Classifications of cutaneous lymphomas and lymphoproliferative disorders: An update from the EORTC cutaneous lymphoma histopathology group.

The classification of primary cutaneous lymphomas and lymphoproliferative disorders (LPD) is continuously evolving by integrating novel clinical, pathological and molecular data. Recently two new classifications for haematological malignancies including entities of cutaneous lymphomas were proposed: the 5th edition of the WHO classification of haematolymphoid tumours and the International Consensus Classification (ICC) of mature lymphoid neoplasms. This article provides an overview of the changes introduced in these two classifications compared to the previous WHO classification. The main changes shared by both classifications include the downgrading of CD8+ acral T-cell lymphoma to CD8+ acral T-cell LPD, and the recognition of entities that were previously categorized as provisional and have now been designated as definite types including primary cutaneous small or medium CD4+ T-cell LPD, primary cutaneous gamma/delta T-cell lymphoma, primary cutaneous CD8+ aggressive epidermotropic cytotoxic T-cell lymphoma, Epstein-Barr virus-positive mucocutaneous ulcer. Both classifications consider primary cutaneous marginal zone B-cell clonal neoplasm as an indolent disease but use a different terminology: primary cutaneous marginal zone lymphoma (WHO) and primary cutaneous marginal zone LPD (ICC). The 5th WHO classification further introduces and provides essential and desirable diagnostic criteria for each disease type and includes chapters on reactive B- or T-cell rich lymphoid proliferations formerly referred as cutaneous pseudolymphomas, as well as histiocyte and CD8 T-cell rich LPD in patients with inborn error of immunity. As already emphasized in previous lymphoma classifications, the importance of integrating clinical, histological, phenotypic and molecular features remains the crucial conceptual base for defining cutaneous (and extracutaneous) lymphomas.

Fast, bedside diagnosis of toxic epidermal necrolysis using ex vivo confocal laser scanning microscopy: A retrospective study.

BACKGROUND: Toxic epidermal necrolysis (TEN) is a severe life-threatening drug eruption with rapid evolution. A fast histologic differentiation between TEN and clinically similarly looking staphylococcal scalded skin syndrome is of vital importance for relevant treatment decision. The recently developed ex vivo confocal laser scanning microscopy (CLSM) offers innovative and extremely fast histological visualization of fresh tissue specimens. OBJECTIVE: To assess the diagnostic efficacy of ex vivo CLSM in comparison with standard histopathology for TEN. METHODS: We performed side-by-side comparison of TEN specimens analysed with ex vivo CLSM and haematoxylin and eosin staining. Analysis focused on typical histopathological features of TEN, including epidermal cleavage in the basal layer and confluent epidermal necrosis. We retrospectively assessed the diagnostic performance of ex vivo CLSM for TEN in clinically confirmed cases. RESULTS: We report substantial agreement between ex vivo CLSM and classical histology for the detection of subepidermal cleavage and confluent epidermal necrosis. When considering full-thickness epidermal loss, epidermal cleavage in the basal layer showed the highest diagnostic performance, reaching 87.5% sensitivity and 100% specificity. CONCLUSION: Based on our data, ex vivo CSLM appears as a rapid, resource-optimizing, and reliable approach for morphological TEN emergency screening on fresh skin samples.

Mechanism of action of chlormethine gel in mycosis fungoides.

Mycosis fungoides (MF), the most common type of cutaneous T-cell lymphoma, is characterized by proliferation of malignant skin-tropic T cells. Progression from early-stage disease (skin patches and/or plaques) to more advanced stages (cutaneous tumours, erythroderma or extracutaneous involvement) occurs slowly and can be discontinuous. Prognosis is poor for the ~25% of patients who progress to advanced disease. Patients at any stage of MF may experience reduced health-related quality of life (QoL) via a spectrum of physically and psychologically debilitating symptoms that can impact many aspects of daily life. Allogeneic stem-cell transplantation is a curative treatment option for some patients with advanced disease, but otherwise there is currently no cure for MF; patients are often refractory to several treatments and require lifelong management. The goals of therapy are symptom control, prevention of disease progression, avoidance of treatment-related toxicity and maintenance/improvement of QoL. Although treatment regimens exist it can be difficult to know how to prioritize them, hence therapies are tailored according to patient needs and drug availabilities, following clinical recommendations. International consensus guidelines recommend skin-directed therapies (SDTs) as first-line treatment for early-stage disease, and SDTs combined with systemic therapy for advanced stages. Chlormethine (CL), also known as mechlorethamine, chlorethazine, mustine, HN2, caryolysine and embichin, is a synthetic deoxyribonucleic acid-alkylating agent that was used as a chemical weapon (mustard gas) during the First World War. Subsequent investigation revealed that survivors of mustard gas exposure had lymphocytopenia, and that CL could inhibit rapidly proliferating malignant T cells. CL has since been developed as a topical treatment for MF and prescribed as such for over 70 years. This review aims to summarize the current knowledge regarding the mechanism of action of CL in the cutaneous micro-environment, in the specific context of MF treatment.

