Allogeneic transplantation in advanced cutaneous T-cell lymphomas (CUTALLO): a propensity score matched controlled prospective study.

BACKGROUND: Advanced-stage cutaneous T-cell lymphomas (CTCLs) are rare, usually refractory, and fatal diseases. Case series have suggested that allogeneic haematopoietic stem cell transplantation (HSCT) might improve the prognosis of advanced-stage CTCLs. The objective of this study was to investigate the effect of allogeneic HSCT compared with non-HSCT therapy on the outcome of individuals with advanced-stage CTCLs. METHODS: In this prospective, multicentre, matched controlled trial, conducted at 30 hospitals, participants with advanced CTCLs were allocated treatment: if they had an available compatible related donor they were assigned to allogeneic HSCT, or if not they were allocated to non-allogeneic HSCT therapy. Key inclusion criteria were participants aged 18-70 years, with advanced stage mycosis fungoides or Sézary syndrome, and at least one poor prognostic criteria. Participants were excluded if they were not in complete or partial remission of the disease. Propensity score 1:1 matching with replacement (ie, that each participant treated with HSCT was matched to the participant with the closest propensity score treated with non-HSCT therapy, even if they had already been matched) was used to handle confounding factors, with the balance of covariate distribution between HSCT and non-HSCT groups assessed using standardised mean differences. The primary endpoint was progression-free survival in the matched intention-to-treat population. This trial is registered with ClinicalTrials.gov (NCT02520908), and is currently active but not recruiting. FINDINGS: From June 1, 2016, to March 3, 2022, total of 99 participants were enrolled at 17 centres in France. Participants with a sibling or matched unrelated donor were assigned to allogeneic HSCT (HSCT group, n=55 [56%]) and participants without a donor were assigned to non-allogeneic HSCT treatment (non-HSCT group, n=44 [44%]). The median follow-up among survivors was 12·6 months (IQR 11·0-35·2). In the HSCT group, 51 participants (93%) were 1:1 matched to participants from the non-HSCT group. In the intention-to-treat analysis, median progression-free survival was significantly longer in the HSCT group (9·0 months [95% CI 6·6-30·5]) than in the non-HSCT group (3·0 months [2·0-6·3]), with a hazard ratio of 0·38 (95% CI 0·21-0·69; p<0·0001). In the per-protocol population, 40 participants (78%) in the HSCT group had 101 serious events and 29 participants (67%) in the non-HSCT group had 70 serious adverse events. The most common serious adverse event other than graft-versus-host disease in both groups was infections, occurring in 30 participants (59%) in the HSCT group and in 19 participants (44%) in the non-HSCT group. INTERPRETATION: Allogeneic HSCT was associated with significantly longer progression-free survival in participants with advanced-stage CTCLs. These results indicate that allogeneic HSCT treatment should be made available to individuals with high-risk, advanced-stage mycosis fungoides or Sézary syndrome who achieve pre-transplant disease remission. FUNDING: French Ministry of Health, National Cancer Institute, Programme Hospitalier de Recherche Clinique en Cancérologie.

Management of relapsed cutaneous T-Cell lymphoma following allogeneic hematopoietic stem cell transplantation: Review with representative patient case.

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is a potentially curative treatment option for patients with refractory cutaneous T-cell lymphoma (CTCL) through replacement of the bone marrow responsible for lymphoma cells and possibly induction of a graft-versus-lymphoma effect. However, allo-HSCT is not always curative; relapse of CTCL occurs in about half of patients post-transplant. Treatment of relapsed CTCL after allo-HSCT is challenging because post-transplant patients are at high risk of graft-versus-host disease, and this condition may be precipitated or exacerbated by standard CTCL therapies. The benefit of each potential therapy must therefore be weighed against its risk of graft versus host disease (GVHD). In this article, we review the management of relapsed CTCL after allo-HSCT. We begin with an exemplative patient whose relapsed Sezary syndrome was successfully treated without development of GVHD. We also report high-throughput T-cell receptor sequencing data obtained during the patient's disease relapse and remission. We then review general guidelines for management of relapsed CTCL and summarize all reported cases and outcomes of relapsed CTCL after transplant. We conclude by reviewing the current CTCL therapies and their risk of GVHD.

Interferon α-induced lupus-like reaction in a mycosis fungoides patient: A case report.

