Clinicopathological diagnosis of Lennert lymphoma: a case report and review of the literature.

BACKGROUND: Lennert lymphoma (LL) is a variant of peripheral T-cell lymphoma, not otherwise specified (PTCL, NOS), also known as a lymphoepithelioid variant of PTCL. Because of the rarity and lack of clear-cut diagnostic criteria, LL is susceptible tomisdiagnosis. Although previously diagnosed with LL might be reclassified and evaluated with the advent of of molecular and/or genetic findings, cytomorphology and immunohistochemistry are still the key to give rise to correct diagnosis. CASE PRESENTATION: We report a case of a patient who was diagnosed as LL based on cytomorphology and immunohistochemistry. Routine stain (Hematoxlin and Eosin-H&E) revealed tumor cells were mainly small to medium-sized CD4(+) T cells, the CD8 +/TIA-1 + cytotoxic cells were less minority, no expressions of follicle helper T cell markers (CD10, BCL6, PD1, CXCL13, ICOS) or CD21(+) hyperplastic FDC network, or proliferation of high edndothelial venules were noted; however, numerous epithelioid histiocytes are noted in the background and scattered EBV(+) cells were also present. The patient was achieved complete remission after six courses of chemotherapy with cyclophosphamide, epirubicin, vincristine, etoposide, and prednisone regimen. She was followed for 5 years without recurrence or progression. CONCLUSIONS: Classic LL is not difficult to diagnose by cytomorphology and immunohistochemistry, and the mutation profiles can be helpful to distinguish LL from other lymphomas.

Response to Azacytidine in a Patient With Refractory Peripheral T-cell Lymphoma With TET2 Mutation.

Peripheral T-cell lymphomas (PTCLs) are an aggressive form of non-Hodgkin lymphomas. PTCLs have multiple subtypes, with PTCL not otherwise specified (PTCL-NOS) being the most common. This subtype usually has a high rate of relapse. Making an accurate diagnosis requires molecular genetic analyses, histopathological examination, and immunophenotyping. Treatment for PTCL traditionally starts with the CHOP regimen (cyclophosphamide, doxorubicin, vincristine, and prednisone). We present a case of a patient with PTCL-NOS who progressed despite multiple treatment regimens, including both traditional and novel therapeutic agents, and finally achieved good results with azacytidine, selected based on a TET2 mutation. This case proposes future research into Azacytidine's efficacy in this patient population and further exploration of the broader utility of epigenetic therapies in PTCL.

Incidence trends for common subtypes of T-cell lymphoma in Taiwan and the United States from 2008-2020.

The incidence of T-cell lymphoma (TCL) has been continually increasing in Taiwan and the United States (US) in recent years. This epidemiological study using population-based registry data aimed to determine the incidence patterns of common subtypes of TCL in Taiwan from 2008-2020 and compare them with those in the US and the Asian/Pacific Islander (API) population. Subtypes included angioimmunoblastic T-cell lymphoma (AITL); extranodal NK/T-cell lymphoma, nasal or other type (ENKTL); peripheral T-cell lymphoma, not otherwise specified (PTCL-NOS); and anaplastic large cell lymphoma (ALCL). The total number of patients newly diagnosed with TCL during 2008-2020 was 4477, 3171, and 48,889 in Taiwan, API, and the US, respectively. Except the incidence rate of AITL in Taiwan, the incidence rates of these common TCL subtypes showed downward trends in all studied populations. There was also a significant increase in the relative frequency of AITL among TCL in Taiwan, with an annual percent change of 4.44 (p < 0.001), from 8.44% in 2002 to 20.63% in 2020. The rapid development of diagnostics may be the main factor contributing to this rise in incidence.

Challenges in nodal peripheral T-cell lymphomas: from biological advances to clinical applicability.

T cell lymphomas are a heterogenous group with varying biological and clinical features that tend to have poor outcomes with a few exceptions. They account for 10-15% of all non-Hodgkin lymphomas (NHL), and 20% of aggressive NHL. There has been little change in the overall prognosis of T cell lymphomas over the last 2 decades. Most subtypes carry an inferior prognosis when compared to the B cell lymphomas, with a 5-year OS of 30%. Gene expression profiling and other molecular techniques has enabled a deeper understanding of these differences in the various subtypes as reflected in the latest 5th WHO and ICC classification of T cell lymphomas. It is becoming increasingly clear that therapeutic approaches that target specific cellular pathways are needed to improve the clinical outcomes of T cell lymphomas. This review will focus on nodal T cell lymphomas and describe novel treatments and their applicability to the various subtypes.

