Epstein-Barr virus-associated B-cell lymphoproliferative disorders in angloimmunoblastic T-cell lymphoma and peripheral T-cell lymphoma, unspecified

Composite diffuse large B-cell lymphoma and peripheral T-cell lymphoma: a case report with two-year follow-up and literature review

Composite lymphoma is an uncommon type of lymphoid malignancy, and those consisting of concurrent diffuse large B-cell lymphoma (DLBCL) and peripheral T-cell lymphoma, not otherwise specified (PTCL-NOS) in the same organ are rare. Here, we report a case of a 75-year-old male patient admitted to our emergency department with intestinal obstruction presenting with abdominal pain and vomiting. He underwent partial resection of the small intestine under general anesthesia, and subsequent histopathology confirmed the mass to be composite DLBCL and PTCL-NOS. The patient received chemotherapy with a rituximab-based regimen and achieved complete remission (CR). However, the recurrent disease presented with obstruction again ten months after treatment. He refused a second surgery, but salvage treatment was not effective. The patient survived for 20 months after diagnosis. In addition, we did a literature review to understand the clinical features, pathology, treatment, and prognosis of this type of composite lymphoma.

Extranodal natural killer/T-cell lymphoma coexisting with peripheral T-cell lymphoma, not otherwise specified

We report the case of a 52-year-old male who presented to our hospital with cervical lymphadenopathy. Lymph node biopsy revealed small atypical lymphoid cells positive for CD3 and CD5 and negative for CD56 and Epstein-Barr virus (EBV)-encoded small RNA (EBER) by in situ hybridization. CD4-positive cells and CD8-positive cells were mixed in almost equal numbers. He was diagnosed with peripheral T-cell lymphoma, not otherwise specified (PTCL-NOS). The patient received one cycle of chemotherapy, resulting in severe sepsis. While undergoing treatment in the intensive care unit with an antimicrobial agent and prednisone, ascitic fluid appeared. Abdominal aspiration revealed neutrophil-predominant ascites and microbiological studies revealed Candida albicans. However, ascites did not improve when treated with micafungin for Candida peritonitis. Abdominal aspiration was re-performed, and atypical lymphoid cells that were positive for CD3 and CD56 were detected. EBV-DNA levels in whole blood were significantly elevated. Atypical lymphoid cells were positive for EBER by in situ hybridization and Southern blot analysis showed EBV terminal repeat monoclonal patterns. Bone marrow examination revealed the same atypical lymphoid cells. Therefore, the patient was diagnosed with extranodal natural killer/T-cell lymphoma (ENKTL) with bone marrow involvement 3 months after the diagnosis of PTCL-NOS. Complications associated with PTCL-NOS and ENKTL are rare. PTCL-NOS, chemotherapy, sepsis, and prednisone might have led to immunodeficiency and reactivation of EBV, which might be one of the pathophysiologies for developing ENKTL. Our case indicates that measuring EBV-DNA in the blood is a simple and prompt examination to detect complications of EBV-associated lymphoma.

Advances in the pathogenesis and therapeutic strategies of angioimmunoblastic T-cell lymphoma

Angioimmunoblastic T-cell lymphoma (AITL) is an aggressive subtype of peripheral T-cell lymphomas with its cell origin determined to be follicular helper T-cells. AITL is characterized by a prominent tumor microenvironment involving dysregulation of immune cells, signaling pathways, and extracellular matrix. Significant progress has been made in the molecular pathophysiology of AITL, including genetic mutations, immune metabolism, hematopoietic-derived microenvironment, and non-hematopoietic microenvironment cells. Early diagnosis, detection of severe complications, and timely effective treatment are crucial for managing AITL. Treatment typically involves various combination chemotherapies, but the prognosis is often poor, and relapsed and refractory AITL remains challenging, necessitating improved treatment strategies. Therefore, this article provides an overview of the pathogenesis and latest advances in the treatment of AITL, with a focus on potential therapeutic targets, novel treatment strategies, and emerging immunotherapeutic approaches.

Composite Angioimmunoblastic T-Cell Lymphoma and Diffuse Large B-Cell Lymphoma Presenting with Distributive Shock

Diffuse large B-cell lymphoma (DLBCL) and angioimmunoblastic T-cell lymphoma (AITL) are two subtypes of non-Hodgkin lymphoma (NHL). The simultaneous occurrence of DLBCL and AITL in a composite lymphoma is very rare, and there are no established treatment regimens. We present the case of an 85-year-old male admitted to the intensive care unit with distributive shock, lymphocytosis, and lymphadenopathy, who was subsequently diagnosed with composite AITL and DLBCL, and treated with brentuximab vedotin (BV) and rituximab. To our knowledge, this is the first case of composite lymphoma presenting with distributive shock and treated with BV and rituximab, with successful resolution of shock.

Composite B-cell and T-cell lymphomas: clinical, pathological, and molecular features of three cases and literature review

Composite lymphoma (CL) involving B-cell lymphoma and T-cell lymphoma is extremely rare. Herein, we report three such cases using immunohistochemistry, flow cytometry, and the next-generation sequencing (NGS) to identify the pathological and molecular characteristics of CL. In the first case, the patient was admitted to hospital for generalized pruritic maculopapular rash over the whole body. An excisional biopsy of the skin lesions showed T-cell lymphoma. At the same time, the staging bone marrow (BM) biopsy revealed a diffuse large B-cell lymphoma (DLBCL). After R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone) therapies, the patient produced a good response with substantial dissipation of the rashes and relief of skin. The other two patients were admitted to hospital due to lymphadenopathy and were diagnosed with DLBCL and follicular lymphoma (FL) after core needle biopsy of lymph nodes, BM biopsy, BM aspiration, and flow cytometry. Following R-CHOP and R-COP (rituximab, cyclophosphamide, vincristine, and prednisone) therapies, they achieved complete remission unconfirmed (CRu) and complete remission (CR). However, one or two years later, they suffered a relapse of lymphadenopathy. The shocking fact was that re-biopsy of lymphadenopathy revealed peripheral T-cell lymphoma (PTCL) and angioimmunoblastic T-cell lymphoma (AITL). NGS findings identified DNA methyltransferase 3a (DNMT3a), isocitrate dehydrogenase 2 (IDH2), Ras homolog gene family, member A (RHOA), splicing factor 3B subunit 1 (SF3B1), and tumor protein p53 (TP53) mutations. After immunochemotherapy, these patients achieved CRu and CR again. Nevertheless, they suffered a second relapse of T-cell lymphoma. Finally, they died due to progression of disease. We found that the occurrence of CL is associated with Epstein-Barr virus infection and DNMT3a, IDH2, and TP53 mutations, and the prognosis of the disease is closely related to the T-cell lymphoma components.

A novel conditioning regimen of chidamide, cladribine, gemcitabine, and busulfan in the autologous stem cell transplantation of aggressive T-cell lymphoma

Background

The prognosis of patients with peripheral T-cell (PTCL) or lymphoblastic T-cell lymphoma (T-LBL) remains poor under current conditioning regimens before receiving autologous stem cell transplantation (ASCT).

