Peripheral T-cell lymphoma--not otherwise specified.

Peripheral T-cell lymphoma, not otherwise specified (PTCL-NOS) does correspond to a heterogeneous group of nodal and extranodal mature T-cell lymphomas, with a low prevalence in Western countries. PTCL-NOS accounts for about 25% of all PTCL, which represent over 15% of all lymphomas. In the lymph node, PTCL-NOS shows paracortical or diffuse infiltrates with effacement of the normal architecture, with a broad cytological spectrum and a frequently observed inflammatory background. Some morphological variants include: lymphoepithelioid or Lennert's type, T-zone, and follicular. PTCL-NOS is characterized by an aberrant T-cell phenotype, with frequent loss of CD5 and CD7. A CD4+/CD8- phenotype predominates in nodal cases. CD4/CD8 +/+ or -/- is at times seen, as is CD8, CD56 and cytotoxic granule expression. Ki-67 rate is typically high. TCR β-chain is usually expressed; TCR genes are most often clonally rearranged. PTCL-NOS typically occurs in adults (median age 55-60 years), with a higher prevalence in males. It presents more often as disseminated disease, occasionally with eosinophilia, pruritis or hemophagocytic syndrome. Patients often have B symptoms, generalized lymphadenopathy, bone marrow infiltration, and extranodal involvement, with high or high-intermediate IPI score in 50-70% of cases. Prognosis is poor, with a 5-year OS of 20-30%. Some variables, like ST2(L), CXCR5, CXCR3, EBV infection, cytotoxic granule expression, high proliferative index, NF-κB expression, were proposed as prognostic indicators, but the IPI score, and its variant called PIT, remains the most effective prognostic factor. Patients with PTCL-NOS should be treated with anthracycline-containing chemotherapy, followed by radiotherapy in cases of stage I-II disease. This strategy is associated with an overall response rate higher than 60%, but the 5-year overall survival is only 20-30%. Upfront high-dose chemotherapy supported by autologous or allogeneic SCT is an investigational approach, with a 4-year overall survival of about 40%. Patients with chemosensitive relapse respond favorably to high-dose chemotherapy and ASCT, with long-term survival rates of 35-45%. Graft-versus-lymphoma effect following allogeneic SCT has been observed; and reduced intensity conditioning emerges as an attractive strategy for frail patients. Most patients with PTCL-NOS are enrolled in prospective trials to explore new approaches, and new agents, like gemcitabine, alemtuzumab and pralatrexate, are being investigated.

Savage KJ ，Ferreri AJ ，Zinzani PL ，Pileri SA ... -  《-》

Anaplastic large cell lymphoma, ALK-negative.

Anaplastic large cell lymphoma (ALCL), anaplastic lymphoma kinase (ALK)-negative (ALCL-ALK-) is a provisional entity in the WHO 2008 Classification that represents 2-3% of NHL and 12% of T-cell NHL. No particular risk factor has been clearly identified for ALCL, but a recent study showed an odds ratio of 18 for ALCL associated with breast implants. Usually, the architecture of involved organs is eroded by solid, cohesive sheets of neoplastic cells, with peripheral T-cell lymphoma-not otherwise specified (PTCL-NOS) and classical Hodgkin lymphoma being the main differential diagnoses. In this regard, staining for PAX5 and CD30 is useful. Translocations involving ALK are absent, TCR genes are clonally rearranged. CGH and GEP studies suggest a tendency of ALCL-ALK- to differ both from PTCL-NOS and from ALCL-ALK+. Patients with ALCL-ALK- are usually adults with a median age of 54-61 years, and a male-to-female ratio of 0.9. At presentation, ALCL-ALK- is often in III-IV stage, with B symptoms, high International Prognostic Index score, high lactate dehydrogenase serum levels, and an aggressive course. ALCL-ALK- presents with lymph node involvement in ∼50% of cases; extranodal spread (20%) is less common. Staging work-up for ALCL-ALK- is similar to that routinely used for nodal NHL. Overall prognosis is poor, with a 5-year OS of 30-49%, which is significantly worse when compared to OS reported in patients with ALCL-ALK+ (5-year: 70-86%). Patients with systemic ALCL exhibit a significantly better survival compared with patients with PTCL-NOS, with a 5-year OS of 51% and 32%, respectively. Age, PIT scoring system, β2-microglobulin, and bone marrow infiltration are the main prognostic factors. The expression of proteins involved in the regulation of apoptosis (caspase 3, Bcl-2, PI9) and of CD56 is related to clinical outcome. ALCL-ALK- is generally responsive to doxorubicin-containing chemotherapy, but relapses are frequent. CHOP is the most commonly used regimen to treat systemic ALCL with complete remission rates of 56%, and a 10-year DFS of 28%. Encouraging results have been reported with more intensive chemotherapy regimens. The addition of etoposide improved outcome. Alemtuxumab-CHOP regimen was associated with excellent remission rate but increased toxicity. The role of high-dose chemotherapy supported by ASCT has not been investigated in a trial of exclusively ALCL patients. When used in first remission, it was associated with a 5-year PFS of 64%. High-dose chemotherapy with ASCT is the standard therapeutic option for patients with relapsed or refractory disease. The role of allogeneic transplantation in patients with relapsed/refractory ALCL remains to be defined but there are data to support the contention that a graft-versus-lymphoma effect does exist. Myeloablative conditioning has been associated with 5-year PFS and OS of 40% and 41%, respectively, but a 5-year TRM of 33% was reported. Allo-SCT can be an option for relapsed/refractory ALCL in younger patients, preferably in the setting of a clinical trial. Pralatrexate, anti-CD30 monoclonal antibodies, brentuximab vedotin (SGN-35) in particular, (131)I-anti-CD45 radioantibody, yttrium-anti-CD25 radioimmunoconjugates, histone deacetylase inhibitors, bortezomib, gemcitabine, vorinostat, lenalidomide, and their combinations represent the most appealing chemotherapy and/or targeted agents to be investigated in future trials.

