Search Results (119)

Whether the spongiotic reaction caused by the interaction of keratinocytes, T-lymphocytes, inflammatory dendritic epidermal cells (IDECs), and Langerhans cells (LCs) observed in atopic dermatitis (AD) represents a common feature of spongiosis in various skin diseases remains unclear. We analyzed the characteristics of spongiosis in AD compared with those in other eczematous dermatitis and inflammatory skin diseases by using immunohistochemical methods. Infiltration of IDECs (CD11c+ cells and/or CD206+ cells) and T-lymphocytes, accompanied by degenerated keratinocytes and aggregated LCs (CD207+ cells), was frequently observed as a common feature of spongiosis in multiple conditions. However, IDECs expressing IgE were identified exclusively in IgE-mediated AD. Aggregation of IDECs was predominantly observed in the spongiosis of adaptive immune-mediated eczematous disorders, such as AD and allergic contact dermatitis. These IDEC aggregations constituted the major components of the epidermal dendritic cell clusters seen in AD and other eczematous or eczematoid dermatoses, and may serve as a useful distinguishing marker from Pautrier collections seen in cutaneous T-cell lymphoma. These findings suggest that IDECs, in cooperation with other immune cells, may play a pivotal role in spongiosis formation in AD and various skin diseases, although the underlying immunopathological mechanisms differ among these conditions. Full article

In this review, we explore the complexities of objectively assessing the response to immunotherapy in mycosis fungoides (MF), a prevalent form of cutaneous T-cell lymphoma. The core challenge lies in distinguishing between reactive and malignant lymphocytes amidst treatment, particularly given the absence of uniform pathological biomarkers for MF. We highlight the vital role of emerging histological technologies, such as multispectral imaging and spatial transcriptomics, in offering a more profound insight into the tumor microenvironment (TME) and its dynamic response to immunomodulatory therapies. Drawing on parallels with melanoma—another immunogenic skin cancer—our review suggests that methodologies and insights from melanoma could be instrumental in refining the approach to MF. We specifically focus on the prognostic implications of various TME cell types, including CD8+ tumor-infiltrating lymphocytes, natural killer (NK) cells, and histiocytes, in predicting therapy responses. The review culminates in a discussion about adapting and evolving treatment response quantification strategies from melanoma research to the distinct context of MF, advocating for the implementation of novel techniques like high-throughput T-cell receptor gene rearrangement analysis. This exploration underscores the urgent need for continued innovation and standardization in evaluating responses to immunotherapies in MF, a field rapidly evolving with new therapeutic strategies. Full article

Intravascular lymphoma (IVL) is a rare, aggressive subtype of non-Hodgkin lymphoma (NHL) characterized by the selective proliferation of neoplastic lymphoid cells within small and medium-sized blood vessels, most frequently of B-cell origin (IVLBCL). Its protean clinical presentation, lack of pathognomonic findings, and absence of tumor masses or lymphadenopathies often lead to diagnostic delays and poor outcomes. IVLBCL can manifest in classic, hemophagocytic syndrome-associated (HPS), or cutaneous variants, with extremely variable organ involvement including the central nervous system (CNS), skin, lungs, and endocrine system. Diagnosis requires histopathologic identification of neoplastic intravascular lymphoid cells via targeted or random tissue biopsies. Tumor cells are highly atypical and display a non-GCB B-cell phenotype, often expressing CD20, MUM1, BCL2, and MYC; molecularly, they frequently harbor mutations in MYD88 and CD79B, defining a molecular profile shared with ABC-type DLBCL of immune-privileged sites. Therapeutic approaches are based on rituximab-containing chemotherapy regimens (R-CHOP), often supplemented with CNS-directed therapy due to the disease’s marked neurotropism. Emerging strategies include autologous stem cell transplantation (ASCT) and novel immunotherapeutic approaches, potentially exploiting the frequent expression of PD-L1 by tumor cells. A distinct but related entity, intravascular NK/T-cell lymphoma (IVNKTCL), is an exceedingly rare EBV-associated lymphoma, showing unique own histologic, immunophenotypic, and molecular features and an even poorer outcome. This review provides a comprehensive overview of the current understandings about clinicopathological, molecular, and therapeutic landscape of IVL, emphasizing the need for increased clinical awareness, standardized diagnostic protocols, and individualized treatment strategies for this aggressive yet intriguing malignancy. Full article

