsed leading to 20 deaths. Partial responders showed more frequent relapse (10/18, 55.6%) than complete responders (11/28, 39.2%). The median progression-free survival (PFS) was 17 months (95% confidence interval, 11.5-22.5), and the 2-year overall survival was 52 +/- 7% with a median follow-up of 50 months (range 8-152). Treatment outcome of T-LBL and B-LBL was not significantly different in terms of response and survival. The presence of pleural effusion was significantly prognostic for overall and PFS (p < 0.05). In conclusion, clinical features and treatment outcome of Asian adult LBL were comparable to previous results, and the prognosis is still poor despite intensive chemotherapy.

Distribution and clinicopathologic characteristics of non-Hodgkin's lymphoma in India: a study of 935 cases using WHO classification of lymphoid neoplasms (2000)

The frequency of various subtypes of non-Hodgkin's lymphoma (NHL) differs in various regions worldwide. We studied distribution of various subtypes of NHL by using WHO classification of lymphoid neoplasms (2000), immunophenotyping and clinicopathologic characteristics of various histologic subtypes in 935 cases. B- and T-cell NHL constituted 79.3% and 18.8% of cases. Diffuse large B-cell lymphoma (DLBL) was the most common subtype (50.2%). A lower frequency of follicular lymphoma, marginal zone lymphoma and mantle cell lymphoma (MCL) was noted compared to that observed in the developed countries, whereas a lower frequency of peripheral T-cell lymphoma - not otherwise specified (PTCL-NOS) and extranodal NK/T-cell lymphoma was seen compared to that in the other Asian countries. A higher frequency of DLBL and precursor T-lymphoblastic leukemia/lymphoma was noted. Extranodal and bone marrow involvement in MCL and PTCL-NOS was less frequent. Anaplastic variant of DLBL was noted in 21.5% of all DLBLs. Null/T-cell anaplastic large cell lymphoma presented in the older age.

Clinicopathologic characteristics of T-cell non-Hodgkin's lymphoma: a single institution experience

BACKGROUND/AIMS

Although the incidence of T-cell non-Hodgkin's lymphoma (NHL) is higher in Far East Asia than in Western countries, its incidence and clinical course in Korea are not well-defined. Therefore, we assessed the relative frequency and clinical features of T-cell NHL in Korea.

METHODS

We performed a retrospetcive analysis of 586 patients with NHL.

RESULTS

101 (17.2%) had T-cell NHL. The most frequent subtypes of T-cell NHL were extranodal NK/T-cell lymphoma, nasal type (NASAL), peripheral T-cell lymphoma, unspecified type (PTCL-U), and anaplastic large cell lymphoma, T/null cell, primary systemic type (ALCL). The seven pathological subtypes could be classified into three prognostic subgroups. When patients with the three most frequent subtypes were grouped together, their survival was reflected in the International Prognostic Index (IPI) scores. Univariate analysis of IPI elements and other clinical features showed that clinical stage and extranodal sites were significant predictors of survival. Cox multivariate analysis showed that the number of extranodal sites was the only independent prognostic indicator.

CONCLUSIONS

The relative frequency of T-cell NHL seems to be decreasing in Korea, although NASAL remains frequent. Korean patients with ALCL appear to have an unfavorable prognosis. Large-scale studies are warranted for Korean patients with T-cell NHL.

Diffuse large B-cell lymphoma: experience from a tertiary care center in North India

Limited information is available from developing countries regarding clinico-pathological presentation of diffuse large B-cell lymphoma (DLBCL). We undertook a retrospective case record study to determine the clinico-laboratory characteristics, treatment outcomes, and prognostic factors for DLBCL and additionally analyzed percentage distribution and patient characteristics for other major subtypes of non-Hodgkin's lymphoma (NHL). DLBCL, constituting 59.3% of all NHL cases, was the predominant subtype. For DLBCL, males:females ratio was 2.7:1 and the median age at presentation was 47 years. Lymphadenopathy was present in 57% patients and B symptoms in 56.7%. A total of 49.3% of patients had Ann Arbor Stage IV disease. Significant differences were observed between favorable (international prognostic index [IPI]-0, 1, and 2) and unfavorable prognosis groups (IPI-3, 4, and 5) with regards to mean hemoglobin levels (P < 0.005), platelet counts (P < 0.05), serum albumin levels (P < 0.05), and erythrocyte sedimentation rates (P < 0.005), thereby suggesting their role as prognostic markers in our population. The median event free survival was 32 months (95% CI: 0-92 months) and the median overall survival was 47 months (95% CI: 3-100 months). Among total NHL, the earlier age of onset, male dominant sex ratio, and higher frequency of B symptoms sets apart NHL in Indian population from that in the developed countries.

