Clinical and Pathological Features of Primary Cutaneous Lymphomas in Nepal: A retrospective cohort study from a dermatology referral centre.

Background Primary cutaneous lymphomas (PCLs) are rare diagnoses in Nepal and are not well characterized till date. Objective To evaluate clinical and pathological features of Primary cutaneous lymphomas in Nepal. Method We retrospectively reviewed outpatient and inpatient records of a dermatology referral centre of Kathmandu, Nepal for clinical and pathological findings of cases diagnosed as cutaneous lymphomas from July 2010 through July 2020. The final diagnosis was made based on 2008 World Health Organization classification and its update 2018. Result There were 12 cases of Primary cutaneous lymphomas diagnosed during this period. The age of presentation ranged from 19 years to 81 years (Mean: 53.4 years ± 21.5 years, SD). There were ten cases of cutaneous T-cell lymphoma (CTCLs) and two cases of cutaneous B- cell lymphomas (CBCLs). Among cutaneous T-cell lymphoma, there were four cases of primary cutaneous anaplastic large- cell Lymphoma (PCALCL), two cases of classic (patch/plaque) mycosis fungoides (MF), two cases of folliculotropic mycosis fungoides (FMF), and one case each of primary cutaneous aggressive epidermotropicCD8+ T-cell lymphoma and lymphomatoid papulosis. Among cutaneous B- cell lymphomas, there was one case of primary cutaneous marginal zone B- cell lymphoma, and one case of primary cutaneous follicle centre lymphoma. Most cases of MF presented at stage IB (75%), and three patients of primary cutaneous lymphomas died during this period. Conclusion Primary cutaneous lymphomas appear to be very rare in this study and presentations ranged from classic Mycoses Fungoides to aggressive T-cell lymphomas. Cutaneous T-cell lymphomas appeared to be more common than cutaneous B- cell lymphomas in this study.

Clinical Remission of Cutaneous Lymphoma in a Dog Treated with Verdinexor.

A 5 yr old female spayed pit bull terrier mix was evaluated for development of multiple dermal nodules over the previous 2 wk with concurrent weight loss and lethargy. A definitive diagnosis of cutaneous epitheliotropic T-cell lymphoma was obtained through histopathology and immunohistochemistry. Treatment was initiated with 32.9 mg/m2 (1.2 mg/kg) of oral verdinexor twice per week, according to label guidance. One week after treatment initiation, clinical remission was noted with complete resolution of the cutaneous nodules. The dog has continued twice-weekly treatments without any interruption and remains in complete remission 17 mo following initiation of verdinexor therapy. This case provides evidence for the utility of verdinexor in the treatment of canine cutaneous epitheliotropic T-cell lymphoma.

Prevalence, clinical features, and survival outcome trends of 627 patients with primary cutaneous lymphoma over 29 years: a retrospective review from single tertiary center in Korea.

The relative frequency of primary cutaneous lymphoma (PCL) subtypes shows wide variation across different geographical regions. This retrospective study was conducted in a tertiary referral center located in Korea to describe the relative frequency, demographics, survival outcomes, and temporal trend in PCL. A total of 627 PCL cases diagnosed between January 1994 and December 2022 were included. The majority of PCL cases (87.2%) were of T-/NK-cell lineage (CTCL), while the remaining cases (12.8%) were B-cell lineage lymphomas (CBCL). The prevalence of mycosis fungoides (MF) in CTCL increased significantly over time, while other CTCL subtypes, including primary cutaneous extranodal NK/T-cell lymphoma and subcutaneous panniculitis-like T-cell lymphoma (SPTCL), decreased in frequency. Notably, the prevalence of CD4-positive small/medium T-cell lymphoproliferative disorder showed a substantial increase over time. Primary cutaneous marginal zone lymphoma was consistently the commonest CBCL subtype. Survival analysis demonstrated that CTCL had a more favorable 5-year overall survival (OS) than CBCL. OS rate of MF, SPTCL, and primary cutaneous peripheral T-cell lymphoma, NOS improved significantly over time. This study provides comprehensive insights into the dynamic change in the relative frequency and overall survival of PCL subtypes over time.

Navigating Diagnostic and Therapeutic Challenges in Primary Cutaneous Gamma/Delta T-Cell Lymphoma: A Case Study of Fatal Outcomes Within Two Months.