Background/Objectives: Subcutaneous panniculitis-like T-cell lymphoma (SPTCL) is a rare and aggressive cutaneous lymphoma, often misdiagnosed due to nonspecific clinical features. Early diagnosis and treatment remain challenging. Methods: We report the case of a 31-year-old female with a chronic non-healing gluteal wound initially treated as an abscess. The lack of improvement prompted repeated investigations, culminating in the diagnosis of SPTCL with an alpha–beta T-cell phenotype. Results: Management involved combined chemotherapy and surgical wound reconstruction. Six cycles of CHOEP-21 chemotherapy led to complete clinical remission. A soft tissue defect superinfected with multidrug-resistant organisms was successfully reconstructed using Integra Dermal Regeneration Template followed by split-thickness skin grafting. Conclusions: This case highlights the diagnostic complexity of SPTCL and the therapeutic potential of dermal matrix application in complex wound management, especially in immuno-compromised patients. Full article

Myeloid/lymphoid neoplasms with tyrosine kinase gene fusions (MLN-TK) represent a distinct group of hematologic malignancies recognized in the latest WHO classification due to shared clinical, morphological, and molecular features, and their responsiveness to tyrosine kinase inhibitors (TKIs). Among these, fusions involving the SYK gene, such as ETV6::SYK and ITK::SYK, have emerged as rare but potentially targetable genetic events in both myeloid and lymphoid neoplasms. SYK, a non-receptor tyrosine kinase critical for hematopoietic signalling, can become constitutively activated through gene fusions, driving oncogenesis via the PI3K/AKT, MAPK, and JAK-STAT pathways. ETV6::SYK has been primarily associated with myeloid neoplasms, often presenting with eosinophilia, bone marrow dysplasia, and skin involvement. In vitro and in vivo models confirm its leukemogenic potential and identify SYK as a therapeutic target. Although SYK inhibitors like fostamatinib have shown transient efficacy, resistance mechanisms, possibly involving alternative pathway activation, remain a challenge. The ITK::SYK fusion, on the other hand, has been identified in peripheral T-cell lymphomas, particularly of the follicular helper T-cell subtype, with similar pathway activation and potential for targeted intervention. Additional rare SYK fusions, such as PML::SYK and CTLC::SYK, have been reported in myeloid neoplasms and juvenile xanthogranuloma, respectively, expanding the spectrum of SYK-driven diseases. Accumulating evidence supports the inclusion of SYK fusions in future classification systems and highlights the need for broader molecular screening and clinical evaluation of SYK-targeted therapies. Full article

Background: Primary cutaneous peripheral T-cell lymphoma, not otherwise specified (pcPTCL-NOS), is a rare and aggressive form of lymphoma. Its characteristics and treatment outcomes remain poorly understood. Methods: We identified 15 patients who were diagnosed with pcPTCL-NOS between January 2014 and August 2024 at Tianjin Medical University Cancer Institute and Hospital (TMUCIH) in this retrospective study. The clinical and immunophenotypic features, treatment regimens, and outcomes of these patients were investigated. Results: All patients (4 men, 11 women; median age 54 years) presented with skin lesions, including five stage T1, four stage T2 and six stage T3 lesions. pcPTCL-NOS manifests clinically either with solitary or disseminated rapidly growing nodules/tumors and papules and, less often, ulcers. The lesion sites in patients presenting with solitary/localized tumors (stage T1 and T2) were the head and limbs, and those in patients presenting with disseminated lesions (stage T3) were the trunk, head, and limbs. The CD4/CD8 immunophenotypic characteristics were as follows: CD4+/CD8− 53.33%; CD4+/CD8+ 26.67%; CD4−/CD8− 13.33%; and CD4−/CD8+ 6.67%. One patient had a T follicular helper (TFH) phenotype. Five patients had aberrant expression of the B-cell marker CD20 by tumor cells. All patients received CHOP or CHOP-like regimens as the initial treatment, with three patients undergoing complete lesion resection before chemotherapy, seven patients receiving treatment combined with chidamide (tucidinostat), two patients receiving treatment combined with brentuximab vedotin, two patients receiving treatment combined with mitoxantrone liposomes (Lipo-Mit), three patients receiving treatment combined with radiotherapy, and two patients receiving ASCT after the first-line treatment. The OS rates at 1 year, 2 years, and 3 years were 80%, 77.8%, and 77.8%, respectively; the PFS rates were 60%, 44.4%, and 33.3%, respectively. With a median follow-up of 40 months, the median PFS was 21 months, and the median OS was not reached. Univariate analyses revealed that patients with B symptoms and the CD4−/CD8− phenotype had inferior outcomes (p < 0.05). Age, sex, tumor stage, PIT score, Ki-67 index, elevated β2-MG levels, expression of CD20 or PD1, and treatment selection were not associated with the prognosis. A trend of a survival benefit in patients with solitary (T1) tumors compared with patients with disseminated (T2, T3) tumors was observed, suggesting that it is possible to reduce the intensity of treatment in patients with T1 tumors in the future. Conclusions: pcPTCL-NOS is an aggressive but poorly characterized lymphoma that may require early and active systemic treatment. However, for patients with T1 tumors, reducing the intensity of treatment with CHOP should be appropriately considered. Full article