Clinical characteristics and treatment response of Hodgkin's lymphoma in Taiwan

BACKGROUND/PURPOSE

Hodgkin's lymphoma (HL) is particularly rare in Asia, including Taiwan. The report concerning its clinical features and treatment outcomes in Asians is limited. An exploration of the characteristics of HL in this area is of importance for future studies.

METHODS

In this study, 133 patients with HL diagnosed between January 1985 and December 2004 at National Taiwan University Hospital were analyzed retrospectively.

RESULTS

The age distribution revealed a young-adult peak at the age around 20 years. The nodular sclerosis type (NS-HL) was the most common histopathologic subtype (45%), followed by mixed cellularity (29%), lymphocyte predominant (13%), and lymphocyte depleted subtype (2%). The incidence of NS-HL was, however, lower compared with that in the West (around 70%). The male to female ratio was approximately 1:2 in patients with NS-HL, in contrast to the male predominance in patients with other subtypes. Induction therapy led to complete remission (CR) in 87% of patients. At a median follow-up of 78 months, the 10-year overall survival (OS) was 79% in all HL patients and was 90% in those who achieved first CR. In multivariate analysis, the achievement of CR was the only independent factor associated with good OS.

CONCLUSION

The treatment response of HL in Taiwan is good and comparable to that in Western countries. The epidemiologic differences between Taiwan and the West mandate further studies.

Results of CHOP chemotherapy for diffuse large B-cell lymphoma

Patients with diffuse large B-cell lymphoma treated in a University Hospital were studied from 1990 to 2001. Two treatment regimens were used: ProMACE-CytaBOM and then, from November 1996 on, the CHOP regimen. Complete remission (CR), disease-free survival (DFS), and overall survival (OS) rates were determined. Primary refractory patients and relapsed patients were also assessed. A total of 111 patients under 60 years of age were assessed and ranked according to the international prognostic index adjusted to age. Twenty (18%) of them were classified as low risk, 40 (36%) as intermediate risk, 33 (29.7%) as high intermediate risk, and 18 (16.3%) as high risk. Over a five-year period, OS and DFS rates were 71 and 59%, respectively, for all patients. For the same time period, OS and DFS rates were 72.8 and 61.3%, respectively, for 77 patients treated with CHOP chemotherapy and 71.3 and 60% for patients treated with the ProMACE-CytaBOM protocol. There was no significant difference in OS or DFS between the two groups. Eleven of 50 refractory and relapsed patients were consolidated with high doses of chemotherapy. Three received allogenic and 8 autologous bone marrow transplantation. For the latter, CR was 62.5% and mean OS was 41.1 months. The clinical behavior, CR, DFS, and OS of the present patients were similar to those reported in the literature. We conclude that both the CHOP and ProMACE-CytaBOM protocols can be used to treat diffuse large B-cell lymphoma patients, although the CHOP protocol is preferable because of its lower cost and lower toxicity.

Primary systemic anaplastic large cell lymphoma in a single Korean institution: clinical characteristics and treatment outcome

Despite advances in the characterization of anaplastic large cell lymphoma (ALCL), little data is available on Asian patients. We report here upon single Korean institution's experience regarding the clinical characteristics and outcomes of ALCL. We performed a retrospective study of 32 adults with ALCL. Most of the patients received anthracycline-based chemotherapy. Ann Arbor stage III-IV, B symptoms, high-intermediate/ high International Prognostic Index (IPI), and extranodal disease at diagnosis were present in 56%, 44%, 41%, and 63%, respectively. Compared with Western studies, the male/female ratio (4.3) was markedly higher and skin (9%) and bone involvement (9%) were less frequent. The staining results for anaplastic lymphoma kinase were positive in 6 (33%) of 18 cases available. The complete response (CR) rate was 62% (95% CI, 44-80%). With a median follow-up of 51.0 months, 5 yr overall survival was 40+/-11%. The 3 yr relapse-free survival for the 18 patients who achieved CR was 74+/-12%. Age, performance status, lactate dehydrogenase, extranodal disease sites number, and IPI were correlated with treatment response and survival. Our data suggest that Korean ALCL patients appear to have a higher male/female ratio, less frequent skin/bone involvement, and lower CR rate compared with those of Western studies.

