Bexarotene is active against subcutaneous panniculitis-like T-cell lymphoma in adult and pediatric populations

Primary Cutaneous Gamma-Delta T-cell Lymphoma: A Case Report and Review of Literature

Primary cutaneous gamma-delta T-cell lymphoma (PCGD-TCL) is a rare type of lymphoma, representing less than 1% of all cutaneous T-cell lymphomas. It is typically aggressive and chemotherapy-refractory. Hence, most institutions tend to employ intensive chemotherapy followed by stem cell transplantation although there is no standard of care established. We report a case of PCGD-TCL and discuss the challenges associated with the diagnosis and management of PCGD-TCL.

A Clinical Case of a Homozygous Deletion in the APOA5 Gene with Severe Hypertriglyceridemia

Background: Hypertriglyceridemia (HTG) is one of the most common forms of lipid metabolism disorders. The leading clinical manifestations are pancreatitis, atherosclerotic vascular lesions, and the formation of eruptive xanthomas. The most severe type of HTG is primary (or hereditary) hypertriglyceridemia, linked to pathogenic genetic variants in LPL, APOC2, LMF1, and APOA5 genes. Case: We present a clinical case of severe primary hypertriglyceridemia (TG level > 55 mmol/L in a 4-year-old boy) in a consanguineous family. The disease developed due to a previously undescribed homozygous deletion in the APOA5 gene (NM_052968: c.579_592delATACGCCGAGAGCC p.Tyr194Gly*68). We also evaluate the clinical significance of a genetic variant in the LPL gene (NM_000237.2: c.106G>A (rs1801177) p.Asp36Asn), which was previously described as a polymorphism. In one family, we also present a different clinical significance even in heterozygous carriers: from hypertriglyceridemia to normotriglyceridemia. We provide evidence that this heterogeneity has developed due to polymorphism in the LPL gene, which plays the role of an additional trigger. Conclusions: The homozygous deletion of the APOA5 gene is responsible for the severe hypertriglyceridemia, and another SNP in the LPL gene worsens the course of the disease.

Clinical, Diagnostic and Prognostic Characteristics of Primary Cutaneous Gamma Delta T-cell Lymphomas

Primary cutaneous γδ T-cell lymphoma (PCGDTL) is a rare subtype of non-Hodgkin lymphoma (NHL) that arises from T-cells with γδ T-cell receptors. The exact incidence of PCGDTL is unknown, as it is usually lumped with other cutaneous lymphomas, which are also uncommon. It is one of the peripheral T-cell lymphoma (PTCL) subtypes which is known to have a dismal prognosis due to poor response and the paucity of available therapies. Despite the rarity and uncertainties of PCGDTL, a number of studies over the past decade were published about the pathologic, diagnostic, cytogenetic and clinical features of this disease. These diagnostic advances will open the doors to explore new therapeutics for this rare entity, specifically targeted and immune therapies. In this review, we highlight these advances, summarize the contemporary treatment approaches, and shed the light on future potential therapeutic targets.

Management of hypertriglyceridemia

Hypertriglyceridemia is one of the most common lipid abnormalities encountered in clinical practice. Many monogenic disorders causing severe hypertriglyceridemia have been identified, but in most patients triglyceride elevations result from a combination of multiple genetic variations with small effects and environmental factors. Common secondary causes include obesity, uncontrolled diabetes, alcohol misuse, and various commonly used drugs. Correcting these factors and optimizing lifestyle choices, including dietary modification, is important before starting drug treatment. The goal of drug treatment is to reduce the risk of pancreatitis in patients with severe hypertriglyceridemia and cardiovascular disease in those with moderate hypertriglyceridemia. This review discusses the various genetic and acquired causes of hypertriglyceridemia, as well as current management strategies. Evidence supporting the different drug and non-drug approaches to treating hypertriglyceridemia is examined, and an easy to adopt step-by-step management strategy is presented.

How do we treat cutaneous T-cell lymphoma?

