Peripheral T-Cell Lymphoma, not Otherwise Specified (PTCL-NOS)

Intestinal T-cell lymphoma not otherwise specified: a case report and literature review

Intestinal T-cell lymphoma, not otherwise specified (ITCL, NOS), primarily affects the small bowel but can involve the stomach and large bowel. This report presents an uncommon case of ITCL, NOS in a patient affecting the large bowel, supported by a literature review. An 87-year-old female presented with abdominal pain, fever, vomiting and weight loss. Imaging revealed nodular thickening of the transverse and right colon, confirmed as polypoid mass lesions with ulceration through colonoscopy and biopsy, indicating ITCL, NOS. CT scan showed adrenal nodes classifying it as stage VI. The patient was referred for palliative care and passed away 40 days later, likely due to tumor progression. This case underscores the rarity of large bowel ITCL, NOS and the diagnosis challenge.

Granulomatous Slack Skin With Lung and Esophagus Involvement: A Case Report and Molecular Analysis

ABSTRACT

Granulomatous slack skin (GSS) is a rare subtype of mycosis fungoides, and few cases have been known to spread to the blood, lymph nodes, or viscera. We present a case with early dissemination to the lung. A 27-year-old woman, previously healthy, presented with scattered disseminated scaly patches, associated with vulvar and intergluteal firm swelling and groin-skin induration for 1 year. She also reported mild fatigue and breathlessness on moderate exertion. The patient underwent blood tests, skin biopsies, and computed tomography scan. The skin biopsy showed a mildly atypical T-cell lymphoid infiltrate involving the dermis/hypodermis, with focal epidermotropism, associated with a granulomatous infiltrate and elastophagocytosis. The computed tomography scan revealed bilateral ground-glass lung nodular opacities. Positron emission tomography showed an increased signal in the skin and subcutis around the buttocks, inguinal and mediastinal lymph nodes, and lungs. The lung biopsy confirmed a dense T-cell infiltrate with numerous multinucleated giant cells. Subsequently, esophageal involvement was also observed following biopsy. Molecular analyses demonstrated identical T-cell clones in the skin and lung. After 6 cycles of chemotherapy/localized external radiotherapy, the patient had a partial skin response and stable lung disease. A preferred diagnosis of GSS with systemic spread was made based on clinical/histologic/molecular findings, after considering granulomatous mycosis fungoides and peripheral T-cell lymphoma, not otherwise specified. This case highlights the frequent diagnostic difficulty in distinguishing GSS from an inflammatory granulomatous dermatitis. Pulmonary and esophageal involvements are rare in GSS, and the simultaneous presentation of characteristic cutaneous GSS with systemic disease poses an additional classification challenge.

Clinical significance and predictive risk factors for event-free survival at 24 months in patients with PTCL, NOS

Peripheral T cell lymphoma, not otherwise specified (PTCL, NOS), is a heterogeneous and aggressive type of non-Hodgkin's lymphoma with a bleak prognosis. This study was designed to assess the value of EFS24 as an alternative clinical endpoint and identify prognosis-related factors in PTCL, NOS. Patients diagnosed with PTCL, NOS were retrospectively collected and slides were reviewed by two hematopathologists. EFS was defined as the time from diagnosis to the occurrence of disease progression after initial treatment, retreatment, or death. Subsequent overall survival (OS) was defined from EFS24 or time of progression, if it occurred within 24 months, to the last follow-up or death. 97 cases with complete follow-up were selected. Approximately 66 patients (68.04%) failed to achieve ES24, with the median OS of 12.17 months, and 5-year OS rate of 15.17%. While patients who reached EFS24 had a median OS of 60.57 months and a 5-year OS rate of 68.77%. Multivariate Cox analysis indicated that bone marrow involvement and elevated β2 Microglobulin (β2-MG) were associated with a poor prognosis. B symptoms, extranodal involvement more than one site, and a high Ki67 index were significant factors in predicting the failure of EFS24. EFS24 can help stratify the subsequent outcomes of PTCL, NOS. Patients who achieve EFS24 have a favorable prognosis, although it does not reach that of the general population. On the other hand, patients who do not achieve EFS24 have an extremely poor prognosis. Therefore, EFS24 can be used for patient risk stratification, patient counseling, and study design.