Mycosis fungoides (MF) and Sézary syndrome (SS) are the most prevalent forms of cutaneous T-cell lymphoma (CTCL) and are characterized by the proliferation of CD4⁺ T-helper cells. The pathogenesis of CTCLs involves a critical interaction between neoplastic cells and the tumor microenvironment. This interaction is driven not only by cytokines but also by surface proteins that mediate cell–cell contact. One such protein, OX40 (also known as CD134), is a member of the TNF receptor superfamily and serves as an induced costimulatory molecule that facilitates the interaction between T-cells and antigen-presenting cells. In this narrative review, we explore the literature surrounding the OX40–OX40L interaction in CTCLs, highlighting its pathogenic and prognostic significance. Additionally, we compare the expression and function of OX40–OX40L in chronic inflammatory skin diseases, such as atopic dermatitis and psoriasis, with their role in CTCLs. Finally, we provide an overview of the current state of therapeutic research, discussing the potential of targeting the OX40–OX40L axis in CTCL treatment. Full article

Background/Objectives: Primary cutaneous lymphomas (CLs) are a group of skin-limited lymphoproliferative disorders, including cutaneous T-cell (CTCLs) and B-cell lymphomas (CBCLs). Photodynamic therapy (PDT), a non-invasive, light-activated treatment, has gained attention as a skin-directed therapy for early-stage CLs due to its selectivity and favorable safety profile. This systematic review evaluates the current evidence on the clinical use of PDT in managing CLs. Methods: A systematic literature search was conducted in PubMed, Scopus, and Embase through 1 September 2024 following PRISMA guidelines. Search terms included “primary cutaneous skin lymphoma”, “CTCL”, “CBCL”, “mycosis fungoides”, “lymphomatoid papulosis”, and “photodynamic therapy”. After screening 1033 records, 30 studies were included. Data were extracted and categorized by lymphoma subtype and clinical outcomes. Results: Of the included studies, 23 focused on mycosis fungoides (MF), 5 on lymphomatoid papulosis (LyP), and 2 on CBCL. PDT demonstrated notable clinical efficacy in early-stage and localized disease, particularly MF, using methyl aminolevulinate (MAL) or 5-aminolevulinic acid (5-ALA) as photosensitizers. Adjunctive techniques like microneedling and laser-assisted delivery improved treatment outcomes. PDT was generally well tolerated, with mild, transient side effects; rare complications such as localized neuropathy were reported. Conclusions: PDT is a promising, non-invasive treatment for early-stage CLs, especially MF and indolent CBCL variants. While current evidence supports its safety and effectiveness, further comparative and prospective studies are needed to refine protocols, evaluate long-term efficacy, and compare different photosensitizers. Full article