Clinicopathological analysis of 598 malignant lymphomas in Taiwan: seven-year experience in a single institution

The clinicopathological characteristics of malignant lymphomas vary according to geography. The purpose of this study is to determine the distribution and clinicopathological characteristics of malignant lymphomas in Taiwan. Archival tissue from 598 malignant lymphomas during the period of 1995-2002 was retrieved. They were reclassified according to the World Health Organization classification system. Clinical data, including age, gender, clinical staging, and follow-up, were scrutinized. There were 330 males and 268 females. The median age at onset of disease was 56 years for B-cell lymphoma (BCL), 50 years for T/NK-cell lymphoma (TCL), and 26 years for Hodgkin's lymphoma (HL). BCL accounted for 80.6%, TCL for 12.4%, and HL for 7%. The major subtypes of non-HL were diffuse large B-cell lymphoma, follicular lymphoma, plasma cell myeloma, marginal zone lymphoma of mucosa-associated lymphoid tissue type, mantle cell lymphoma, unspecified peripheral TCL, and nasal type T/NK-cell lymphoma. Nodular sclerosing subtype was the most common in HL. The frequencies of TCL and HL were relatively low. For histological subtype, enteropathy-type TCL and primary bone marrow HL had higher frequency and poorer prognosis. The 5-year overall survival of BCL, TCL, and HL was 58.9, 34.7, and 83.5%, respectively. To the best of our knowledge, this is the largest series study of malignant lymphoma in Taiwan. Immunophenotype, histological subtype, and clinical stage play significant roles in prognosis (P < 0.05).

Distinct B-cell and T-cell lymphoproliferative disease prevalence among dog breeds indicates heritable risk

Immunophenotypes in lymphoproliferative diseases (LPD) are prognostically significant, yet causative factors for these conditions, and specifically those associated with heritable risk, remain elusive. The full spectrum of LPD seen in humans occurs in dogs, but the incidence and lifetime risk of naturally occurring LPD differs among dog breeds. Taking advantage of the limited genetic heterogeneity that exists within dog breeds, we tested the hypothesis that the prevalence of LPD immunophenotypes would differ among different breeds. The sample population included 1,263 dogs representing 87 breeds. Immunophenotype was determined by the presence of clonal rearrangements of immunoglobulin heavy chain or T-cell receptor gamma chain. The probability of observing the number of B-cell or T-cell tumors in a particular breed or breed group was compared with three reference populations. Significance was computed using chi2 test, and logistic regression was used to confirm binomial predictions. The data show that, among 87 breeds tested, 15 showed significant differences from the prevalence of LPD immunophenotypes seen across the dog population as a whole. More significantly, elevated risk for T-cell LPD seems to have arisen ancestrally and is retained in related breed groups, whereas increased risk for B-cell disease may stem from different risk factors, or combinations of risk factors, arising during the process of breed derivation and selection. The data show that domestic dogs provide a unique and valuable resource to define factors that mediate risk as well as genes involved in the initiation of B-cell and T-cell LPD.

Clinicopathologic features and treatment outcome of mature T-cell and natural killer-cell lymphomas diagnosed according to the World Health Organization classification scheme: a single center experience of 10 years

BACKGROUND

Data on mature T-cell and natural killer (NK)-cell lymphomas diagnosed with the World Health Organization (WHO) classification scheme are scarce. They are regarded to be more common in Asian populations.

METHODS

Consecutive T-cell and NK-cell lymphomas classified according to the WHO scheme within 10 years in a Chinese population were reviewed.

RESULTS

There were 148 cases, constituting 16.6% (T-cell, n=90, 10.1%, NK-cell, n=58, 6.5%) of all non-Hodgkin lymphomas in this period. There was a male predominance (male:female = 2.5), young age at diagnosis (median age 50 years, range 8-86) and frequent extranodal presentation. Commonest T-cell lymphomas included anaplastic large cell lymphoma (ALCL, n=25, median age 35 years, nodal 60%, stage I/II 60%), peripheral T-cell lymphoma, unspecified (PTCL, n=24, median age 54 years, nodal 42%, stage I/II 42%), and angioimmunoblastic T-cell lymphoma (AILT, n=19, median age 67 years, nodal 95%, stage I/II 26%). Overall frequencies of T-cell lymphomas were comparable to Western patients. AILT, PTCL and ALCL were aggressive with a poor outcome. NK-cell lymphomas were predominantly extranodal (96%) and aggressive, with a frequency much higher than Western patients.