Methods

Patients with PTCL or T-LBL were enrolled to receive ASCT using the conditioning regimen of chidamide, cladribine, gemcitabine, and busulfan (ChiCGB). Positron emission tomography-computed tomography (PET/CT) was used to evaluate the response to ASCT. Overall survival (OS) and progression-free survival (PFS) were employed to assess the patient outcome, and adverse events were used to assess the regimen’s safety. The survival curve was estimated via the Kaplan-Meier method.

Results

Twenty-five PTCL and 11 T-LBL patients were recruited. The median time to neutrophile and platelet engraftments was 10 days (8–13 days) and 13 days (9–31 days), respectively. The 3-year PFS and OS were 81.3 ± 7.2% and 88.5 ± 5.4% for all patients; 92.0 ± 5.4% and 81.2 ± 8.8% for PTCL patients; and both 81.8 ± 11.6% for T-LBL patients, respectively. The 3-year PFS and OS were both 92.9 ± 4.9% for patients with complete response (CR) but 50.0 ± 17.7% and 75.0 ± 15.3% for patients with non-CR, respectively. Infection was the most common non-hematological toxicity, and all toxicities were mild and controllable.

Conclusions

ChiCGB was a potentially effective and well-tolerated conditioning regimen to improve the prognosis of patients with aggressive T-cell lymphoma. Future randomized controlled trials are needed to assess ChiCGB as a conditioning regimen for ASCT.

Pathologic and molecular insights in nodal T-follicular helper cell lymphomas

T-follicular helper (TFH) cells are one of the T-cell subsets with a critical role in the regulation of germinal center (GC) reactions. TFH cells contribute to the positive selection of GC B-cells and promote plasma cell differentiation and antibody production. TFH cells express a unique phenotype characterized by PD-1^hi, ICOS^hi, CD40L^hi, CD95^hi, CTLA^hi, CCR7^lo, and CXCR5^hi . Three main subtypes of nodal TFH lymphomas have been described: 1) angioimmunoblastic-type, 2) follicular-type, and 3) not otherwise specified (NOS). The diagnosis of these neoplasms can be challenging, and it is rendered based on a combination of clinical, laboratory, histopathologic, immunophenotypic, and molecular findings. The markers most frequently used to identify a TFH immunophenotype in paraffin-embedded tissue sections include PD-1, CXCL13, CXCR5, ICOS, BCL6, and CD10. These neoplasms feature a characteristic and similar, but not identical, mutational landscape with mutations in epigenetic modifiers (TET2, DNMT3A, IDH2), RHOA, and T-cell receptor signaling genes. Here, we briefly review the biology of TFH cells and present a summary of the current pathologic, molecular, and genetic features of nodal lymphomas. We want to highlight the importance of performing a consistent panel of TFH immunostains and mutational studies in TCLs to identify TFH lymphomas.

Angioimmunoblastic T-cell lymphoma induced hemophagocytic lymphohistiocytosis and disseminated intravascular coagulopathy: A case report

BACKGROUND

Angioimmunoblastic T-cell lymphoma (AITL) is a subtype of peripheral T-cell lymphoma, with heterogenous clinical manifestations and poor prognosis. Here, we report a case of AITL induced hemophagocytic lymphohistiocytosis (HLH) and disseminated intravascular coagulopathy (DIC).

CASE SUMMARY

An 83-year-old man presented with fever and purpura of both lower limbs for one month. Groin lymph node puncture and flow cytometry indicated a diagnosis of AITL. Bone marrow examination and other laboratory related indexes indicated DIC and HLH. The patient rapidly succumbed to gastrointestinal bleeding and septic shock.

CONCLUSION

This is the first reported case of AITL induced HLH and DIC. AITL is more aggressive in older adults. In addition to male gender, mediastinal lymphadenopathy, anaemia, and sustained high level of neutrophil-to-lymphocyte ratio may indicate a greater risk of death. Early diagnosis, early detection of severe complications, and prompt and effective treatment are vital.

IDH2 and TET2 mutations synergize to modulate T Follicular Helper cell functional interaction with the AITL microenvironment

Angioimmunoblastic T cell lymphoma (AITL) is a peripheral T cell lymphoma that originates from T follicular helper (Tfh) cells and exhibits a prominent tumor microenvironment (TME). IDH2 and TET2 mutations co-occur frequently in AITL, but their contribution to tumorigenesis is poorly understood. We developed an AITL mouse model that is driven by Idh2 and Tet2 mutations. Malignant Tfh cells display aberrant transcriptomic and epigenetic programs that impair TCR signaling. Neoplastic Tfh cells bearing combined Idh2 and Tet2 mutations show altered cross-talk with germinal center B cells that promotes B cell clonal expansion while decreasing Fas-FasL interaction and reducing B cell apoptosis. The plasma cell count and angiogenesis are also increased in the Idh2-mutated tumors, implying a major relationship between Idh2 mutation and the characteristic AITL TME. Our mouse model recapitulates several features of human IDH2-mutated AITL and provides a rationale for exploring therapeutic targeting of Tfh-TME cross-talk for AITL patients.

How I Diagnose EBV-Positive B- and T-Cell Lymphoproliferative Disorders

OBJECTIVES

Epstein-Barr virus (EBV)-associated lymphoproliferative disorders (LPDs) encompass a group of well-defined entities of B-, T-, and natural killer (NK)-cell derivation. The diagnosis of these disorders is challenging because of clinical and morphologic features that may overlap with other benign and malignant EBV+ lymphoproliferations. This review describes our approach to the diagnosis of EBV-associated LPDs.

METHODS

Two cases are presented that illustrate how we diagnose EBV-associated LPDs. The first case represents a systemic EBV+ T-cell lymphoma of childhood and the second case an EBV+ mucocutaneous ulcer. The clinicopathologic features that help distinguish these entities from biological and morphologic mimickers are emphasized.

RESULTS

The accurate diagnosis of EBV-associated LPDs requires the incorporation of histologic and immunophenotypic features, the assessment of the EBV latency program, and, most important, complete clinical findings. Clonality analysis is not helpful in distinguishing benign from malignant EBV+ LPDs.

CONCLUSIONS

The better understanding of EBV-associated LPDs has resulted in the recognition of well-defined entities of B-, T-, and NK-cell derivation and consequently improvement of their treatment with curative intent. It is critical to distinguish benign from malignant EBV+ LPDs to avoid overtreatment.

Primary cutaneous peripheral T-cell lymphomas with a T-follicular helper phenotype: an integrative clinical, pathological and molecular case series study

BACKGROUND

Primary cutaneous peripheral T-cell lymphomas with a T-follicular helper phenotype (pcTFH-PTCL) are poorly characterized, and often compared to, but not corresponding with, mycosis fungoides (MF), Sézary syndrome, primary cutaneous CD4⁺ lymphoproliferative disorder, and skin manifestations of angioimmunoblastic T-cell lymphomas (AITL).

OBJECTIVES

We describe the clinicopathological features of pcTFH-PTCL in this original series of 23 patients, and also characterize these cases molecularly.