Multicentric EORTC retrospective study shows efficacy of brentuximab vedotin in patients who have mycosis fungoides and Sézary syndrome with variable CD30 positivity.

BACKGROUND: Brentuximab vedotin (BV) was approved as a therapy for mycosis fungoides (MF) based on the ALCANZA trial. Little real-world data, however, are available. OBJECTIVES: To evaluate the efficacy and safety of BV in patients with MF/Sézary Syndrome (SS) with variable CD30 positivity in a real-world cohort and to explore potential predictors of response. METHODS: Data from 72 patients with MF/SS across nine EORTC (European Organization for Research and Treatment of Cancer) centres were included. The primary endpoint was to evaluate the proportion of patients with: overall response (ORR), ORR lasting over 4 months (ORR4), time to response (TTR), response duration (RD), progression-free survival (PFS) and time to next treatment (TTNT). Secondary aims included a safety evaluation and the association of clinicopathological features with ORR, RD and TTNT. RESULTS: All 72 patients had received at least one systemic treatment. ORR was achieved in 45 of 67; ORR4 in 28 of 67 with a median TTR of 8 weeks [interquartile range (IQR) 5·5-14] and with a median RD of 9 months (IQR 3·4-14). Median PFS was 7 months (IQR 2-12) and median TTNT was 30 days (6-157·5). Patient response, RD, PFS and TTNT were not associated with any clinicopathological characteristics. In the MF group, patients with stage IIB/III vs. IV achieved longer PFS and had a higher percentage of ORR4. There was a statistically significant association between large-cell transformation and skin ORR (P = 0·03). ORR4 was more frequently achieved in patients without lymph node involvement (P = 0·04). CONCLUSIONS: BV is an effective option for patients with MF/SS, including those with variable CD30 positivity, large-cell transformation, SS, longer disease duration and who have been treated previously with several therapies.

Treatment of early-stage mycosis fungoides: results from the PROspective Cutaneous Lymphoma International Prognostic Index (PROCLIPI) study.

BACKGROUND: The PROspective Cutaneous Lymphoma International Prognostic Index (PROCLIPI) study is a prospective analysis of an international database. Here we examine front-line treatments and quality of life (QoL) in patients with newly diagnosed mycosis fungoides (MF). OBJECTIVES: To identify (i) differences in first-line approaches according to tumour-nodes-metastasis-blood (TNMB) staging; (ii) parameters related to a first-line systemic approach and (iii) response rates and QoL measures. METHODS: In total, 395 newly diagnosed patients with early-stage MF (stage IA-IIA) were recruited from 41 centres in 17 countries between 1 January 2015 and 31 December 2018 following central clinicopathological review. RESULTS: The most common first-line therapy was skin-directed therapy (SDT) (322 cases, 81·5%), while a smaller percentage (44 cases, 11·1%) received systemic therapy. Expectant observation was used in 7·3%. In univariate analysis, the use of systemic therapy was significantly associated with higher clinical stage (IA, 6%; IB, 14%; IIA, 20%; IA-IB vs. IIA, P < 0·001), presence of plaques (T1a/T2a, 5%; T1b/T2b, 17%; P < 0·001), higher modified Severity Weighted Assessment Tool (> 10, 15%; ≤ 10, 7%; P = 0·01) and folliculotropic MF (FMF) (24% vs. 12%, P = 0·001). Multivariate analysis demonstrated significant associations with the presence of plaques (T1b/T2b vs. T1a/T2a, odds ratio 3·07) and FMF (odds ratio 2·83). The overall response rate (ORR) to first-line SDT was 73%, while the ORR to first-line systemic treatments was lower (57%) (P = 0·027). Health-related QoL improved significantly both in patients with responsive disease and in those with stable disease. CONCLUSIONS: Disease characteristics such as presence of plaques and FMF influence physician treatment choices, and SDT was superior to systemic therapy even in patients with such disease characteristics. Consequently, future treatment guidelines for early-stage MF need to address these issues.