CONCLUSIONS

The apparent high prevalence of T-cell and NK-cell lymphomas in the Chinese was due to more frequent NK-cell but not T-cell lymphomas.

Lymphoproliferative disease of the ocular adnexa: a clinical and pathologic study with statistical analysis of 69 patients

PURPOSE

To evaluate the clinical features, treatment, and outcomes of a cohort of patients with ocular adnexal lymphoproliferative disease classified according to the World Health Organization modification of the Revised European-American Classification of Lymphoid neoplasms and to perform a robust statistical analysis of these data.

METHODS

Sixty-nine cases of ocular adnexal lymphoproliferative disease, seen in a tertiary referral center from 1992 to 2003, were included in the study. Lesions were classified by using the World Health Organization modification of the Revised European-American Classification of Lymphoid neoplasms classification. Outcome variables included disease-specific survival, relapse-free survival, local control, and distant control.

RESULTS

Stage IV disease at presentation, aggressive lymphoma histology, the presence of prior or concurrent systemic lymphoma at presentation, and bilateral adnexal disease were significant predictors for reduced disease-specific survival, local control, and distant control. Multivariate analysis found that aggressive histology and bilateral adnexal disease had significantly reduced disease-specific survival.

CONCLUSIONS

The typical presentation of adnexal lymphoproliferative disease is with a painless mass, swelling, or proptosis; however, pain and inflammation occurred in 20% and 30% of patients, respectively. Stage at presentation, tumor histology, primary or secondary status, and whether the process was unilateral or bilateral were significant variables for disease outcome. In this study, distant spread of lymphoma was lower in patients who received greater than 20 Gy of orbital radiotherapy.

Chromosomal abnormalities of 200 Chinese patients with non-Hodgkin's lymphoma in Taiwan: with special reference to T-cell lymphoma

BACKGROUND

The distribution of the histopathological subtypes of non-Hodgkin's lymphoma (NHL) is different among various geographical areas. However, there are few reports concerning cytogenetic findings of NHL, especially T-cell lymphoma, in Asian people.

PATIENTS AND METHODS

We analyzed the chromosomal abnormalities of 200 adult patients with NHL in Taiwan and correlated the non-random aberrations with the histological subtypes.

RESULTS

One hundred and thirty-eight patients (69%) had B-cell lymphoma. The incidence of the t(14;18) in total lymphoma was lower in Taiwan (12%) than in the West (20-30%), but its incidence in follicular lymphoma was comparable between the two areas (17 of 28 patients, 61% versus approximately 50-60%). Sixty-two patients (31%) had T-cell lymphoma, including 11 angiocentric T/natural killer (NK)-cell lymphoma and only two angioimmunoblastic T-cell lymphoma (AILD). The recurrent chromosomal abnormalities in T-cell lymphoma comprised 6q deletion (30%), 11q deletion (20%), 17p deletion (16%), -17 (16%), -Y (14%) and + 8 (11%). Angiocentric T/NK-cell lymphoma had a significantly higher frequency of 1q duplication (P=0.001), 6p duplication (P <0.001) and 11q deletion (P=0.011) than other T-cell lymphoma. The incidences of +3 and +5, two common abnormalities in AILD, were quite low in T-cell lymphoma in Taiwan (4% and 2%, respectively), compared with those in the West (16-32% and approximately 15%, respectively). The 11q deletion, not a common aberration in T-cell lymphoma in western countries, occurred quite frequently in Taiwan.

CONCLUSIONS

The chromosomal aberrations of NHL are quite different among various geographical areas, which may reflect the differences in the distribution of the histological subtypes of lymphoma among various areas.

