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Based on their own experience and knowledge of the literature, the authors review the pathobiological characteristics of peripheral T-cell lymphomas (PTCLs), focusing on the available prognostic indicators. The International Prognostic Index (IPI), which is based on age, performance status, lactate dehydrogenase [LDH], stage, and extranodal involvement, appears to be efficient as a prognostic index for PTCLs, at least in part and especially for certain PTCL subtypes. However, it is not so satisfactory for the two commonest PTCLs, PTCL not otherwise specified (PTCL/NOS) and angioimmunoblastic T-cell lymphoma (AITL), for which novel scores, possibly based on the biologic features of the tumors, have been explored. An Italian cooperative group proposed a revision of the IPI for PTCL unspecified (PTCL-U), the Prognostic Index for PTCL-U (PIT), which includes age, performance status, LDH, and bone marrow involvement. The PIT apparently offered some advantages, but they were not confirmed in subsequent studies. A clinical-biological score (the Bologna score) was then proposed, including tumor proliferation and clinical features (age, LDH, and performance status). This score appears promising and offers the intriguing advantage of integrating biological and clinical elements, but independent validation on a large series is still warranted. More recently, gene expression profiling has been used to identify novel molecular prognostic factors. In particular, inactivation of the NFκB pathway, high expression of proliferation-associated genes, and cytotoxic molecular phenotype seem to be associated with a worse outcome. So far, however, none of these indicators has been validated in an independent series. Finally, various reports have dealt specifically with the prognostication of NK-derived tumors, including nasal and nasal-type lymphomas. Both the IPI and dedicated models have turned out to be of prognostic relevance for these tumors. In conclusion, although the IPI is somewhat effective for PTCL prognostication, novel scores that are more refined and possibly disease-specific are warranted. The validation process for several models, including clinical-pathological and molecular models, is now ongoing.

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.

Background: The prognosis for patients with most forms of T-cell lymphoma is poor. Allogeneic hematopoietic stem-cell transplantation (HSCT) may improve the outcome.

Patients and methods: This study examines the outcome of 52 patients who underwent ablative or nonablative allogeneic HSCT for peripheral T-cell lymphoma (PTCL) or advanced mycosis fungoides/Sezary syndrome over a 12-year period at a single institution. We divided the patients into those with predominantly nodal histologies: peripheral T-cell not otherwise specified (PTCL NOS), angioimmunoblastic (AITL), or anaplastic large cell lymphoma, T/null type (systemic) (ALCL), and predominantly extranodal histologies: natural killer (NK)/T cell, enteropathy type, hepatosplenic, subcutaneous panniculitic, mycosis fungoides, or T cell or NK cell other.

Results: Median follow-up of survivors is 49 months. Non-relapse mortality and relapse at 3 years was 27% and 43%, respectively. The incidence of grade II–IV acute graft-versus-host disease (GVHD) was 21%. The incidence of extensive chronic GVHD at 2 years was 27%. The 3-year progression-free survival was 30%: 45% in patients with predominantly nodal histologies (PTCL NOS, AITL, and ALCL) and 6% in patients with predominantly extranodal histologies (P = 0.016). Overall survival at 3 years was 41% for all patients.

Conclusion: Allogeneic HSCT can produce long-term remissions in relapsed/refractory T-cell lymphoma, especially those with nodal histologies.

Background

It has generally been proven that histone acetylation and deacetylation are involved in the malignant transformation. To date, however, this has rarely been studied in cases of malignant lymphoma.

Methods

We studied nine cases of reactive lymphoid hyperplasia, 78 cases of diffuse large B-cell lymphoma (DLBCL), 13 cases of peripheral T-cell lymphoma, not otherwise specified (PTCL-NOS), and 13 cases of extranodal NK/T-cell lymphoma, nasal type (NKTCL). Thus, we attempted to elucidate the associations of the degree of the expression of histone acetyltransferase 1 (HAT1), histone deacetylase (HDAC) 1, HDAC2, and HDAC3 with the clinical behaviors of above malignant lymphomas using the immunohistochemistry and a western blot analysis.