Mycosis fungoides (MF) is the most common form of cutaneous T-cell lymphomas and interferon α is one of the treatment modalities for MF patients. So far, various side effects have been reported in connection with interferon use, including lupus-like reaction, which is relatively rare and classified as an injection-site reactions (ISR). We report a 38-year-old female with history of MF for 2 years who developed cutaneous lesions at the sites of interferon α-2b injections. There are few reports of lupus-like reaction due to therapy with interferon in malignant melanoma and multiple sclerosis (MS) patients, but there is no report in the literature about this side effect among patients with MF.

Efficacy of narrowband UVB phototherapy in early-stage mycosis fungoides in Iranian patients.

Narrowband UVB (NB-UVB) has been shown to be effective for the treatment of early mycosis fungoides (MF) in light-skinned patients, but the effect of NB-UVB on patients with darker skin phototypes needs further investigation. The aim of this study was to evaluate the effect of NB-UVB in the treatment of early-stage MF in Iranian patients. In this retrospective study, 24 patients with the diagnosis of early MF (9 stage AI, 15 stage IB) were enrolled. All patients were treated with NB-UVB phototherapy 2-3 times weekly. After achieving complete response, a maintenance treatment was recommended. The response rate, side effects, and recurrence rate in the follow-up period were assessed. The follow-up period was ranged 6 to 24 months. Ten patients (41.7%) had complete remission after a mean number of 42.9 treatment and mean cumulative dose of 58.11 J/cm2. Twelve patients (50%) had partial response, and 2 patients (8.3%) had no response. After discontinuation of maintenance treatment, 4 of 10 patients (40%) with complete remission relapsed within a mean of 5 months. Side effects were limited to erythema (12.5%) and hyperpigmentation (4%). NB-UVB is a safe and effective method for the treatment of early MF, but it seems that more treatment sessions and higher doses of NB-UVB are required for darker skin phototypes.

Predictors of adherence to Narrowband ultraviolet B first-month treatment dosage plan.

BACKGROUND: The adherence to a narrowband ultraviolet B (NB-UVB) treatment plan is derived, in large part, from the patient's skin tolerance to the phototherapy dose. At present, the initial and first-month incremental phototherapy doses are determined prior to treatment initiation based on the patient's Fitzpatrick skin phototyping. OBJECTIVES: To identify variables that predict adherence to NB-UVB first-month treatment dosage plan. METHODS: Charts of 1000 consecutive patients receiving NB-UVB at a hospital-based phototherapy unit were retrospectively analyzed. We included patients receiving NB-UVB for atopic dermatitis, psoriasis, vitiligo, and mycosis fungoides. The first-month NB-UVB treatment plan was determined based on the patient's Fitzpatrick phototype. Adherence to treatment was defined as receiving at least 80% of the planned first-month cumulative dose. We compared adherent vs. non-adherent patient groups for age, sex, Fitzpatrick phototype, presence of freckles, nevus count category, and type of dermatological disease. RESULTS: The study included 817 eligible patients, mean age 40 (2-95) years; 54% men; 32% had Fitzpatrick phototype I-II. Distribution by diagnosis was atopic dermatitis (29%), psoriasis (27%), vitiligo (23%), and mycosis fungoides (21%). Adherence to NB-UVB treatment plan was observed in 71% of patients. Adherence decreased with age, with 7% decrease per year (P = 0.03) and was higher among mycosis fungoides patients (77.3%) compared to all other diagnoses (69.8%; P = 0.02). CONCLUSIONS: Adherence to NB-UVB treatment may be related to age and diagnosis. Fitzpatrick phototype-based first-month treatment plans should be modified accordingly.

Cutaneous T-cell lymphomas: 2021 update on diagnosis, risk-stratification, and management.

DISEASE OVERVIEW: Cutaneous T-cell lymphomas are a heterogenous group of T-cell neoplasms involving the skin, the majority of which may be classified as Mycosis Fungoides (MF) or Sézary Syndrome (SS). DIAGNOSIS: The diagnosis of MF or SS requires the integration of clinical and histopathologic data. RISK-ADAPTED THERAPY: TNMB (tumor, node, metastasis, blood) staging remains the most important prognostic factor in MF/SS and forms the basis for a "risk-adapted," multi-disciplinary approach to treatment. For patients with disease limited to the skin, expectant management or skin-directed therapies is preferred, as both disease-specific and overall survival for these patients is favorable. In contrast, patients with advanced-stage disease with significant nodal, visceral or blood involvement are generally approached with systemic therapies, including biologic-response modifiers, histone deacetylase inhibitors, or antibody-based strategies, in an escalating fashion. In highly-selected patients, allogeneic stem-cell transplantation may be considered, as this may be curative in some patients.