Epidemiology of non-Hodgkin's lymphoma (NHL): trends, geographic distribution, and etiology

While for most cancers incidence and mortality are decreasing, those of non-Hodgkin's lymphoma (NHL) are steadily increasing. Research to define reasons for this increase is extensive, but has not yet resolved them. We have conducted a literature analysis on trends regarding changes in the incidence, geographic distribution, and etiologic factors of NHL. From our own and previous analyses, an increasing NHL incidence at a rate of 3-4% per year was observed for the 1970s and 1980s. This stabilized in the 1990s, nevertheless still with an annual rise of 1-2%, resulting in almost a doubling of the NHL incidence. This rise has been noted worldwide, particularly in elderly persons >55 years. Concerning gender subgroups, a male predominance throughout all age groups is apparent. Although the NHL incidence has historically been higher in whites than blacks, disproportional increases have recently been observed in the latter group. Increases in high-grade NHL and extranodal disease are predominant. Differences in geographic distribution are striking for follicular lymphoma, which is more common in Western countries than elsewhere. Asians have higher rates of aggressive NHL, T-cell lymphomas, and extranodal disease. In the Middle East, high rates of intestinal extranodal disease are observed, whereas in Africa, endemic Burkitt's lymphoma accounts for a substantial proportion. Risks for developing NHL include immunosuppression and a causal link between infectious agents, and lymphomagenesis has also been determined, particularly for human T-cell leukemia/lymphoma virus type 1 (HTLV-1), Epstein-Barr virus (EBV), and Helicobacter pylori infections. Exposure to environmental agents and occupational risks have been studied; however, their significance is as yet uncertain.

Pattern of Epstein-Barr virus association in childhood non-Hodgkin's lymphoma: Experience of University of Malaya Medical Center

The pattern of childhood non-Hodgkin's lymphoma (NHL) usually differs in adults. The most common subtypes are lymphoblastic, Burkitt's and anaplastic large cell lymphoma. Recent data indicate that a higher risk of developing lymphoma is associated in children of certain ethnic origins. The difference is probably related to the underlying etiological factors of these diseases, and Epstein-Barr virus (EBV) is a strong candidate. The present study aims to determine the disease pattern of childhood lymphomas in the University Hospital Kuala Lumpur, for a direct comparison to the reported data of adults from the same medical center. A total of 69 and 34 childhood NHL and Hodgkin's lymphomas, respectively, were retrieved. The most common subtypes were lymphoblastic (23 cases), Burkitt's (25 cases) and anaplastic large cell lymphomas (9 cases). Epstein-Barr virus association was more prevalent in B-cell (23%) than T-cell (12%) lymphomas. The most common EBV-associated tumor was Burkitt's lymphoma, and there was an increased risk of EBV association for Burkitt's lymphoma in Chinese patients. In conclusion, the pattern of childhood lymphoma in Malaysia is relatively similar to children elsewhere in the world. The EBV association of B- and T-NHL differs between children and adults from the same medical center because of differences in the subtype composition in these two age groups.

Prognostic value of cell-cycle markers in ocular adnexal lymphoma: an assessment of 230 cases

BACKGROUND

To determine the prognostic value of cell-cycle associated markers in ocular adnexal lymphoma (OAL).

METHODS

Two hundred sixty-one consecutive cases of ocular adnexal lymphoproliferative lesions were subdivided into reactive lymphoid hyperplasia (RLH), atypical lymphoid hyperplasia (ALH) and OAL. The latter were sub-typed according to the new WHO Lymphoma Classification. All lesions were investigated applying standard immunohistochemical methods with antibodies specific for pRB, p53, p16, p21, BCL-6 and for multiple myeloma oncogene-1-protein (MUM1, also known as IRF4). The main endpoints included the development of a local recurrence, of systemic disease and of lymphoma-related death. The association of prognostic variables with endpoints was assessed by multiple logistic and Cox regression models, respectively.

RESULTS

The ocular adnexal lymphoproliferative lesions were categorised as OAL ( n=230; 88%), RLH ( n=29; 11%), and ALH ( n=2; 1%). The major lymphoma subtypes included 136 extranodal marginal zone B-cell lymphoma (EMZL), 31 diffuse large cell B-cell lymphomas, 27 follicular lymphomas, 9 plasmacytomas, 9 lymphoplasmocytic lymphoma/immunocytomas and 8 mantle cell lymphomas. The median follow-up time was 44.5 months. Most OAL patients had Stage IE disease and were treated with radiotherapy. Thirty-seven (25%) Stage IE patients had tumour relapses: these were significantly associated with an increased BCL6 blast percentage. Sixty-two (42%) Stage IE patients developed systemic disease: they had "non-EMZL" with large growth fractions and increased blast percentages for BCL6. Fifty-seven (25%) OAL patients died because of their lymphoma; lymphoma-related death was significantly associated on multivariable analysis with advanced clinical stage, an age >60 years and large tumour growth fractions.

