Search Results (38)

Introduction: Cutaneous T cell lymphoma (CTCL), most commonly known as mycosis fungoides (MF), is characterized by an increasingly immunosuppressive tumor microenvironment (TME) as the disease progresses. Cancer-associated fibroblasts (CAFs) are key stromal components that support a permissive niche, in part through the secretion of small extracellular vesicles (sEVs), predominantly exosomes, that mediate intercellular communication. We investigated the immunomodulatory role of exosome-enriched sEVs derived from MF fibroblasts (MF-Fs) compared to normal fibroblasts (N-Fs). Materials and Methods: Primary MF-Fs from early-stage MF biopsies and N-Fs from healthy skin were cultured in vitro. sEVs enriched with exosomes were isolated by ultracentrifugation and characterized by flow cytometry (CD81), electron microscopy, Nanosight analysis, and protein quantification, and their uptake by normal peripheral blood mononuclear cells (nPBMCs) was confirmed using PKH26-labeled sEVs. nPBMCs, monocytes, CD4⁺ and CD8⁺ T cells from healthy donors were exposed to MF-F or N-F sEVs. Cell viability was assessed using MTT and trypan blue exclusion assays. Mass cytometry (CyTOF) profiled immune subsets and regulatory proteins for preliminary observation. Monocyte polarization was evaluated by flow cytometry for M1 (CD80, CD86) and M2 (CD163, CD206) markers and PD-L1 expression; M1/M2-associated cytokines and sEV-microRNAs were quantified by qRT-PCR. Results: Both MF-F and N-F sEVs were internalized by nPBMCs and reduced their viability, with a more pronounced effect observed for MF-F sEVs. In nPBMCs, MF-F sEVs also increased the frequency of M2-like macrophages, decreased M1 polarization, and enhanced PD-L1 expression. In primary monocytes, MF-F- compared with N-F-derived sEVs upregulated M2-associated cytokines (IL-10, TGF-β), increased PD-L1 expression, and generated M2-like cells that suppressed CD4⁺ and CD8⁺ T cell viability. Conclusions: MF-F sEVs promote an immunosuppressive TME and represent potential therapeutic or biomarker targets in MF. Full article

Cutaneous T-cell lymphoma (CTCL), primarily mycosis fungoides (MF) and Sézary syndrome (SS), has long been characterized as a neoplasm of mature memory T cells, based on monoclonal T-cell receptor (TCR) rearrangements and tissue-resident memory (TRM)/central memory (TCM) T-cell phenotypes. This review synthesizes converging population-genetic, multi-omic, and single-cell evidence to argue that this characterization is incomplete and that a progenitor-based model better accounts for the full spectrum of disease biology. We present evidence that initiating mutations arise in hematopoietic stem or early lymphoid progenitor survive thymic selection, and diversify after TCR assembly, resulting in branched evolution across both blood and skin. In SS, paired analyses reveal > 200 shared variants between CD34⁺ progenitors and Sézary cells, as well as signal-joint T-cell receptor excision circle (sjTREC) positivity, providing direct progenitor-level evidence. In MF, convergent signals, multiple malignant clonotypes per lesion, greater blood–skin than skin–skin clonotype overlap, and compartment-specific CNV subclones, implicate hematogenous seeding and reseeding. Population-scale lymphoid clonal hematopoiesis and lymphoid-pattern mosaic chromosomal alterations define a compatible antecedent state. Spatial single-cell atlases and trajectory analyses map site-conditioned programs in skin, including Th2-skewed cytokines, microbial responses, and UV signatures, that select and expand subclones and explain inter- and intra-patient heterogeneity. This framework reconciles mature immunophenotypes with upstream initiation and clarifies why compartment-focused therapies often reshape rather than eradicate disease. It yields testable predictions and actionable implications: trials should pair multicompartment cytoreduction with strategies that attenuate progenitor-derived reservoirs, restore immune balance, and repair skin barrier dysfunction. A progenitor-initiated, niche-adapted model provides a coherent scaffold for more durable control in CTCL. Full article