Ferreri AJ ，Govi S ，Pileri SA ，Savage KJ ... -  《-》

Lymphoblastic lymphoma.

Lymphoblastic lymphoma (LBL) is a neoplasm of immature B cells committed to the B-(B-LBL) or T-cell lineage (T-LBL) that accounts for approximately 2% of all lymphomas. From a histopathological point of view, blasts may be encountered in tissue biopsy and/or bone marrow (BM). In tissue sections, LBL is generally characterized by a diffuse or, as in lymph nodes and less commonly, paracortical pattern. Although histological features are usually sufficient to distinguish lymphoblastic from mature B- or T-cell neoplasms, a differential diagnosis with blastoid variant of mantle cell lymphoma, Burkitt lymphoma or myeloid leukemia may arise in some cases. Of greater importance is the characterization of immunophenotype by flow cytometry. In B-LBL, tumour cells are virtually always positive for B cell markers CD19, CD79a and CD22. They are positive for CD10, CD 24, PAX5, and TdT in most cases, while the expression of CD20 and the lineage independent stem cell antigen CD34 is variable and CD45 may be absent. Surface immunoglobulin is usually absent. In T-LBL, neoplastic cells are usually TdT positive and variably express CD1a, CD2, CD3, CD4, CD5, CD7 and CD8. The only reliable lineage-specific is surface CD3. Most B-LBL have clonal rearrangements of the Ig heavy chain or less frequently of light chain genes. T-cell receptor γ or β chain gene rearrangements may be seen in a significant number of cases, but rearrangements are not helpful for lineage assignment. LBL occurs more commonly in children than in adults, mostly in males. Although 80% of precursor B-cell neoplasms present as acute leukemias, with BM and peripheral blood (PB) involvement, a small proportion present with a mass lesion and have <25% blasts in the BM. Unlike precursor T-LBL, mediastinal masses and involvement of BM are rare, but lymph nodes and extranodal sites are more frequently involved. T-LBL patients, compared to those with B-LBL, show younger age, a higher rate of mediastinal tumours or BM involvement. Patients are usually males in their teens to twenties and present with lymphadenopathy in cervical, supraclavicular and axillary regions, or with a mediastinal mass. In most patients the mediastinal mass is anterior, bulky, and associated with pleural effusions, superior vena cava syndrome, tracheal obstruction, and pericardial effusions. They frequently present with advanced disease, B symptoms and elevated serum LDH levels. Abdominal involvement (liver and spleen) is unusual. LBL is highly aggressive, but frequently curable with current therapy. The prognosis in all age groups has dramatically improved with the use of intensive ALL-type chemotherapy regimes, with a disease-free survival of 73-90% in children and 45-72% in adults. Intensive intrathecal chemotherapy prophylaxis is required to reduce the CNS relapse incidence, while the role of prophylactic cranial irradiation is unclear. Consolidation mediastinal irradiation may decrease mediastinal relapse. Patients with adverse prognostic features should be considered for high-dose chemotherapy and SCT. Autologous SCT has been shown to produce similar good results as chemotherapy alone, and allogeneic SCT is likely to be a more appropriate option for patients who are beyond first remission or with more advanced disease.