METHODS

Clinical and histopathological data of the selected patients were reviewed. Patient biopsy samples were also analysed by targeted next-generation sequencing.

RESULTS

All patients (15 men, eight women; median age 66 years) presented with skin lesions, without systemic disease. Most were stage T3b, with nodular (n = 16), papular (n = 6) or plaque (atypical for MF, n = 1) lesions. Three (13%) developed systemic disease and died of lymphoma. Nine (39%) patients received more than one line of chemotherapy. Histologically, the lymphomas were CD4⁺ T-cell proliferations, usually dense and located in the deep dermis (n = 14, 61%), with the expression of at least two TFH markers (CD10, CXCL13, PD1, ICOS, BCL6), including three markers in 16 cases (70%). They were associated with a variable proportion of B cells. Eight patients were diagnosed with an associated B-cell lymphoproliferative disorder (LPD) on biopsy, including Epstein-Barr virus (EBV)-positive diffuse large B-cell lymphoma (n = 3), EBV⁺ LPD (n = 1) and monotypic plasma cell LPD (n = 4). Targeted sequencing showed four patients to have a mutated TET2-RHOAG17V association (as frequently seen in AITL) and another a TET2/DNMT3A/PLCG1/SETD2 mutational profile. The latter patient, one with a TET2-RHOA association, and one with no detected mutations, developed systemic disease and died. Five other patients showed isolated mutations in TET2 (n = 1), PLCG1 (n = 2), SETD2 (n = 1) or STAT5B (n = 1).

CONCLUSIONS

Patients with pcTFH-PTCL have pathological and genetic features that overlap with those of systemic lymphoma of TFH derivation. Clinically, most remained confined to the skin, with only three patients showing systemic spread and death. Whether pcTFH-PTCL should be integrated as a new subgroup of TFH lymphomas in future classifications is still a matter of debate. What is already known about this topic? There is a group of cutaneous lymphomas that express T-follicular helper (TFH) markers that do not appear to correspond to existing World Health Organization diagnostic entities. These include mycosis fungoides, Sézary syndrome, or primary cutaneous CD4⁺ small/medium-sized T-cell lymphoproliferative disorder or cutaneous extensions of systemic peripheral T-cell lymphomas (PTCL) with TFH phenotype. What does this study add? This is the first large original series of patients with a diagnosis of primary cutaneous PTCL with a TFH phenotype (pcTFH-PTCL) to be molecularly characterized. pcTFH-PTCL may be a standalone group of cutaneous lymphomas with clinicopathological and molecular characteristics that overlap with those of systemic TFH lymphomas, such as angioimmunoblastic T-cell lymphoma, and does not belong to known diagnostic groups of cutaneous lymphoma. This has an impact on the treatment and follow-up of patients; the clinical behaviour needs to be better clarified in further studies to tailor patient management.

Lymphomas associated with Epstein-Barr virus infection in 2020: Results from a large, unselected case series in France

Background

Despite mounting evidence for a causal role in an increasing number of lymphoma subtypes, very few studies have systematically tested the entire spectrum of Hodgkin and non-Hodgkin lymphomas for the presence of Epstein-Barr virus (EBV). Here, we describe the prevalence of EBV in a large, unselected series of patients diagnosed with any type of lymphoma during 2020, in the pathology department of a single University Hospital in France.

Methods

A total of 756 lymphoma cases (89% new diagnoses and 11% relapses), were registered in the department between Jan 1 and Sept 30, 2020 and 616 were successfully tested for EBV presence in tumour cells by EBV-encoding RNA in-situ hybridisation, using double-blinded assessment and a scoring system designed in accordance with the current state of knowledge in the literature.

Findings

A strong association with EBV was described in 27/87 (31%) classic Hodgkin lymphomas, 12/223 (5%) diffuse large B-cell lymphomas, and 18/71 (25%) NK and T-cell lymphomas: 4 extranodal NK/T-cell lymphomas, nasal type, 14 angioimmunoblastic T-cell lymphomas (48%). In Hodgkin and NK and T-cell lymphomas, there was a statistically significant association between EBER positivity and relapse (p < 0·01). Among other subtypes, a potential association with EBV (≥10% stained cells) was found in 2/97 (2%) follicular lymphomas, both of grades 1-2, 1/19 (5%) chronic lymphocytic leukaemia (CLL), 1/9 lymphoplasmacytic lymphomas (11%), and 2/47 (4%) marginal zone lymphomas.

Interpretation

When applied to the distribution of lymphomas in France as described in the Lymphopath database, our data suggested that at least 8% of all combined Hodgkin and non-Hodgkin lymphomas are associated with EBV.

Funding

International Agency for Research on Cancer (IARC/WHO).

A Rare Case of BCL2-Positive Multiple Myeloma Complicated with Follicular Lymphoma

A 68-year-old woman presented with follicular lymphoma complicated by IgG kappa-positive multiple myeloma. In this case, both follicular lymphoma and plasma cells were positive for BCL2 by immunostaining. T-cell association in the FL and MM was also analyzed in this case. Some CD3-positive T-cells were found around the plasma cells. These cells were mainly CD8-positive T-cells and not CD4-positive T-cells. These results suggest that CD4-positive T-cells were not associated with the proliferation of the plasma cells in this case. Although the FL that developed was initially positive for BCL2 protein, this does not indicate that plasma cells were derived from FL cells because of the eventual complication that occurred in this case. Furthermore, in this case, rituximab and bendamustine were effective for FL. They were not effective for MM, however, demonstrating that additional treatment options are necessary for the simultaneous treatment of BCL2-positive MM with FL.

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.

Case Report: Immune Microenvironment and Mutation Features in a Patient With Epstein–Barr Virus Positive Large B-Cell Lymphoma Secondary to Angioimmunoblastic T-Cell Lymphoma

On rare occasions, secondary Epstein–Barr virus (EBV)-associated B-cell lymphoma can develop in patients with angioimmunoblastic T-cell lymphoma (AITL). Here, we describe the tumor microenvironment and mutation features of a patient with EBV + large B-cell lymphoma (LBCL) secondary to AITL. He was admitted to hospital due to a 1-year history of fever and enlarged right inguinal lymph nodes. A biopsy of the right inguinal lymph node demonstrated that numerous diffuse medium-sized atypical lymphocytes proliferated, together with increased extrafollicular follicular dendritic cell meshwork, and the lymphocytes expressed CD3, CD4, BCL6, CD10, PD-1, CXCL13, and Ki-67 (75%). Thus, a diagnosis of AITL was made. However, the disease progressed following treatment by CHOP regimen (cyclophosphamide, adriamycin, vincristine, and prednisone). Biopsy showed that most of the cells were positive for CD20 staining and IgH rearrangement. Analysis of 22 kinds of immune cells showed that the numbers of activated NK cells and activated memory T cells increased, while the T-follicular helper population decreased in the transformed sample. In addition, compared with the primary sample, RHOA (G17V) mutation was not detected, while JAK2 and TRIP12 gene mutations were detected in the transformed sample. Overall, we described the immune microenvironment and mutation features of a patient with EBV + LBCL secondary to AITL. This study will help us to understand the mechanisms by which AITL transforms to B-cell lymphoma.