ABSTRACT: Primary cutaneous gamma/delta T-cell lymphoma (PCGD-TCL) is a rare yet highly aggressive subtype of primary cutaneous lymphoma. Characterized by its challenging diagnosis and poor prognosis, PCGD-TCL presents unique clinical and histopathological features that distinguish it from other primary cutaneous lymphoma subtypes. Here, we report the case of a 75-year-old man who initially presented with multiple erythematous indurated plaques over his back and bilateral lower extremities. The initial biopsy suggested primary cutaneous T-cell lymphoma (PCTCL) with a CD30-negative phenotype. However, within a 2-month interval, the disease progressed rapidly, manifesting as extensive skin involvement across the chest and upper extremities. A repeat skin biopsy was performed, revealing dermal atypical lymphocytes without epidermotropism. Immunohistochemical analysis demonstrated positivity for CD3, CD5, and CD4, as well as T-cell receptor delta (TCR delta) expression, along with the loss of CD8 and CD30 expression. These findings were consistent with a diagnosis of PCGD-TCL. Despite therapeutic interventions, including systemic treatments, the patient's condition deteriorated rapidly, ultimately leading to his demise within a month of receiving the PCGD-TCL diagnosis. This case highlights the diagnostic complexities associated with PCGD-TCL, emphasizing the importance of careful histopathological examination and immunophenotypic characterization. Given its aggressive nature and propensity for rapid dissemination, early recognition of PCGD-TCL is paramount for initiating appropriate therapeutic interventions. However, effective treatment options for PCGD-TCL remain limited, and the disease typically carries an unfavorable prognosis. Further research is needed to elucidate the underlying molecular mechanisms driving the pathogenesis of PCGD-TCL, to identify novel therapeutic targets, and to improve patient outcomes. In addition, increased awareness among clinicians and pathologists regarding the clinical presentation and diagnostic criteria of PCGD-TCL is crucial for facilitating timely diagnosis and management of this challenging malignancy.

Cutaneous T-cell Lymphoma.

Cutaneous T-cell lymphoma is a group of non-Hodgkin T-cell lymphomas that develop in and affect the skin but can potentially spread to other organs. There are many subtypes, the most common of which are mycosis fungoides, Sezary syndrome, lymphomatoid papulosis, and primary cutaneous anaplastic large cell lymphoma. Cutaneous lymphoma is a common cause of recalcitrant chronic skin rash and notoriously mimics other dermatologic and hematologic conditions, often resulting in diagnostic delays of months to years. This review provides an introduction to cutaneous T-cell lymphoma, with a primary focus on the clinical presentation, diagnosis, immunopathogenesis, and management of the condition.

Primary cutaneous lymphoproliferations in the gray zone between marginal zone lymphoma and CD4+ small/medium T-cell lymphoproliferative disease.

BACKGROUND: Primary cutaneous marginal zone lymphoma (PCMZL) and primary cutaneous CD4+ small/medium T-cell lymphoproliferative disease (CD4+ TLPD) are two distinct entities with excellent prognosis; however, they show profound clinical and histopathological similarities, leading to differential diagnostic uncertainty. AIMS: Our aim was to review and reanalyze cases of primary cutaneous lymphoproliferations diagnosed at Semmelweis University, featuring characteristics of PCMZL and CD4+ TLPD. MATERIALS AND METHODS: Cutaneous lymphoma biopsy specimens between 2018 and 2022 were collected and re-evaluated. Medical history, clinical picture, imaging, and laboratory findings were collected. Immunohistochemical staining for CD20, CD3, BCL6, CD10, PD1, CD3, CD4, CD8, and PCR tests for IGH, IGK, TCRB, and TCRG were repeated in selected cases. RESULTS: Among 55 cases diagnosed as PCMZL (16) or CD4+ TLPD (39), 3 patients had been diagnosed with both LPDs at different time points of their disease course. Four additional patients were identified with single lesions featuring overlapping histopathological characteristics of both LPDs and both monoclonal IGH and TCR rearrangements. All patients are currently in complete remission with local treatment. CONCLUSION: We propose that besides the overlapping histopathological, molecular, and clinical features, the subsequent appearance of PCMZL and CD4+ TLPD in a short timeframe in the same patients may suggest a common pathogenic background.

Cutaneous Lymphoma in a Tertiary Skin Hospital and Referral Centre in Nepal.

