Primary cutaneous T-cell lymphoma: a review of the most common entities with focus on recent updates.

Cutaneous T-cell lymphomas are an heterogeneous group of uncommon lymphoid neoplasms that are challenging to diagnose and require close collaboration between dermatologists, pathologists and hematologists/oncologists. This article reviews the most common cutaneous T-cell lymphomas: mycosis fungoides (both classic and variant forms) as well as its leukemic counterpart Sézary syndrome, CD30+ T-cell lymphoproliferative disorders including the ever-expanding group of lymphomatoid papulosis and primary cutaneous anaplastic large cell lymphoma, and primary cutaneous CD4+ small/medium lymphoproliferative disorder. We discuss the classic clinical and histopathologic features of these lymphomas and review how they can be distinguished from reactive entities. In particularly, updates to these diagnostic categories and current controversies in classification are highlighted. Moreover, we review the prognosis and treatment for each entity. These lymphomas exhibit variable prognosis, and therefore it is important to correctly classify atypical cutaneous T-cell infiltrates for appropriate patient treatment and prognosis. Cutaneous T-cell lymphomas are at the interface of several medical specialties; this review seeks to summarize key features of these lymphomas and highlight new and emerging insights into these lymphomas.

CD30-positive lymphoproliferative disorders-An Australian Clinical Practice Statement from the Peter MacCallum Cancer Centre.

The CD30-postive lymphoproliferative disorders, including lymphomatoid papulosis and primary cutaneous anaplastic large cell lymphoma, account for up to 30% of all cutaneous T-cell lymphomas (CTCLs) and are the second most common form of CTCLs after mycosis fungoides. Both conditions differ in their clinical presentations; however, they share the expression of the CD30 antigen as a common immunophenotypic hallmark. There is a wide spectrum of management options depending on factors such as extent of disease, staging and treatment tolerability. This Clinical Practice Statement is reflective of the current clinical practice in Australia.

Etiopathogenesis, Diagnosis, and Treatment Strategies for Lymphomatoid Papulosis with Particular Emphasis on the Role of the Immune System.

Lymphomatoid papulosis (LyP) is a very rare disease that belongs to the group of CD30+ lymphoproliferative skin diseases. LyP is localized or generalized and usually presents as isolated or clustered red/brown-red lesions in the form of nodules and/or papules. The course of the disease is in most cases mild; however, depending on concomitant risk factors and history, it may progress to lymphoma, significantly reducing the survival rate and prognosis. Importantly, the clinical picture of the disease remains somewhat ambiguous, leading to a large number of misdiagnoses that result in inappropriate treatment, which is usually insufficient to alleviate symptoms. In addition to clinical manifestations, the histological characteristics vary widely and usually overlap with other conditions, especially those belonging to the group of lymphoproliferative disorders. Although diagnosis remains a challenge, several recommendations and guidelines have been introduced to standardize and facilitate the diagnostic process. This article reviews the available literature on the most important aspects of etiopathogenesis, clinical and histopathological features, diagnostic criteria, and possible treatment strategies for LyP, with particular emphasis on the role of the immune system.

Understanding Cell Lines, Patient-Derived Xenograft and Genetically Engineered Mouse Models Used to Study Cutaneous T-Cell Lymphoma.

Cutaneous T cell lymphoma (CTCL) is a spectrum of lymphoproliferative disorders caused by the infiltration of malignant T cells into the skin. The most common variants of CTCL include mycosis fungoides (MF), Sézary syndrome (SS) and CD30+ Lymphoproliferative disorders (CD30+ LPDs). CD30+ LPDs include primary cutaneous anaplastic large cell lymphoma (pcALCL), lymphomatoid papulosis (LyP) and borderline CD30+ LPD. The frequency of MF, SS and CD30+ LPDs is ~40-50%, <5% and ~10-25%, respectively. Despite recent advances, CTCL remains challenging to diagnose. The mechanism of CTCL carcinogenesis still remains to be fully elucidated. Hence, experiments in patient-derived cell lines and xenografts/genetically engineered mouse models (GEMMs) are critical to advance our understanding of disease pathogenesis. To enable this, understanding the intricacies and limitations of each individual model system is highly important. Presently, 11 immortalized patient-derived cell lines and different xenograft/GEMMs are being used to study the pathogenesis of CTCL and evaluate the therapeutic efficacy of various treatment modalities prior to clinical trials. Gene expression studies, and the karyotyping analyses of cell lines demonstrated that the molecular profile of SeAx, Sez4, SZ4, H9 and Hut78 is consistent with SS origin; MyLa and HH resemble the molecular profile of advanced MF, while Mac2A and PB2B represent CD30+ LPDs. Molecular analysis of the other two frequently used Human T-Cell Lymphotropic Virus-1 (HTLV-1)+ cell lines, MJ and Hut102, were found to have characteristics of Adult T-cell Leukemia/Lymphoma (ATLL). Studies in mouse models demonstrated that xenograft tumors could be grown using MyLa, HH, H9, Hut78, PB2B and SZ4 cells in NSG (NOD Scid gamma mouse) mice, while several additional experimental GEMMs were established to study the pathogenesis, effect of drugs and inflammatory cytokines in CTCL. The current review summarizes cell lines and xenograft/GEMMs used to study and understand the etiology and heterogeneity of CTCL.