How to Sequence Therapies in Mycosis Fungoides.

OPINION STATEMENT: Choice of therapy in mycosis fungoides is based on both patient- and lymphoma-specific factors, such as disease characteristics, comorbidities, symptoms and effect on quality of life, potential associated toxicities of therapy, response and tolerance to prior lines of therapy, and convenience and practicality. Generally, we sequence therapies from least toxic, targeted, nonimmunosuppressive to more toxic, immunosuppressive and from single agent to multiple agents, as necessary. If more toxic, immunosuppressive agents are required to alleviate disease burden or symptoms, we generally use them just long enough to control the disease, then transition to a maintenance regimen with less toxic, less immunosuppressive agents.

Mycosis Fungoides and Sézary Syndrome: Updates and Review of Current Therapy.

OPINION STATEMENT: While most patients with early-stage mycosis fungoides (MF) follow an indolent course, patients with advanced-stage MF/Sézary syndrome (SS) have a poor prognosis with a median survival of less than 5 years. Although there are a number of treatments currently available, achieving and maintaining a durable response remain challenging, especially in advanced-stage MF/SS. The choice of frontline therapy is dependent on the stage of disease. For early-stage MF, the treatment concept is to control skin lesions mainly by skin-directed therapies, such as topical therapies, phototherapies, and radiotherapies. For advanced-stage MF/SS, systemic treatments by biological or targeted therapies including bexarotene and interferon either alone or in combination are tried first, with more immunosuppressive chemotherapies being reserved for refractory or rapidly progressive disease. Recent improvements in biological or targeted therapies include brentuximab vedotin and mogamulizumab. When biopsy samples have 10% or more CD30-positive malignant cells, brentuximab vedotin, an anti-CD30 antibody conjugated to monomethyl auristin E, can be a desirable treatment option. For cases with blood involvement, mogamulizumab, an antibody binding to C-C chemokine receptor 4, is effective with high response rates. In the refractory setting, alemtuzumab, histone deacetylase inhibitors, pralatrexate, gemcitabine, and doxorubicin are considered as the treatment option. Because only allogeneic hematopoietic stem cell transplantation can offer a chance of cure with durable complete remission, advanced-stage patients with a markedly short life expectancy should be evaluated for eligibility. Given that there are few randomized controlled studies in the literature, it is necessary to investigate which therapy is preferable for each patient with MF/SS by comparative prospective trials.

Granulomatous slack skin mycosis fungoides developing simultaneously with sarcoid-like lesions in a patient with repeated anabolic injections in the past?

We present a 32-year-old man with successful treatment and remission of mycosis fungoides of both axillae in 2016 after PUVA therapy and systemic and local administration of corticosteroids. Subsequently, in 2017, the patient also achieved remission of a T-cell CD 30 positive, ALK-1 negative large-cell lymphoma of a retroperitoneal and inguinal lymph node after chemotherapy and radiotherapy. One year later, in 2018, the patient presented to our clinic with progression of skin lesions in both axillary areas and the appearance of а tumor in the right gluteal region.Dermatological examination showed livid-to-erythematous, partly sclerotic plaques in the right inguinal area, cutis laxa-like plaque formations in the right axillary region with similar but less-developed changes in the left axillary fold, a solitary subcutaneous tumor formation affecting the entire right gluteal region, and enlarged, palpable lymph nodes in the right para-axillary area. Biopsies were obtained from an axillary lesion and the surgically removed axillary lymph nodes, and histological examination revealed changes of granulomatous slack skin in the axilla and reactive inflammatory changes in the lymph nodes. Histology of gluteal tissue showed a "foreign body" type of reaction with sarcoid-like features, where the patient in the past have been injected with anabolic and steroidal drugs. Herein we describe a patient with simultaneous occurrence of granulomatous slack skin type mycosis fungoides and a sarcoid-like reaction. The question remains open whether this represents the so-called sarcoidosis-lymphoma syndrome or, more likely, granulomatous slack skin MF associated with a sarcoid-like reaction of "foreign body" type. The possibility that disturbance of tissue homeostasis by incorporation of certain adjuvants within injections (for example) in the past might have been an inducer of cutaneous T cell lymphoma and sarcoidosis/sarcoid like lesions seems reasonable but also speculative.

The impact of environmental ultraviolet exposure on the clinical course of mycosis fungoides.