The gene expression profile and cell of origin of canine peripheral T-cell lymphoma

BACKGROUND

Peripheral T-cell lymphoma (PTCL) refers to a heterogenous group of T-cell neoplasms with poor treatment responses and survival times. Canine PTCL clinically and immunophenotypically resembles the most common human subtype, PTCL-not otherwise specified (PTCL-NOS), leading to interest in this canine disease as a naturally occurring model for human PTCL. Gene expression profiling in human PTCL-NOS has helped characterize this ambiguous diagnosis into distinct subtypes, but similar gene expression profiling in canine PTCL is lacking.

METHODS

Bulk RNA-sequencing was performed on tumor samples from 33 dogs with either CD4+ (26/33), CD8+ (4/33), or CD4-CD8- (3/33) PTCL as diagnosed by flow cytometry, and sorted CD4+ and CD8+ lymphocytes from healthy control dogs. Following normalization of RNA-seq data, we performed differential gene expression and unsupervised clustering methods. Gene set enrichment analysis was performed to determine the enrichment of canine CD4+ PTCL for human PTCL-NOS, oncogenic pathways, and various stages of T-cell development gene signatures. We utilized gene set variation analysis to evaluate individual canine CD4+ PTCLs for various human and murine T-cell and thymocyte gene signatures. Cultured canine PTCL cells were treated with a pan-PI3K inhibitor, and cell survival and proliferation were compared to DMSO-treated controls. Expression of GATA3 and phosphorylated AKT was validated by immunohistochemistry.

RESULTS

While the canine CD4+ PTCL phenotype exhibited a consistent gene expression profile, the expression profiles of CD8+ and CD4-CD8- canine PTCLs were more heterogeneous. Canine CD4+ PTCL had increased expression of GATA3, upregulation of its target genes, enrichment for PI3K/AKT/mTOR signaling, and downregulation of PTEN, features consistent with the more aggressive GATA3-PTCL subtype of human PTCL-NOS. In vitro assays validated the reliance of canine CD4+ PTCL cells on PI3K/AKT/mTOR signaling for survival and proliferation. Canine CD4+ PTCL was enriched for thymic precursor gene signatures, exhibited increased expression of markers of immaturity (CD34, KIT, DNTT, and CCR9), and downregulated genes associated with the T-cell receptor, MHC class II associated genes (DLA-DQA1, DLA-DRA, HLA-DQB1, and HLA-DQB2), and CD25.

CONCLUSIONS

Canine CD4+ PTCL most closely resembled the GATA3-PTCL subtype of PTCL-NOS and may originate from an earlier stage of T-cell development than the more conventionally posited mature T-helper cell origin.

Impact of primary organ site of involvement by peripheral T-cell lymphoma not otherwise specified on survival

INTRODUCTION

Peripheral T-cell lymphoma, not otherwise specified (PTCL-NOS) is a rare, highly heterogeneous group of mature T-cell neoplasms that historically has been associated with poor outcomes. We sought to investigate the influence of primary disease site on PTCL-NOS outcomes using a large national cancer registry.

METHODS

Baseline clinical and demographic data including primary organ of involvement and Ann Arbor disease stage were extracted from the SEER database. Patients were grouped into nine organ system groups and compared to nodal disease acting as a control. Cox regression models were utilized for adjusted survival analyses.

RESULTS

A total of 3095 patients were identified in the SEER database and included in the final analysis. The median age was 61 and a majority of patients were male (60%) and identified as non-Hispanic white (68%). A plurality of patients had stage IV disease (32%). Lymph nodes and spleen were the most common primary disease sites (67%), while central nervous system was the least common (1%). Patients with early-stage PTCL-NOS of the gastrointestinal/genitourinary systems had worse overall survival [HR = 1.97 (1.50-2.59); p < 0.001] and lymphoma-specific survival [HR = 1.74 (1.26-2.40); p < 0.001] which was statistically significant even after adjusting for other variables. Early-stage PTCL-NOS of the central nervous system also had worse overall survival [HR = 1.90 (1.11-3.27); p = 0.020] and lymphoma-specific survival [HR = 2.11 (1.17-3.80); p = 0.013]. Early-stage PTCL-NOS of the skin had better overall survival [HR = 0.54 (0.42-0.68); p < 0.001] and lymphoma-specific survival [HR = 0.388 (0.28-0.53); p < 0.001] which was statistically significant even after adjustments.