CONCLUSION

Subtyping of OAL according to the new WHO Lymphoma Classification, the stage of disease and tumour cell growth fraction aided the prediction of (1) tumour relapse, (2) the development of systemic disease and (3) lymphoma-related death in OAL.

Detection of germinal center B-cell lymphoma in archival specimens: critical evaluation of Bcl-6 protein expression in diffuse large B-cell lymphoma of the tonsil

Expression of Bcl-6 and CD10, markers for the tumor of the germinal center (GC) B-cell derivation, has been studied in primary diffuse large B-cell lymphomas (DLBCLs) of the lymph node, gastrointestinal tract, and mediastinum. In these studies, the coexpression rate of CD10 and Bcl-6 was relatively constant at 30% approximately 40%, but the frequency of Bcl-6+ tumors varied from 55% to 100%, raising doubts about the usefulness of Bcl-6 expression in identifying the tumor of GC B-cell derivation. Because the expression of Bcl-6 in tumors of non-GC B-cell origin has recently been reported, we critically evaluated the expression of Bcl-6 and CD10 in primary DLBCLs of the tonsil, a relatively common tumor in Japan and Korea. The cases (n = 51) represented a consecutive series for any recent 2-year period at several teaching hospitals in Korea and Japan. Formalin-fixed, paraffin-embedded specimens were used for immunostaining. Staining for Bcl-6 and CD10 was positive in 44 (86%) and 22 cases (45%), respectively. However, among those positive for Bcl-6 (>10% Bcl-6+ tumor cells), 2 basic patterns were recognized: uniform and nonuniform. The uniform pattern was characterized by a dense population (>75%) and a consistent density in any given area, resembling the staining pattern observed in GC or follicular lymphoma (FL) (the "GC/FL" pattern). In contrast, the nonuniform pattern exhibited a varying density from area to area, as well as a less-dense population (<75%). The uniform pattern was observed in 26 cases (51%). All but 1 (95%) of the CD10+ tumors coexpressed Bcl-6, with most (82%) displaying the uniform pattern. We conclude that tumors showing a uniform pattern of Bcl-6 expression should be distinguished from those showing a nonuniform pattern, because the former most likely represent tumors of GC B-cell derivation and the latter most likely represent tumors of non-GC derivation. GC B-cell lymphoma thus defined accounted for 51% of tonsillar DLBCL, a proportion comparable to that of the nodal DLBCL. CD10 expression correlated with the "GC/FL" pattern, but appeared to be not essential for the identification of GC B-cell lymphoma. This study suggests that a significant proportion of tonsillar DLBCLs in Asia is of GC B-cell origin rather than of mucosa-associated lymphoid tissue origin. This finding may have significance for clinical management of these lymphomas.

Ocular adnexal lymphomas: five case presentations and a review of the literature

The ocular adnexal lymphomas represent the malignant end of the spectrum of lymphoproliferative lesions that occur in these locations. The Revised European and American Lymphoma (REAL) Classification and the new World Health Organization Classification of Tumors of Hemopoietic and Lymphoid Tissues are the most suitable for subdividing the ocular adnexal lymphomas, whereby the extranodal marginal zone B-cell lymphoma represents the most common lymphoma subtype. This review is based on five cases subtyped according to the above classifications-three "typical" lymphomas (an extranodal marginal zone B-cell lymphoma, a diffuse large cell B-cell lymphoma arising from an extranodal marginal zone B-cell lymphoma, and a follicular lymphoma) and two "atypical" lymphomas (a non-endemic Burkitt lymphoma in an immune competent elderly patient, and a primary Hodgkin lymphoma of the eyelid) of the ocular adnexa. Management of patients with ocular adnexal lymphomas includes a thorough systemic medical examination to establish the clinical stage of the disease. The majority of patients with ocular adnexal lymphoma have stage IE disease. Current recommended therapy in stage IE tumors is radiotherapy, while disseminated disease is treated with chemotherapy. Despite usually demonstrating an indolent course, extranodal marginal zone B-cell lymphomas are renowned for recurrence in extranodal sites, including other ocular adnexal sites. Long-term follow-up with 6-month examinations are therefore recommended. Major prognostic criteria for the ocular adnexal lymphomas include anatomic location of the tumor; stage of disease at first presentation; lymphoma subtype as determined using the REAL classification; immunohistochemical markers determining factors such as tumor growth rate; and the serum lactate dehydrogenase level.