Cutaneous T-cell lymphoma (CTCL), characterized by malignant T-cell proliferation primarily in the skin, includes subtypes such as mycosis fungoides (MF) and Sézary syndrome (SS). The tumor microenvironment (TME) is central to their pathogenesis, with flow cytometry and histology being the gold standards for detecting malignant T cells within the TME. Alongside emerging molecular markers, particularly clonality analysis, these tools are indispensable for accurate diagnosis and treatment planning. Of note, adenosine signaling within the TME has been shown to suppress immune responses, affecting various cell types. The expression of CD39, CD73, and CD38, enzymes involved in adenosine production, can be elevated in MF and SS, contributing to immune suppression. Conversely, the expression of CD26, part of the adenosine deaminase/CD26 complex, that degrades adenosine, is often lost by circulating tumoral cells. Flow cytometry has demonstrated increased levels of CD39 and CD73 on Sézary cells, correlating with disease progression and prognosis, while CD38 shows a variable expression, with its prognostic significance remaining under investigation. Understanding these markers’ roles in the complexity of TME-mediated immune evasion mechanisms might enhance diagnostic precision and offer new therapeutic targets in CTCL. Full article

Mycosis fungoides (MF), the most common form of cutaneous T-cell lymphoma, poses significant diagnostic challenges due to its overlap with benign inflammatory skin diseases and the absence of specific symptoms. Accurate early diagnosis and stratification of patients by progression risk are essential for effective treatment. This study proposes a proof-of-concept for integrating T-cell receptor (TCR) clonality analysis with somatic mutation profiling to enhance diagnostic confidence and prognostic accuracy in early-stage MF. This study’s methodology comprised the analysis of nine patients with early MF (stages IA/IB) using whole-exome sequencing and TCR repertoire profiling. The analysis revealed the presence of clonal TCR rearrangements in seven patients, while somatic mutations were identified in two. A notable finding was a recurrent chromosome 7 trisomy in these two cases. The patients were stratified into three molecular profiles: (1) somatic mutations with clonal TCR rearrangement (n = 2), (2) clonal TCR rearrangement without somatic mutations (n = 4), and (3) neither somatic mutations nor clonal TCR rearrangement (n = 3). These findings emphasise the heterogeneity of MF and underscore the limitations of relying solely on TCR clonality or mutation burden for diagnosis. This study underscores the potential of somatic mutations as diagnostic markers to distinguish MF from benign conditions and as prognostic indicators for disease progression. A combined genetic approach may refine treatment decisions, particularly for patients with higher tumor cell fractions and pronounced genetic alterations. Despite the limited size of the cohort, the results advocate for larger, multi-center studies to validate these findings and integrate genetic analyses into routine MF management. Full article

Background: Cutaneous T-cell lymphoma (CTCL) is a type of non-Hodgkin’s lymphoma that primarily affects the skin, rich in hyaluronic acid (HA). HA is a component of the extracellular matrix in the dermis and likely affects the development of CTCL, but the mechanism is poorly understood. Here we show that low-molecular-weight HA (LMWHA) possibly exacerbates CTCL, and bexarotene, already used in CTCL treatment, decreases HA production. Methods: We conducted immunohistochemistry, qRT-PCR, immunoblotting, and HA quantification using both mouse and human specimens to evaluate the impact of HA on CTCL. Additionally, we assessed the effect of bexarotene, which is already used for CTCL treatment, on HA metabolism. Results: HA expression was higher in patients’ serum and skin sections than in healthy controls. HA extracted from the skin of mice inoculated with tumors showed an increase in LMWHA. LMWHA increased lymphoma cell proliferation in vitro and accelerated tumor formation in mice in vivo. LMWHA also created a favorable environment for tumor cells by affecting fibroblasts, vascular endothelial cells, and tumor-associated macrophages. Thus, increased levels of HA, mainly LMWHA, exacerbate CTCL progression by affecting tumor cells and their microenvironment. Bexarotene treatment reduced the amount of total HA in murine tumor-inoculated skin, as well as the supernatant of cultured normal human dermal fibroblasts (NHDFs) and HuT78 cells. Detailed in vitro analyses showed that bexarotene treatment decreased HA synthase (HAS)1 and HAS2 expression in NHDFs and HAS1 and HAS3, and CEMIP expression in HuT78 cells. Chromatin immunoprecipitation assays revealed that bexarotene reduced retinoid X receptor-α binding to the HAS1 and HAS2 promoters in NHDFs. Conclusions: Bexarotene potentially exerts its anti-tumor effect by reducing HA levels through decreased expression of HAS. These findings provide new insights into the process of CTCL development and additional insights regarding bexarotene treatment. Full article