PTCL, NOS: An update on classification, risk-stratification, and treatment.

The peripheral T-cell lymphomas (PTCL) are relatively rare, heterogeneous, and therapeutically challenging. While significant therapeutic gains and improved understanding of disease pathogenesis have been realized for selected PTCL subtypes, the most common PTCL in North America remains "not otherwise specified (NOS)" and is an unmet need. However, improved understanding of the genetic landscape and ontogeny for the PTCL subtypes currently classified as PTCL, NOS have been realized, and have significant therapeutic implications, which will be reviewed here.

Non-Hodgkin lymphoma treatment in middle-income countries in Latin America: perspective of the Latin American Study Group of Lymphoproliferative Disorders [Grupo de Estudio de Linfoproliferativos de Latino América (GELL)].

INTRODUCTION: Non-Hodgkin lymphomas (NHL) are the most frequently recognized entities among lymphoproliferative syndromes and rank fifth among neoplasms not associated with gender. There is scarce information on the clinical characteristics of the most frequent NHL, and no data on treatment regimens and their outcomes in Latin America. Although many factors affect a patient's possibilities of receiving treatment, the annual income per person/country is pivotal in Latin America. AIM: We present the clinical characteristics, risk groups, and treatment regimens of the three most frequent lymphoma subtypes in Latin America [diffuse large B-cell lymphoma (DLBCL), follicular lymphoma (FL), and peripheral T-cell lymphoma (PTCL)], based on the data collected by the largest study group of lymphoproliferative diseases in Latin America: The Latin American Study Group of Lymphoproliferative Disease [Grupo de Estudio de Linfoproliferativos de Latino America (GELL)]. OUTCOMES: The most frequent treatment regimen for B-cell lymphomas is immunochemotherapy (R-CHOP ≥70%), and CHOP for PTCL. Survival is similar to that reported by industrialized nations. We have no solid data on the results of treatment with salvage regimens nor stem cell transplantation in refractory/ relapsed NHL. CONCLUSION: In Latin America, the same treatment regimens are used as in highly developed countries, although we lack the necessary technology to apply CAR T-cell therapies or a network of trials sponsored by the pharmaceutical industry.

Management of Peripheral T-cell Lymphomas and the Role of Transplant.

PURPOSE OF REVIEW: Here, we review the management of peripheral T-cell lymphoma, particularly focusing on the role of autologous and allogeneic stem cell transplant. RECENT FINDINGS: Peripheral T-cell lymphomas are a rare subset of non-Hodgkin's lymphomas that are treated with curative intent. While therapy has been based on other aggressive lymphoid malignancies, outcomes are generally poorer than B-cell lymphomas with 5-year overall and progression-free survival of 30-40% and 20-30%, respectively. In effort to improve outcomes, transplant has been used in both the frontline and salvage settings. Although not studied in randomized studies, consolidation with autologous stem cell transplant in first remission has been associated with an approximate 5-year overall survival of 50-60% and 5-year progression-free survival of 40-45%. Unfortunately, most patients relapse, and, in this setting, allogeneic transplant remains the only curative option for those who are transplant-eligible. Multiple series have now shown that 3-year overall survival with allogeneic transplant is approximately 60%. However, outcomes with transplant are associated with disease control at the time of transplant. In contrast to B-cell malignancies, treatment decisions for peripheral T-cell lymphomas are supported mostly by phase II studies, retrospective series, and expert opinion. For patients with peripheral T-cell lymphoma able to achieve sufficient disease control, autologous stem cell transplantation in first remission and allogeneic stem cell transplantation in relapsed disease offer modest benefit over chemotherapy alone.

Pathological and Molecular Features of Nodal Peripheral T-Cell Lymphomas.