Epstein-Barr Virus (EBV) Is Mostly Latent and Clonal in Angioimmunoblastic T Cell Lymphoma (AITL)

The Epstein-Barr virus (EBV) is associated with angioimmunoblastic T cell lymphoma (AITL), a peripheral T lymphoma of poor prognosis in at least 90% of cases. The role of EBV in this pathology is unknown. Using next-generation sequencing, we sequenced the entire EBV genome in biopsies from 18 patients with AITL, 16 patients with another EBV-associated lymphoma, and 2 controls. We chose an EBV target capture method, given the high specificity of this technique, followed by a second capture to increase sensitivity. We identified two main viral strains in AITL, one of them associated with the mutations BNRF1 S542N and BZLF1 A206S and with mutations in the EBNA-3 and LMP-2 genes. This strain was characterized in patients with short post-diagnosis survival. The main mutations found during AITL on the most mutated latency or tegument genes were identified and discussed. We showed that the virus was clonal in all the AITL samples, suggesting that it may be involved in this pathology. Additionally, EBV was latent in all the AITL samples; for one sample only, the virus was found to be latent and probably replicative, depending on the cells. These various elements support the role of EBV in AITL.

A preclinical model of peripheral T-cell lymphoma GATA3 reveals DNA damage response pathway vulnerability

Peripheral T-cell lymphoma (PTCL) represents a rare group of heterogeneous diseases in urgent need of effective treatments. A scarcity of disease-relevant preclinical models hinders research advances. Here, we isolated a novel mouse (m)PTCL by serially transplanting a lymphoma from a germinal center B-cell hyperplasia model (Cγ1-Cre Blimp1fl/fl ) through immune-competent mice. Lymphoma cells were identified as clonal TCRβ+ T-helper cells expressing T-follicular helper markers. We also observed coincident B-cell activation and development of a de novo B-cell lymphoma in the model, reminiscent of B-cell activation/lymphomagenesis found in human PTCL. Molecular profiling linked the mPTCL to the high-risk "GATA3" subtype of PTCL, showing GATA3 and Th2 gene expression, PI3K/mTOR pathway enrichment, hyperactivated MYC, and genome instability. Exome sequencing identified a human-relevant oncogenic β-catenin mutation possibly involved in T-cell lymphomagenesis. Prolonged treatment responses were achieved in vivo by targeting ATR in the DNA damage response (DDR), a result corroborated in PTCL cell lines. This work provides mechanistic insight into the molecular and immunological drivers of T-cell lymphomagenesis and proposes DDR inhibition as an effective and readily translatable therapy in PTCL.

Epstein-Barr virus-positive mucocutaneous ulcer, plasmablastic type, associated with nodal CD4+ angioimmunoblastic T-cell lymphoma and generalised pruritus: a self-limiting lymphoproliferative disorder resembling cutaneous plasmablastic lymphoma

A woman in her 80s reported of generalised pruritus, which was treated with phototherapy and steroid administration. Two months after onset, lymph node biopsy revealed CD4+ angioimmunoblastic T-cell lymphoma with systemic superficial nodal involvement. Intractable prurigo was judged as T-cell lymphoma related. After effective chemotherapy (7 months later), skin nodules appeared multifocally, including on the lip, thumb and lower leg. The biopsied infiltrative lesion on the right lower leg microscopically revealed subcutaneous growth of atypical plasmablasts with nearly 100% Ki-67 labelling and Epstein-Barr virus (EBV)-encoded small nuclear RNA positivity. Plasmablastic lymphoma (CD45/CD19/CD38/CD138/MUM1+, CD20/CD79a/PAX5-) was suspected. Immunoglobulin light-chain restriction and nuclear expression of c-myc protein were undetectable, and the ulcers were spontaneously epithelialised by the cessation of steroid administration. After 10 months, non-progressive prurigos persisted on the extremities, but without regrowth of nodal T-cell lymphoma and cutaneous lymphoproliferative lesion. Reactive nature of the EBV-induced mucocutaneous plasmablastic growth (EBV-positive mucocutaneous ulcer, plasmablastic type) is discussed.

Human Germinal Center-associated Lymphoma (HGAL) Is a Reliable Marker of Normal and Neoplastic Follicular Helper T Cells Including Angioimmunoblastic T-Cell Lymphoma

The diagnosis of angioimmunoblastic T-cell lymphoma (AITL) is complex and requires the demonstration of a T-follicular helper (TFH) phenotype. Immunophenotypic markers that detect the TFH phenotype are highly variable, thereby necessitating the use of 3 to 5 TFH markers to substantiate a TFH phenotype. We tested the utility of germinal center markers human germinal center-associated lymphoma (HGAL) and LIM-domain only 2 (LMO2) in detecting a TFH phenotype. We compared their staining to that of 6 TFH markers in current use, PD-1, ICOS, CXCL13, SAP, CD10, and BCL6, in a cohort of 23 AITL. Our results show that although both markers can detect a TFH phenotype, HGAL was superior to LMO2 in the percent of cells stained and the intensity of staining, 2 variables used to generate H-scores. Using H-scores as the metric, HGAL was most comparable to BCL6 among the currently used TFH markers and was more sensitive than CXCL13, SAP, CD10, and LMO2. PD-1 and ICOS emerged as the most robust of the 8 markers tested in this study in detecting a TFH phenotype. We conclude that HGAL is a reliable marker of TFH cells and can aid in the diagnosis of lymphomas of TFH derivation, particularly in the recognition of early patterns of AITL.

T-Cell Lymphomas, Version 2.2022, NCCN Clinical Practice Guidelines in Oncology

Peripheral T-cell lymphomas (PTCLs) are a heterogeneous group of lymphoproliferative disorders arising from mature T cells, accounting for about 10% of non-Hodgkin lymphomas. PTCL-not otherwise specified is the most common subtype, followed by angioimmunoblastic T-cell lymphoma, anaplastic large cell lymphoma, anaplastic lymphoma kinase-positive, anaplastic large cell lymphoma, anaplastic lymphoma kinase-negative, and enteropathy-associated T-cell lymphoma. This discussion section focuses on the diagnosis and treatment of PTCLs as outlined in the NCCN Guidelines for T-Cell Lymphomas.

Peripheral T cell lymphoma of the nasopharynx with expansion of EBV-positive B cells masquerading as an extranodal NK/T cell lymphoma, nasal type

Epstein-Barr virus-infected B cells are found at high frequency in peripheral T cell lymphoma. Herein, we report a case involving excessive EBV-positive B cells accompanying peripheral T cell lymphoma, not otherwise specified in the nasopharynx masquerading as nasopharyngeal extranodal NK/T cell lymphoma. A large number of Epstein-Barr virus-infected B cells infiltrate in between CD3-positive cytotoxic tumor T cells, as if EBV was infecting tumor T cells. After chemotherapy, the T cell lymphoma population decreased, but the B cell population expanded to form EBV-positive diffuse large B cell lymphoma in the tonsils and nasopharynx. At the follow-up, bone marrow biopsy exhibited infiltration of composite peripheral T cell lymphoma, not otherwise specified, and EBV-positive diffuse large B cell lymphoma. Although this condition is rare, the cell lineage of EBV-infected cells must be confirmed when diagnosing extranodal NK/T cell lymphoma to exclude the possibility of misdiagnosis by Epstein-Barr virus-infected B cells.