BACKGROUND: As phototherapy plays an important role in the treatment of early-stage mycosis fungoides (MF), it is possible that environmental ultraviolet (UV) exposure affects the natural history of the disease. OBJECTIVE: To assess the impact of environmental UV exposure on the clinical course of MF. METHODS: The National Solar Radiation Database was used to identify the top and bottom registries for UV exposure from the Surveillance, Epidemiology, and End Results-18 database. Incidence and survival were determined. RESULTS: The high-UV cohort had a 30% lower risk of developing MF than did the low-UV cohort (hazard ratio, 1.3; 95% confidence interval, 1.20-1.41; P < .001). When stratified by stage and race, this difference was appreciable only among those with early-stage disease and white race. There was no difference in survival between the high- and low-UV cohorts (P = .098); however, a small difference was observed among those with early-stage disease and white race, favoring high UV exposure. LIMITATIONS: Retrospective design, use of the National Solar Radiation Database as a surrogate for individual sunlight exposure. CONCLUSION: It is possible that environmental solar UV exposure may play a role in controlling early-stage MF among patients with photosensitive features.

Folliculotropic mycosis fungoides in a pediatric patient mimicking black dot tinea capitis.

Immunosuppression following organ transplantation is a known risk factor for the development of lymphoproliferative disorders. Mycosis fungoides, a rare entity in pediatric patients, has seldom been reported as a post-transplant lymphoproliferative disorder. We report a case of folliculotropic mycosis fungoides in a pediatric patient following liver transplantation that was initially diagnosed as tinea capitis.

Oncogenic role of microRNA-155 in mycosis fungoides: an in vitro and xenograft mouse model study.

BACKGROUND: MicroRNA (miR)-155 contributes to the proliferation of mycosis fungoides (MF) in vitro and is upregulated in tumours of MF compared with early MF lesions. OBJECTIVES: To investigate the contribution of miR-155 to the cancerous phenotype and drug resistance of MF/Sézary cell lines. METHODS: miR-155 was inhibited in MF cell lines (MyLa and MJ) by transduction of miRZip anti-miR-155, and overexpressed in Hut78 cells by transduction of miRVec-miR-155; empty plasmids served as controls. Cells were analysed for response to inducers of apoptosis and cell-cycle arrest, using fluorescence-activated cell sorting. Transduced MyLa cells were subcutaneously injected into severe combined immunodeficient mice, and tumours were analysed immunohistochemically and for final size. RESULT: MyLa and MJ cells expressed a high level of miR-155; Hut78 cells expressed a low level. MF cell lines stably expressing miR-155 inhibitor showed increased G2/M arrest in response to N-p-tolyl-2-(3,4,5-trimethoxyphenyl quinazolin-4-amine) (SL111), an inducer of cell-cycle arrest, followed by increased apoptosis. Additionally, they showed increased apoptosis in response to suberoylanilide hydroxamic acid (SAHA). Tumours formed in mice from injected anti-miR-155-expressing MyLa cells had a significantly lower volume and higher occurrence of apoptosis than controls. Stable overexpression of miR-155 in Hut78 cells had no effect. CONCLUSIONS: Oncogenic miR-155 appears to contribute to the cancerous phenotype of MyLa and MJ cells, but not of Hut78 cells, by interrupting activation of the G2/M checkpoint in response to SL111, and decreasing apoptosis in response to SL111 and SAHA, thereby facilitating tumour growth. These findings have implications for the potential development of novel therapeutic modalities for MF incorporating miR-155 inhibitors.

Early clinical manifestations of Sézary syndrome: A multicenter retrospective cohort study.

BACKGROUND: Classic Sézary syndrome (SS) is defined by erythroderma, generalized lymphadenopathy, and leukemic blood involvement. Clinical observations suggest that SS begins as a nonerythrodermic disease. OBJECTIVE: To describe the early clinical characteristics of patients with SS. METHODS: A retrospective, multicenter chart review was performed for 263 confirmed cases of SS diagnosed during 1976-2015. RESULTS: Erythroderma was the earliest recorded skin sign of SS in only 25.5% of cases, although most patients (86.3%) eventually developed erythroderma. In patients without erythroderma during their initial visit, the first cutaneous signs of SS were nonspecific dermatitis (49%), atopic dermatitis-like eruption (4.9%), or patches and plaques of mycosis fungoides (10.6%). The mean diagnostic delay was 4.2 years overall, 2.2 years for cases involving erythroderma at the initial presentation, and 5.0 years for cases not involving erythroderma at the initial presentation. LIMITATIONS: This study is retrospective. CONCLUSION: Erythroderma is uncommon as an initial sign of SS. Early SS should be considered in cases of nonerythrodermic dermatitis that is refractory to conventional treatments. In these cases, examination of the blood by PCR for monoclonal T-cell receptor rearrangement and by flow cytometry to identify an expanded or aberrant T-cell population should be considered.