Cutaneous T-cell lymphomas are a heterogeneous group of non-Hodgkin lymphomas which are based on the malignant proliferation of skin-related T lymphocytes. The clinical appearance, as well as the course and the associated therapeutic approach, are sometimes very different between the different subtypes. Since allogeneic stem cell transplantation is currently the only curative option, and the morbidity and mortality are not insignificant, a therapy concept should be developed that considers its often rather indolent but chronic course. This concept should enable a good disease control with as few side effects as possible and preserve or improve the quality of life. In the early stages of the disease, skin-oriented therapies are generally used first before systemic and increasingly aggressive therapeutic agents are used as the disease progresses. Considering the current guidelines, literature and subjective experience, we summarize in this review how we treat cutaneous T-cell lymphomas.

Molecular Insight into the Therapeutic Promise of Targeting APOE4 for Alzheimer's Disease

Alzheimer's disease (AD) is a progressive neurodegenerative disease that causes chronic cognitive dysfunction. Most of the AD cases are late onset, and the apolipoprotein E (APOE) isoform is a key genetic risk factor. The APOE gene has 3 key alleles in humans including APOE2, APOE3, and APOE4. Among them, APOE4 is the most potent genetic risk factor for late-onset AD (LOAD), while APOE2 has a defensive effect. Research data suggest that APOE4 leads to the pathogenesis of AD through various processes such as accelerated beta-amyloid aggregations that raised neurofibrillary tangle formation, cerebrovascular diseases, aggravated neuroinflammation, and synaptic loss. However, the precise mode of actions regarding in what way APOE4 leads to AD pathology remains unclear. Since APOE contributes to several pathological pathways of AD, targeting APOE4 might serve as a promising strategy for the development of novel drugs to combat AD. In this review, we focus on the recent studies about APOE4-targeted therapeutic strategies that have been advanced in animal models and are being prepared for use in humans for the management of AD.

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.

Retinoid X Receptor Activation During Adipogenesis of Female Mesenchymal Stem Cells Programs a Dysfunctional Adipocyte

Early life exposure to endocrine-disrupting chemicals (EDCs) is an emerging risk factor for the development of obesity and diabetes later in life. We previously showed that prenatal exposure to the EDC tributyltin (TBT) results in increased adiposity in the offspring. These effects linger into adulthood and are propagated through successive generations. TBT activates two nuclear receptors, the peroxisome proliferator-activated receptor (PPAR) γ and its heterodimeric partner retinoid X receptor (RXR), that promote adipogenesis in vivo and in vitro. We recently employed a mesenchymal stem cell (MSC) model to show that TBT promotes adipose lineage commitment by activating RXR, not PPARγ. This led us to consider the functional consequences of PPARγ vs RXR activation in developing adipocytes. We used a transcriptomal approach to characterize genome-wide differences in MSCs differentiated with the PPARγ agonist rosiglitazone (ROSI) or TBT. Pathway analysis suggested functional deficits in TBT-treated cells. We then compared adipocytes differentiated with ROSI, TBT, or a pure RXR agonist IRX4204 (4204). Our data show that RXR activators ("rexinoids," 4204 and TBT) attenuate glucose uptake, blunt expression of the antidiabetic hormone adiponectin, and fail to downregulate proinflammatory and profibrotic transcripts, as does ROSI. Finally, 4204 and TBT treatment results in an inability to induce markers of adipocyte browning, in part due to sustained interferon signaling. Taken together, these data implicate rexinoids in the development of dysfunctional white adipose tissue that could potentially exacerbate obesity and/or diabetes risk in vivo. These data warrant further screening and characterization of EDCs that activate RXR.