European dermatology forum: Updated guidelines on the use of extracorporeal photopheresis 2020 - Part 2.

BACKGROUND: Following the first investigational study on the use of extracorporeal photopheresis for the treatment of cutaneous T-cell lymphoma published in 1983, this technology has received continued use and further recognition for additional earlier as well as refractory forms. After the publication of the first guidelines for this technology in the JEADV in 2014, this technology has maintained additional promise in the treatment of other severe and refractory conditions in a multidisciplinary setting. It has confirmed recognition in well-known documented conditions such as graft-vs.-host disease after allogeneic bone marrow transplantation, systemic sclerosis, solid organ transplant rejection including lung, heart and liver and to a lesser extent inflammatory bowel disease. MATERIALS AND METHODS: In order to further provide recognized expert practical guidelines for the use of this technology for all indications, the European Dermatology Forum (EDF) again proceeded to address these questions in the hands of the recognized experts within and outside the field of dermatology. This was done using the recognized and approved guidelines of EDF for this task. All authors had the opportunity to review each contribution as it was added. RESULTS AND CONCLUSION: These updated 2020 guidelines provide at present the most comprehensive available expert recommendations for the use of extracorporeal photopheresis based on the available published literature and expert consensus opinion. The guidelines were divided into two parts: PART I covers Cutaneous T-cell lymphoma, chronic graft-vs.-host disease and acute graft-vs.-host disease, while PART II will cover scleroderma, solid organ transplantation, Crohn's disease, use of ECP in paediatric patients, atopic dermatitis, type 1 diabetes, pemphigus, epidermolysis bullosa acquisita and erosive oral lichen planus.

Should we be imaging lymph nodes at initial diagnosis of early-stage mycosis fungoides? Results from the PROspective Cutaneous Lymphoma International Prognostic Index (PROCLIPI) international study.

BACKGROUND: Early-stage mycosis fungoides (MF) includes involvement of dermatopathic lymph nodes (LNs) or early lymphomatous LNs. There is a lack of unanimity among current guidelines regarding the indications for initial staging imaging in early-stage presentation of MF in the absence of enlarged palpable LNs. OBJECTIVES: To investigate how often imaging is performed in patients with early-stage presentation of MF, to assess the yield of LN imaging, and to determine what disease characteristics promoted imaging. METHODS: A review of clinicopathologically confirmed newly diagnosed patients with cutaneous patch/plaque (T1/T2) MF from PROspective Cutaneous Lymphoma International Prognostic Index (PROCLIPI) data. RESULTS: PROCLIPI enrolled 375 patients with stage T1/T2 MF: 304 with classical MF and 71 with folliculotropic MF. Imaging was performed in 169 patients (45%): 83 with computed tomography, 18 with positron emission tomography-computed tomography and 68 with ultrasound. Only nine of these (5%) had palpable enlarged (≥ 15 mm) LNs, with an over-representation of plaques, irrespectively of the 10% body surface area cutoff that distinguishes T1 from T2. Folliculotropic MF was not more frequently imaged than classical MF. Radiologically enlarged LNs (≥ 15 mm) were detected in 30 patients (18%); only seven had clinical lymphadenopathy. On multivariate analysis, plaque presentation was the sole parameter significantly associated with radiologically enlarged LNs. Imaging of only clinically enlarged LNs upstaged 4% of patients (seven of 169) to at least IIA, whereas nonselective imaging upstaged another 14% (24 of 169). LN biopsy, performed in eight of 30 patients, identified N3 (extensive lymphomatous involvement) in two and N1 (dermatopathic changes) in six. CONCLUSIONS: Physical examination was a poor determinant of LN enlargement or involvement. Presence of plaques was associated with a significant increase in identification of enlarged or involved LNs in patients with early-stage presentation of MF, which may be important when deciding who to image. Imaging increases the detection rate of stage IIA MF, and identifies rare cases of extensive lymphomatous nodes, upstaging them to advanced-stage IVA2.