Background: T cell clonality is commonly assessed in the diagnostic work-up of mature T cell lymphoid neoplasms. Although fragment-length polymerase chain reaction (FL-PCR) assays are most widely used, next-generation sequencing (NGS) of the TRG and TRB genes is increasingly being used to assess T cell clonality. Objective: The present work is a scoping review of studies that assessed T cell clonality by NGS for diagnostic purposes, including only studies that provided integrated clinicopathologic diagnoses in comparing FL-PCR and NGS assays to evaluate if it is preferable to use NGS-based assays for T cell clonality evaluation in diagnostic pathology. Methods: Papers published from 1992 to 3 August 2024 were searched in PubMed. Twenty-nine cohort studies and five instructive case reports, published from 2013–2024 from the USA, UK, Europe, and Australia that provided integrated clinicopathologic diagnoses and used NGS to evaluate T cell clonality in clinical specimens from patients with mature T cell neoplasms and related non-neoplastic and neoplastic diseases were included, with additional relevant studies. Results: Ten (34.4%) of the 29 cohorts included clinical samples from patients having various cutaneous and non-cutaneous T cell malignancies, related neoplasms, and reactive conditions; 2 (6.8%) studies focused on T cell prolymphocytic leukemia, 16 (55%) on cutaneous T cell lymphoma, and one on pediatric pityriasis lichenoides. Eleven (38%) of the 29 cohort studies compared NGS with FL-PCR assays in 908 clinical samples. Eight (72.7%) of the 11 studies compared TRG FL-PCR with TRG NGS (n = 5), TRB NGS (n = 2), and TRG NGS and TRB NGS (n = 1); the remaining three compared EuroClonality/BIOMED-2 FL-PCR (TRG and TRB) with TRG NGS (n = 1), TRB NGS (n = 1), and the EuroClonality-NGS DNA capture assay (n = 1). TRB NGS was used in 16 (55%) of 29, TRG NGS in 6 (20.6%) of 29, and both TRG and TRB NGS in 7 (24%) of 29. Two (6.8%) of the 29 studies compared TRB NGS with flow cytometric immunophenotyping assays for Vβ and T cell receptor β constant region 1. One additional study compared long-read sequencing with NGS for TRG and TRB rearrangements. Conclusions: NGS is highly specific and sensitive for assessing T cell clonality. NGS precisely tracks unique rearranged sequences, which FL-PCR cannot. NGS findings for clonality must be interpreted in the context of all clinicopathologic and immunophenotypic findings, like FL-PCR. With such interpretations, NGS is much preferable to FL-PCR for evaluating T cell clonality for diagnostic purposes. It is necessary to reduce costs, increase accessibility, and educate providers about NGS for clonality evaluation. TRB NGS has been primarily assessed in the peripheral blood and skin, whereas TRG NGS has also been evaluated in formalin-fixed and non-cutaneous fresh lymphoid tissues. TRG NGS performed better than TRB NGS in comparative studies. Full article

Cutaneous T-cell lymphoma (CTCL) is a rare T-cell malignancy characterized by inflamed and painful rash-like skin lesions that may affect large portions of the body’s surface. Patients experience recurrent infections due to a compromised skin barrier and generalized immunodeficiency resulting from a dominant Th2 immune phenotype of CTCL cells. Given the role of the unfolded protein response (UPR) in normal and malignant T-cell development, we investigated the impact of UPR-inducing drugs on the viability, transcriptional networks, and Th2 phenotype of CTCL. We found that CTCL cells were >5-fold more sensitive to the proteasome inhibitor bortezomib (Btz) and exhibited a distinct signaling and transcriptional response compared to normal CD4+ cells. The CTCL response was dominated by the induction of the HSP70 family member HSPA6 (HSP70B’) and, to a lesser extent, HSPA5 (BiP/GRP78). To understand the significance of these two factors, we used a novel isoform selective small-molecule inhibitor of HSPA5/6 (JG-023). JG-023 induced pro-apoptotic UPR signaling and enhanced the cytotoxic effects of proteasome inhibitors and other UPR-inducing drugs in CTCL but not normal T cells. Interestingly, JG-023 also selectively suppressed the production of Th2 cytokines in CTCL and normal CD4+ T cells. Conditioned media (CM) from CTCL were immunosuppressive to normal T cells through an IL-10-dependent mechanism. This immunosuppression could be reversed by JG-023, other HSP70 inhibitors, Btz, and combinations of these UPR-targeted drugs. Our study points to the importance of the UPR in the pathology of CTCL and demonstrates the potential of proteasome and targeted HSPA5/6 inhibitors for therapy. Full article