Results

The degree of the expression of HAT1 was higher in cases of DLBCL, PTCL-NOS or NKTCL as compared with reactive lymphoid hyperplasia (p<0.05). The degree of the expression of HAT1 was correlated with that of HDAC1 in cases of DLBCL or NKTCL (p<0.05). The degree of the expression of HAT1 and HDAC1 was correlated with a poor survival in cases of DLBCL or PTCL-NOS (p>0.05).

Conclusions

HAT1, HDAC1, and HDAC2 play a critical role in the development of malignant lymphomas. Both HAT1 and HDAC1 might be indicators for a poor prognosis in cases of DLBCL as cooperating factors.

Peripheral T-cell lymphomas (PTCL) are generally less common and pursue a more aggressive clinical course than B-cell lymphomas, with the T-cell phenotype itself being a poor prognostic factor in adult non-Hodgkin lymphoma (NHL). With notable exceptions such as ALK+ anaplastic large cell lymphoma (ALCL, ALK+), the molecular abnormalities in PTCL remain poorly characterised. We had previously identified circulating antibodies to ALK in patients with ALCL, ALK+. Thus, as a strategy to identify potential antigens associated with the pathogenesis of PTCL, not otherwise specified (PTCL, NOS), we screened a testis cDNA library with sera from four PTCL, NOS patients using the SEREX (serological analysis of recombinant cDNA expression libraries) technique. We identified nine PTCL, NOS-associated antigens whose immunological reactivity was further investigated using sera from 52 B- and T-cell lymphoma patients and 17 normal controls. The centrosomal protein CEP250 was specifically recognised by patients sera and showed increased protein expression in cell lines derived from T-cell versus B-cell malignancies. TCEB3, BECN1, and two previously uncharacterised proteins, c14orf93 and ZBTB44, were preferentially recognised by patients' sera. Transcripts for all nine genes were identified in 39 cancer cell lines and the five genes encoding preferentially lymphoma-recognised antigens were widely expressed in normal tissues and mononuclear cell subsets. In summary, this study identifies novel molecules that are immunologically recognised in vivo by patients with PTCL, NOS. Future studies are needed to determine whether these tumor antigens play a role in the pathogenesis of PTCL.

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.

Background/Aims

Rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone chemotherapy (R-CHOP) has improved survival in patients with diffuse large B-cell lymphoma (DLBCL) and weakened the prognostic power of the international prognostic index (IPI). We evaluated the efficacy of the IPI and revised IPI (R-IPI) in patients with DLBCL who were treated with R-CHOP, focusing on extranodal site number (ENS) because extranodal involvement occurs frequently in Koreans.

Methods

A total of 126 R-CHOP-treated patients with stage III/IV DLBCL were analyzed. We performed a retrospective analysis of the clinicopathologic factors and verified the predictive power of the standard IPI and R-IPI. Various numbers of extranodal sites were analyzed for further stratification, and we set the extranodal site-modified IPI (E-IPI) as the IPI when the number of extranodal sites was stratified as < 3 vs. ≥ 3.

Results

A univariate analysis showed that ENS was associated with complete response (CR, p = 0.04), event-free survival (EFS, p = 0.01), and overall survival (OS, p < 0.001) when the ENS cut-off was set at ≥ 3. A multivariate analysis revealed that an ENS ≥ 3 remained associated with EFS (p < 0.01; hazard ratio [HR], 2.60; 95% confidence interval [CI], 1.29 to 5.26) and OS (p < 0.01; HR, 3.52; 95% CI, 1.68 to 7.35). The IPI was effective for determining prognosis in terms of OS (p = 0.04) but not EFS (p = 0.17). The R-IPI was effective in terms of both variables (p = 0.02 and 0.04, respectively), as was the E-IPI (p = 0.01 and 0.001, respectively).