Angioimmunoblastic T-cell lymphoma diagnosed from pleural fluid by integration of morphologic, immunophenotypic, and molecular findings

An 88-year-old man with end-stage renal disease on hemodialysis presented with shortness of breath and was found to have lower extremity edema and bilateral pleural effusions on a chest X-ray. A therapeutic and diagnostic thoracentesis was performed, and cytologic examination revealed atypical mononuclear cells. Based on this, flow cytometry was performed on the pleural fluid, along with immunostains on the cellblock and a next-generation sequencing (NGS) panel. A definitive diagnosis of angioimmunoblastic T-cell lymphoma (AITL) was made based on demonstrating an atypical T follicular helper cell population expressing CD10, BCL6, CXCL13, CD200, CD57, and PD1, and detection of pathogenic variants in RHOA, IDH2, and TET2. This case represents the first reported case where a primary diagnosis of AITL was made on a body fluid specimen and highlights how immunophenotyping and NGS can provide a definitive diagnosis of AITL on a cytologic specimen.

How I Diagnose Angioimmunoblastic T-Cell Lymphoma

OBJECTIVES

Angioimmunoblastic T-cell lymphoma (AITL) is a subtype of peripheral T-cell lymphoma derived from T-follicular helper cells. For pathologists, diagnosing AITL may be challenging due to its wide clinical and histopathologic spectrum, which can mimic a variety of reactive and neoplastic processes.

METHODS

We summarize and discuss the clinicopathologic features of AITL, emphasizing diagnostic tools available to the practicing pathologist. Common diagnostic dilemmas are discussed.

RESULTS

AITL exhibits various histologic patterns and is often associated with a prominent microenvironment that can obscure the neoplastic cells. Atypical B-cell proliferations, which can take a number of forms, are common in AITL, and clonal B-cell expansion can be seen. The atypical B cells can closely resemble Hodgkin/Reed-Sternberg cells, leading to misdiagnosis as classic Hodgkin lymphoma. Molecular studies have revealed recurrent genetic alterations, which can aid in differential diagnosis, particularly in problematic cases.

CONCLUSIONS

Given the complex diagnostic challenges in AITL, an integrated approach, incorporating clinical, morphologic, immunophenotypic, and molecular findings, is helpful to reach an accurate diagnosis.

Management of Angioimmunoblastic T-Cell Lymphoma (AITL) and other T Follicular Helper Cell lymphomas (TFH PTCL)

Despite the remarkable improvements in the treatment and outcome of patients with aggressive B-cell lymphoma, the peripheral T-cell lymphomas (PTCL) continue to carry a poor prognosis with the presently available treatment options. The PTCL are very rare diseases that account for only 10,000 to 15,000 new cases per year in the United States. The World Health Organization's 2016 classification describes 29 distinct subtypes of PTCL, thus making these both rate and incredibly heterogenous. The 2 most common forms of PTCL, for example, peripheral T-cell lymphoma-not otherwise specified and angioimmunoblastic T-cell lymphoma , have an incidence of only 2500 and 1800 cases per year respectively, in the United States.

Phase I studies of darinaparsin in patients with relapsed or refractory peripheral T-cell lymphoma: a pooled analysis of two phase I studies conducted in Japan and Korea

OBJECTIVE

Two phase I studies of darinaparsin including Japanese and Korean patients with relapsed/refractory peripheral T-cell lymphoma were performed to evaluate its safety (primary purpose), efficacy and pharmacokinetic profile (ClinicalTrials.gov: NCT01435863 and NCT01689220).

METHODS

Patients received intravenous darinaparsin for 5 consecutive days at 200 mg/m2/day in 4-week cycles, 300 mg/m2/day in 4-week cycles or 300 mg/m2/day in 3-week cycles.

RESULTS

Seventeen Japanese and 6 Korean patients were enrolled and treated. Drug-related adverse events developed in 18 patients (78%). Dose-limiting toxicity, grade 3 hepatic dysfunction, was reported on Day 15 of cycle 1 in 1 Japanese patient who received 300 mg/m2/day. The most common drug-related, grade ≥ 3 adverse events were lymphopenia (9%), neutropenia (9%) and thrombocytopenia (9%). No deaths occurred. In 14 evaluable patients, 1 and 3 patients had complete response and partial response, respectively. The plasma concentration-time profiles of arsenic, a surrogate marker for darinaparsin, were similar between Japanese and Korean patients. No significant difference was found in its pharmacokinetic profile.

CONCLUSIONS

These data indicate the good tolerability and potential efficacy of darinaparsin in patients with relapsed/refractory peripheral T-cell lymphoma. Darinaparsin 300 mg/m2/day for 5 consecutive days in 3-week cycles is the recommended regimen for phase II study.

Comprehensive Epstein-Barr Virus Transcriptome by RNA-Sequencing in Angioimmunoblastic T Cell Lymphoma (AITL) and Other Lymphomas

The Epstein-Barr virus (EBV) is associated with angioimmunoblastic T cell lymphoma (AITL) in more than 80% of cases. Few studies have focused on this association and it is not clear now what role the virus plays in this pathology. We used next-generation sequencing (NGS) to study EBV transcriptome in 14 AITLs compared to 21 other lymphoma samples and 11 cell lines including 4 lymphoblastoid cell lines (LCLs). Viral transcripts were recovered using capture probes and sequencing was performed on Illumina. Bam-HI A rightward transcripts (BARTs) were the most latency transcripts expressed in AITLs, suggesting they may play a role in this pathology. Thus, BARTs, already described as highly expressed in carcinoma cells, are also very present in AITLs and other lymphomas. They were poorly expressed in cell lines other than LCLs. AITLs showed a latency IIc, with BNLF2a gene expression. For most AITLs, BCRF1, which encodes a homologous protein of human interleukin 10, vIL-10, was in addition expressed. This co-expression can contribute to immune escape and survival of infected cells. Considering these results, it can be assumed that EBV plays a pathogenic role in AITLs.

The utility and limitations of B- and T-cell gene rearrangement studies in evaluating lymphoproliferative disorders

A hallmark of lymphoid malignancies is the presence of a monoclonal lymphocyte population. Monoclonality of B- and T-cell populations can be established through immunoglobulin (IG) or T-cell receptor (TCR) gene rearrangement analysis, respectively. The biological rationale of IG and TCR gene rearrangement analysis is that due to the extensive combinatorial repertoire made possible by V(D)J recombination in lymphocytes, it is unlikely that any substantive lymphocyte population would share the same IG or TCR gene rearrangement pattern unless there is an underlying neoplastic or reactive origin. Modern IG and TCR gene rearrangement analysis is typically performed by polymerase chain reaction (PCR) using commercially available primer sets followed by gel capillary electrophoresis. This process is highly sensitive in the detection of nearly all lymphoid malignancies. Several pitfalls and limitations, both biological and technical, apply to IG/TCR gene rearrangement analysis, but these can be minimised with high quality controls, performance of assays in duplicate, and adherence to strict criteria for interpreting and reporting results. Next generation sequencing (NGS) will likely replace PCR based methods of IG/TCR gene rearrangement analysis but is not yet widespread due to the absence of standardised protocols and multicentre validation.