European dermatology forum - updated guidelines on the use of extracorporeal photopheresis 2020 - part 1.

BACKGROUND: Following the first investigational study on the use of extracorporeal photopheresis for the treatment of cutaneous T-cell lymphoma published in 1983, this technology has received continued use and further recognition for additional earlier as well as refractory forms. After the publication of the first guidelines for this technology in the JEADV in 2014, this technology has maintained additional promise in the treatment of other severe and refractory conditions in a multi-disciplinary setting. It has confirmed recognition in well-known documented conditions such as graft-versus-host disease after allogeneic bone marrow transplantation, systemic sclerosis, solid organ transplant rejection including lung, heart and liver and to a lesser extent inflammatory bowel disease. MATERIALS AND METHODS: In order to further provide recognized expert practical guidelines for the use of this technology for all indications, the European Dermatology Forum (EDF) again proceeded to address these questions in the hands of the recognized experts within and outside the field of dermatology. This was done using the recognized and approved guidelines of EDF for this task. All authors had the opportunity to review each contribution as it was added. RESULTS AND CONCLUSION: These updated 2020 guidelines provide at present the most comprehensive available expert recommendations for the use of extracorporeal photopheresis based on the available published literature and expert consensus opinion. The guidelines are divided in two parts: PART I covers cutaneous T-cell lymphoma, chronic graft-versus-host disease and acute graft-versus-host disease while PART II will cover scleroderma, solid organ transplantation, Crohn's disease, use of ECP in paediatrics practice, atopic dermatitis, type 1 diabetes, pemphigus, epidermolysis bullosa acquisita and erosive oral lichen planus.

Clinical diversity and treatment approaches to blastic plasmacytoid dendritic cell neoplasm: a retrospective multicentre study.

BACKGROUND: Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare, aggressive type of haematologic precursor malignancy primarily often manifesting in the skin. We sought to provide a thorough clinical characterization and report our experience on therapeutic approaches to BPDCN. METHODS: In the present multicentric retrospective study, we collected all BPDCN cases occurring between 05/1999 and 03/2018 in 10 secondary care centres of the German-Swiss-Austrian cutaneous lymphoma working group. RESULTS: A total of 37 BPDCN cases were identified and included. Almost 90% of the patients had systemic manifestations (bone marrow, lymph nodes, peripheral blood) in addition to skin involvement. The latter presented with various types of cutaneous lesions: nodular (in more than 2/3) and bruise-like (in 1/3) skin lesions, but also maculopapular exanthema (in circa 1/6). Therapeutically, 22 patients received diverse combinations of chemotherapeutic regimens and/or radiotherapy. Despite initial responses, all of them ultimately relapsed and died from progressive disease. Eleven patients underwent haematopoietic stem cell transplantation (HSCT; autologous HSCT n = 3, allo-HSCT n = 8). The mortality rate among HSCT patients was only 33.33% with a median survival time of 60.5 months. CONCLUSION: Our study demonstrates the clinical diversity of cutaneous BPDCN manifestations and the positive development observed after the introduction of HSCT.

Characteristics associated with significantly worse quality of life in mycosis fungoides/Sézary syndrome from the Prospective Cutaneous Lymphoma International Prognostic Index (PROCLIPI) study.