Background and Objectives: Mycosis fungoides (MF) is the predominant subtype of cutaneous T-cell lymphoma, whereas large plaque parapsoriasis (LPP) closely resembles early-stage MF, making differential diagnosis challenging. Immune markers, such as CD47, CD163, and B7-H3, play crucial roles in tumor immune evasion and macrophage polarization. However, their expression profiles and potential diagnostic or prognostic implications in early-stage MF and LPP remain poorly defined. Therefore, this study aimed to evaluate the expression of CD47, CD163, and B7-H3 in early-stage MF and LPP and analyze their associations with clinicopathological characteristics and patient outcomes. Materials and Methods: This retrospective study evaluated the immunohistochemical expression of CD47, CD163, and B7-H3 in 46 patients with early-stage mycosis fungoides (MF) and 46 patients with large plaque parapsoriasis (LPP). Expression levels were assessed using an immunoreactivity scoring system and analyzed for their associations with clinical parameters and disease-free survival (DFS). The study included patients diagnosed and followed at Sivas Cumhuriyet University between 1 March 2015 and 31 March 2025. Results: High CD47 expression was detected in 72.7% of MF patients, high B7-H3 expression in 45.7%, and high CD163 expression in 46.7% compared with LPP patients (p < 0.001). These markers showed positive correlations, and elevated expression, especially of B7-H3 and CD163, was associated with shorter disease-free survival in univariate analysis. Conclusions: The higher expression of CD47, CD163, and B7-H3 in early-stage MF compared with LPP suggests that these markers may contribute to the differential diagnosis and could represent potential therapeutic targets; however, their independent prognostic value requires confirmation in larger studies. Full article

Cutaneous T-Cell Lymphomas (CTCL) are a heterogenous group of T-cell malignancies in the skin and have poor treatment outcomes in advanced stages. CD5, a surface glycoprotein expressed on most mature T cells, has emerged as a promising target for chimeric antigen receptor (CAR) T-cell therapy in systemic T-cell lymphomas. However, its expression profile in CTCL and relevance for targeted therapy remain unclear. Notably, in CTCL, the cell surface expression of receptors, such as CD7 and CD26, tends to become downregulated on the surfaces of malignant T cells In this study, we analyzed single-cell RNA sequencing (scRNA-seq) data from patients at two institutions with mycosis fungoides (MF), the most common subtype of CTCL with a predominantly CD4 phenotype. We utilized 5 patch/plaque MF skin biopsies (majority from early-stage patients), 8 MF tumor biopsies (all from advanced-stage patients), and 8 healthy control biopsies to evaluate lesion-specific CD5 gene expression on CD4 T cells. We found that CD5 was significantly increased in malignant MF CD4 T cells compared to healthy control CD4 T cells (21.1% of MF CD4 T cells expressed CD5 vs. 5.2% of healthy control CD4 T cells, respectively). In subgroup analysis, patch/plaque stage MF biopsies showed higher expression of CD5 in CD4 T cells than tumor stage MF biopsies. Notably, 94.3% of malignant CD4⁺ T cells in tumor stage MF lesions exhibited complete CD5 loss compared to only 76.6% in patch-plaque MF lesions, suggesting antigen escape in tumor stage disease. These findings demonstrate that CD5 expression in CTCL is dynamic and varies based on lesion type. Our work suggests CD5 may be a viable therapeutic target in MF with patch/plaque presentations but may not be as effective in advanced stages of MF with tumor presentations. This work informs CD5 gene expression in MF based on clinical lesion type and further information is needed to clarify clinical implications as a future therapeutic target. Full article

Background/Objectives: High-frequency ultrasonography (HFUS) has gained increasing attention in dermatology as a non-invasive imaging technique capable of visualizing cutaneous structures with high resolution. In cutaneous T-cell lymphomas (CTCL), including mycosis fungoides (MF)/Sézary syndrome (SS), HFUS may provide an objective method for assessing disease activity and monitoring treatment response. This study aimed to evaluate the clinical utility of HFUS in detecting therapy-induced changes in subepidermal low-echogenic band (SLEB) thickness. Methods: We conducted a prospective, single-center study between May 2021 and May 2025. Thirty-three patients with histologically confirmed MF (n = 31) or SS (n = 2) underwent HFUS at baseline and after 4–8 weeks of treatment. SLEB thickness was measured before (E1) and after early treatment (E2). Patients received systemic agents, phototherapy, or topical regimens. Statistical analysis included mixed-model ANOVA with repeated measures to assess SLEB changes, and post hoc tests were applied to explore the influence of therapy type, age, and gender. Results: Among 31 evaluable patients with MF, HFUS revealed a significant reduction in SLEB thickness after treatment (0.90 ± 1.10 mm vs. 0.69 ± 0.89 mm; F(1,29) = 8.88, p = 0.006, η² = 0.23). The type of early therapy (systemic vs. topical) did not significantly affect outcomes (p = 0.452). Age emerged as a relevant factor: patients ≥ 66 years exhibited higher baseline SLEB values and a significant reduction post-treatment (p < 0.001), whereas no comparable effect was observed in younger patients. Gender did not significantly influence SLEB changes. Conclusions: HFUS is a sensitive and clinically applicable imaging tool for monitoring treatment response in MF/SS. Reductions in SLEB thickness were observed across therapeutic modalities and aligned with early clinical improvement. HFUS may serve as a valuable adjunct to standard clinical and histopathological evaluation in the routine management of MF/SS. Full article