Sequential Complications of Hypercalcemia, Necrotizing Granulomatous Vasculitis, and Aplastic Anemia Occurring in One Patient with Angioimmunoblastic T-cell Lymphoma

In this case report of a patient with angioimmunoblastic T-cell lymphoma (AITL), we describe the occurrence of three sequential complications that have been reported uncommonly in this disease subtype. Firstly, the patient developed hypercalcemia due to elevated 1,25-didydroxyvitamin D. Although hypercalcemia in AITL is not rare (1-2% incidence), this case was unusual in that the complication developed when disease appeared stable and symptomatically, he was doing well otherwise. Hypercalcemia surprisingly resolved a few months later at a time when his disease appeared to be progressing. A year later, the patient presented with digital ischemia necessitating partial amputation of a finger. Pathological exam revealed granulomatous vasculitis of small and medium arterioles with infiltrating malignant T lymphocytes. Although skin manifestations are common in AITL, necrotizing granulomatous vasculitis with accompanying tumor cells leading to severe digital ischemia appears rare. Subsequently the patient developed profound pancytopenia with bone marrow confirming severe aplastic anemia. To our knowledge only one other case of aplastic anemia has been reported in a patient with AITL. We discuss the diagnostic and management considerations involved in this patient care and review similar reported cases.

New preclinical models for angioimmunoblastic T-cell lymphoma: filling the GAP

Mouse models are essential to study and comprehend normal and malignant hematopoiesis. The ideal preclinical model should mimic closely the human malignancy. This means that these mice should recapitulate the clinical behavior of the human diseases such as cancer and therapeutic responses with high reproducibility. In addition, the genetic mutational status, the cell phenotype, the microenvironment of the tumor and the time until tumor development occurs, should be mimicked in a preclinical model. This has been particularly challenging for human angioimmunoblastic lymphoma (AITL), one of the most prominent forms of peripheral T-cell lymphomas. A complex network of interactions between AITL tumor cells and the various cells of the tumor microenvironment has impeded the study of AITL pathogenesis in vitro. Very recently, new mouse models that recapitulate faithfully the major features of human AITL disease have been developed. Here, we provide a summary of the pathology, the transcriptional profile and genetic and immune-phenotypic features of human AITL. In addition, we give an overview of preclinical models that recapitulate more or less faithfully human AITL characteristics and pathology. These recently engineered mouse models were essential in the evaluation of novel therapeutic agents for possible treatment of AITL, a malignancy in urgent need of new treatment options.

T-cell and NK-cell lymphomas in the lung

While the lung is frequently involved by systemic lymphoma, primary pulmonary lymphoma accounts for less than 1% of all extranodal ymphomas. In particular, T-cell lymphoma is very rare in the lung, as a primary or secondary lesion. Patients with pulmonary T-cell lymphoma usually present with cough, dyspnea, pain, fever, recurrent infections, and hemoptysis. Typical radiologic features include pulmonary nodules, consolidation, solid pulmonary opacities, cystic changes, hilar adenopathy, and pleural effusions. Patients with these clinical and radiologic findings are frequently presumed to have pneumonia and initially treated with empirical antibiotics. Therefore, CT-guided needle biopsy, bronchoscopic examination, or even wedge biopsy should be considered when clinical symptoms show deterioration despite adequate antibiotic therapy. Precise pathologic diagnosis and molecular characterization are recommended in all cases, following the World Health Organization (WHO) classification. Principles of treatment typically vary with the different histologic types of T-cell lymphoma.

Alemtuzumab plus CHOP versus CHOP in elderly patients with peripheral T-cell lymphoma: the DSHNHL2006-1B/ACT-2 trial

PTCL patients exhibit poor survival with existing treatments. We investigated the efficacy of CHOP combined with alemtuzumab in 116 PTCL patients age 61-80 in an open-label, randomized phase 3 trial. Alemtuzumab was given on day 1, to a total of 360 mg in 21 patients, or 120 mg in 37. Hematotoxicity was increased with A-CHOP resulting in more grade ≥3 infections (40% versus 21%) and 4 versus 1 death due to infections, respectively. CR/CRu rate was 60% for A-CHOP and 43% for CHOP, and OR rate was 72% and 66%, respectively. Three-year-EFS, PFS and OS were 27% [15%-39%], 28% [15%-40%], and 37% ([23%-50%] for A-CHOP, and 24% [12%-35%], 29% [17%-41%], and 56% [44%-69%] for CHOP, respectively, showing no significant differences. Multivariate analyses, adjusted for strata and sex confirmed these results (hazard ratio HR_EFS: 0.7 ([95% CI: 0.5-1.1]; p = 0.094), HR_PFS: 0.8 ([95% CI: 0.5-1.2]; p = 0.271), HR_OS: 1.4 ([95% CI: 0.9-2.4]; p = 0.154). The IPI score was validated, and male sex (HR_EFS 2.5) and bulky disease (HR_EFS 2.2) were significant risk factors for EFS, PFS, and OS. Alemtuzumab added to CHOP increased response rates, but did not improve survival due to treatment-related toxicity.

Impact of treatment variability and clinicopathological characteristics on survival in patients with Epstein-Barr-Virus positive diffuse large B cell lymphoma

Patients with EBV-positive diffuse large B cell lymphoma not otherwise specified (EBV⁺ DLBCL (NOS)) recurrently present with advanced age and reduced performance status. They are therefore insufficiently represented in clinical trials and treatment is likely to differ. Here we assess clinicopathological characteristics, therapeutic variability and clinical outcome in the largest consecutively diagnosed EBV⁺ DLBCL (NOS) cohort published to date (n = 80; median age 70 years; range 19-90). Centralized and systematic haematopathological panel review was performed. By immunohistochemistry 60/80 patients were CD30-positive. Further, we identified nine EBV⁺ DLBCL (NOS) patients with associated or composite peripheral T cell lymphoma at diagnosis or relapse (preceded by clonal T cell populations within the initial DLBCL biopsy in 4/5 cases). Most patients (80%) were treated with R-CHOP-type therapy and 16 patients received none or less intensiveprotocols. Upon univariate analysis both R-CHOP-type therapy (OS: P < 0.0001; PFS: P = 0.0617) and negativity for CD30 (OS: P = 0.0002; PFS: P = 0.0002) showed a protective 66 effect, maintained upon multivariate analysis. In a propensity-score matched analysis with a cohort of non-EBV⁺ DLBCL (NOS) patients, balanced for all revised-international prognostic index factors, we found an EBV-association to hold no significant impact on progression-free and overall survival whilst exhibiting a trend favouring EBV-negativity (OS: P = 0.116; PFS: P = 0.269). Our findings provide insight into the clinical course of EBV⁺ DLBCL (NOS), highlight the ramifications of CD30-expression and underline the superior therapeutic efficacy of R-CHOP immunochemotherapy. Alternative therapies, incorporating tumour biology (e.g. CD30 directed therapies) need to be explored in EBV⁺ DLBCL (NOS) patients. Moreover our data advert to the close relationship between EBV⁺ DLBCL (NOS) and peripheral T cell lymphomas.