BACKGROUND: Primary cutaneous lymphomas are a distinct group of rare lymphoid neoplasms with absence of extracutaneous lymphomas at the time of presentation. They are rare in Nepal and no data on cutaneous lymphoma have been published from this country till date. METHODS: This retrospective study included 15 cases of cutaneous lymphomas retrieved from the records of department of Dermatopathology, DI Skin Hospital and Referral Centre, Bansbari, Kathmandu, Nepal. Patients were diagnosed according to the current WHO classification for cutaneous lymphoma. RESULTS: A total of 15 cases were studied with median age of 45 years (range: 22 to 81 years) and male to female ratio of 1.5:1. Primary cutaneous lymphomas constituted 13 cases out of 15 and the most common type of cutaneous lymphoma was mycosis fungoides and variants 5 (33%), followed by CD30 positive primary cutaneous anaplastic large cell lymphoma constituting 2 (13%). T-cell cutaneous lymphoma constituted 13 (87%) and B-cell cutaneous lymphoma 2 (13%). CONCLUSIONS: Cutaneous T-cell lymphomas were more frequent than cutaneous B-cell lymphomas in Nepalese patients. Mycosis fungoides and variants are commonest type of primary cutaneous lymphomas.

[Translated article] Survival Analysis and Prognostic Factors in a Case Series of 148 Cutaneous T-Cell Lymphomas.

BACKGROUND AND OBJECTIVE: Cutaneous T-cell lymphomas (CTCL) such as mycosis fungoides (MF) and Sézary syndrome (SS) are rare lymphomas with varying prognoses. The aim of the study was to describe the survival of a cohort of patients with MF/SS and evaluate the prognostic factors impacting disease survival. MATERIALS AND METHODS: All cases of MF/SS diagnosed from 2008 through 2022 were retrospectively analyzed. The demographic variables, histological parameters, and analytical data were analyzed too. Progression-free survival (PFS) and disease-specific survival (DSS) were calculated. RESULTS: A total of 148 cases were included. A total of 121 (82%) and 27 cases were diagnosed with MF, and SS, respectively. A total of 37 patients (25%) experienced progression at some point disease progression. The median PFS and median DSS were 127 and 135 months, respectively. Age >60 years, diagnosis of SS, the presence of large cell transformation (LCT) at diagnosis, folliculotropism in early stages, high Ki-67 expression, the presence of the clonal T-cell receptor (TCR) in blood, elevated LDH and B2M levels, and advanced stages (IIB, IVA, T3, T4, N3/Nx) were associated with worse prognosis across the entire cohort. CONCLUSIONS: Stage IVA and the presence of LCT at diagnosis stood out as independent factors of unfavorable prognosis. LCT was the variable that most significantly impacted the patients' survival and was closely associated with tumor skin involvement and stage IIB.

Phase I/II clinical trial of brentuximab vedotin for pretreated Japanese patients with CD30-positive cutaneous T-cell lymphoma.

Brentuximab vedotin (BV), a conjugate of anti-CD30 antibody and monomethyl auristatin E, has emerged as a promising treatment option for refractory CD30+ mycosis fungoides (MF) and primary cutaneous anaplastic large-cell lymphoma (pcALCL). BV has been shown to be safe and effective in treating Hodgkin's lymphoma and peripheral T-cell lymphoma. This multicenter, prospective, single-arm phase I/II study evaluated the efficacy of BV in Japanese patients with CD30+ cutaneous lymphomas, namely CD30+ cutaneous T-cell lymphoma. Participants were divided into two groups: those with CD30+ MF or pcALCL (cohort 1, n = 13) and those with CD30+ lymphoproliferative disorders other than those in cohort 1 (cohort 2, n = 3). The studied population included the full analysis set (FAS), modified FAS (mFAS), and safety analysis set (SAF). These sets were identified in cohorts 1 and 1 + 2 and labeled FAS1 and FAS2, mFAS1 and mFAS2, and SAF1 and SAF2, respectively. Each treatment cycle lasted 3 weeks, and BV was continued for up to 16 cycles after the third cycle based on treatment response. The primary endpoint was the 4-month objective response rate (ORR4) determined by the Independent Review Forum (IRF). ORR4 was 69.2% for FAS1 and 62.5% for FAS2 (P < 0.0001). Secondary endpoints of ORR, assessed using the global response score (53.8% in FAS1) and modified severity-weighted assessment tool (62.5% in FAS1), using the IRF, provided results comparable to the primary findings. The incidence of ≥grade 3 adverse events (≥15%) in SAF1 was peripheral neuropathy in three patients (23%) and fever and eosinophilia in two patients (15%). In conclusion, BV showed favorable efficacy, tolerability, and safety profile in Japanese patients with relapsed or refractory CD30+ primary cutaneous T-cell lymphoma. The trial was registered with University Hospital Medical Information Network Clinical Trials Registry, Japan (protocol ID: UMIN000034205).