CONCLUSION

Our findings suggest an association between primary organ involved by PTCL-NOS and both overall and lymphoma-specific survival even after adjusting for common variables. These results warrant validation in future prospective studies.

Successful anti-tumor effects with two novel bifunctional chemotherapeutic compounds that combine a LAT1 substrate with cytotoxic moieties in aggressive T-cell lymphomas

T-cell lymphomas are aggressive neoplasms characterized by poor responses to current chemotherapeutic agents. Expression of the l-type amino acid transporter 1 (LAT 1, SLC7A5) allows for the expansion of healthy T-cell counterparts, and upregulation of LAT1 has been reported in precursor T-cell acute leukemia. Therefore, the expression of LAT1 was evaluated in a cohort of cutaneous and peripheral T-cell lymphomas. The findings demonstrated that LAT1 is upregulated in aggressive variants and absent in low-grade or indolent disease such as mycosis fungoides. In addition, upregulated LAT1 expression was seen in a large proportion of aggressive peripheral T-cell lymphomas, including peripheral T-cell lymphoma not otherwise specific (PTCL-NOS) and angioimmunoblastic T-cell lymphoma (AITL). The anti-tumor effects of two novel non-cleavable and bifunctional compounds, QBS10072S and QBS10096S, that combine a potent cytotoxic chemotherapeutic domain (tertiary N-bis(2-chloroethyl)amine) with the structural features of a selective LAT1 substrate (aromatic β-amino acid) were tested in vitro and in vivo in T-cell lymphoma cell lines. The findings demonstrated decreased survival of T-cell lymphoma lines with both compounds. Overall, the results demonstrate that LAT1 is a valuable biomarker for aggressive T-cell lymphoma counterparts and QBS10072S and QBS10096S are successful therapeutic options for these aggressive diseases.

Diagnostic significance of dysregulated miRNAs in T-cell malignancies and their metabolic roles

T-cell malignancy is a broad term used for a diverse group of disease subtypes representing dysfunctional malignant T cells transformed at various stages of their clonal evolution. Despite having similar clinical manifestations, these disease groups have different disease progressions and diagnostic parameters. The effective diagnosis and prognosis of such a diverse disease group demands testing of molecular entities that capture footprints of the disease physiology in its entirety. MicroRNAs (miRNAs) are a group of noncoding RNA molecules that regulate the expression of genes and, while doing so, leave behind specific miRNA signatures corresponding to cellular expression status in an altered stage of a disease. Using miRNAs as a diagnostic tool is justified, as they can effectively distinguish expressional diversity between various tumors and within subtypes of T-cell malignancies. As global attention for cancer diagnosis shifts toward liquid biopsy, diagnosis using miRNAs is more relevant in blood cancers than in solid tumors. We also lay forward the diagnostic significance of miRNAs that are indicative of subtype, progression, severity, therapy response, and relapse. This review discusses the potential use and the role of miRNAs, miRNA signatures, or classifiers in the diagnosis of major groups of T-cell malignancies like T-cell acute lymphoblastic lymphoma (T-ALL), peripheral T-cell lymphoma (PTCL), extranodal NK/T-cell lymphoma (ENKTCL), and cutaneous T-cell lymphoma (CTCL). The review also briefly discusses major diagnostic miRNAs having prominent metabolic roles in these malignancies to highlight their importance among other dysregulated miRNAs.

Epigenetic inhibitors for cancer treatment

Epigenetics is a heritable and reversible modification that occurs independent of the alteration of primary DNA sequence but remarkably affects genetic expression. Aberrant epigenetic regulators are frequently observed in cancer progression not only influencing the behavior of tumor cells but also the tumor-associated microenvironment (TME). Increasing evidence has shown their great potential as biomarkers to predict clinical outcomes and chemoresistance. Hence, targeting the deregulated epigenetic regulators would be a compelling strategy for cancer treatment. So far, current epigenetic drugs have shown promising efficacy in both preclinical trials and clinical treatment of cancer, which encourages research discoveries on the development of novel epigenetic inhibitors either from natural compounds or artificial synthesis. However, only a few have been approved by the FDA, and more effort needs to be put into the related research. This chapter will update the applications and latest progress of epigenetic inhibitors in cancer treatment and provide prospects for the future development of epigenetic drugs.