Peripheral T-cell lymphomas (PTCLs) are uncommon neoplasms derived from mature T cells or NK cells. PTCLs comprise numerous disease entities, with over 30 distinct entities listed in the latest WHO classification. They predominantly affect adults and elderly people and usually exhibit an aggressive clinical course with poor prognosis. According to their presentation, PTCLs can be divided into nodal, extranodal or cutaneous, and leukemic types. The most frequent primary sites of PTCLs are lymph nodes, with over half of cases showing nodal presentation. Nodal PTCLs include ALK-positive and ALK-negative anaplastic large cell lymphoma; nodal T-cell lymphoma with T follicular helper cell origin; and PTCL, not otherwise specified. Adult T-cell leukemia/lymphoma also frequently affects lymph nodes. Recent pathological and molecular findings in nodal PTCLs have profoundly advanced the identification of tumor signatures and the refinement of the classification. Therefore, the therapies and pathological diagnosis of nodal PTCLs are continually evolving. This paper aims to provide a summary and update of the pathological and molecular features of nodal PTCLs, which will be helpful for diagnostic practice.

Epigenetic Aberrations and Targets in Peripheral T-Cell Lymphoma.

Peripheral T cell lymphomas (PTCL) comprise a diverse group of aggressive T-cell and NK-cell lymphomas with many subtypes sharing same treatment algorithms despite having different pathobiology and responses to treatment. The molecular advances made in discovery of genetic mutations that disrupt epigenetic modulation in some subtypes of PTCL such as angioimmunoblastic T cell lymphoma and PTCL-not otherwise specified (NOS) may explain the poor outcomes and unsatisfactory responses to frontline line CHOP and CHOP-like therapy seen in this group of lymphomas. In this article, we address the main genetic mutations such as IDH2, TET2 and DNMT3A seen in PTCL and that disrupt the epigenetic modulation pathways, focusing on acetylation, deacetylation and methylation. Since therapeutic agents that target the disrupted epigenetic modulation pathways in PTCL may change treatment landscape in the near future, we will highlight the ones approved for treatment of refractory and/or relapsed PTCL and also the pivotal regimens being evaluated in clinical trials for treatment of frontline and refractory relapsed disease. We stress the importance of determining whether there is an association between the discussed genetic mutations and responses to the highlighted therapeutic agents such that treatments could be better tailored in patients with this kind of lymphoma with unmet needs.

Diagnostic and prognostic implications of tumor expression of the GATA-3 gene in nodal peripheral T-cell lymphoma (nPTCL): Retrospective data from a Latin American cohort.

BACKGROUND: Nodal peripheral T-cell lymphomas (nPTCL) encompass a heterogeneous group of mature and aggressive lymphoid malignancies, including peripheral T-cell lymphoma, not otherwise specified (PTCL, NOS), angioimmunoblastic T-cell lymphoma (AITL) and anaplastic large cell lymphoma (ALCL) ALK-positive and ALK-negative. Their differential diagnosis and prognosis are an issue in clinical practice. Accurate biomarkers to define the different subtypes of nPTCL and to stratify their prognosis are essential to improve their treatment approach. The aim of this study was to test the prognostic impact of GATA-3 gene expression, and its capability to discriminate the different subtypes of nPTCL. PATIENTS AND METHODS: We retrospectively assessed GATA-3 gene expression by quantitative real time PCR (qRT-PCR) from neoplastic biopsies in Formalin-Fixed Paraffin-Embedded samples (FFPE) of 80 patients with nPTCL that were admitted in a single cancer treatment center from 2000 to 2017. RESULTS: Median age was 49 years-old (IqR 34-59), 43/80 (53.7%) were male. Median follow-up was 1.72 years, 36.3% were classified as PTCL, NOS, 31.2% as ALK-negative ALCL, 21.2% as ALK-positive ALCL and 11.3% as AITL. The majority of cases had advanced stage cancer (III/IV). Two-year estimated overall survival (OS) and progression-free survival (PFS) were 52.2% and 39.5%, respectively. The median GATA-3 gene expression level was 0.49 (range 0 - 7.07) in all cohort, with 0.11 for ALK-positive ALCL, 0.46 for ALK-negative ALCL, 0.86 for PTCL, NOS and 0.67 for AITL. The difference of GATA-3 gene expression among distinct variants of nPTCL was statistically significant (p < 0.001). GATA-3 gene expression levels ≥ 0.71 discriminate PTCL, NOS from ALK-negative ALCL and AITL with sensitivity of 62.0% and specificity of 80.3%. GATA-3 gene expression level ≥ median was associated with poor 2-year OS for PTCL, NOS (46.7% versus 21.4%, p = 0.04) and ALK-negative ALCL (85.7% versus 54.5%, p = 0.04). In multivariate analysis, GATA-3 expression ≥ median was an independent factor associated with poor OS in nPTCL (HR: 2.34, 95% CI: 1.12-4.39, p = 0.041). CONCLUSION: GATA-3 gene overexpression may be an important biomarker associated with poor prognosis in PTCL, NOS and ALK-negative ALCL. Moreover, it may also discriminate different subtypes of nPTCL. Further studies with larger series of patients should confirm our findings.