EBV status has prognostic implication among young patients with angioimmunoblastic T-cell lymphoma

Epstein‐Barr virus (EBV)‐positive B cells have been detected in 66%‐86% of patients with angioimmunoblastic T‐cell lymphoma (AITL). However, it remains controversial whether EBV status has an impact on the survival of patients with AITL. In this study, we aimed to reevaluate the impact of EBV on the clinicopathological characteristics of AITL. In particular, we focused on the impact of EBV in younger patients with AITL. In total, 270 cases of AITL were studied. Epstein‐Barr virus‐positive B cells were detected in 191 (71%) cases (EBER⁺ group). Among the patients who received anthracycline‐based therapy, the EBER status did not affect the overall survival (OS) or progression‐free survival (PFS). In the younger group of AITL (≤60 years), PFS was significantly worse in the EBER⁻ group compared to the EBER⁺ group (P = .0013). Furthermore, the multivariate analysis identified EBER‐negative status, thrombocytopenia, and elevated serum IgA level as significant adverse prognostic factors for PFS (P < .001, P < .001, and P = .002). Based on these findings, we constructed new prognostic model for the younger group, based on three adverse factors. We classified the patients into two risk groups: low risk (no or 1 adverse factor) and high risk (2 or 3 adverse factors). This new model for younger patients with AITL showed that both OS and PFS were significantly related to the level of risk (P < .0001). In summary, this study showed that, among younger patients with AITL, an EBER⁺ status significantly improved prognosis compared to an EBER⁻ status. Our new prognostic model should be applicable to younger patients with AITL.

Approach to nodal-based T-cell lymphomas

Peripheral T-cell lymphomas (PTCLs) represent a heterogeneous group of uncommon malignancies derived from mature T cells and usually characterised by an aggressive clinical course. Their clinical presentation, localisation and pattern of dissemination are highly variable, but the majority of cases present as nodal diseases. The recently revised classification of lymphomas has incorporated many new molecular genetic data derived from gene expression profiling and next generation sequencing studies, which refine the definition and diagnostic criteria of several entities. Nevertheless, the distinction of PTCL from various reactive conditions, and the diagnosis of PTCL subtypes remains notably challenging. Here, an updated summary of the clinicopathological and molecular features of the most common nodal-based PTCLs (angioimmunoblastic T-cell lymphoma and other nodal lymphomas derived from follicular T helper cells, anaplastic large cell lymphomas and peripheral T-cell lymphoma, not otherwise specified) is presented. Practical recommendations in the diagnostic approach to nodal T-cell lymphoproliferations are presented, including indications for the appropriate use and interpretation of ancillary studies. Finally, we discuss commonly encountered diagnostic problems, including pitfalls and mimics in the differential diagnosis with various reactive conditions, and the criteria that allow proper identification of distinct PTCL entities.

Limited Tissue Biopsies and Hematolymphoid Neoplasms

OBJECTIVES

Use of fine-needle aspiration/needle core biopsy (FNA/CNB) in evaluating hematolymphoid processes has been debated. We investigate its applicability in various clinicopathologic settings.

METHODS

We retrospectively analyzed 152 cases of FNA/CNB.

RESULTS

Of 152 FNA/CNBs, 124 (81.6%) resulted in diagnoses without excisional biopsies, while 28 required subsequent excisional biopsies. Of these, 43 FNA/CNBs performed for suspected lymphoma relapse demonstrated 95.4% diagnostic rate (41/43), which was significantly better than those without history of lymphoma (77/109, 71%; odds ratio [OR], 8.5; confidence interval, 1.9-37.4). Patients with immunodeficiency also showed a high rate of diagnosis by FNA/CNB (100%). When stratified by types of disease, diffuse large B-cell lymphoma/high-grade B-cell lymphoma demonstrated a higher success rate (92.7%) than small B-cell lymphoma (79.2%), though the difference was not statistically significant (OR, 3.3; P value = .07). A subsequent excisional biopsy was required in 28 cases, 23 of which resulted in diagnoses concordant with the FNA/CNB. Five cases showed diagnostic discordance, reflecting pitfalls of FNA/CNB in unusual cases with complex pathology.

CONCLUSIONS

FNA/CNB is practical in evaluating most hematolymphoid lesions, with high efficacy in recurrent disease and some primary neoplasms with homogeneous/ aggressive histology, or characteristic immunophenotype.

High-Throughput Sequence Analysis of Peripheral T-Cell Lymphomas Indicates Subtype-Specific Viral Gene Expression Patterns and Immune Cell Microenvironments

Certain peripheral T-cell lymphomas (PTCLs) have been associated with viral infection, particularly infection with Epstein-Barr virus (EBV). However, a comprehensive virome analysis across PTCLs has not previously been reported. Here we utilized published whole-transcriptome RNA sequencing (RNA-seq) data sets from seven different PTCL studies and new RNA-seq data from our laboratory to screen for virus association, to analyze viral gene expression, and to assess B- and T-cell receptor diversity paradigms across PTCL subtypes. In addition to identifying EBV in angioimmunoblastic T-cell lymphoma (AITL) and extranodal NK/T-cell lymphoma (ENKTL), two PTCL subtypes with well-established EBV associations, we also detected EBV in several cases of anaplastic large-cell lymphoma (ALCL), and we found evidence of infection by the oncogenic viruses Kaposi's sarcoma-associated herpesvirus and human T-cell leukemia virus type 1 in isolated PTCL cases. In AITLs, EBV gene expression analysis showed expression of immediate early, early, and late lytic genes, suggesting either low-level lytic gene expression or productive infection in a subset of EBV-infected B-lymphocyte stromal cells. Deconvolution of immune cell subpopulations demonstrated a greater B-cell signal in AITLs than in other PTCL subtypes, consistent with a larger role for B-cell support in the pathogenesis of AITL. Reconstructed T-cell receptor (TCR) and B-cell receptor (BCR) repertoires demonstrated increased BCR diversity in AITLs, consistent with a possible EBV-driven polyclonal response. These findings indicate potential alternative roles for EBV in PTCLs, in addition to the canonical oncogenic mechanisms associated with EBV latent infection. Our findings also suggest the involvement of other viruses in PTCL pathogenesis and demonstrate immunological alterations associated with these cancers.IMPORTANCE In this study, we utilized next-generation sequencing data from 7 different studies of peripheral T-cell lymphoma (PTCL) patient samples to globally assess viral associations, provide insights into the contributions of EBV gene expression to the tumor phenotype, and assess the unique roles of EBV in modulating the immune cell tumor microenvironment. These studies revealed potential roles for EBV replication genes in some PTCL subtypes, the possible role of additional human tumor viruses in rare cases of PTCLs, and a role for EBV in providing a unique immune microenvironmental niche in one subtype of PTCLs. Together, these studies provide new insights into the understudied role of tumor viruses in PTCLs.