Emerging predictive biomarkers for novel therapeutics in peripheral T-cell and natural killer/T-cell lymphoma

Peripheral T-cell lymphoma (PTCL) and natural killer/T-cell lymphoma (NKTCL) are rare subtypes of non-Hodgkin's lymphoma that are typically associated with poor treatment outcomes. Contemporary first-line treatment strategies generally involve the use of combination chemoimmunotherapy, radiation and/or stem cell transplant. Salvage options incorporate a number of novel agents including epigenetic therapies (e.g. HDAC inhibitors, DNMT inhibitors) as well as immune checkpoint inhibitors. However, validated biomarkers to select patients for individualized precision therapy are presently lacking, resulting in high treatment failure rates, unnecessary exposure to drug toxicities, and missed treatment opportunities. Recent advances in research on the tumor and microenvironmental factors of PTCL and NKTCL, including alterations in specific molecular features and immune signatures, have improved our understanding of these diseases, though several issues continue to impede progress in clinical translation. In this Review, we summarize the progress and development of the current predictive biomarker landscape, highlight potential knowledge gaps, and discuss the implications on novel therapeutics development in PTCL and NKTCL.

Classification and challenges in the histopathological diagnosis of peripheral T-cell lymphomas, emphasis on the WHO-HAEM5 updates

Mature T-cell lymphomas represent neoplastic expansions of T-cell lymphocytes with a post-thymic derivation. Most of these tumors feature aggressive clinical behavior and challenging histopathological diagnosis and classification. Novel findings in the genomic landscape of T-cell lymphomas are helping to improve the understanding of the biology and the molecular mechanisms that underly its clinical behavior. The most recent WHO-HAEM5 classification of hematolymphoid tumors introduced novel molecular and histopathological findings that will aid in the diagnostic classification of this group of neoplasms. The current review article summarizes the most relevant diagnostic features of peripheral T-cell lymphomas with an emphasis on the updates that are incorporated at the WHO-HAEM5.

Tumor buster - where will the CAR-T cell therapy 'missile' go?

Chimeric antigen receptor (CAR) T cell (CAR-T cell) therapy based on gene editing technology represents a significant breakthrough in personalized immunotherapy for human cancer. This strategy uses genetic modification to enable T cells to target tumor-specific antigens, attack specific cancer cells, and bypass tumor cell apoptosis avoidance mechanisms to some extent. This method has been extensively used to treat hematologic diseases, but the therapeutic effect in solid tumors is not ideal. Tumor antigen escape, treatment-related toxicity, and the immunosuppressive tumor microenvironment (TME) limit their use of it. Target selection is the most critical aspect in determining the prognosis of patients receiving this treatment. This review provides a comprehensive summary of all therapeutic targets used in the clinic or shown promising potential. We summarize CAR-T cell therapies’ clinical trials, applications, research frontiers, and limitations in treating different cancers. We also explore coping strategies when encountering sub-optimal tumor-associated antigens (TAA) or TAA loss. Moreover, the importance of CAR-T cell therapy in cancer immunotherapy is emphasized.

Noncirrhotic portal hypertension due to peripheral T-cell lymphoma, not otherwise specified: A case report

BACKGROUND

Peripheral T-cell lymphoma (PTCL), an aggressive and rare disease that belongs to a heterogeneous group of mature T-cell lymphomas, develops rapidly and has a poor prognosis. Early detection and treatment are essential to improve patient cure and survival rates. Here, we report a rare case of PTCL with clinical presentation of noncirrhotic portal hypertension, which provides a basis for early vigilance of lymphomas in the future.

CASE SUMMARY

A 65-year-old Chinese woman was admitted to our hospital because of abdominal distension for 3 months and pitting oedema of both lower limbs for 2 months. Physical examinations and associated auxiliary examinations showed the presence of hepatosplenomegaly, and her hepatic venous pressure gradient was 10 mmHg. Immunohistochemical analysis of the liver biopsy confirmed the diagnosis of PTCL. The patient underwent combination therapy with dexamethasone, VP-16, and chidamide. Unfortunately, after 41 days of chemotherapy, the patient died of multiple organ failure.