A Case Report of Double Positive Peripheral T Cell Lymphoma­ Not Otherwise Specified in A Young Pregnant Female.

Peripheral T-cell lymphoma (PTCL) comprises 5-20% of all non-Hodgkin lymphomas (NHL). These all have different morphological patterns, phenotypes, and clinical presentations making it a diverse group of lymphomas. PTCL, not otherwise specified (PTCL-NOS), is a subtype considered to have a poor prognosis and a low overall survival rate of only about 30-40%. We report a case of primary cutaneous PTCL-NOS presenting in a young pregnant female with multiple progressive, tender, and necrosed nodules all over her body for 3 months. Her skin biopsy findings led us to suspect malignancy, and via immunohistochemistry (IHC), her diagnosis was confirmed. Cutaneous lymphoma is a dangerous albeit rare entity and should be kept in mind when the commoner differentials have been ruled out.

Cost-effectiveness of brentuximab vedotin plus chemotherapy for previously untreated CD30-positive peripheral T-cell lymphoma in Canada.

AIMS: To support reimbursement requests in Canada, we evaluated the cost-effectiveness of brentuximab vedotin (Adcetris) in combination with cyclophosphamide, doxorubicin, and prednisone (A + CHP) compared with cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) as frontline treatment for CD30-expressing peripheral T-cell lymphomas (PTCLs) using results from the ECHELON-2 clinical trial. The PTCL subtypes included were systemic anaplastic large cell lymphoma (sALCL), PTCL-not otherwise specified (PTCL-NOS), and angioimmunoblastic T-cell lymphoma (AITL). MATERIALS AND METHODS: A partitioned survival model consisting of three health states (progression-free survival [PFS], post-progression survival [PPS], and death) was constructed from the perspective of the Canadian publicly funded healthcare system over a lifetime horizon. Efficacy, safety, and health-related quality-of-life (HRQoL) data were obtained from ECHELON-2. Medical resource use and costs were derived from Canadian literature and standard sources. Incremental cost-effectiveness ratios (ICERs) per life-years (LYs) and quality-adjusted life-years (QALYs) gained were calculated. Sensitivity analyses were performed to account for uncertainty in key parameters. All costs are reported in Canadian dollars. RESULTS: A + CHP, when compared with CHOP, was associated with an estimated mean gain of 2.90 LYs and 2.38 QALYs and a mean incremental cost of $76,491. The ICER for A + CHP compared with CHOP was estimated at $26,340 per LY gained and $32,177 per QALY gained. In sensitivity analyses, the ICERs remained below $60,000 per QALY gained. Time horizon, patient starting age, and discount rate affected the results, as the ICER was driven by long-term survival gains observed with A + CHP compared with CHOP. LIMITATIONS: Real-world downstream treatments (such as stem cell transplantation) may differ from the treatment protocol followed in the ECHELON-2 trial. CONCLUSIONS: A + CHP compared with CHOP provides a cost-effective treatment option with improved clinical outcomes that are clinically relevant and a comparable safety profile for adults with previously untreated CD30-expressing sALCL, PTCL-NOS, or AITL in Canada.

Coexistence of T-Large Granular Lymphocyte Leukemia and Peripheral T Cell Lymphoma-NOS with Indolent Behavior.

T-cell lymphomas and leukemias are highly heterogeneous groups of rare disorders. We report a case of a 68-year-old man patient who developed two different T-cell neoplasms (Large Granular Lymphocyte Leukemia [LGLL] in 2018 and Peripheral T-cell non-Hodgkin lymphoma not otherwise specified [PTCL-NOS] in 2019) with a previous diagnosis of B-cell marginal zone lymphoma in 2010, treated with two lines of chemo-immunotherapy. The coexistence of these different T-cell neoplasms is rarely reported in the literature. Moreover, it is usually described as an LGLL transformation into PTCL-NOS; differently from these examples, herein, the simultaneous conditions appear to be driven by different T-cell clones. Furthermore, the PTCL-NOS had quite unusual behavior, with good disease control without intensive treatment. Because of these features, it could belong to a subgroup of indolent PTCL-NOS, not yet described in the WHO classification of T-cell neoplasms, which could benefit from less aggressive treatment.