New Therapies and Immunological Findings in Cutaneous T-Cell Lymphoma

Primary cutaneous lymphomas comprise a group of lymphatic malignancies that occur primarily in the skin. They represent the second most common form of extranodal non-Hodgkin’s lymphoma and are characterized by heterogeneous clinical, histological, immunological, and molecular features. The most common type is mycosis fungoides and its leukemic variant, Sézary syndrome. Both diseases are considered T-helper cell type 2 (Th2) diseases. Not only the tumor cells but also the tumor microenvironment can promote Th2 differentiation, which is beneficial for the tumor cells because a Th1 environment enhances antitumor immune responses. This Th2-dominant milieu also underlies the infectious susceptibility of the patients. Many components, such as tumor-associated macrophages, cancer-associated fibroblasts, and dendritic cells, as well as humoral factors, such as chemokines and cytokines, establish the tumor microenvironment and can modify tumor cell migration and proliferation. Multiagent chemotherapy often induces immunosuppression, resulting in an increased risk of serious infection and poor tolerance. Therefore, overtreatment should be avoided for these types of lymphomas. Interferons have been shown to increase the time to next treatment to a greater degree than has chemotherapy. The pathogenesis and prognosis of cutaneous T-cell lymphoma (CTCL) differ markedly among the subtypes. In some aggressive subtypes of CTCLs, such as primary cutaneous gamma/delta T-cell lymphoma and primary cutaneous CD8⁺ aggressive epidermotropic cytotoxic T-cell lymphoma, hematopoietic stem cell transplantation should be considered, whereas overtreatment should be avoided with other, favorable subtypes. Therefore, a solid understanding of the pathogenesis and immunological background of cutaneous lymphoma is required to better treat patients who are inflicted with this disease. This review summarizes the current knowledge in the field to attempt to achieve this objective.

Managing Patients with Cutaneous B-Cell and T-Cell Lymphomas Other Than Mycosis Fungoides

Cutaneous lymphomas (CL) are a heterogeneous group of neoplasms characterized with clinical and histopathological variation, as well as overlap with benign dermatoses. Diagnosis and treatment of CLs is challenging and often requires a multidisciplinary approach. However, prognostic knowledge of these conditions and awareness of treatment options can help optimize appropriate use of available regimens, thereby improving care for patients. Here, we review the most recent literature and outline treatment themes for managing patients with cutaneous B-cell and T-cell lymphomas other than mycosis fungoides.

Autologous and Allogeneic Hematopoietic Cell Transplantation in Peripheral T/NK-cell Lymphomas: A Histology-Specific Review

Peripheral T-cell lymphoma and natural killer/T-cell lymphomas (PT/NKCL) make up a diverse subgroup of non-Hodgkin's lymphomas characterized by an aggressive clinical course. The use of hematopoietic stem cell transplantation (HSCT) in the treatment of PT/NKCL remains controversial because of the absence of randomized controlled trials. The best available data suggest that certain subtypes of PT/NKCL may benefit more from the application of HSCT than other subtypes and that this benefit results from their unique clinical characteristics and underlying biology. Ultimately, however, prospective randomized controlled trials are needed to clarify the optimal type and timing of HSCT in patients with PT/NKCL.

Uncommon Variants of T-Cell Lymphomas

Peripheral T-cell lymphomas represent 10% to 15% of non-Hodgkin lymphomas and comprise more than 20 different entities. Treatment of very rare T-cell lymphomas can be challenging because there are no large or randomized studies to guide clinical decision making, and treatment paradigms are often based on small series or imperfect data. Although a strict algorithm cannot be written with certainty, through the literature that exists and clinical experience, themes and principles of approaches do emerge that when coupled with clinical judgment allow reasonable and logical decisions.

Primary Cutaneous Lymphomas in Children and Adolescents

Primary cutaneous lymphomas are rare in children and mostly represented by mycosis fungoides and CD30(+) lymphoproliferative disorders. Most pediatric cutaneous lymphomas have similar clinical/pathological features as their adult counterparts, particularly the T-cell subtypes. With regard to outcome, adult cutaneous mature T-cell lymphomas have a tendency to progression, while this appears to be relatively infrequent in children. The outcome of cutaneous B-cell lymphomas depends on subtype, with the B-lymphoblastic entity being associated with similar outcomes to precursor B acute lymphoblastic leukemia, while there are insufficient data on other entities. The diagnosis and treatment of these patients require a close collaboration between experienced pediatric pathologists, dermatologists, and oncologists. Prospective collection of longitudinal clinical and biological data from children with these rare lymphomas is needed to better understand their biological and clinical behavior and to ultimately discover the best therapeutic strategies.