CONCLUSION

PCTL accompanied by noncirrhotic portal hypertension is rarely reported. This case report discusses the diagnosis of a patient according to the literature.

Aggressive T-cell lymphomas: 2021 Updates on diagnosis, risk stratification and management

INTRODUCTION

Aggressive T-cell lymphomas continue to have a poor prognosis. There are over 27 different subtypes of peripheral T-cell lymphoma (PTCL), and we are now beginning to understand the differences between the various subtypes beyond histologic variations.

MOLECULAR PATHOGENESIS OF VARIOUS SUBTYPES OF PTCL

Gene expression profiling (GEP) can help in diagnosis and prognostication of various subtypes including PTCL-nos and anaplastic large cell lymphoma (ALCL). In addition, mutational analysis is now being incorporated in clinical trials of novel agents to evaluate various biomarkers of response to allow better therapeutic choices for patients.

TARGETED THERAPIES

There are many targeted agents currently in various stages of clinical trials for PTCL that take advantage of the differential expression of specific proteins or receptors in PTCL tumors. This includes the CD30 directed antibody drug conjugate brentuximab vedotin. Other notable targets are CD25, CCR4, inhibition of PI3kinase - m TOR and JAK/STAT pathways. The ALK inhibitors are promising for ALK expressing tumors.

IMMUNOTHERAPIES

Allogeneic stem cell transplant continues to be the curative therapy for most aggressive subtypes of PTCL. The use of checkpoint inhibitors in the treatment of PTCL is still controversial. The most promising results have been seen in cases of extranodal natural killer cell/T-cell (ENK/T) lymphomas and cutaneous T-cell lymphomas (CTCL). Bispecific antibody based treatments as well as CAR-T cell based therapies are in clinical trials.

CD8-positive peripheral T cell lymphoma in a patient following long-term nivolumab for advanced lung adenocarcinoma: A case report

A 54-year-old male smoker presented with hemoptysis. Advanced lung adenocarcinoma, cT1cN3M1b, stage IVB, was diagnosed. Enlargement of multiple intraperitoneal and inguinal lymph nodes and peripheral atypical lymphocytosis appeared after 33 cycles of second-line treatment with nivolumab, and a specimen obtained by left inguinal lymph node biopsy showed peripheral T cell lymphoma (PTCL), not otherwise specified. Lymphoma cells expressed CD3+, CD8+, and CD56+, but not CD4+ or PD-1. Despite systemic chemotherapy with cyclophosphamide, hydroxydaunorubicin, oncovin, and prednisolone, the patient died of PTCL 864 days after the initial visit. The possible relationship between treatment with immune checkpoint inhibitors (ICIs) and PTCL development is discussed here.

Diagnostic Utility of SOX4 Expression in Adult T-Cell Leukemia/Lymphoma

Differentiation between adult T-cell leukemia/lymphoma (ATLL) and peripheral T-cell lymphoma, not otherwise specified (PTCL-NOS), is often challenging based on pathological findings alone. Although serum anti-HTLV-1 antibody positivity is required for ATLL diagnosis, this information is often not available at the time of pathological diagnosis. Therefore, we examined whether the expression of SOX4 and p16 would be helpful for differentiating the two disease entities. We immunohistochemically examined SOX4 and p16 expression (which have been implicated in ATLL carcinogenesis) in 11 ATLL patients and 20 PTCL-NOS patients and classified them into four stages according to the percentage of positive cells. Among the ATLL cases, 8/11 (73%) were SOX4-positive, while only 2/20 (10%) PTCL-NOS cases expressed SOX4. The mean total score was 4.2 (standard deviation (SD): 0.61) in the ATLL group and 0.50 (SD: 0.46) in the PTCL-NOS group (p < 0.001). Positive expression of p16 was noted in 4/11 (36%) patients with ATLL and 3/20 (15%) patients with PTCL-NOS, with mean total scores of 1.9 (SD: 0.64) and 0.70 (SD: 0.48) in the ATLL and PTCL-NOS groups, respectively (p = 0.141). These results suggest that SOX4 may be strongly expressed in ATLL compared to PTCL-NOS cases. Therefore, it may be helpful to perform immunohistochemical staining of SOX4 when pathologists face challenges discriminating between ATLL and PTCL-NOS.