A Case of Composite Lymphoma with Extranodal NK/T-cell Lymphoma, Nasal-type and Diffuse Large B-cell Lymphoma

Composite lymphoma (CL) is defined as the occurrence of two distinct types of lymphoma within the same patient. Most cases of CL involve Hodgkin and non-Hodgkin lymphomas or two distinct types of B-cell lymphomas; true CL is a composite B-cell and T-cell lymphoma, and is rare. We herein report a case involving concurrent extranodal NK/T-cell lymphoma, nasal-type and diffuse large B-cell lymphoma, which has not been previously reported. As the mechanisms and treatments of composite B-cell and T-cell lymphomas are unclear, further studies are required to improve the prognosis.

A case of AITL complicated by EBV-positive B cell and monoclonal plasma cell proliferation and effectively treated with lenalidomide

Angioimmunoblastic T-cell lymphoma (AITL) is a common subtype of peripheral T-cell lymphoma with an aggressive clinical course and poor prognosis after conventional chemotherapy, for which there is no current standard of care. We describe here an 87-year-old woman with AITL, whose clinical diagnosis was complicated by the presence of B immunoblasts positive for Epstein-Barr virus in the lymph nodes and monoclonal plasma cells in the bone marrow at initial presentation. Rebiopsy of the lymph node led to the correct diagnosis of AITL with concurrent smoldering plasma cell myeloma. She was treated with several courses of conventional chemotherapy, resulting in progressive disease, and then switched to the immunomodulatory drug lenalidomide, which used in Japan for the treatment of multiple myeloma. Lenalidomide was effective in controlling both AITL and plasma cell myeloma.

Epidemiology and Pathology of T- and NK-Cell Lymphomas

PURPOSE

This review will describe and update readers on the recent changes in the 2017 WHO classification regarding peripheral T-cell lymphomas.

RECENT FINDINGS

Signficant advances in molecular studies have resulted in revisions to the classification as well as introduction to provisional entities such as breast implant-associated ALCL and nodal PTCL with T-follicular helper phenotype.

SUMMARY

Major advances in molecular and gene expression profiling has expanded our knowledge of these rare and aggressive diseases.

Hemophagocytic lymphohistiocytosis presenting with annular erythema multiforme-like eruptions in a patient with angioimmunoblastic T cell lymphoma: A case report

Angioimmunoblastic T cell lymphoma (AITL)-associated hemophagocytic lymphohistiocytosis (HLH) rarely occurs with annular erythema multiforme-like rashes. The present case report describes a patient who was misdiagnosed with erythema multiforme at an early stage of the disease due to annular erythema multiforme-like eruptions. However, antihistamine treatment was ineffective. The patient progressed rapidly with high fever, hepatosplenomegaly and pharyngitis. The number of copies of Epstein-Barr virus DNA continuously increased. Accompanied by the swelling of lymph nodes, the blood cell count decreased. Further bone-marrow examination and biopsy of the lymph nodes were conducted. The patient was eventually diagnosed with AITL-associated HLH, and treated with etoposide together with cyclophosphamide, doxorubicin, vincristine and prednisolone. The patient was successfully treated with several courses of chemotherapy. In view of the fact that AITL-associated HLH with annular erythema multiforme-like rashes is relatively rare worldwide and is associated with a high mortality rate, the data on previous cases were reviewed with the hope of providing clinical bases for early diagnosis and treatment of AITL-associated HLH.

Multicenter phase 1/2 study of forodesine in patients with relapsed peripheral T cell lymphoma

Peripheral T cell lymphomas are an aggressive group of non-Hodgkin lymphomas with poor outcomes for most subtypes and no accepted standard of care for relapsed patients. This study evaluated the efficacy and safety of forodesine, a novel purine nucleoside phosphorylase inhibitor, in patients with relapsed peripheral T cell lymphomas. Patients with histologically confirmed disease, progression after ≥ 1 prior treatment, and an objective response to last treatment received oral forodesine 300 mg twice-daily. The primary endpoint was objective response rate (ORR). Secondary endpoints included duration of response, progression-free survival (PFS), overall survival (OS), and safety. Forty-eight patients (median age, 69.5 years; median of 2 prior treatments) received forodesine. In phase 1 (n = 3 evaluable), no dose-limiting toxicity was observed during the first 28 days of forodesine treatment. In phase 2 (n = 41 evaluable), the ORR for the primary and final analyses was 22% (90% CI 12–35%) and 25% (90% CI 14–38%), respectively, including four complete responses (10%). Median PFS and OS were 1.9 and 15.6 months, respectively. The most common grade 3/4 adverse events were lymphopenia (96%), leukopenia (42%), and neutropenia (35%). Dose reduction and discontinuation due to adverse events were uncommon. Secondary B cell lymphoma developed in five patients, of whom four were positive for Epstein-Barr virus. In conclusion, forodesine has single-agent activity within the range of approved therapies in relapsed peripheral T cell lymphomas, with a manageable safety profile, and may represent a viable treatment option for this difficult-to-treat population.

Molecular assessment of clonality in lymphoid neoplasms

Molecular clonality assays in B- and T-cell lymphoproliferative disorders often provide critical information in establishing a diagnosis of a lymphoproliferative disorder. These assays rely on the unique genetic structures that serve as assay targets, created in the process of generating immunoglobulin and T-cell receptors during B- and T-cell development. Molecular clonality assays are generally used when flow cytometry or immunohistochemistry has not sufficiently clarified the benign or malignant nature of a lymphoid proliferation. Additionally, since molecular clonality assays are tumor specific, they allow the clinician to distinguish recurrences from second tumors, and have the sensitivity to monitor minimal residual disease. In this review, we discuss the principles underlying these tests, the current approaches to clonality testing, some of the pitfalls in their interpretation, and the future applications of next generation sequencing technology to clonality testing.

Composite lymphoma of follicular B-cell and peripheral T-cell types with distinct zone distribution in a 75-year-old male patient: a case study

Composite lymphoma of T-/B-cell type is rare, and follicular lymphoma composite with peripheral T-cell lymphoma (PTCL) has not previously been reported. We report such a case with both neoplastic components displaying a unique zone of distribution. A 75-year-old male patient presented with generalized lymphadenopathy. Sections of axillary lymph node demonstrated potentially 2 clonal processes, PTCL with aberrant CD20 expression and follicular lymphoma. Interestingly, the 2 neoplastic components were confined to their respective classic distribution zones, with PTCL occupying the interfollicular areas and follicular lymphoma residing in follicles. Both populations were detected by flow cytometry, but their immunophenotypes were insufficient to define clonality. Nonetheless, biclonality was demonstrated by lymphoid receptor gene rearrangement analyses. Molecular cytogenetics showed IGH/BCL2 fusion in the follicular lymphoma and amplification of IGH gene or trisomy/tetrasomy 14 in the PTCL. The current case underscores the complexity of composite lymphoma and advocates a multimodal approach to establishing the diagnosis.