Primary Cutaneous CD30+ Lymphoproliferative Disorders: a Comprehensive Review.

PURPOSE OF REVIEW: Primary cutaneous CD30+ T-cell lymphoproliferative disorders (CD30+ LPDs) are the second most common cutaneous lymphomas after mycosis fungoides and Sezary syndrome. They include primary cutaneous anaplastic large cell lymphoma (pcALCL), lymphomatoid papulosis (LyP), and borderline lesions. The purpose of this literature review is to consolidate the available evidence on the primary cutaneous CD30+ LPD in order to define the tools for correct diagnosis and appropriate treatment. RECENT FINDINGS: The current body of knowledge regarding the clinical features, histopathologic changes, recently described genetic alterations, and therapeutic options will be covered in this comprehensive review. Primary cutaneous CD30+ LPD represent rare cutaneous lymphomas that have significant histologic overlap within the defined group as well as with other neoplastic and reactive entities. The importance of differentiating these entities is crucial, as each one has a different clinical course and prognosis.

Clinical Characteristics and Disease Course in Black Patients With Lymphomatoid Papulosis: A Case Series

INTRODUCTION: Lymphomatoid papulosis (LyP) is a CD30+ T-cell lymphoproliferative disorder (LPD) presenting as a recurrent eruption of papules and nodules which resolve spontaneously. CD30+ LPD prevalence in African American (AA)/Black patients is lower compared to White patients. CD30+ LPD has been recently reported to have worse outcomes in AA patients compared to White patients. METHODS: A retrospective chart review identified eight AA patients with LyP. We describe our experience with these eight patients and review the literature on similar cases. RESULTS: In half of the eight included patients, lesions occurred 1-4 years before they were diagnosed. In six patients (75%), resolution of the lesions resulted in hyperpigmented macules and scars. Five patients (63%) had also mycosis fungoides. Most of the patients who were followed (4/7, 57%) did not have complete resolution at their last visit, despite different treatment approaches. Discussion: Our results highlight that although LyP has an indolent course in AA/Black patients, residual hyperpigmentation and scars frequently occur, highlighting the need for better treatments of this lymphoproliferative disorder in this specific population. J Drugs Dermatol. 2020;19(1):89-91. doi:10.36849/JDD.2020.4602

Primary Cutaneous Anaplastic Large Cell Lymphoma (pcALCL) in the Elderly and the Importance of Sport Activity Training.

Primary cutaneous anaplastic large cell lymphoma (pcALCL) is part of a spectrum of cutaneous CD30+ lymphoproliferative disease that also includes lymphomatoid papulosis. It often occurs in elderly patients, presenting at a median age of 60 years, although it may occur at any age. It is a CD30+ T-cell neoplasm composed of large cells with anaplastic, pleomorphic, or immunoblastic morphology, with exclusively cutaneous onset and localization. The clinical course of pcALCL is predominantly indolent. Most elderly patients with lymphoma tend to have a sedentary lifestyle, which has a negative effect on their quality of life (QoL) and survival. Several studies indicate that exercise has a positive impact on QoL because it reduces peak oxygen consumption, improves physical capacity, increases self-esteem, reduces accumulated stress, and promotes relaxation. Therefore, particularly in indolent lymphomas, it is necessary to indicate a program of physical activity to be practiced systematically. Complete surgical excision and local radiotherapy are the first line gold standard in pcALCL with a solitary lesion.

Lymphomatoid papulosis.

Lymphomatoid papulosis (LyP) is a non-aggressive skin disorder characterized by papulonodular injuries, sometimes necrotic, often scattered, relapsing, which frequently regress spontaneously. LyP represents about 12% of cutaneous lymphomas. The etiology of LyP is unknown. Based on its histopathology, in 2018, the World Health Organization (WHO) classified LyP into six types with similar prognosis (A,B,C,D,E and DUSP22). Once the diagnosis of LyP has been made, having an excellent prognosis, this pathology must be managed mainly with a "watch and wait" strategy. Treatment should be given only in the presence of diffuse, symptomatic lesions with disfiguring evolution, with the aim of reducing time of resolution and preventing recurrences or the formation of new lesions.