Clinical manifestations and pathogenesis of cutaneous lymphomas: current status and future directions

The primary cutaneous lymphomas are a heterogeneous group of T-, Natural Killer- and B- cell neoplasms with a wide range of clinical and pathological presentations, and with very different prognoses compared to systemic lymphomas. Recent studies have shown that the skin microenvironment, which is composed of various immune cell subsets as well as their spatial distribution and T-cell interactions through different chemokines and cytokines, has an important role in the development and pathogenesis of cutaneous lymphomas and has assisted in the development of novel and more effective immunotherapies. The following review will focus on the major subtypes of primary cutaneous lymphomas, including the clinical and histological patterns, molecular hallmarks, and current and future treatment strategies.

Morphology, in vivo distribution and antitumor activity of bexarotene nanocrystals in lung cancer

The objective of this study was to develop and evaluate the morphology, biodistribution and antitumor activity of bexarotene nanocrystals delivery system. The morphology was investigated using scanning electron microscopy (SEM), transmission electron microscopy (TEM), atomic force microscope and bexarotene nanocrystals exhibited the advantages of making the efficacy more steady and durable compared with control group in lung with less cardiac accumulation as shown by biodistribution studies in vivo. In addition, MTT assay, flow cytometry analysis, observation of morphological changes and apoptotic body demonstrated that bexarotene nanocrystals could significantly enhance the in vitro cytotoxicity and induced G1 cycle arrest and apoptosis against A549 cells. Also, bexarotene nanocrystals had significant antitumor activity in mice bearing A549 cell line. This finding was correlated with both in vitro and in vivo. Thereby, the overall results suggest that the bexarotene nanocrystals represent a potential source of medicine, which made bexarotene nanocrystals a promising candidate for the treatment of lung cancer.

Apolipoprotein E as a Therapeutic Target in Alzheimer's Disease: A Review of Basic Research and Clinical Evidence

Alzheimer's disease (AD) is a devastating neurodegenerative disorder that causes progressive cognitive decline. The majority of AD cases are sporadic and late-onset (>65 years old) making it the leading cause of dementia in the elderly. While both genetic and environmental factors contribute to the development of late-onset AD (LOAD), APOE polymorphism is a major genetic risk determinant for LOAD. In humans, the APOE gene has three major allelic variants: ε2, ε3, and ε4, of which APOE ε4 is the strongest genetic risk factor for LOAD, whereas APOE ε2 is protective. Mounting evidence suggests that APOE ε4 contributes to AD pathogenesis through multiple pathways including facilitated amyloid-β deposition, increased tangle formation, synaptic dysfunction, exacerbated neuroinflammation, and cerebrovascular defects. Since APOE modulates multiple biological processes through its corresponding protein apolipoprotein E (apoE), APOE gene and apoE properties have been a promising target for therapy and drug development against AD. In this review, we summarize the current evidence regarding how the APOE ε4 allele contributes to the pathogenesis of AD and how relevant therapeutic approaches can be developed to target apoE-mediated pathways in AD.

Rare Pediatric Non-Hodgkin Lymphomas: A Report From Children's Oncology Group Study ANHL 04B1

BACKGROUND

Non-Hodgkin lymphoma (NHL) is a relatively common malignancy in pediatric patients; however, a small subgroup have unusual lymphoma subtypes for the pediatric population.

PROCEDURE

The Children's Oncology Group Rare and Cutaneous NHL registry's (protocol ANHL 04B1) main objectives were to determine the pathologic, biologic, and clinical features of rare and cutaneous pediatric NHL and establish a bank of centrally reviewed tissue specimens. We report the clinical data, treatment data, and outcome for rare pediatric NHL.

RESULTS

In 101 lymphomas, there is a 97.8% concordance between the reviewing study pathologists and an 87.6% concordance between the central and institutional pathology review. Samples in the specimen bank include primary tumor tissue that is snap frozen, in paraffin blocks, or H&E-stained and unstained paraffin slides as well as blood, serum, and bone marrow. This descriptive analysis shows that children with pediatric follicular lymphoma, mucosa-associated lymphoid tissue, nodal marginal zone lymphoma, primary cutaneous, primary central nervous system lymphoma, and subcutaneous panniculitis-like T-cell lymphomas have 100% survival at a median of 2 years from enrollment. There are early deaths, mostly from progressive disease, in subjects with peripheral T-cell (not otherwise specified), NKT, and hepatosplenic T-cell lymphomas.