CCR4-positive peripheral T-cell lymphoma presenting as eosinophilic pneumonia and developing from prolonged pustular psoriasis

A 29-year-old woman with chronic, prolonged pustular psoriasis was admitted to our hospital because of high-grade fever and a systemic skin rash. General examination revealed a whole-body skin rash and superficial lymphadenopathy. Peripheral blood examination showed unclassified cells positive for CD3, CD4, and T-cell receptor αβ, and negative for CD20 and CD56. Soon after administration, she developed acute respiratory failure and required artificial ventilation. Bronchoalveolar lavage fluid showed increased numbers of eosinophils and abnormal lymphocytes of the same phenotype in peripheral blood and skin. She was diagnosed with eosinophilic pneumonia, and her respiratory failure was improved by corticosteroid therapy. Based on the histological findings of skin, lymph node, and bone marrow biopsies, a diagnosis of peripheral T-cell lymphoma not otherwise specified (PTCL-NOS), with positivity for CC chemokine receptor 4 was made. She received chemotherapy followed by allogeneic stem cell transplantation, which resulted in complete remission of her PTCL-NOS. She remained alive and disease-free 6 years later. This is the first reported case of PTCL-NOS developing during the clinical course of pustular psoriasis. The clinical manifestations of PTCL-NOS are complex, but an accurate diagnosis and appropriate therapy may produce a good clinical outcome in patients with PTCL-NOS.

Low serum cholesterol levels predict inferior prognosis and improve prognostic index scoring for peripheral T-cell lymphoma, unspecified

Peripheral T-cell lymphomas, unspecified (PTCL-U) is a heterogeneous group of non-Hodgkin lymphomas, arising from the transformation of mature, post-thymic T-cells. Prognostic index for PTCL-U (PIT) is based on Europeans and may not be applicable for Chinese PTCL-U patients. Besides, low circulating cholesterol concentration is associated with elevated cancer incidence and mortality. The purpose of our study was to assess the prognostic value of serum lipid levels in PTCL-U and improve PIT. We screened the prognostic factors associated with progression-free survival (PFS) and overall survival (OS) by multivariate Cox regression analysis in ninety-one enrolled patients. The results showed that low-level high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C) were associated with unfavorable OS. Furthermore, we developed a new risk model, PITC, based on low-level HDL-C, LDL-C and PIT. In Chinese PTCL-U, PITC was superior to PIT in PFS and OS. In conclusion, serum cholesterol levels may be good candidates for predicting prognosis in PTCL-U.

CD3-positive plasmablastic lymphoma reported in two cases: A potential diagnostic caveat

Plasmablastic lymphoma (PBL) is a rare aggressive subtype of mature large B cell lymphoma involving almost exclusively the extranodal regions particularly the oral cavity, frequently described in immunocompromised patients. PBL is characterized histologically by diffuse proliferation of large neoplastic cells resembling B immunoblasts or plasmablasts. The diagnosis of PBL can be difficult due to its ambiguous histopathological features mimicking most large cell lymphomas and lacking a distinctive immunophenotypic pattern. They typically lack expression of CD20 and CD79a but may express plasma cell marker, CD138. Aberrant immunoexpression of CD3, a T-cell marker in PBL in the absence of other B-cell markers is exceptionally rare, may potentially lead to incorrect interpretation. Herein, we report a case series of CD3-positive PBL of oral cavity in two individuals, which were initially misdiagnosed as high-grade T-cell lymphomas including extranodal NK/T-cell lymphoma, nasal type. Useful distinguishing clinical settings, histomorphological features, immunohistochemistry and molecular expression profiles of PBL are discussed.

Facial nerve paralysis caused by a T-cell lymphoma

Facial nerve paralysis due to the infiltration by a lymphoma is rare and the prognosis remains poor. If perineural spread and meningeosis are suspected, quick interdisciplinary diagnostic work-up is recommended. It should include magnetic resonance imaging, biopsy of the lesion, bone marrow biopsy, and lumbar puncture. Therapy should be initiated immediately.