Lymphomatoid papulosis: an update and review.

Lymphomatoid papulosis (LyP) is a benign chronic often relapsing skin condition that belongs to the CD30-positive cutaneous lymphoproliferative disorders. LyP typically presents as crops of lesions with a tendency to self-resolve, and morphology can range from solitary to agminated or diffuse papules and plaques to nodules or tumours. The clinical-histological spectrum can range from borderline cases to overlap with primary cutaneous anaplastic cell lymphoma (pcALCL). Histology and immunophenotype commonly show overlap with other CD30-positive disorders and sometimes may be identical to pcALCL, making its diagnosis more difficult. Patients with LyP have an increased risk of developing a second neoplasm such as mycosis fungoides, pcALCL and/or Hodgkin lymphoma. Clinical correlation allows its proper classification and diagnosis, which is fundamental for treatment and prognosis. This review focuses on the clinical appearance, histopathological features, diagnosis, differential diagnosis and management of LyP.

Lymphomatoid Papulosis and Other Lymphoma-Like Diseases.

Pityriasis lichenoides et varioliformis acuta and pityriasis lichenoides chronica are the 2 main subtypes of pityriasis lichenoides. They represent the acute and chronic forms of the disease; both may have clonal T cells. Several treatment modalities are used, but it has been difficult to determine efficacy because of the possibility of spontaneous remission. Cutaneous CD30+ lymphoproliferative disorders constitute many cutaneous T-cell lymphomas and comprise lymphomatoid papulosis and primary cutaneous anaplastic large cell lymphoma (ALCL). Both have an excellent prognosis. Lymphomatoid papulosis often only requires observation or treatment of symptoms. First-line therapies for primary cutaneous ALCL are surgical excision or radiotherapy.

CD30-Positive Lymphoproliferative Disorders.

Primary cutaneous CD30-positive lymphoproliferative disorders (CD30+ LPD) encompass lymphomatoid papulosis (LyP), primary cutaneous anaplastic large cell lymphoma (pcALCL), and borderline lesions [1]. CD30+ LPD are the second most common cutaneous T-cell lymphomas (CTCL) after mycosis fungoides (MF) and represent approximately 25% of all CTCL cases [2]. Their common phenotypic hallmark is an expression of the CD30 antigen, a cytokine receptor belonging to the tumor necrosis factor (TNF) receptor superfamily. Both LyP and pcALCL show numerous clinical, histological and immunophenotypic variants, and generally have an indolent course with a favorable prognosis. Overlapping features of LyP and pcALCL with other CD30+ T-cell lymphomas, inflammatory, and/or infectious conditions emphasize the importance of careful clinicopathologic correlation and staging.

Long-term Follow-up of a Case of Lymphomatoid Papulosis with a Benign Course.

Dear Editor,We present the case of a 40-year old male patient with lymphomatoid papulosis of a waxing and waning course on whom three biopsies were performed during a 14-year period with no change in histopathological or immunophenotypical characteristics. Lymphomatoid papulosis (LP) is a chronic, recurrent, self-healing papulonodular skin eruption with the histopathologic features of a cutaneous T-cell lymphoma but an often benign and indolent clinical course (1). It is designated as a primary, cutaneous, CD30+ lymphoproliferative disorder. The histopathologic features of LP are variable, with five main types (A-E) and several other variants (2). In most cases, LP presents with a generalized eruption of reddish-brown papules or nodules usually smaller than one cm on the trunk and limbs. Rarely, large, rapidly growing nodules may be the first manifestation of the disease (3). Patients with LP have an excellent prognosis even though they are at increased risk of developing secondary cutaneous or nodal lymphomas such as mycosis fungoides, primary cutaneous anaplastic large cell lymphoma (PC-ALCL), or Hodgkin lymphoma (4). LP-associated lymphomas develop in between 10% and, as recently reported, 52% percent of patients and may occur before, concurrent with, or after the onset of LP (4,5). Our patient was diagnosed with "conventional" type An LP 14 years earlier based on the clinicopathologic correlation. The diagnosis was confirmed a year later after excision of a rapid growing ulcerated nodule on the forearm measuring 17 mm in diameter, which was clinically suspected to be anaplastic large cell lymphoma. During these 14 years, there were only a few worrisome recurrences of the disease, which resolved spontaneously or were successfully controlled with local steroids. During a recent exacerbation, when the third biopsy was performed, the patient presented with a large number of generalized reddish-brown pruritic papules and nodules on the trunk, extremities, neck, and face, predominantly up to one cm, some among which were necrotic and excoriated (Figure 1). There were three sites of clustered papules on the trunk, groin, and neck that resembled large, infiltrated plaques larger than two cm, at a glance mimicking cutaneous lymphoma (Figure 1, b, c). There were also older residual hyper- and hypopigmentations on the skin with prominent scarring. Excisional skin biopsy of one larger papule from the abdominal plaque was performed and was not morphologically or immunophenotypically different from the previous ones (Figure 2). Immunohistochemistry showed expression of CD 30 and the phenotypic markers of T-helper lymphocytes (CD 3+/-, CD4+) by neoplastic cells (Figure 2, c, d). Associated systemic malignant lymphoma was excluded based on examination findings, normal laboratory tests, the absence of palpably enlarged lymph nodes, hepatosplenomegaly, and systemic symptoms followed with MSCT. Serology for HIV and EBV was performed and was positive for EBV EBNA, VCA IgG, and IgM, which could be associated with the exacerbation of LP. Topical corticosteroids and phototherapy were administered when needed in this 14-year period, and methotrexate in a lower dose was prescribed during the extensive generalized eruptions. All of the applied therapeutic modalities led to a partial response. LP is a self-limiting disease for which many patients do not require specific treatment. Therapy should be directed at controlling symptoms in generalized eruptions or minimizing the frequency of recurrences, but none of the available treatment options disrupt the natural history of LP or reduce the risk of developing an associated lymphoma (6). Low-dose methotrexate is the initial therapy of choice in patients with the extensive or symptomatic disease or disease involving cosmetically sensitive areas like the face or hands, which were the affected areas in our patient (6,7). There are no markers that can help predict the course of the disease in a given patient, although some indicators have been suggested (8,9). Because of this lack of markers that can help predict the course of the disease and occurrence of malignant lymphoma, patients should remain in monitoring for the rest of their life.