Peripheral T-Cell Lymphoma, Not Otherwise Specified - a case report and short literature review.

Peripheral T-cell lymphoma, not otherwise specified (PTCL-NOS) is the most common subgroup of peripheral T-cell lymphomas (PTCL), and constitutes a diagnosis of exclusion. At presentation, most patients exhibit B symptoms and generalized lymphadenopathy, with or without concomitant extra-nodal involvement. We present a case of a man admitted to the hospital with B symptoms, generalized lymphadenopathy and a pruritic exanthema. Laboratory workup reveled persistent eosinophilia and malignant hypercalcemia. The excisional lymph node biopsy diagnosed PTCL-NOS, and the skin biopsy demonstrated a lichenoid dermatitis, compatible with the presumptive clinical diagnosis of a drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome. The patient was treated with topical betamethasone with good overall response, and initiated the first cycle of chemotherapy before discharge. This case report describes a PTCL-NOS with a concomitant non-lymphoproliferative disease, the challenging diagnostic workup of the two diseases and reinforces the most important features of the lymphoproliferative neoplasm.

[Genetic alterations in new category of Peripheral T-cell lymphoma, not otherwise specified].

Peripheral T-cell lymphomas (PTCLs) are mature T-cell and natural killer (NK) cell neoplasms with poor prognosis and no available standard treatment. The 2016 revision of the World Health Organization classification of hematological malignancies recognized a new group of nodal T-cell lymphoma with T follicular helper cell phenotype due to the presence of a group of PTCLs, not otherwise specified. This new subgroup of tumors showed clinical and molecular similarities with angioimmunoblastic T-cell lymphoma (AITL). AITL patients have mutations in the Vav guanine nucleotide exchange factor-1 (VAV1) gene. We established a transgenic mouse model harboring VAV1 gene mutation. These mice developed tumors that mimic human T-lymphoblastic lymphoma and the newly proposed PTCL-GATA3 subtype. To develop personalized treatment strategies by analyzing subgroup-specific mouse models, our study supports the establishment of PTCL subgroups based on genetic alterations or gene expression profiles.

The role of pre-treatment and mid-treatment 18F-FDG PET/CT imaging in evaluating prognosis of peripheral T-cell lymphoma-not otherwise specified (PTCL-NOS).

BACKGROUND: It has been reported the prognostic value of MTV in predicting the disease prognosis of peripheral T-cell lymphoma (PTCL) through pre-treatment PET/CT imaging. However, these are limited data on pretreatment evaluation and prognosis assessments of peripheral T-cell lymphoma-not otherwise specified (PTCL-NOS). This study aimed to determine the prognostic values of pre-treatment and mid-treatment total metabolic tumor volume (MTV), total lesion glycolysis (TLG), and Deauville 5-Point Scale (D-5PS) in accessing the prognosis of PTCL-NOS. METHODS: A retrospective analysis was conducted in 31 patients with pathologically diagnosed PTCL-NOS. These patients have undergone positron emission PET/CT scanning before and during chemotherapy. Follow-ups were also done to investigate the 2-year progression-free survival (PFS) and Overall Survival (OS) of these patients. During [Formula: see text]F-fluorodeoxyglucose ([Formula: see text]F-FDG) PET/CT scans, the MTV and TLG were recorded. Meanwhile, [Formula: see text]MTV and [Formula: see text]TLG were calculated. Furthermore, the receiver operating characteristic (ROC) curve was employed to classify and to define the threshold values. On the other hand, the mid-chemotherapy assessment and staging of these 31 patients were done by utilizing D-5PS. Subsequently, based on the D-5PS scores obtained, these patients were grouped into two categories: a group of patients with a score of <4 and another group with [Formula: see text]4 points. For these two groups of patients, the survival analysis was done by Kaplan-Meier analysis and a multivariate COX regression model. Moreover, Pearson's chi-square test ([Formula: see text] test) and Spearman rank correlation coefficient were used to comparing the collected data, respectively. RESULTS: During the 2-year follow-up period, 15 out of the 31 patients experienced disease progression. The optimal threshold values for both baseline MTV and TLG were 158.16 cm[Formula: see text] and 677.40.Additionally, the difference in 2-year PFS between the progressive and non-progressive groups was statistically significant ([Formula: see text], [Formula: see text]; [Formula: see text], [Formula: see text]), significant between-group difference was detected for MTV and for TLG ([Formula: see text], [Formula: see text]; [Formula: see text], [Formula: see text]). On the other hand, when these patients were classified into two groups according to the mid-chemotherapy Deauville score of <4 and [Formula: see text]4, the statistical difference of 2-year PFS between these two groups was significant, too ([Formula: see text], [Formula: see text]),but there is no significant between-group difference in OS ([Formula: see text], [Formula: see text]). COX analysis revealed that D-5PS are the independent factors influencing PFS, while MTV is the independent influencing factor of OS. CONCLUSION: The baseline total MTV obtained by PET/CT scanning, and D-5PS are crucial prognostic factors in evaluating the prognosis of PTCL-NOS.