CONCLUSIONS

This registry provides high-quality biologic specimens with clinical data to investigators working on the biology of these unusual pediatric diseases.

Subcutaneous Panniculitis-Like T-Cell Lymphoma with Hemophagocytic Syndrome in a Child

Subcutaneous panniculitis-like T-cell lymphoma (SPTCL) characterized by subcutaneous infiltration of pleomorphic T-cells of the α/β phenotype rarely affects children. Development of hemophagocytic syndrome (HPS) leads to a poor prognosis with this otherwise indolent lymphoma. We report a case of SPTCL in a 5-year-old child complicated by HPS treated successfully with combination chemotherapy. We discuss the potential pitfalls in reaching an early diagnosis and challenges in its management. Previously reported cases of SPTCL with HPS in children are briefly reviewed.

[Subcutaneous panniculitis-like T-cell lymphoma : Two case reports]

Histopathology, immunohistochemical, and molecular genetic findings revealed the diagnosis of subcutaneous panniculitis-like T-cell-lymphoma in two patients, aged 44 and 70 years. The clinical morphology of the lymphoma manifestations showed varied significantly. One patient presented with a singular erythematous nodule in the chin region. The other patient suffered from extended plate-like resistances and atrophy of the face, upper arms and left breast. Hemophagocytic syndrome was not present in either patient. Prognosis of subcutaneous panniculitis-like T-cell lymphoma without associated hemophagocytic syndrome is reported to be favorable. Radiotherapy of the singular lesion on the chin and systemic corticosteroids of the extended plaques induced complete remission in both patients.

Rescuing effects of RXR agonist bexarotene on aging-related synapse loss depend on neuronal LRP1

Apolipoprotein E (apoE) plays a critical role in maintaining synaptic integrity by transporting cholesterol to neurons through the low-density lipoprotein receptor related protein-1 (LRP1). Bexarotene, a retinoid X receptor (RXR) agonist, has been reported to have potential beneficial effects on cognition by increasing brain apoE levels and lipidation. To investigate the effects of bexarotene on aging-related synapse loss and the contribution of neuronal LRP1 to the pathway, forebrain neuron-specific LRP1 knockout (nLrp1(-/-)) and littermate control mice were administered with bexarotene-formulated diet (100mg/kg/day) or control diet at the age of 20-24 months for 8 weeks. Upon bexarotene treatment, levels of brain apoE and ATP-binding cassette sub-family A member 1 (ABCA1) were significantly increased in both mice. While levels of PSD95, glutamate receptor 1 (GluR1), and N-methyl-d-aspartate receptor NR1 subunit (NR1), which are key postsynaptic proteins that regulate synaptic plasticity, were decreased with aging, they were restored by bexarotene treatment in the brains of control but not nLrp1(-/-) mice. These results indicate that the beneficial effects of bexarotene on synaptic integrity depend on the presence of neuronal LRP1. However, we also found that bexarotene treatment led to the activation of glial cells, weight loss and hepatomegaly, which are likely due to hepatic failure. Taken together, our results demonstrate that apoE-targeted treatment through the RXR pathway has a potential beneficial effect on synapses during aging; however, the therapeutic application of bexarotene requires extreme caution due to its toxic side effects.

Zebras and hen's teeth: recognition and management of rare T and NK lymphomas

Although all the peripheral T-cell lymphomas are uncommon, there are some entities that are truly rare. Subtypes, such as enteropathy-associated T-cell lymphoma, hepatosplenic T-cell lymphoma, extranodal NK/T-cell lymphoma, and subcutaneous panniculitis-like T-cell lymphoma, have an approximate annual incidence in United States of <500 each. In these very rare subtypes, there is limited data to guide clinical decision-making. As such, our treatment decisions are often based on extrapolation, case series, personal experience, and biases. We summarize the existing data regarding initial management of these entities and compare how that management follows paradigms established for the more common T-cell lymphomas.