Introduction: Mycosis fungoides (MF) is the most common cutaneous T-cell lymphoma, often exhibiting loss of pan-T-cell markers such as CD2, CD3, CD5, and CD7. While these immunophenotypic alterations assist in diagnosis, their prognostic relevance in early-stage MF remains uncertain. This study aimed to determine whether immunohistochemical loss of T-cell markers CD2, CD3, CD5, and CD7 in patients with early-stage mycosis fungoides is associated with overall survival and progression-free survival. Methods: This retrospective included 83 patients with stage IA–IIA MF diagnosed between 2003 and 2012 at a single institution. Immunohistochemical staining of archived biopsy specimens was performed for CD2, CD3, CD5, and CD7. Loss of marker expression was defined as absence in ≥30% of lymphocytes. Clinical and histopathological data were correlated with survival and progression outcomes using Kaplan–Meier curves and log-rank tests. Results: Loss of at least one T-cell marker was identified in 66% of patients, most commonly CD7 (72%), followed by CD5 (11%) and CD2 (11%). No cases showed loss of CD3 expression. CD7 loss was significantly associated with shorter progression-free survival (p < 0.05), but not with overall survival. No significant associations were found between CD2 or CD5 loss and either survival or disease progression. Conclusions: CD7 loss was the only immunohistochemical abnormality significantly associated with earlier disease progression in early-stage MF, suggesting a potential prognostic role. In contrast, loss of CD2 and CD5 did not affect survival or progression, and CD3 was preserved in all cases. These findings highlight the value of incorporating CD7 status into prognostic assessment, although larger studies are needed to confirm its utility. Full article

Background: Dermoscopy, a non-invasive diagnostic technique, is being increasingly used to evaluate cutaneous T-cell lymphomas such as mycosis fungoides (MF) and Sézary syndrome (SS). However, its diagnostic accuracy and role in staging remain underexplored. Objective: This study aimed to assess the dermoscopic patterns in MF and SS, correlating the findings with the disease stage and lesion type to evaluate dermoscopy’s diagnostic utility. Methods: A retrospective, monocentric analysis was conducted on patients with histologically confirmed MF or SS. Dermoscopic images were evaluated for vascular patterns, pigmentation, scaling, and keratin plugs. The statistical analysis assessed the correlations between these dermoscopic features and the TNMB staging and lesion type. A literature review was also performed to contextualize the findings, focusing on studies describing dermoscopic features in MF based on retrospective, prospective, and cross-sectional data. Results: The study included 30 patients with histologically confirmed MF or SS (19 males and 11 females; mean age: 64.5 years). The dermoscopic evaluation revealed that all the lesions were pigment-free, with vascular structures as the predominant feature. Linear vessels (40%) and serpentine vessels (13.3%) were the most frequently observed, along with dotted vessels (36.7%) and clods (10%). The vessel distribution was diffuse (40%) or perifollicular (36.7%), with a predominant red (56.7%) or orange (40%) background. Scaling was present in 76.7% of cases, either diffuse (40%) or perifollicular (36.7%), and keratin plugs were detected in 40% of the lesions. No statistically significant correlations were found between dermoscopic features and the TNMB stage or lesion type (p > 0.05). A cluster analysis identified two patient groups with differing vascular and scaling features but no clear association with disease stage. The literature review identified studies that commonly reported features in MF dermoscopy, including fine, short linear vessels and an orange-yellow background, particularly in early-stage MF. Spermatozoa-like structures have been marked as highly specific for diagnosing MF. Some studies also suggested a transition in vascular morphology from linear vessels in early disease to branched vessels and ulceration in advanced stages. Conclusions: Our results showed some vascular patterns have some potential but lack sensitivity for staging MF and SS. The terminology used and the reproducibility of our results compared to those reported in the literature showed little consistency, with none of our cases showing spermatozoa-like structures. Moreover, the same issues with the use of non-reproducible terminology were noted across the studies because it is not standardized and due to different incongruent dermoscopic patterns. More significant prospective studies with standardized descriptors and larger groups are needed to refine its diagnostic and staging utility. Full article