Conclusions

An ENS < 3 vs. ≥ 3, rather than the original < 2 vs. ≥ 2, was the most significant prognostic factor for EFS and OS. All three indices were predictive, but only the E-IPI identified the high-risk group of R-CHOP-treated Korean patients with disseminated DLBCL.

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.

Introduction:

Testicular lymphoma is a rare and deadly disease representing 1% to 2% of all non-Hodgkin lymphomas (NHLs) and approximately 5% of all testicular neoplasms. Our objective is this study was to identify the presenting signs and symptoms, treatment and outcome of patients with testicular lymphoma diagnosed at our institution from 1992 to 2005, and to identify any differences in survival based on Ann Arbor Stage and International Prognostic Index (IPI).

Methods:

A retrospective chart review was performed to identify demographic characteristics, presenting signs and symptoms, treatment and outcomes. Survival was assessed using Kaplan-Meier survival curves and log-rank testing.

Results:

Thirteen cases were identified; 1 of these cases was ultimately excluded due to a diagnosis of lymphoma a year before he presented with testicular involvement. Of the remaining 12 cases, the mean age was 65 years. Most patients presented with testicular and scrotal swelling or mass. B symptoms (weight loss, fever, night sweats) were present in 1 case. Of the 12 cases, 7 cases were stage I, 1 stage II and 4 stage IV. International Prognostic Index was low risk (≤1) in 7 cases and high risk (>1) in 4 cases. Orchiectomy was performed in all cases. Three patients received no further treatment. Of the remaining 9 patients, overall 7 received systemic chemotherapy, and 7 radiation therapy (prophylactic in 6). Three patients received intrathecal chemotheraphy prophylaxis. Seven patients achieved complete remission. Four patients (57%) relapsed following complete remission. Median time to relapse was 32 months (range 11 to 73 months). Six patients died. Median survival was 29 months, and was significantly different between early versus advanced stage (stage I/II disease: 71 months; stage IV: 5 months p = 0.007).

Conclusion:

Testicular lymphoma is a rare and deadly form of extra-nodal lymphoma. Survival was significantly different in early stage I/II and IPI low-risk versus advanced stage IV and IPI high-risk disease. Randomized, prospective treatment trials may help to establish better treatment strategies.

The peripheral T cell lymphomas (PTCL) carry a worse prognosis compared to B cell non-Hodgkin lymphoma. There is no uniform standard therapy for PTCL, and autologous hematopoietic cell transplant (AHCT) is often offered as consolidation in first remission or at relapse because of the poor outcomes with conventional therapy. We conducted a retrospective review of patients who underwent AHCT for PTCL from 1989 to 2006. Fifty-three cases were identified consisting of systemic anaplastic large cell (n = 18), PTCL unspecified (n = 17), angioimmunoblastic (n = 9), nasal type extranodal NK/T (n = 7), hepatosplenic (n = 2), and adult T cell leukemia/lymphoma (n = 1). Fifteen patients were transplanted in first complete or partial response (CR1/PR1), 32 in second or beyond CR or PR (CR2/PR2+), and 11 with primary refractory disease (REF). With a median follow-up was 5 years (range: 1.0–11.5), the 5-year progression-free survival (PFS) and overall survival (OS) were 25% and 48%, respectively. Disease status at AHCT had a significant impact on PFS and OS. The 5-year PFS for patients in CR1/PR1, CR2/PR2+, and REF was 51%, 12%, and 0%, respectively, and the corresponding figures for OS were 76%, 40%, and 30%, respectively. The pretransplant factors that impacted survival were disease status and the number of prior regimens. Histology, age, sex, stage, B symptoms, bone marrow involvement, and duration of first response did not significantly affect PFS or OS. Based on these results, AHCT as consolidation therapy in first complete or partial response may offer a durable survival benefit. However, AHCT with conventional salvage chemotherapy has minimal durable benefit in patients with relapsed or refractory PTCL, and thus novel strategies and/or allogeneic HCT should be more aggressively explored in lieu of AHCT for relapsed/ refractory PTCL.