Subcutaneous Panniculitis-Like T-Cell Lymphoma in Children: A Review of the Literature

Subcutaneous panniculitis-like T-cell lymphoma (SPTCL) is a type of skin lymphoma. Pleomorphic T-cells infiltrate the subcutaneous tissue and mimic lobular panniculitis. We report a case occurring in a 12-year-old Chinese boy who presented with multiple indolent erythematous subcutaneous nodules on both extremities without systemic symptoms. He had a protracted course of multiple erythematous subcutaneous nodules for 1 year and underwent biopsy of lesional skin for histology and T-cell receptor (TCR) gene analysis. Histopathology showed infiltration of medium to large atypical pleomorphic cells involving the subcutis with characteristic rimming of fat spaces. TCR gene rearrangement shows monoclonal rearrangements of the TCR β and γ chains. Immunophenotypic studies showed that CD3, CD4, and CD8 were strongly and diffusely positive in lesional cells and that CD56 was focally positive. In contrast, these cells were negative for CD20, CD30, and CD68. The combined morphology, characteristic histologic features, and positive T-CR gene rearrangement supported a diagnosis of SPTCL. He is being treated with combination chemotherapy of cyclophosphamide, doxorubicin, vincristine, and prednisolone.

Uncommon non-Hodgkin lymphomas of childhood: pathological diagnosis, clinical features and treatment approaches

We provide a review of the pathological and clinical features for uncommon B-cell and T-cell lymphomas of childhood with a specific focus on advances in treatment approaches and outcomes. There is clearly a need for prospective investigation of both the clinical and biological features of the uncommon non-Hodgkin lymphoma subtypes in childhood. These results should lead to more uniform and more effective treatment approaches.

Molecular characterization of subcutaneous panniculitis-like T-cell lymphoma reveals upregulation of immunosuppression- and autoimmunity-associated genes

Background

Subcutaneous panniculitis-like T cell lymphomas represent a rare and difficult to diagnose entity of cutaneous T cell lymphomas. SPTL affects predominantly young adults and presents with multifocal subcutaneous nodules and frequently associated autoimmune features. The pathogenesis of SPTL is not completely understood.

Methods

The aim of this study was to unravel molecular pathways critical to the SPTL pathogenesis. Therefore, we analyzed 23 skin samples from 20 newly diagnosed SPTL patients and relevant control samples of adipose and non-malignant panniculitis tissue by using gene expression microarray, quantitative PCR, and two-colour immunohistochemistry.

Results

Interestingly, indoleamine 2,3-dioxygenase (IDO-1), an immunotolerance-inducing enzyme, was among the most highly overexpressed genes in all comparisons. The expression of Th1-specific cytokines, known to be associated with autoimmune inflammation (i.e. IFNG, CXCR3, CXCL9, CXCL10, CXCL11, and CCL5), were also significantly increased. Confirmed using immunohistochemistry, the morphologically malignant lymphocytes expressed CXCR3 and CXCL9. IDO-1 expression was found both in some morphologically malignant lymphocytes rimming the adipocytes and in surrounding CD11c⁻ CD68⁻ cells but not in CD11c⁺ dendritic cells in the microenvironment. The proportion of FoxP3+ cells in SPTL exceeded that in the benign panniculitis samples.

Conclusions

Our results indicate that the up regulation of the tolerogenic IDO-1 together with the up regulation of IFNG, CXCR3 ligands, and CCL5 are features of SPTL lesions. We anticipate that the IFNG-inducible IDO-1 expression contributes to the formation of an immunosuppressive microenvironment, favorable for the malignant T cells. This study provides a relevant molecular basis for further studies exploring novel therapeutic means for subcutaneous T cell lymphoma.

Electronic supplementary material

The online version of this article (doi:10.1186/s13023-014-0160-2) contains supplementary material, which is available to authorized users.