Focal follicular features in tonsillar diffuse large B-cell lymphomas: follicular lymphoma with diffuse areas or follicular colonization

Focal follicular features in diffuse large B-cell lymphomas (DLBCLs) are bound to raise the question of follicular lymphoma (FL) with diffuse areas, because the diagnosis of FL is based on the presence of follicular areas, even though focal. We report 7 cases of primary tonsillar DLBCLs with focal follicular features that presented with morphologic, immunohistochemical, and biological features distinct from those of FL. Histologically, these tumors were characterized by involvement of pericryptal follicles with adjacent dominant diffuse areas. Monomorphous large tumor cells were evenly spaced with abundant, often clear cytoplasm, and blastoid nuclei often with a delicate nuclear membrane. Importantly, residual germinal centers (GCs) were present in the form of either an intrafollicular GC remnant or an isolated GC in the midst of diffuse tumor. An extrafollicular and/or parafollicular growth pattern was also observed. Bcl-6 staining revealed a predominantly sporadic occurrence of Bcl-6(+) cells, comprising <50% of tumor cells, and none displayed diffusely dense collections (>75%) of Bcl-6(+) tumor cells characteristic of the GC or FL. Staining for CD10 was negative in 6 cases. Five of 7 patients were younger than 60, the median age of other patients with primary tonsillar DLBCL. No extratonsillar involvement was seen at 18 months after diagnosis. After chemotherapy or radiotherapy, complete remission was achieved with ease in all patients, but 2 patients who were treated with chemotherapy alone relapsed at 24 and 30 months. In conclusion, tonsillar DLBCL includes a small (10%) but distinct subgroup that warrants distinction from FL with predominant diffuse areas or de novo DLBCL. It appears that the focal follicular features in tonsillar DLBCL likely represent follicular colonization of marginal zone B-cell lymphoma, probably high-grade, if the possibility of FL is excluded.

Insights into the molecular pathogenesis of follicular lymphoma arising from analysis of geographic variation

Incidence rates of follicular lymphoma (FL) inexplicably vary markedly between Western and Asian countries. A hallmark of FL is the bcl-2 translocation, characterized by 1 of 2 common breakpoints known as major breakpoint region (MBR) and minor cluster region (mcr). We analyzed previously published data to compare rates of bcl-2 translocation in FL across geographic regions. Available data from the literature suggest that the incidence of bcl-2 in healthy persons in the absence of FL may be as high as 50% in Western and Asian populations. However, in FL our results show that the frequency of bcl-2 positivity was significantly higher for US than for Asian populations (P <.0001). This pattern persisted for MBR and mcr subgroups. We conclude that a significant gradient exists in the bcl-2 frequency between these FL populations. We therefore suggest that the relatively low incidence of FL in Asian populations is caused not by a lower frequency of bcl-2 rearrangements in healthy populations but by distinct molecular pathways developing in different geographic regions that nonetheless culminate in FL, which is morphologically similar but molecularly distinct. Studies demonstrating differences in clinical characteristics according to the presence or absence of bcl-2 rearrangements support this concept. Thus we hypothesize that FL may in fact be a heterogeneous malignancy encompassing entities with distinct molecular pathogenesis and potentially distinct clinical manifestations. If these findings were confirmed in prospective studies, it would imply that different etiologic or genetic factors might influence the development of FL across separate regions.

Polymerase chain reaction-based diagnosis of bone marrow involvement in 170 cases of non-Hodgkin lymphoma

BACKGROUND

Up to the current time, diagnosis of bone marrow (BM) involvement in non-Hodgkin lymphoma (NHL) has been based on morphologic findings. Polymerase chain reaction (PCR) for antigen receptor gene rearrangements has the potential to increase the detection sensitivity of minimal degrees of BM involvement. The authors therefore assessed PCR-based clonalities of BM concurrently with morphology from 170 cases with NHL and evaluated the usefulness of comparative analysis of clonalities between bilateral BMs and the lymph node and the clinical significance of PCR based clonalities of BM.

METHODS

Bilateral BM clot sections of 170 cases and 47 lymph nodes were tested for immunoglobulin heavy chain gene rearrangement or T-cell receptor gamma gene rearrangement according to the B- or T-lineage of the lymph node.