BACKGROUND: Mycosis fungoides (MF) and Sézary Syndrome (SS) are the most common cutaneous T-cell lymphomas. MF/SS is accompanied by considerable morbidity from pain, itching and disfigurement. AIM: To identify factors associated with poorer health-related quality of life (HRQoL) in patients newly diagnosed with MF/SS. METHODS: Patients enrolled into Prospective Cutaneous Lymphoma International Prognostic Index (PROCLIPI; an international observational study in MF/SS) had their HRQoL assessed using the Skindex-29 questionnaire. Skindex-29 scores were analysed in relation to patient- and disease-specific characteristics. RESULTS: The study population consisted of 237 patients [60·3% male; median age 60 years, (interquartile range 49-70)], of whom 179 had early MF and 58 had advanced MF/SS. In univariate analysis, HRQoL, as measured by Skindex-29, was worse in women, SS, late-stage MF, those with elevated lactate dehydrogenase, alopecia, high modified Severity Weighted Assessment Tool and confluent erythema. Linear regression models only identified female gender (ß = 8·61; P = 0·003) and alopecia (ß = 9·71, P = 0·02) as independent predictors of worse global HRQoL. Item-level analysis showed that the severe impairment in symptoms [odds ratio (OR) 2·14, 95% confidence interval (CI) 1·19-3·89] and emotions (OR 1·88, 95% CI 1·09-3·27) subscale scores seen in women was caused by more burning/stinging, pruritus, irritation and greater feelings of depression, shame, embarrassment and annoyance with their diagnosis of MF/SS. CONCLUSIONS: HRQoL is significantly more impaired in newly diagnosed women with MF/SS and in those with alopecia. As Skindex-29 does not include existential questions on cancer, which may cause additional worry and distress, a comprehensive validated cutaneous T-cell lymphoma-specific questionnaire is urgently needed to more accurately assess disease-specific HRQoL in these patients. What's already known about this topic? Cross-sectional studies of mixed populations of known and newly diagnosed patients with mycosis fungoides (MF)/Sézary syndrome (SS) have shown significant impairment in health-related quality of life (HRQoL). Previous studies on assessing gender-specific differences in HRQoL in MF/SS are conflicting. More advanced-stage disease and pruritus is associated with poorer HRQoL in patients with MF/SS. What does this study add? This is the first prospective study to investigate HRQoL in a homogenous group of newly diagnosed patients with MF/SS. In patients newly diagnosed with MF/SS, HRQoL is worse in women and in those with alopecia and confluent erythema. MF/SS diagnosis has a multidimensional impact on patient HRQoL, including a large burden of cutaneous symptoms, as well as a negative impact on emotional well-being.

The PROCLIPI international registry of early-stage mycosis fungoides identifies substantial diagnostic delay in most patients.

BACKGROUND: Survival in mycosis fungoides (MF) is varied and may be poor. The PROCLIPI (PROspective Cutaneous Lymphoma International Prognostic Index) study is a web-based data collection system for early-stage MF with legal data-sharing agreements permitting international collaboration in a rare cancer with complex pathology. Clinicopathological data must be 100% complete and in-built intelligence in the database system ensures accurate staging. OBJECTIVES: To develop a prognostic index for MF. METHODS: Predefined datasets for clinical, haematological, radiological, immunohistochemical, genotypic, treatment and quality of life are collected at first diagnosis of MF and annually to test against survival. Biobanked tissue samples are recorded within a Federated Biobank for translational studies. RESULTS: In total, 430 patients were enrolled from 29 centres in 15 countries spanning five continents. Altogether, 348 were confirmed as having early-stage MF at central review. The majority had classical MF (81·6%) with a CD4 phenotype (88·2%). Folliculotropic MF was diagnosed in 17·8%. Most presented with stage I (IA: 49·4%; IB: 42·8%), but 7·8% presented with enlarged lymph nodes (stage IIA). A diagnostic delay between first symptom development and initial diagnosis was frequent [85·6%; median delay 36 months (interquartile range 12-90)]. This highlights the difficulties in accurate diagnosis, which includes lack of a singular diagnostic test for MF. CONCLUSIONS: This confirmed early-stage MF cohort is being followed-up to identify prognostic factors, which may allow better management and improve survival by identifying patients at risk of disease progression. This study design is a useful model for collaboration in other rare diseases, especially where pathological diagnosis can be complex.

Interferon alfa-2a maintenance after salvage autologous stem cell transplantation in atypical mycosis fungoides with central nervous system involvement.