Oncogenic alterations in KIR3DL1 in cutaneous acral CD8+ lymphoproliferative disorder.

BACKGROUND: Primary cutaneous acral CD8+ T-cell lymphoproliferative disorder (TLPD) is a rare and indolent lymphoma entity. Although TLPD was first identified many years ago, the molecular pathogenesis is still not fully understood. OBJECTIVES: In order to better understand the molecular pathogenesis of cutaneous acral CD8+ TLPD and to identify further discriminatory markers to differentiate this lymphoma subtype from other CD8+ cutaneous lymphomas, we analysed five cases of cutaneous acral CD8+ TLPD for putative molecular alterations. METHODS: Somatic alterations were assessed using whole-exome and targeted sequencing of paraffin-embedded tissue. Results were evaluated using immunohistochemical staining of respective relevant proteins. CD8+ cutaneous T-cell lymphomas (n = 12) served as control for KIR3DL1 staining. RESULTS: Copy number variation analysis revealed a homozygous deletion of the KIR3DL1 gene in two of the analysed cases. This resulted in loss of KIR3DL1 protein expression, which was observed in all cases of cutaneous acral CD8+ TLPD. In contrast, KIR3DL1 expression was more variable in other CD8+ cutaneous T-cell lymphomas with 50% of analysed cases (n = 12) found to be positive. In addition, one further case of acral CD8+ TLPD harboured a loss-of-function mutation in the PIK3R1 gene, presumably activating the phosphoinositide 3-kinase-AKT pathway. CONCLUSIONS: Alterations of the KIR3DL1 gene may be of pathogenetic relevance for acral CD8+ TLPD. Loss of KIR3DL1 protein expression may support the diagnosis of this indolent lymphoma entity; however, this is not a subtype-specific discriminative feature.

Cutaneous acral CD8+ T-cell lymphoproliferative disorder (TLPD) is a very rare form of lymphoma, with only around 60 cases reported worldwide. The progression of this lymphoma is usually slow, and most people will present with a solitary plaque or a small papule, without any risk of rapid worsening. For this reason, treatment directly on the skin with topical steroids, excision or radiation are usually sufficient. However, it can be difficult to differentiate this type of lymphoma from other CD8+ cutaneous types upon microscopy. This is important because other CD8+ cutaneous lymphomas can follow an aggressive course and will need to be treated differently, using systemic therapies. Previous findings have shown that abnormal expression of a protein (called CD68) in a dotlike pattern is a specific feature of acral CD8+ TLPD and could help to accurately diagnose this lymphoma. Until now, the underlying molecular differences in cutaneous acral CD8+ TLPD have not been identified. Therefore, this German study was carried out to look at the genetic alterations in the tissue of five patients with this type of lymphoma. To do this, we used a method that examined whole-exome and targeted gene sequencing. We detected alterations in a gene important for T-cell function (called KIR3DL1), in two of five analysed cases. Of note, a loss of KIR3DL1 protein expression has been observed in all analysed cases of acral CD8+ TLPD. Our study findings suggest that genetic defects in KIR3DL1 in acral CD8+ TLPD could be a novel diagnostic marker for this lymphoma subtype and may help to better distinguish it from other, potentially aggressive forms of cutaneous lymphoma.

Chart review study of real-world clinical outcomes in patients with cutaneous T-cell lymphoma treated with extracorporeal photopheresis in the US in 2017-2019.

BACKGROUND: Response rates of approved systemic therapies for cutaneous T-cell lymphoma (CTCL) hover near 30%, suggesting unmet need. This study describes real-world treatment patterns and response rates of extracorporeal photopheresis (ECP) in CTCL patients. METHODS: A chart review was conducted in the United States of adults with CTCL who initiated ECP between January 1, 2017, and February 28, 2019, and received at least three months of ECP treatment as monotherapy or concomitant therapy. Clinical outcomes were collected quarterly for up to 18 months. RESULTS: The 52 patients were predominantly Caucasian. Half were male; median age was 69 years. Most patients had Sézary syndrome (50%) or mycosis fungoides (36.5%). Nearly 40% of patients had stage IV disease; 33% had lymph node involvement. Nineteen patients (36.5%) achieved response (>50% reduction in BSA affected); median time to response was 6.5 months. The percentage of patients rated as at least minimally improved was 59.5% at 6 months (N = 22), 75.0% at 9 months (N = 24), and 60.0% at 12 months (N = 15) after ECP initiation. CONCLUSIONS: Despite the ECP treated population in this study being older and having more advanced-stage disease than recent trials, response rates were comparable. These real-world findings support ECP as an effective treatment option for CTCL patients.