Biopsies and cell lines of NK/T-cell lymphoma, nasal-type (NKTCL) were subject to combined gene expression profiling and array-based comparative genomic hybridization analyses. Compared to PTCL, NOS, NKTCL had higher transcript levels for NK-cell markers and cytotoxic molecules, especially granzyme H, a novel sensitive biomarker of NKTCL. Compared to normal NK cells, tumors were closer to activated than resting cells and overexpressed several genes related to vascular biology, EBV-induced genes and PDGFRA. Notably, PDGFRα and its phosphorylated form were confirmed at the protein level, and in vitro the MEC04 NKTCL-cell line was sensitive to imatinib. Deregulation of the AKT, JAK-STAT and NF-κB pathways suggested by bioinformatical analysis, was corroborated by nuclear expression of phosphorylated AKT, STAT3 and RelA in NKTCL, and several deregulated genes in these pathways mapped to regions of recurrent copy number aberrations (AKT3 (1q44), IL6R (1q21.3), CCL2 (17q12), TNFRSF21 (6p12.3)). Several features of NKTCL uncovered by this analysis (overexpression of VEGFA and its receptor KDR by the tumor cells, overexpression of MET-HGF) suggest perturbation of angiogenic pathways. Integrative analysis also evidenced deregulation of the tumor suppressor HACE1 in the frequently deleted 6q21 region. This study highlights emerging oncogenic pathways in NKTCL and identifies novel diagnostic and therapeutic targets.

This study aims to retrospectively analyze the clinical characteristics, treatments, and prognosis of aggressive peripheral T cell lymphoma (PTCL) patients with a lymphoma-associated hemophagocytosis syndrome (LAHS). We compared the clinical features and the overall survival (OS) rates of 159 PTCL patients with and without LAHS as well as the treatment outcomes of these patients with CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisone) or intensive chemotherapy regimens. We observed that in 23 % (36/159) patients PTCL was associated with LAHS. Different subtypes of PTCL in LAHS patients were diagnosed and peripheral T cell lymphoma, not otherwise specified (PTCL-NOS) was the main subtype (78 %). The median survival rates of the LAHS and non-LAHS groups were 3 and 16 months, respectively. The elevated rates of serum β2-microglobulin, ferritin, fasting triglycerides, and hypofibrinogen levels were higher in the LAHS group, so were bone marrow involvement, liver dysfunction, hepatosplenomegaly, and B symptoms. Three patients who were treated with a plasma exchange had a longer survival time. There was no statistically significant difference in the OS rates between the intensive chemotherapy and CHOP regimen groups (P > 0.05). PTCL patients with LAHS had a poorer prognosis. Awareness of the clinical symptoms and laboratory findings are crucial in order to diagnose LAHS in an early stage and repeated biopsies of multiple bone marrows from different locations in those patients without enlargement of superficial lymph nodes are necessary to improve the diagnosis. Intensive chemotherapy due to its severe toxicity was not obviously advantageous for the OS rate compared to the CHOP regimen.

Anthracycline-based chemotherapy remains standard treatment for peripheral T-cell lymphoma (PTCL) although its benefits have been questioned. We performed systematic literature review and meta-analyses examining the complete response (CR) and overall survival (OS) rates for patients with PTCL. The CR rate for PTCL patients ranged from 35.9% (95% CI 23.4–50.7%) for enteropathy-type T-cell lymphoma (ETTL) to 65.8% (95% CI 54.0–75.9%) for anaplastic large cell lymphoma (ALCL). The 5-year OS was 38.5% (95% CI 35.5–41.6%) for all PTCL patients and ranged from 20.3% (95% CI 12.5–31.2%) for ETTL to 56.5% (95% CI 42.8–69.2%) for ALCL. These data suggest that there is marked heterogeneity across PTCL subtypes in the benefits of anthracycline-based chemotherapy. While anthracyclines produce CR in half of PTCL patients, this yields reasonable 5-year OS for patients with ALCL but not for those with PTCL-NOS or ETTL. Novel agents and regimens are needed to improve outcomes for these patients.