Gamma-delta t-cell lymphomas

Gamma-delta T-cell lymphomas are aggressive and rare diseases originating from gamma-delta lymphocytes. These cells, which naturally play a role in the innate, non-specific immune response, develop from thymic precursor in the bone marrow, lack the major histocompatibility complex restrictions and can be divided into two subpopulations: Vdelta1, mostly represented in the intestine, and Vdelta2, prevalently located in the skin, tonsils and lymph nodes. Chronic immunosuppression such as in solid organ transplanted subjects and prolonged antigenic exposure are probably the strongest risk factors for the triggering of lymphomagenesis. Two entities are recognised by the 2008 WHO Classification: hepatosplenic gamma-delta T-cell lymphoma (HSGDTL) and primary cutaneous gamma-delta T-cell lymphoma (PCGDTL). The former is more common among young males, presenting with B symptoms, splenomegaly and thrombocytopenia, usually with the absence of nodal involvement. Natural behaviour of HSGDTL is characterised by low response rates, poor treatment tolerability, common early progression of disease and disappointing survival figures. PCGDTL accounts for <1% of all primary cutaneous lymphomas, occurring in adults with relevant comorbidities. Cutaneous lesions may vary, but its clinical behaviour is usually aggressive and long-term survival is anecdotal. Available literature on gamma-delta T-cell lymphomas is fractioned, mostly consisting of case reports or small cumulative series. Therefore, clinical suspicion and diagnosis are usually delayed, and therapeutic management remains to be established. This review critically analyses available evidence on diagnosis, staging and behaviour of gamma-delta T-cell lymphomas, provides recommendations for therapeutic management in routine practice and discusses relevant unmet clinical needs for future studies.

Primary cutaneous γδ-T-cell lymphoma (CGD-TCL) with unilateral lower extremity swelling as first-onset symptom: a rare case report

Primary cutaneous γδ-T-cell lymphoma (CGD-TCL) is a distinct disease entity which is an extremely rare neoplasm with poor prognosis, characterized by the γ/δ T-cell receptor expression on atypical lymphocytes. We report the case of a 42-year-old man who first presented with a swelling in the extremities and subsequent appeared subcutaneous nodule over the body. In order to clarify the diagnosis, a biopsy of subcutaneous nodule for pathology had been done. CGD-TCL was diagnosed by histopathology, immunophenotype, in situ hybridization and analysis of TCRγ genes rearrangement. The patient was treated with chemotherapeutic regimens-CHOP (cyclophosphamide, doxorubicin, vincristine and prednisolone). After one period of chemotherapy, subcutaneous nodules became small, even disappeared, swelling and ulcer in the left pedal gone away gradually. One month later after first chemotherapy, tumor relapsed with lesions growing back rapidly, also showed disease in double lungs. The patient was just 10-month survival time from the onset. To our knowledge, this case is the first report of CGD-TCL with unilateral lower extremity swelling as the first-onset symptom. If patient is presented the first symptoms such as swelling of extremities, especially when ulceration appears, it is of great significance to be considerate about the possibility of CGD-TCL.

Topical and oral bexarotene

Bexarotene is a retinoid that specifically binds retinoid X receptors and has numerous effects on cellular growth and differentiation. It is approved for the treatment of cutaneous T cell lymphoma both topically and systemically. Adverse effects include hyperlipidemia, central hypothyroidism, and neutropenia with bexarotene capsules, and an irritant dermatitis with bexarotene gel. With aggressive management of these potential side effects, bexarotene is an additional option in the armamentarium for management of cutaneous T cell lymphoma.

Bexarotene nanocrystal-Oral and parenteral formulation development, characterization and pharmacokinetic evaluation

Bexarotene (Targretin®) is a synthetic retinoid that selectively activates the retinoid X receptor subfamily of retinoid receptors and exhibits potent anti-tumor activity. However, the poor solubility and bioavailability limit its application. The main aim of this study is to investigate the potential of oral and parenteral nanocrystals in enhancing the bioavailability of bexarotene. In this work, the orthogonal design was used to screen the optimum stabilizers and precipitation-combined microfluidization method was employed to obtain the optimal nanocrystals. According to DSC, X-ray diffraction analysis and Raman examination, the nanocrystals were still in crystalline state after the preparation procedure. By reducing the particle size, the in vitro dissolution rate of bexarotene was increased significantly. The in vivo test was carried out in rats and pharmacokinetic parameters of the bexarotene solution and bexarotene nanocrystals were compared after gavage and intravenous administration. The higher AUC and lower Cmax indicated that oral bexarotene nanocrystals significantly increased the bioavailability of bexarotene and decreased its side effects. Compared to the oral nanocrystals, the intravenous nanocrystals cut losses and increased bioavailability because of the absence of first pass effect and enterohepatic circulation.