Primary Central Nervous System Lymphomas: A Diagnostic Overview of Key Histomorphologic, Immunophenotypic, and Genetic Features.

Primary central nervous system lymphoma (PCNSL) is a rare form of extranodal non-Hodgkin lymphoma that primarily arises in the brain, spinal cord, leptomeninges, and vitreoretinal compartment of the eye. The term is sometimes used interchangeably with primary central nervous system diffuse large B-cell lymphoma (PCNS DLBCL) because DLBCL comprises a great majority (90-95%) of PCNSL. Although rare, other types of lymphomas can be seen in the central nervous system (CNS), and familiarity with these entities will help their recognition and further workup in order to establish the diagnosis. The latter is especially important in the case of PCNSL where procurement of diagnostic specimen is often challenging and yields scant tissue. In this review, we will discuss the most common types of primary lymphomas that can be seen in the CNS with emphasis on the diagnostic histomorphologic, immunophenotypic, and molecular genetic features. The differential diagnostic approach to these cases and potential pitfalls will also be discussed.

[Present and future perspective of the treatment of peripheral T-cell lymphoma].

Peripheral T-cell lymphoma (PTCL) is a kind of aggressive lymphoma with a poorer prognosis than mature B-cell lymphoma. Presently, the standard of care for PTCL is considered to be the CHOP regimen, yet clinical outcomes remain insufficient. The intensification of chemotherapy and front-line high-dose chemotherapy have been examined as potential therapeutic strategies by several clinical trials. A recent double-blind phase III trial examining the effects of brentuximab vedotin (BV) when incorporated into front-line chemotherapy involved CD30-positive PTCL cases and found that a progression-free survival benefit was observed by adding BV to the therapeutic regimen, especially in the context of anaplastic large-cell lymphoma. Other molecular target agents, i.e., antibodies and small molecules, have also actively been developed. Investigators should conduct further clinical trials to establish the next standard treatment by the optimization of classic chemotherapeutic agents and molecular target agents.

Genomics of Peripheral T-Cell Lymphoma and Its Implications for Personalized Medicine.

Peripheral T-cell lymphoma (PTCL) is a rare, heterogenous group of mature T-cell neoplasms that comprise 10-15% of non-Hodgkin lymphoma cases in the United States. All subtypes of PTCL, except for ALK+ anaplastic T-cell lymphoma, are associated with poor prognosis, with median overall survival (OS) rates of 1-3 years. The diagnosis of PTCL is mainly based on clinical presentation, morphologic features, and immunophenotypes. Recent advances in genome sequencing and gene expression profiling have given new insights into the pathogenesis and molecular biology of PTCL. An enhanced understanding of its genomic landscape holds the promise of refining the diagnosis, prognosis, and management of PTCL. In this review, we examine recently discovered genetic abnormalities identified by molecular profiling in 3 of the most common types of PTCL: RHOA G17V and epigenetic regulator mutations in angioimmunoblastic T-cell lymphoma, ALK expression and JAK/STAT3 pathway mutations in anaplastic T-cell lymphoma, and T-follicular helper phenotype and GATA3/TBX21 expression in PTCL-not otherwise specified. We also discuss the implications of these abnormalities for clinical practice, new/potential targeted therapies, and the role of personalized medicine in the management of PTCL.