This study investigated autophagy in 37 cases of nasopharyngeal lymphomas including 23 nasal natural killer (NK)/T-cell lymphomas (NKTCL), 3 cytotoxic T-cell lymphomas (cytotoxic-TML) and 9 B-cell lymphomas (BML) by means of antigen-retrieval immunohistochemistry of beclin-1, LC3, mitochondria (AE-1) and cathepsin D. Peculiar necrosis was noted in EBV+ lymphomas comprising 21 NKTCL, 2 cytotoxic-TML and 1 BML. Lymphomas without peculiar necrosis showed high expression of beclin-1, macrogranular cytoplasmal stain of LC3 with sporadic nuclear stain, a hallmark of autophagic cell death (ACD), some aggregated mitochondria and high expression of cathepsin D, suggesting a state of growth with enhanced autophagy with sporadic ACD. EBV+ NKTCL with the peculiar necrosis, showed significantly low level of macrogranular staining of LC3, aggregated mitochondria and low expression of cathepsin D in the cellular areas when degenerative lymphoma cells showed decreased beclin-1, significantly advanced LC3-labeled autophagy, residual aggregated mitochondria and significantly reduced expression of cathepsin D, suggesting advanced autophagy with regional ACD. Consequently it was suggested that enhanced autophagy and reduced expression of lysosomal enzymes induced regional ACD under EBV infection in NKTCL.

Summary

The anti-CD52 antibody alemtuzumab has been explored as a novel targeted therapy in T-cell malignancies. To assess the suitability of alemtuzumab therapy we carried out a comprehensive study of CD52 expression using flow cytometry (FC) in 78 untreated patients diagnosed with mature T/NK cell neoplasms, including 34 adult T-cell leukemia /lymphomas (ATLL), two anaplastic large cell lymphomas (ALCL), three angioimmunoblastic T-cell lymphomas (AITL), 16 cutaneous T-cell lymphomas (CTCL), four extra-nodal T/NK cell lymphomas (ENT/NKCL), four hepatosplenic T-cell lymphomas (HSTCL), 13 peripheral T-cell lymphomas, unspecified (PTCL-NOS), and two T-prolymphocytic leukemia (T-PLL). The level of CD52 expression was quantitated using QuantiBRITE standard beads. The level of CD52 expression varied widely within each diagnostic category. All AITL, HSTCL, and T-PLL cases were CD52 positive and the frequency of CD52 expression was high in PTCL-NOS (92.3%), ATLL (94.1%) and CTCL (87.5%), implying a rational role for alemtuzumab in the treatment of these diseases; however, CD52 expression was low in ALCL (50%) and ENT/NKCL (25%). FC testing for cell surface expression of CD52 is indicated in patients with T/NK cell malignancies being considered for alemtuzumab therapy. Further studies are necessary to determine if the level of CD52 expression correlates with response to therapy.

Extranodal natural killer (NK)/T-cell lymphoma of nasal type (NKTCL) is a malignant disorder of cytotoxic lymphocytes of NK or more rarely T cells associated with clonal Epstein-Barr virus infection. Extranodal NKTCL is rare in Western countries, but in Asia and Central and South America it can account for up to 10% of non-Hodgkin's lymphomas. It is an aggressive neoplasm with very poor prognosis. Although the pathogenesis of extranodal NKTCL remains poorly understood, some insights have been gained in the recent years, especially from genome-wide studies. Based on our own experience and knowledge of the literature, we here review some of the genomic and functional pathway alterations observed in NKTCL that could provide a rationale for the development of innovative therapeutic strategies.