Atypical Mature T-Cell Neoplasms: The Relevance of the Role of Flow Cytometry

Lymphoproliferative disorders are a heterogeneous group of malignant clonal proliferations of lymphocytes whose diagnosis remains challenging, despite diagnostic criteria are now well established, due to their heterogeneity in clinical presentation and immunophenotypic profile. Lymphoid T-cell disorders are more rarely seen than B-cell entities and more difficult to diagnose for the absence of a specific immunophenotypic signature. Flow cytometry is a useful tool in diagnosing T-cell lymphoproliferative disorders since it is not only able to better characterize T-cell neoplasms but also to resolve some very complicated cases, in particular those in which a small size population of neoplastic cells is available for the analysis. Here, we report three patients with mature T-cell neoplasms with atypical clinical and biological features in which analysis of peripheral blood and bone marrow specimens by means of multicolor flow cytometry was very useful to identify and characterize three rare T-cell lymphoproliferative disorders, such as angioimmunoblastic T-cell lymphoma, peripheral T-cell lymphoma not otherwise specified and T-cell prolymphocytic leukemia. The aim of this case series report is not only to describe three rare cases of lymphoproliferative neoplasms but also to raise awareness that a fast, highly sensitive, and reproducible procedure, such as flow cytometry immunophenotyping, can have a determinant diagnostic role in these patients.

Peripheral T-cell lymphoma, not otherwise specified- Case report

T-cell lymphomas are rare malignancies that are often found in older individuals. Here we present the case of a 63 year old female that presented with diffuse cervical, inguinal, and axillary lymphadenopathy with associated weight loss and night sweats. The patient underwent excisional lymph node biopsy which revealed a T-cell lymphoma with findings characteristic of peripheral T-cell lymphoma, not otherwise specified.

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EBV may be found positive in PTCL-NOS, Lennert lymphoma variant.

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There is frequent loss or decreased expression of CD5 and CD7 in PTCL-NOS.

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Excisional biopsy is necessary to diagnose malignancy if there is high suspicion and FNA/core biopsy are negative.

CD20-positive primary nasal peripheral T-cell lymphoma: An analysis of one case and review of the literature

CD20-positive T-cell lymphoma (TCL) is a very rare disease entity that is associated with the co-expressions of a range of T cell lineage makers, such as, CD2, CD3, CD5, or CD7, and CD20. The biological and clinical significance of CD20 antigen expressed in TCL has been unclear. Here, we are reporting an unusual case of CD20-positive primary nasal peripheral T-cell lymphoma, not otherwise specified (PTCL-NOS) in a 62-year-old female with both peripheral blood (PB) and bone marrow (BM) involvement. Flow cytometry (FC) analysis revealed CD20+ lymphoma cells in PB, BM, and lymph node (LN) and was consistent with pathological findings. FC immunophenotyping was proved of great diagnostic contribution.

Aggressive T-cell lymphomas: 2019 updates on diagnosis, risk stratification, and management

INTRODUCTION

Aggressive T-cell lymphomas continue to have a poor prognosis. There are over 27 different subtypes of peripheral T-cell lymphoma (PTCL) and we are now beginning to understand the differences between the various subtypes beyond histologic variations.

MOLECULAR PATHOGENESIS OF VARIOUS SUBTYPES OF PTCL

Gene expression profiling can help in diagnosis and prognostication of various subtypes including PTCL-nos and anaplastic large cell lymphoma. In addition, mutational analysis is now being incorporated in clinical trials of novel agents to evaluate various biomarkers of response to allow better therapeutic choices for patients.

TARGETED THERAPIES

There are many targeted agents currently in various stages of clinical trials for PTCL that take advantage of the differential expression of specific proteins or receptors in PTCL tumors. The most promising is the CD30 directed antibody drug conjugate brentuximab vedotin. This has recently been approved by the Food and Drug Administration for the upfront treatment of CD30 expressing PTCLs in combination with cyclophosphamide, doxorubicin, and prednisone chemotherapy. Other notable targets are CD25, CCR4 tag, PI3kinase inhibitors, and JAK/STAT inhibitors. Anaplastic lymphoma kinase (ALK) inhibitors are promising for ALK expressing tumors.

IMMUNOTHERAPIES

The use of checkpoint inhibitors in the treatment of PTCL is still controversial. The most promising results have been seen in cases of extranodal natural killer cell/T-cell lymphomas and cutaneous T-cell lymphomas. For all other subtypes, immune checkpoint inhibitors should be used with extreme caution and only in the context of a clinical trial. Allogeneic stem cell transplant continues to be the curative therapy for most aggressive subtypes of PTCL.