Role of bexarotene in the treatment of cutaneous T-cell lymphoma: the clinical and immunological sides

Cutaneous T-cell lymphomas (CTCLs) are a heterogeneous group of lymphoid neoplasms. The incidence of CTCLs has risen over the last three decades. The most common CTCLs are mycosis fungoides and Sèzary syndrome. Therapies for CTCLs are various and range from skin-directed therapy to chemotherapy. Retinoids have been used in CTCL treatment since the 1980s with good results. Bexarotene is the first retinoid approved by the US FDA for CTCL therapy. Since then, numerous experiences of both its efficacy and mechanism of action have been reported. The aim of this paper is to review bexarotene action on CTCLs, as well as to highlight its immunological targets.

Subcutaneous panniculitis-like T-cell lymphoma in the pediatric age group: a lymphoma of low malignant potential

BACKGROUND

Subcutaneous panniculitis-like T-cell lymphoma (SPTCL) is a rare neoplasm of mature αβ cytotoxic T-cells. Most commonly occurring in young adults, few reports are described in children. A separate analysis of a significant cohort of pediatric patients has not previously been performed.

PROCEDURE

We analyzed the pathology including molecular results as well as available clinical data from 16 pediatric patients (age 5 months to 21 years) who had a total of 19 biopsies submitted to the National Cancer Institute from 1999 to 2011. This included 6 males and 10 females.

RESULTS

Most patients (10/16, 62.5%) had multiple skin lesions at the time of biopsy. Histologic features included rimming of adipocytes by atypical lymphocytes, fat necrosis, and karyorrhectic debris. Four biopsies showed only partial involvement by lymphoma; and plasma cells were identified in 14/19 (74%) cases, including three in which they were focally prominent. The neoplastic cells in general were positive for CD3, CD8, TIA-1, and βF1 and were negative for CD4 and CD56. CD5 expression was weak to negative in 5/8 cases (63%). A clonal T-cell receptor gene rearrangement was demonstrated in 11/17 (65%). Patients were treated with a variety of agents. While 5/9 (56%) patients had evidence of recurrent skin lesions, no deaths were attributed to disease for the seven patients with follow-up information.

CONCLUSIONS

Pediatric SPTCL shares many clinical and pathologic features with adult SPTCL. The presence of partial involvement or admixed plasma cells makes the differential diagnosis with reactive conditions challenging in some cases.

Peripheral T-cell and NK-cell lymphomas in the WHO classification: pearls and pitfalls

Peripheral T-cell and NK-cell lymphomas are functionally, pathologically, and clinically complex. Most nodal T-cell lymphomas belong to the adaptive immune system, whereas many extranodal T-cell and NK-cell lymphomas are derived from innate immune cells. The pathological manifestations often reflect the functional attributes of the neoplastic cells. Several forms of peripheral T-cell lymphoma are derived from T-follicular helper cells (T(FH)), and include angioimmunoblastic T-cell lymphoma, the follicular variant of peripheral T-cell lymphoma, not otherwise specified, and primary cutaneous small/medium CD4-positive T-cell lymphoma. T(FH)-derived neoplasms are often associated with atypical and clonal B-cell proliferations, which take a number of forms, sometimes mimicking classical Hodgkin's lymphoma, and sometimes showing marked plasmacytic differentiation. Most extranodal T-cell lymphomas are cytotoxic and often arise in mucosal-associated sites. They can be derived from either αβ or γδ cytotoxic T cells, and include subcutaneous panniculitis-like T-cell lymphoma, and enteropathy-associated T-cell lymphomas, both Type I and Type II. Type I enteropathy-associated lymphomas occur in association with celiac disease, whereas Type II lymphomas are more often sporadic. For some T-cell lymphomas, such as hepatosplenic T-cell lymphoma, immunophenotypic heterogeneity is seen within a single disease entity. New data are emerging on the molecular pathogenesis of T-cell and NK-cell lymphoma, but most tumor types remain poorly characterized.