Background: We herein review the most important clinico-pathological features of mycosis fungoides (MF). These evolving clinico-pathological aspects are paired with innovative therapeutic schemes. Moreover, we indicate cutaneous lymphomas as a new frontier of artificial intelligence application. Methods: We encompass new diagnostic and prognostic data derived from the recent medical literature describing the possible histological features which could be the targets of deep learning in conjunction with available clinical data. Results: In spite of decades of research, MF diagnosis still represents the most challenging debate from a dermatopathologist’s point of view. Genetic alterations have been identified mainly in late stages of the disease, and their importance for disease initiation is still unclear. The exploration of the genome-wide expression of individual genes in skin samples may be useful in elucidating MF pathogenesis and improving early diagnosis, while artificial intelligence could offer the possibility of searching for biomarkers of disease progression. Conclusions: MF still deserves the name of the ‘great imitator’, both clinically and histopathologically. The goal of summing up all the clinico-pathological information before reaching a final diagnosis is the approach needed to reach diagnostic accuracy, especially in early MF cases. It is advisable to think of the most common clinical presentations, to be aware of the most common histopathological features, and to interpret the results of ancillary studies only in the right clinico-pathological context. 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

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/objectives: Mycosis fungoides (MF) is a rare malignancy, with an indolent course in the early stages of the disease. However, due to major molecular and clinical heterogeneity, patients at an advanced stage of the disease have variable responses to treatment and considerably reduced life expectancy. Today, there is a lack of specific markers for the progression from early to advanced stages of the disease. To address these challenges, the non-interventional BIO-MUSE trial was initiated. Here, we report on a case study involving one patient, where combined omics analysis of tissue and blood was used to reveal the unique molecular features associated with the progression of the disease. Methods: We applied 10× genomics-based single-cell RNA sequencing to CD3+ peripheral T-cells, combined with T-cell receptor sequencing, to samples collected at multiple timepoints during the progression of the disease. In addition, GeoMx-based digital spatial profiling of T-helper (CD3+/CD8−), T-cytotoxic (CD3+/CD8+), and CD163+ cells was performed on skin biopsies. Results. The results pinpoint targets, such as transforming growth factor β1, as some of the mechanisms underlying disease progression, which may have the potential to improve patient prognostication and the development of precision medicine efforts. Conclusions: We propose that in patients with MF, the evolution of the malignant clone and the associated immune response need to be studied jointly to define relevant strategies for intervention. Full article

Background: Mycosis fungoides (MF) represents the most prevalent entity of cutaneous T cell lymphoma (CTCL). The MF aetiopathogenesis is incompletely understood, due to significant transcriptomic heterogeneity and conflicting views on whether oncologic transformation originates in early thymocytes or mature effector memory T cells. Recently, using clinical specimens, our group showed that the skin microbiome aggravates disease course, mainly driven by an outgrowing, pathogenic S. aureus strain carrying the virulence factor spa, which was shown by others to activate the T cell signalling pathway NF-κB. Methods: To explore the role of the skin microbiome in MF aetiopathogenesis, we here performed RNA sequencing, multi-omic data integration of the skin microbiome and skin transcriptome using Multi-Omic Factor Analysis (MOFA), virome profiling, and T cell receptor (TCR) sequencing in 10 MF patients from our previous study group. Results: We observed that inter-patient transcriptional heterogeneity may be largely attributed to differential activation of T cell signalling pathways. Notably, the MOFA model resolved the heterogenous activation pattern of T cell signalling after denoising the transcriptome from microbial influence. The MOFA model suggested that the outgrowing S. aureus strain evoked signalling by non-canonical NF-κB and IL-1B, which in turn may have fuelled the aggravated disease course. Further, the MOFA model indicated aberrant pathways of early thymopoiesis alongside enrichment of antiviral innate immunity. In line with this, viral prevalence, particularly of Epstein–Barr virus (EBV), trended higher in both lesional skin and the blood compared to nonlesional skin. Additionally, TCRs in both MF skin lesions and the blood were significantly more likely to recognize EBV peptides involved in latent infection. Conclusions: First, our findings suggest that S. aureus with its virulence factor spa fuels MF progression through non-canonical NF-κB and IL-1B signalling. Second, our data provide insights into the potential role of viruses in MF aetiology. Last, we propose a model of microbiome-driven MF aetiopathogenesis: Thymocytes undergo initial oncologic transformation, potentially caused by viruses. After maturation and skin infiltration, an outgrowing, pathogenic S. aureus strain evokes activation and maturation into effector memory T cells, resulting in aggressive disease. Further studies are warranted to verify and extend our data, which are based on computational analyses. Full article