Advances in the pharmacological management of cutaneous T-cell lymphoma.

INTRODUCTION: Current treatment guidelines for cutaneous T cell lymphoma (CTCL) advocate a stage-driven approach, considering clinical presentation, symptom burden, and patient comorbidities. Therapy selection hinges on factors like disease subtype, severity, and treatment availability. The primary goal is to enhance the quality of life by mitigating symptoms, as achieving lasting complete remission is infrequent. AREAS COVERED: Over the past decade (2013-2023), the therapeutic landscape of CTCL has experienced substantial transformation with the introduction of innovative therapies. This review explores the main pivotal developments in traditional treatment schedules and recently introduced drugs, aiming to offer clinicians and researchers a thorough perspective on the decade's progress in the field. EXPERT OPINION: Despite the progress made in CTCL therapeutics, ranging from topical chemotherapeutics to immunomodulatory agents, several unmet needs persist. Firstly, there is a pressing need for the incorporation of readily available predictors for treatment response, encompassing clinical, pathological, and molecular features. Secondly, a more profound comprehension of the tumor microenvironment is imperative to optimize the landscape of targetable molecules. Lastly, the undertaking of studies on combination regimens should be encouraged as it enhances therapy efficacies by synergistically combining agents with diverse modes of action.

CASE OF THE TRANSFORMATION OF PSORIASIS INTO CUTANEOUS T-CELL LYMPHOMA.

Psoriasis is a long-known skin pathology, the incidence of which is constantly rising, though it is not possible to clearly establish the trend due to the differences in the research design. In recent years, the number of cases among children and adolescents has increased. Psoriasis becomes more aggressive, severe forms are more common. It can be combined with other diseases but is rarely complicated. Isolated cases of the transformation of psoriatic plaques into skin cancer have already been described in the literature. Probable causes were the long-term use of photosensitizers and phototherapy, naphthalene, and tar. However, in general, the risk of the malignant recurrence in patients with psoriasis does not increase significantly. We present a clinical observation of the transformation of psoriasis into cutaneous T-cell lymphoma in a patient with more than 37 years of psoriasis experience, where on the background of typical psoriatic rashes, fungal growths of doughy consistency appeared, which were initially misinterpreted as a warty form of psoriasis. Based on the data of additional methods of examination and the results of histological examination, the diagnosis was clarified. Specific treatment was prescribed, which proved its effectiveness. The probable causes of degeneration, in our opinion, are prolonged irritating external therapy and excessive insolation.

Updated cutaneous T-cell lymphoma TNMB staging criteria fail to identify patients with Sézary syndrome with low blood burden.

Comparison of the 2007 EORTC/ISCL and the 2022 EORTC/ISCL/USCLC blood staging guidelines for cutaneous T-cell lymphoma at a single institution reveals the newer guidelines fail to detect a subset of patients with Sézary syndrome with low blood burden.

Histopathologic and Clinical Characterization of Brentuximab Vedotin-associated Rash.

Rash is one of the commonly observed adverse events with brentuximab vedotin (BV), a CD30-targeted antibody-drug conjugate used to treat cutaneous T-cell lymphoma (CTCL). However, clinical and histopathologic characterization of BV-associated rash (BVAR) is limited. Distinguishing BVAR from a patient's underlying CTCL can be challenging and can lead to treatment interruptions or even premature drug discontinuation. We performed a thorough clinical and histopathologic retrospective characterization of BVAR from a single institution. Utilizing polymerase chain reaction (PCR) and T-cell receptor high-throughput sequencing (TCR-HTS), we were able to isolate skin biopsy specimens from rash clinically suggestive of BVAR that also lacked a dominant TCR clone. A retrospective evaluation was performed of 26 biopsy specimens from 14 patients. Clinical features of BVAR included predominantly morbilliform or maculopapular morphology, delayed onset, and the trend toward moderate to severe classification, often requiring oral steroids. Most histopathologic specimens (25/26) showed spongiotic dermatitis as the primary reaction pattern. Many cases showed subtle findings to support a background interface or lichenoid eruption. Langerhans cell microabscesses were seen in one-fourth of specimens, and eosinophils were present in over one-half of the specimens. There were focal features mimicking CTCL, but these were not prominent. In 17 specimens with immunohistochemistry, the CD4:CD8 ratio in intraepidermal lymphocytes was relatively normal (1-6:1) in 65% (11/17) and 1:1 in 35% (6/17), demonstrating a trend toward increased CD8-positive cells compared with baseline CTCL. We have identified features that can help distinguish BVAR from a patient's CTCL, which can, in turn, help guide appropriate clinical management.