A 43-year-old male presented with a painless left testicular mass. The pathologic diagnosis of the radical orchiectomy specimen was peripheral T-cell lymphoma, unspecified (PTCL-u). According to the Ann Arbor staging system, his initial stage was III because of the right nasopharyngeal involvement. After first-line chemotherapy with four courses of the CHOP regimen and this was followed by involved-field radiotherapy, he achieved complete remission. Two months later, disease recurred to the left ciliary body of the left eye without evidence of involvement at other sites. Although the patient received intensive chemotherapy with autologous hematopoietic stem cell transplantation, he ultimately died of leptomeningeal seeding. Because both the central nervous system (CNS) and the orbit are sanctuary sites for chemotherapy, orbital infiltration of lymphoma should prompt physicians to evaluate involvement of the CNS and to consider performing prophylactic intrathecal chemotherapy as a treatment option.

Purpose

Diffuse large B-cell lymphoma (DLBCL) heterogeneity has prompted investigations for new biomarkers that can accurately predict survival. A previously reported 6-gene model combined with the international prognostic index (IPI) could predict patients’ outcome. However, even these predictors are not capable of unambiguously identifying outcome, suggesting that additional biomarkers might improve their predictive power.

Experimental Design

We studied expression of 11 microRNAs that had previously been reported to have variable expression in DLBCL tumors. We measured the expression of each microRNA by quantitative real-time polymerase-chain-reaction analyses in 176 samples from uniformly treated DLBCL patients and correlated the results to survival.

Results

In a univariate analysis, the expression of miR-18a correlated with overall survival (OS), whereas the expression of miR-181a and miR-222 correlated with progression-free survival (PFS). A multivariate Cox regression analysis including the IPI, the 6-gene model-derived Mortality Predictor Score and expression the of miR-18a, miR-181a, and miR-222, revealed that all variables were independent predictors of survival except the expression of miR-222 for OS and the expression of miR-18a for PFS.

Conclusion

The expression of specific miRNAs may be useful for DLBCL survival prediction and their role in the pathogenesis of this disease should be examined further.

B-cell lymphomas with concurrent IGH-BCL2 and MYC rearrangements, also known as “double-hit” lymphomas (DHL), are rare neoplasms characterized by highly aggressive clinical behavior, complex karyotypes, and a spectrum of pathological features overlapping with Burkitt lymphoma (BL), diffuse large B-cell lymphoma (DLBCL) and B-lymphoblastic lymphoma/leukemia (B-LBL). The clinical and pathological spectrum of this rare entity, including comparison to other high-grade B-cell neoplasms, has not been well defined. We conducted a retrospective analysis of clinical and pathologic features of 20 cases of DHL seen at our institution during a 5-year period. In addition, we performed case-control comparisons of DHL with BL and International Prognostic Index (IPI)-matched DLBCL. The 11 men and 9 women had a median age of 63.5 years (range 32-91). Six patients had a history of grade 1-2 follicular lymphoma (FL); review of the prior biopsy specimens in 2 of 5 cases revealed blastoid morphology. Eighteen patients had Ann Arbor stage 3 or 4 disease and all had elevated serum lactate dehydrogenase (LDH) levels at presentation. Extranodal disease was present in 17/20 (85%), bone marrow involvement in 10/17 (59%) and central nervous system (CNS) disease in 5/11 (45%). Nineteen patients were treated with combination chemotherapy, of whom 18 received rituximab and 14 received CNS-directed therapy. Fourteen patients (70%) died within 8 months of diagnosis. Median overall survival in the DHL group (4.5 months) was inferior to both BL (p=0.002) and IPI-matched DLBCL (p=0.04) control patients. Twelve DHL cases (60%) were classified as B-cell lymphoma, unclassifiable, with features intermediate between DLBCL and BL, 7 cases (35%) as DLBCL, not otherwise specified, and 1 case as B-LBL. Distinguishing features from BL included expression of Bcl2 (p<0.0001), Mum1/IRF4 (p=0.006), Ki-67 <95% (p<0.0001), and absence of EBV-EBER (p=0.006). DHL commonly contained the t(8;22) rather than the t(8;14) seen in most BL controls (p=0.001), and exhibited a higher number of chromosomal aberrations (p=0.0009). DHL is a high-grade B-cell neoplasm with a poor prognosis, resistance to multi-agent chemotherapy, and clinical and pathological features distinct from other high-grade B-cell neoplasms. Familiarity with the morphologic and immunophenotypic spectrum of DHL is important in directing testing to detect concurrent IGH-BCL2 and MYC rearrangements when a karyotype is unavailable. The aggressive clinical behavior and combination of genetic abnormalities seen in these cases may warrant categorization as a separate entity in future classifications and call for novel therapeutic approaches.