Background/Objectives: This study is an attempt to reveal the potential of two types of interpenetrating polymer network (IPN) hydrogels based on poly(2-hydroxyethyl methacrylate) (PHEMA) and poly(N,N-dimethylacrylamide) (PDMAM). These IPNs were evaluated for their potential for dermal delivery of the hydrophobic drug dexamethasone (DEX). Methods: The two types of IPNs were analyzed for their rheological behavior, swelling characteristics, and drug-loading capacity with DEX. Drug release profiles were studied in Franz diffusion cells in PBS media. Finally, the cytotoxicity of the PHEMA/PDMAM-based IPNs was studied against T-cell lymphoma cells (HUT-78) and a normal murine fibroblast cell line (CCL-1). Results: The rheological properties of these hydrogels show suitable mechanical properties for dermal application, with G′ values of ~10 kPa. From the rheological data, the mesh size of these hydrogels was found to be influenced by the type of the IPN and its composition, varying between 6.5 and 50 nm. The loading capacity of both IPN types and DEX entrapment efficiency were highly influenced by the IPN’s composition. The loading capacity of the IPNs can reach ~3.5%, with a DEX entrapment efficiency of ~35%. The PHEMA/PDMAM IPNs demonstrate an extended release profile with up to ~95% DEX released in 24 h, while PDMAM/PHEMA IPNs release no more than ~25% DEX in 24 h. The drug release profiles follow either non-Fickian diffusion (n~0.6) or case-II transport (n~0.9–1), depending on the IPN’s composition. The PHEMA/PDMAM-based materials were found to be non-cytotoxic against HUT-78 and CCL-1 cells. Conclusions: The study reveals that the IPNs of PHEMA and PDMAM appear to be suitable platforms for dermal delivery of dexamethasone as they have appropriate mechanical properties, providing tools to control drug loading and release, and they are biocompatible with human skin cells. Full article

Background/Objectives: Cutaneous T-cell lymphoma (CTCL), including Mycosis fungoides (MF) and Sézary syndrome (SS), is a challenging-to-diagnose lymphoproliferative malignancy characterized by T-cell dysfunction and progressive cutaneous and extra cutaneous involvement. Disease severity assessment in CTCL is crucial for guiding treatment. This study aims to evaluate the interrater agreement and interrater reliability of mSWAT among dermatology residents and identify lesion types most prone to scoring variability. Methods: Sixteen dermatology residents with varied experience levels assessed 14 patients with confirmed MF/SS diagnoses. Using mSWAT, residents independently scored lesions severity on a standardized set of patient’s photos. The results were compared with reference mSWAT scores provided by an experienced clinician. Descriptive statistics and the Shapiro–Wilk test were applied to evaluate data distributions, while Student’s t-test assessed score deviations from reference values. Furthemore, we conducted a pilot the high frequency ultrasound (HFUS) study on a single patient, whose mSWAT score and photographs are also presented in the manuscript. Results: Significant discrepancies were observed in 64.29% of cases (9/14), with tumors and infiltrative lesions in erythrodermic SS patients posing particular scoring challenges. Misclassification of tumors as patches or plaques was a frequent issue, leading to underestimations in mSWAT scores. Residents’ assessments of infiltrative lesions were also notably inconsistent. Conclusions: This study highlights significant interobserver variability in mSWAT scoring among less experienced dermatology residents, particularly with tumor and erythrodermic lesions. Findings underscore the need for enhanced training and standardized scoring protocols to improve mSWAT reliability. Similar to other comparable indices, such as PASI, the mSWAT should be employed consistently by the same physician during each assessment to systematically monitor and evaluate the skin condition of a patient under observation. However, broader application requires the acquisition of sufficient experience. The study suggests the use of the HFUS as an objective method of assessment of the skin lesion infiltration in MF/SS patients. Full article