Mycosis fungoides (MF) is a primary cutaneous T-cell lymphoma with unfavourable prognosis for patients with advanced stages of the disease. Refractory disease and advanced-stage disease require systemic therapy. We report on a rare case of an atypical predominantly CD8+ folliculotropic MF, a subtype of MF with poorer prognosis, in a 59-year-old woman. She was initially diagnosed with MF restricted to the skin, of T3N0M0B0/stage IIB according to the current World Health Organization-European Organisation for Research and Treatment of Cancer classification. First-line treatment with local percutaneous radiotherapy in combination with systemic interferon alfa-2a resulted in complete remission. However, 21 months later the disease progressed to T3N0M1B0/stage IVB with development of cerebral manifestation and thus very poor prognosis. Allogeneic stem cell transplantation (SCT) was not a therapeutic option due to the lack of a suitable donor. We initiated methotrexate and cytarabine chemotherapy, followed by high-dose chemotherapy with thiotepa and carmustine with autologous SCT. Despite rapid response and complete remission of the cerebral lesions, disease recurrence of the skin occurred soon after. Interestingly, readministration of interferon alfa-2a as a maintenance treatment after the salvage autologous SCT resulted in a durable complete remission during the follow-up period of currently 17 months after autologous SCT. What's already known about this topic? Mycosis fungoides is a primary cutaneous T-cell lymphoma with unfavourable prognosis for the advanced stages of the disease. A refractory course of disease requires systemic therapy. What does this study add? We report on an unusual case of a patient with mycosis fungoides with cerebral involvement, in which a durable complete remission was achieved upon autologous stem cell therapy and interferon alfa-2a maintenance therapy.

Histiocytosis - cutaneous manifestations of hematopoietic neoplasm and non-neoplastic histiocytic proliferations.

Histiocytoses are rare disorders characterized by the accumulation of cells derived from macrophages, dendritic cells or monocytes in various tissues. There is a broad spectrum of disease manifestations with some subtypes commonly showing skin lesions, while in others, the skin is rarely involved. Here, we describe cutaneous manifestations of histiocytoses belonging to the Langerhans group (L group), the group of cutaneous and mucocutaneous histiocytoses (C group) and the group of Rosai-Dorfman disease (RDD) and related histiocytoses (R group) according to the current classification. Characteristic clinical presentations noted were a rust-brown colour or xanthomatous aspect in many cases of histiocytoses. Histological criteria for differentiation are described. Immunohistochemistry shows positivity for S100 and CD1a in Langerhans-cell histiocytoses (LHCH) of the L group, while CD68 positivity with S100 and CD1a negativity are typical in histiocytoses of the C group of cutaneous and mucocutaneous histiocytoses. RDD in the R group shows positivity for S100 and CD68, while CD1a is negative. We further review the pathogenesis of LHCH based on insights on the central role of the mitogen-activated protein (MAPK) kinase pathway. Common mutations in various histiocytic populations of diverse ontogeny and at different stages of differentiation may be responsible for the diverse clinical picture of this neoplastic entity. For histiocytoses of the C group and R group, a reactive origin is discussed with the exception of the disseminated form of juvenile xanthogranuloma. We suggest exploring the role of an origin from skin residing histiocytes for the isolated cutaneous manifestation in some types. With regard to therapeutic options, skin-directed therapies are the first choice in limited disease, while systemic chemotherapy has traditionally been used in extensive disease. In Langerhans-cell histiocytoses and related entities, therapy by BRAF inhibition has led to a breakthrough especially in patients with an activation of the MAPK pathway.

Adverse Reactions of Antibody-Therapy for Primary Cutaneous Lymphomas: Rituximab, Brentuximab Vedotin, Alemtuzumab, and Mogamulizumab.

Treatment of advanced PCLs is limited and rarely reaches complete remission despite aggressive treatment modalities, such as polychemotherapy with various adverse effects. However, several monoclonal antibodies drug agents in patients with advanced primary cutaneous lymphomas demonstrate promising efficacy and manageable safety profiles. The monoclonal antibodies drug agents have favourable tolerability compared with multi-agent cytotoxic chemotherapy. However, adverse effects manifest with a broad clinical spectrum, hence the markers of targeted therapies are not limited to tumour cells but found on tumour cells and also on benign T and/or B cells. Moreover, the safety profile and direct causal association of drug and adverse effects should be interpreted with caution because many of the patients in clinical studies have received multiple treatments. Here, we focus on the safety profile of mAbs therapies that have recently been approved or are currently under preclinical or clinical investigation for CBCLs (rituximab) and CTCLs (brentuximab, mogamulizumab, and alemtuzumab). Further studies to define clinical safety profile in the patient cohort with cutaneous lymphomas are needed.