Oral bexarotene for post-transplant cutaneous T-cell lymphoma.

Organ transplant recipients receiving immunosuppression have an increased risk of developing post-transplant lymphoproliferative diseases (PTLDs). Traditionally, PTLDs refer to Epstein-Barr virus (EBV)-induced B-cell lymphoma. However, post-transplant T-cell lymphoma may also occur and tends to have a poorer response to reduced immunosuppressive therapy. As such, additional therapy is often needed for post-transplant T-cell lymphoma, including post-transplant cutaneous T-cell lymphoma (PT-CTCL). We present only the third case of PT-CTCL occurring after liver transplantation. The patient was diagnosed with stage IB mycosis fungoides (MF). His lesions were refractory to multiple skin-directed therapies, and so he was given oral bexarotene 150 mg daily and his oral tacrolimus dose was decreased to 2 mg daily. Remarkably, his MF patches have demonstrated a complete response to oral bexarotene 75 mg daily without recurrence over 11 years of follow-up. He developed hypertriglyceridemia with bexarotene 150 mg, so his dose was decreased to 75 mg, without loss of response. Our report is the second to describe PT-CTCL demonstrating a long-term complete response to oral bexarotene. Given its anti-carcinogenic properties and favorable toxicity profile, oral bexarotene represents an appealing treatment option for PT-CTCL refractory to skin-directed therapies.

Toll-like receptor (TLR)7 expression in mycosis fungoides and psoriasis: a case-control study.

BACKGROUND: Toll-like receptors (TLRs) have been implicated in various dermatological diseases. TLR agonists have the capacity to potently activate the innate immune cells of patients with advanced, refractory, cutaneous T-cell lymphoma (CTCL). AIM: To detect TLR7 gene expression in mycosis fungoides (MF) (a neoplastic skin condition) and to compare it with psoriasis (an inflammatory skin condition) in an attempt to clarify the pathogenic role played by TLR7 in both conditions. METHODS: This case-control study enrolled 28 patients with MF: 30 patients with psoriasis, and 30 age- and sex-matched healthy controls (HCs). A 4-mm punch skin biopsy was obtained from lesional skin of patients and from normal skin of HCs for detection of TLR7 gene expression using real-time PCR. RESULTS: Mean TLR7 level in patients with MF (0.4 ± 0.23) was significantly lower than in patients with psoriasis (1.49 ± 0.46) and in HCs (1.22 ± 0.44) (P < 0.001), and mean TLR7 level in patients with psoriasis was significantly higher than in HCs (P < 0.03). Based on MF staging, 21.4% of patients had stage Ia, 28.6% had stage Ib, 28.6% had stage IIa and 21.4% had stage IIb disease. Comparing the TLR7 levels in relation to MF staging revealed the lowest mean value was in stage IIb and highest mean value in stage Ia, and this was significant (P < 0.001). CONCLUSION: Disturbed innate immunity might play a role in the pathogenesis of neoplastic and inflammatory skin conditions. TLR7 could be useful as a prognostic factor in MF.

Development of mycosis fungoides after bone marrow transplantation for chronic myeloid leukaemia: transmission from an allogeneic donor.

We report on a patient who developed donor-derived cutaneous T-cell lymphoma (CTCL) 4 years after successful treatment of chronic myeloid leukaemia with an allogeneic bone marrow transplant. The patient developed an eczematous rash unresponsive to topical therapy and immunosuppression. When CTCL was diagnosed in the recipient, his sibling donor had been attending his local dermatology unit with a maculosquamous rash, which proved subsequently to be mycosis fungoides. An identical pattern of donor and recipient clonality assessment and T-cell receptor gene sequencing indicated that the CTCL was probably transmitted in the bone marrow harvest. This suggests that CTCL cells circulate in the marrow at an early subclinical stage in this disease. This is the second case of donor-derived CTCL reported to date.

Hydrochlorothiazide and cutaneous T cell lymphoma: prospective analysis and case series.