Oncogenes involved in recurrent chromosomal translocations serve as diagnostic markers and therapeutic targets in hematopoietic tumors. In contrast to myeloid and B-cell neoplasms, translocations in peripheral T-cell lymphomas (PTCLs) are poorly understood. Here, we identified recurrent translocations involving the multiple myeloma oncogene-1/interferon regulatory factor-4 (IRF4) locus in PTCLs. IRF4 translocations exist in myeloma and some B-cell lymphomas, but have not been reported previously in PTCLs. We studied 169 PTCLs using fluorescence in situ hybridization and identified 12 cases with IRF4 translocations. Two cases with t(6;14)(p25;q11.2) had translocations between IRF4 and the T-cell receptor-alpha (TCRA) locus. Both were cytotoxic PTCLs, unspecified (PTCL-Us) involving bone marrow and skin. Eight of the remaining ten cases were cutaneous ALCLs without TCRA rearrangements (57% of cutaneous ALCLs tested). These findings identified IRF4 translocations as a novel recurrent genetic abnormality in PTCLs. Cytotoxic PTCL-Us involving bone marrow and skin and containing IRF4/TCRA translocations might represent a distinct clinicopathologic entity. Translocations involving IRF4 but not TCRA appear to occur predominantly in cutaneous ALCLs. Detecting these translocations may be useful in lymphoma diagnosis. Further, due to its involvement in translocations, MUM1/IRF4 protein may play an important biologic role in some PTCLs, and might represent a possible therapeutic target.

Background: The incidence and risk factors of central nervous system (CNS) involvement in peripheral T-cell lymphomas (PTCLs) are still unclear.

Patients and methods: We analyzed 228 patients with PTCLs, excluding cases of extranodal natural killer/T-cell lymphoma and primary cutaneous T-cell lymphoma, by retrospectively collecting the clinical features and outcomes of the patients.

Results: Twenty events (8.77%, 20/228) of CNS involvement were observed during a median follow-up period of 13.9 months (range 0.03–159.43). Based on univariate analysis, elevated serum lactate dehydrogenase (LDH) level [P = 0.019, relative risk (RR) 5.904, 95% confidence interval (CI) 1.334–26.123] and involvement of the paranasal sinus (P = 0.032, RR 3.137, 95% CI 1.105–8.908) adversely affect CNS involvement. In multivariate analysis, both were independently poor prognostic factors for CNS relapse [elevated LDH level: P = 0.011, hazard ratio (HR) 6.716, 95% CI 1.548–29.131; involvement of the paranasal sinus: P = 0.008, HR 3.784, 95% CI 1.420–10.083]. The survival duration of patients with CNS involvement was significantly shorter than that of the patients without CNS involvement (P = 0.009), with median overall survival of 7.60 months (95% CI of 4.92–10.28) versus 27.43 months (95% CI of 0.00–57.38), respectively.

Conclusions: Elevated LDH level and involvement of the paranasal sinus are two risk factors for CNS involvement in patients with PTCLs. Considering the poor prognoses after CNS relapse, prophylaxis should be considered with the presence of any risk factor.

Peripheral T-cell lymphomas (PTCLs) constitute a group of heterogeneous diseases that are uncommon, representing, in Western countries, only approximately 10% of all non-Hodgkin lymphomas. They are typically associated with a poor prognosis compared to their B-cell counterparts and are much less well understood with respect to tumor biology, due to their rarity and biologic heterogeneity, and to the fact that characteristic cytogenetic abnormalities are few compared to B-cell lymphomas. While the outcome for patients with anaplastic large cell lymphoma (ALCL), particularly ALK-positive ALCL, is good, other types of peripheral T-cell lymphomas are associated with a poor prognosis even with aggressive anthracycline-based chemotherapy. In this respect, there is a need for new approaches in these diseases and this review focuses on and explores recent experience with novel therapies in PTCL.