Cortelazzo S ，Ponzoni M ，Ferreri AJ ，Hoelzer D ... -  《-》

Epstein-Barr virus-positive nodal peripheral T cell lymphomas: clinicopathologic and gene expression profiling study.

Epstein-Barr virus-positive peripheral T cell lymphoma, not otherwise specified (EBV+ PTCL-NOS), in which virtually all neoplastic T cells harbor EBV, is a very rare disease with poor prognosis. To analyze the clinicopathologic characteristics and gene expression profile, we retrospectively collected six cases of EBV+ PTCL-NOS with no known primary immunodeficiency. The patients were 5 men and 1 woman, their age ranging from 48 years to 88 years (median 61.5 years). Lymphadenopathy was the most common presentation. Four patients had underlying disease, including HBV carrier, HCV infection, diabetes mellitus, and prostate cancer. All patients showed fatal clinical course in spite of chemotherapy. Histopathologically, monotonous infiltration of atypical lymphocytes of small to medium size was shown in four patients and medium to large tumor cells in two patients. Five patients showed CD4-/CD8+/bF-1+ phenotype with TIA-1 expression. In gene expression analysis using mRNA microarray, genes differentially expressed in EBV+ PTCL-NOS compared to normal reactive lymph nodes included 1515 genes (Mann-Whitney U-test p<0.05, folder change ≥4 times). Enriched functional annotation terms by DAVID were mostly related to immune response, defense response, cell-to-cell signaling, and membrane signaling. Especially, the genes involved in B cell differentiation or activation were mostly down-regulated, and T cell activation was mostly suppressed by down-regulation of activation genes and up-regulation of regulatory genes. Genes associated with cytotoxic activity were mostly up-regulated. Based on its peculiar clinical, histopathologic, and gene expression findings in EBV+ PTCL-NOS, we suggest EBV+ PTCL-NOS as a distinct disease entity from PTCL-NOS. In this study, the finding that most significantly enriched the functional term was immune response, suggesting a specific relation between EBV infection and alteration of immune response in the patients with EBV+ PTCL-NOS.

Ha SY ，Sung J ，Ju H ，Karube K ，Kim SJ ，Kim WS ，Seto M ，Ko YH ... -  《-》

Nodal cytotoxic molecule (CM)-positive Epstein-Barr virus (EBV)-associated peripheral T cell lymphoma (PTCL): a clinicopathological study of 26 cases.

The clinicopathological distinctiveness of nodal cytotoxic molecule (CM)-positive Epstein-Barr virus (EBV)-associated peripheral T cell lymphoma (PTCL) remains to be clarified. We investigated 26 patients with this lymphoma compared to nodal CM(+) EBV(-) PTCL (n = 39) and extranasal natural killer/T cell lymphoma of nasal type (ENKTL, n = 44). Nodal CM(+) EBV(+) PTCL patients were more likely to have B symptoms (P = 0.019) and hepatic involvement (P = 0.026) than nodal CM(+) EBV(-) PTCL patients. The former also had more Stage III/IV disease (P = 0.025) but much less cutaneous involvement (P < 0.001) than ENKTL patients at diagnosis. This nodal EBV(+) lymphoma possessed a distinctive immunophenotype of high CD8(+), CD56(-) pattern with an aggressive clinical course (median, 6.6 months). Thrombocytopenia was present in 11 (50%) patients and found to be the strongest prognostic indicator (P = 0.001) in this nodal EBV(+) group. For all nodal CM(+) PTCL cases CD5 negativity, but not EBV positivity, was the significant adverse prognostic factor (P < 0.002) in a multivariate analysis, independent of prognostic index for PTCL (PIT) or International Prognostic Index (IPI) scores. Nodal CM(+) EBV(+) PTCL constitutes a unique group of lymphomas distinct from ENKTL. The data provide support for our assertion that nodal CM(+) PTCL should be distinguished in the 2008 WHO category of PTCL, not otherwise specified.

Kato S ，Takahashi E ，Asano N ，Tanaka T ，Megahed N ，Kinoshita T ，Nakamura S ... -  《-》