BACKGROUND: Mycosis fungoides (MF) and leukemic Sézary syndrome (SS) are the most common cutaneous T cell lymphomas (CTCL), but their etiology remains unknown. After patients were observed with hydrochlorothiazide (HCTZ)-associated CTCL, HCTZ was examined as a putative chronic antigen in a cohort of prospectively staged patients. METHODS: Demographic and drug exposure data was examined from 1443 confirmed MF and SS patients. Hypertensive CTCL patients were divided into HCTZ users or nonusers for statistical analysis by chi-square and t tests. Causality in a case series was rated by the Naranjo Adverse Drug Reaction Probability Scale. RESULTS: A total of 815 of 1443 MF and SS patients (56.5%) were hypertensive; 205 (25.2%) were taking HCTZ at initial staging. Comparing stage of patients who were using or not using HCTZ, the most significant difference was between stage I and stage IV (odds ratio of 0.45; 95% confidence interval of 0.25-0.78, P = .003), demonstrating reduced likelihood of being stage IV in patients who were on HCTZ. Seventy-seven percent of the MF patients on HCTZ were stage I. A total of 125 patients of 196 (63.8%) started HCTZ prior to developing CTCL lesions, and 35 of 121 (28.0%) started within 1 year of first skin rash. Thirty-six of 125 patients (28.8%) experienced complete or partial remissions after discontinuing HCTZ. A monoclonal T cell receptor rearrangement was detected more frequently in the hypertensive stage I patients not taking HCTZ as compared with those who were (55.3% vs 69.1%, P = .032). Three patients were rechallenged and developed MF lesions that resolved or improved with discontinuation. CONCLUSIONS: HCTZ is commonly prescribed and may be a putative antigen in a small subset of early MF patients. Careful drug histories and a trial off medication are warranted.

Primary cutaneous posttransplant lymphoproliferative disorders in solid organ transplant recipients: a multicenter European case series.

Primary cutaneous posttransplant lymphoproliferative disorders (PTLD) are rare. This retrospective, multicenter study of 35 cases aimed to better describe this entity. Cases were (re)-classified according to the WHO-EORTC or the WHO 2008 classifications of lymphomas. Median interval between first transplantation and diagnosis was 85 months. Fifty-seven percent of patients had a kidney transplant. Twenty-four cases (68.6%) were classified as primary cutaneous T cell lymphoma (CTCL) and 11 (31.4%) as primary cutaneous B cell PTLD. Mycosis fungoides (MF) was the most common (50%) CTCL subtype. Ten (90.9%) cutaneous B cell PTLD cases were classified as EBV-associated B cell lymphoproliferations (including one plasmablastic lymphoma and one lymphomatoid granulomatosis) and one as diffuse large B cell lymphoma, other, that was EBV-negative. Sixteen (45.7%) patients died after a median follow-up of 19.5 months (11 [68.8%] with CTCL [6 of whom had CD30(+) lymphoproliferative disorders (LPD)] and 5 [31.2%] with cutaneous B cell PTLD. Median survival times for all patients, CTCL and cutaneous B cell PTLD subgroups were 93, 93, and 112 months, respectively. Survival rates for MF were higher than those for CD30(+) LPD. The spectrum of primary CTCL in organ transplant recipients (OTR) is similar to that in the general population. The prognosis of posttransplant primary cutaneous CD30(+) LPD is worse than posttransplant MF and than its counterpart in the immunocompetent population. EBV-associated cutaneous B cell LPD predominates in OTR.

Evolving insights in the pathogenesis and therapy of cutaneous T-cell lymphoma (mycosis fungoides and Sezary syndrome).

Cutaneous T-cell lymphomas (CTCL) are a heterogeneous group of malignancies derived from skin-homing T cells. The most common forms of CTCL are Mycosis Fungoides (MF) and Sezary Syndrome (SS). Accurate diagnosis remains a challenge due to the heterogeneity of presentation and the lack of highly characteristic immunophenotypical and genetic markers. Over the past decade molecular studies have improved our understanding of the biology of CTCL. The identification of gene expression differences between normal and malignant T-cells has led to promising new diagnostic and prognostic biomarkers that now need validation to be incorporated into clinical practice. These biomarkers may also provide insight into the mechanism of development of CTCL. Additionally, treatment options have expanded with the approval of new agents, such as histone deacetylase inhibitors. A better understanding of the cell biology, immunology and genetics underlying the development and progression of CTCL will allow the design of more rational treatment strategies for these malignancies. This review summarizes the clinical epidemiology, staging and natural history of MF and SS; discusses the immunopathogenesis of MF and the functional role of the malignant T-cells; and reviews the latest advances in MF and SS treatment.