RESULTS

When compared with morphology, the results of PCR showed an unexpectedly low positive concordance rate of 61.0% for B-cell NHL and 57.1% for T-cell NHL. When the clonality of BM was compared with that of lymph nodes in B-cell NHL, bilateral clonalities of BM showed high concordance with the clonality of the lymph nodes. PCR-based clonality did not show significant impact on survival.

CONCLUSIONS

Morphology remains the gold standard in the evaluation of BM involvement by NHL. Although the comparative analysis of BM clonality and that of the lymph nodes is considered a valuable tool that increases the reliability of clonality, PCR-based clonality of BM does not significantly add to the sensitivity of diagnosing BM involvement by NHL.

A population-based study of pediatric anaplastic large cell lymphoma

BACKGROUND

Anaplastic large cell lymphoma (ALCL) is a relatively rare form of non-Hodgkin lymphoma (NHL) in children constituting 10-15% of this entity. To the authors' knowledge, there are no population-based pediatric studies in the literature, and incidence estimates have not been attempted.

METHODS

A population-based study of all children in British Columbia, Canada, younger than 15 years of age presenting between January 1988 and December 1999 with an immunohistologically confirmed diagnosis of CD30+ ALCL was completed. Demographic, ethnic, clinical, treatment, and outcome details were collected on all patients. Population figures were obtained from census data through the BC STATS.

RESULTS

Ten patients were identified and confirmed to have ALCL on the basis of morphology and immunohistochemical stains. This equates to an annual incidence of 1.2 per million children younger than 15 years of age. The mean age at diagnosis was 8.23 years with a range of 1.4-13.0 years. There was an overrepresentation of East and Southeast Asian patients (40%) in the ALCL group compared with other subtypes of NHL and the pediatric population of British Columbia. Twenty percent of the patients had evidence of central nervous system (CNS) disease at diagnosis.

CONCLUSIONS

The annual incidence of ALCL in children younger than 15 years of age in British Columbia is 1.2 per million. The overrepresentation of East and Southeast Asian ethnic origin remains unexplained. The rate of CNS involvement is much higher than that previously reported in large non-population-based series (0-3%). Although the low numbers do not allow firm conclusions, it would seem prudent to continue to investigate all newly diagnosed patients for CNS involvement in British Columbia.

Successful treatment of nasal T-cell lymphoma with a combination of local irradiation and high-dose chemotherapy

Nasal natural killer (NK)/T-cell lymphoma is characterized by an aggressive clinical course and poor prognosis. The term "NK/T-cell" lymphoma includes both the NK-cell type and the T-cell type, which are classified by immunophenotyping and according to T-cell receptor (TCR) rearrangement. In addition, CD56+ T-cell lymphoma is defined as NK-like T-cell lymphoma. This report concerns a 54-year-old woman with nasal T-cell lymphoma. Its phenotype showed pure T-cell type with CD3+, CD56-, and TCR+ accompanied by Epstein-Barr virus infection. Although the lesions were localized in the nasal mucosa and facial skin (stage IE), local irradiation could not achieve complete remission (CR). We then administered 5 courses of CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisolone) regimen followed by high-dose chemotherapy with an autologous peripheral blood stem cell transplantation. This therapy resulted in CR. Our results suggest that this lymphoma subtype may be cured by means of intensive treatment soon after diagnosis.

Pattern of malignant lymphoma in the United Arab Emirates--a histopathologic and immunologic study in 208 native patients

The aim of this study was to analyze the distribution of the various pathologic types of lymphoma in a native Arab population of the United Arab Emirates (UAE). Two hundred and eight patients with malignant lymphoma diagnosed over a 12-year period (1988-1999) were retrospectively studied morphologically and immunohistochemically with a panel of monoclonal antibodies and classified according to the revised European-American classification of lymphoid neoplasms (REAL). Of the 208 patients in the study, 41% had Hodgkin's disease (HD) and 59% had non-Hodgkin's lymphoma (NHL). The distribution of HD showed a predominance of nodular sclerosis and mixed cellularity types. Among NHLs, the most frequent type was diffuse large B cell (59% of all NHLs) followed by the Burkitt's type (13%). The proportion of primary extranodal NHL was 29%. Immunologically, the percentages of NHL with B-cell and T-cell phenotypes were 83 and 11, respectively. When the International Working Formulation was used, 34% of NHLs were classified as high grade, 59% as intermediate grade and only 7% as low-grade lymphomas.