Mycosis fungoides (MF) is the most prevalent type of cutaneous T cell lymphomas. Studies on the prognosis of MF are limited, and no research exists on the potential of artificial intelligence to predict MF prognosis. This study aimed to compare the predictive capabilities of various machine learning (ML) algorithms in predicting progression, treatment response, and relapse and to assess their predictive power against that of the Cox proportional hazards (CPH) model in patients with early-stage MF. The data of patients aged 18 years and over who were diagnosed with early-stage MF at Ankara University Faculty of Medicine Hospital from 2006 to 2024 were retrospectively reviewed. ML algorithms were utilized to predict complete response, relapse, and disease progression using patient data. Of the 185 patients, 94 (50.8%) were female, and 91 (49.2%) were male. Complete response was observed in 114 patients (61.6%), while relapse and progression occurred in 69 (37.3%) and 54 (29.2%) patients, respectively. For predicting progression, the Support Vector Machine (SVM) algorithm demonstrated the highest success rate, with an accuracy of 75%, outperforming the CPH model (C-index: 0.652 for SVM vs. 0.501 for CPH). The most successful model for predicting complete response was the Ensemble model, with an accuracy of 68.89%, surpassing the CPH model (C-index: 0.662 for the Ensemble model vs. 0.543 for CPH). For predicting relapse, the decision tree classifier showed the highest performance, with an accuracy of 78.17%, outperforming the CPH model (C-index: 0.782 for the decision tree classifier vs. 0.505 for CPH). The results suggest that ML algorithms may be useful in predicting prognosis in early-stage MF patients. Full article

Cutaneous T cell lymphomas (CTCLs) are a heterogeneous group of non-Hodgkin lymphomas, with mycosis fungoides and Sézary syndrome being the two common subtypes. Despite the substantial improvement in early-stage diagnosis and treatments, some patients still progress to the advanced stage with an elusive underpinning mechanism. While this unsubstantiated disease mechanism coupled with diverse clinical outcomes poses challenges in disease management, emerging evidence has implicated the tumor microenvironment in the disease process, thus revealing a promising therapeutic potential of targeting the tumor microenvironment. Notably, malignant T cells can shape their microenvironment to dampen antitumor immunity, leading to Th2-dominated responses that promote tumor progression. This is largely orchestrated by alterations in cytokines expression patterns, genetic dysregulations, inhibitory effects of immune checkpoint molecules, and immunosuppressive cells. Herein, the recent insights into the determining factors in the CTCL tumor microenvironment that support their progression have been highlighted. Also, recent advances in strategies to target the CTCL tumor micromovement with the rationale of improving treatment efficacy have been discussed. Full article

Primary cutaneous lymphomas (PCLs), especially mycosis fungoides (MF), pose significant diagnostic and therapeutic challenges. This study aims to correlate initial histological features with the disease course and survival in MF patients. A retrospective–prospective cohort study was conducted on 83 patients diagnosed with early-stage MF at the Departments of Dermatovenerology and Pathology, UHC Zagreb, from January 2003 to December 2012. The analyzed histopathological parameters included lichenoid dermal lymphocyte infiltrate, Pautrier microabscesses, and lymphocyte atypia. Patients with more than 30 guardian lymphocytes per 100 keratinocytes exhibited worse overall and progression-free survival. Furthermore, those with over 50% atypical lymphocytes demonstrated a faster progression rate. A dense lichenoid dermal infiltrate and a high count of lymphocyte “keepers” significantly increased the mortality risk within five years of diagnosis. This study did not fully confirm the hypothesis regarding the prognostic value of large Pautrier microabscesses but highlighted the importance of dense lichenoid infiltrates. The study identified new potential histopathological prognostic factors in early-stage MF, suggesting the need for larger studies to confirm these findings. The identification of such predictors could enhance the prognostic stratification and guide more tailored therapeutic approaches for MF patients. Full article