Nasal NK/T cell lymphomas (NKTCL) are a subset of aggressive Epstein-Barr virus (EBV)-associated non-Hodgkin's lymphomas. The role of EBV in pathogenesis of NKTCL is not clear. Intriguingly, EBV encodes more than 40 microRNAs (miRNA) that are differentially expressed and largely conserved in lymphocryptoviruses. While miRNAs play a critical role in the pathogenesis of cancer, especially lymphomas, the expression and function of EBV transcribed miRNAs in NKTCL are not known. To examine the role of EBV miRNAs in NKTCL, we used microarray profiling and qRT-PCR to identify and validate expression of viral miRNAs in SNK6 and SNT16 cells, which are two independently derived NKTCL cell lines that maintain the type II EBV latency program. All EBV BART miRNAs except BHRF-derived miRNAs were expressed and some of these miRNAs are expressed at higher levels than in nasopharyngeal carcinomas. Modulating the expression of BART9 with antisense RNAs consistently reduced SNK6 and SNT16 proliferation, while antisense RNAs to BARTs-7 and -17-5p affected proliferation only in SNK6 cells. Furthermore, the EBV LMP-1 oncoprotein and transcript levels were repressed when an inhibitor of BART9 miRNA was transfected into SNK6 cells, and overexpression of BART9 miRNA increased LMP-1 protein and mRNA expression. Our data indicate that BART9 is involved in NKTCL proliferation, and one of its mechanisms of action appears to be regulating LMP-1 levels. Our findings may have direct application for improving NKTCL diagnosis and for developing possible novel treatment approaches for this tumor, for which current chemotherapeutic drugs have limited effectiveness.

Peripheral T/NK-cell lymphomas (PTCLs) are rare malignancies characterized by poor prognosis. So far, no standard therapy has been established, due to the lack of randomised studies. High-dose therapy and autologous stem cell transplantation (HDT-autoSCT) have shown good feasibility with low toxicity in retrospective studies. In relapsing and refractory PTCL several comparison analyses suggest similar efficacy for PTCL when compared with aggressive B-cell lymphoma. In the upfront setting, prospective data show promising results with a long-lasting overall survival in a relevant subset of patients. Achieving a complete remission at transplantation seems to be the most important prognostic factor. Allogeneic stem cell transplantation (alloSCT) has been investigated only as salvage treatment. Especially when using reduced intensity conditioning regimen, eligible patients seem to benefit from this approach. To define the role for upfront stem cell transplantation a randomised trial by the German High-Grade Non-Hodgkin Lymphoma Study Group comparing HDT-autoSCT and alloSCT will be initiated this year.

Peripheral T-cell lymphoma, not otherwise specified (PTCL, NOS) with genomic aberrations has been shown to resemble lymphoma-type adult T-cell leukemia/lymphoma (ATLL) in terms of its genomic aberration patterns, histopathology, and prognosis. We have shown recently that a majority of patients with acute-type ATLL have multiple subclones that were likely produced in lymph nodes. In this study, we analyzed whether PTCL, NOS with genomic aberrations also has multiple subclones as found in ATLL by means of high-resolution oligo-array comparative genomic hybridization (CGH). Thirteen cases of PTCL, NOS were available for 44K high-resolution array CGH analysis. The results showed that 11 (84.6%) of the 13 cases had a log2 ratio imbalance, suggesting that multiple subclones exist in PTCL, NOS with genomic aberrations. In order to analyze the association between multiple subclones and prognosis, we used previous bacterial-artificial chromosome (BAC) array analyses for 29 cases and found that the existence of multiple subclones was associated with a poor prognosis (P = 0.0279).