Safety and effectiveness of mogamulizumab in relapsed or refractory CC chemokine receptor 4-positive peripheral T-cell lymphoma and relapsed or refractory cutaneous T-cell lymphoma: A post-marketing surveillance in Japan.

Mogamulizumab is a humanized antibody targeting CC chemokine receptor 4 (CCR4). This post-marketing surveillance was conducted in Japan as a regulatory requirement from 2014 to 2020 to ensure the safety and effectiveness of mogamulizumab in patients with relapsed or refractory (r/r) CCR4-positive peripheral T-cell lymphoma (PTCL) or r/r cutaneous T-cell lymphoma (CTCL). Safety and effectiveness data were collected for up to 31 weeks after treatment initiation. A total of 142 patients were registered; safety was evaluated in 136 patients. The median number of doses was 8.0 (range, 1-18). The main reasons for treatment termination were insufficient response (22.1%) and adverse events (13.2%). The frequency of any grade adverse drug reaction was 57.4%, including skin disorders (26.5%), infections and immune system disorders (16.2%), and infusion-related reactions (13.2%). Graft-versus-host disease, grade 2, developed in one of two patients who underwent allogeneic-hematopoietic stem cell transplantation after receiving mogamulizumab. Effectiveness was evaluated in 131 patients (103 with PTCL; 28 with CTCL). The best overall response rate was 45.8% (PTCL, 47.6%; CTCL, 39.3%). At week 31, the survival rate was 69.0% (95% confidence interval, 59.8%-76.5%) [PTCL, 64.4% (54.0%-73.0%); CTCL, 90.5% (67.0%-97.5%)]. Safety and effectiveness were comparable between patients <70 and ≥ 70 years old and between those with relapsed and refractory disease. The safety and effectiveness of mogamulizumab for PTCL and CTCL in the real world were comparable with the data reported in previous clinical trials. Clinical Trial Registration.

Primary cutaneous, epidermotropic mycosis fungoides-like presentation: critical appraisal and description of two novel cases, broadening the spectrum of ALK+ T-cell lymphoma.

Leading from a two-case series, including two patients receiving a diagnosis of epidermotropic T-cell lymphoma, featuring a mycosis fungoides (MF)-like clinical pattern and ALK expression and molecular alteration, we performed a critical appraisal of ALK+ primary cutaneous T-cell lymphomas (pcTCL). Considering our patients and the literature, 32 cases were retrieved, 7 of which featured an MF-like clinical picture over a 4-to-20-year period. MF-like cases show distinctive histology, comprising a predominantly epidermotropic infiltration of small-to-large, atypical-to-pleomorphic, with few anaplastic cells, negligible-to-intense CD30-expression, and a CD4+/cytotoxic granule+ phenotype. These features should prompt a search for ALK expression captured by the ALK D5F3 clone. Bona fide ALK+ pcTCL is very rare, and existent data suggest the presence of a broader pattern of disease, including instances mimicking MF and/or primary cutaneous CD8+ aggressive epidermotropic cytotoxic T-cell lymphoma. The major challenges in dealing with this subset include prodromal phases, misinterpreted as inflammatory dermatosis or parapsoriasis/early phase MF both clinically and histologically, while recognition of its ALK-driven biology is hampered both by the unusual clinic-pathologic pattern of the disease, which stands apart from the classical (i.e., nodal) picture of ALK+ anaplastic large cell lymphoma and by the low sensitivity of ALK1 clone. Data on its optimal management are far from being conclusive: An MF-like approach is currently chosen, but depending on CD30 and, most notably, ALK expression, a targeted therapy could be envisaged in advanced stages, as clinical response to ALK inhibition was documented in one patient.