Phototherapy of cutaneous T-cell lymphomas.

Cutaneous T-cell lymphomas (CTCL) are a heterogenous group of non-Hodgkin lymphomas arising in the skin. Mycosis fungoides (MF), the most common variant, is characterised by clonal proliferation of skin residing malignant T-cells. Initially appearing with erythematous patches and plaques it follows a chronic course with progression to cutaneous tumours and extracutaneous involvement in some patients. Phototherapy with ultraviolet A radiation combined with 8-methoxypsoralen (PUVA) and with narrow-band ultraviolet B radiation (NB-UVB) are among the first line options for the treatment of MF and can induce remission in most patients. Sézary syndrome (SS) is a rare and more aggressive CTCL variant with generalized skin involvement. Patients with SS and with erythroderma from MF can benefit from treatment with extracorporeal photochemotherapy (ECP) where peripheral blood is exposed to PUVA. Phototherapy can be safely combined with systemic agents, most notably interferon-alpha and retinoids. Another photoresponsive CTCL variant is lymphomatoid papulosis (LP), a CD30+ lymphoproliferative disease characterised by chronically recurring papules. The disease responds favourably to PUVA but low dose methotrexate might be preferred for long term disease control. Recently updated treatment guidelines have been published to provide evidence-based algorithms for the stage-oriented treatment of MF, SS and LP. Areas of uncertainty are treatment schedules that are currently not optimised for CTCL, the use of phototherapy for maintenance, and the value of ultraviolet A1 radiation, excimer lasers, and photodynamic therapy.

Cutaneous CD30-positive T-cell lymphoproliferative disorders-clinical and histopathologic features, differential diagnosis, and treatment.

Cutaneous CD30+ T-cell lymphoproliferative disorders (CD30+ LPD) are the second most common form of cutaneous T-cell lymphoma. CD30+ LPD include lymphomatoid papulosis, primary cutaneous anaplastic large-cell lymphoma, and borderline lesions. Despite expression of CD30 by the neoplastic cells as the hallmark of these disorders, they differ in their clinical presentation and histological features as well as the course, the prognosis, and consecutively in the treatment. Diagnosis of CD30+ LPD and distinction from the broad spectrum of differential diagnoses essentially depends on clinicopathologic correlation as well as the results of staging examinations. Although the histological findings indicate a high-grade lymphoma, CD30+ LPD in most cases have a favorable prognosis. Recent advances in targeted therapy have led to new therapeutic approaches to CD30+ LPDs. This review describes the clinicopathologic features of CD30+ LPDs, their differential diagnoses, the treatment, and the role of CD30 as a diagnostic marker and therapeutic target.

First-line treatment in lymphomatoid papulosis: a retrospective multicentre study.

BACKGROUND: Data regarding response to treatment in lymphomatoid papulosis (LyP) are scarce. AIM: To assess the daily clinical practice approach to LyP and the response to first-line treatments. METHODS: This was a retrospective study enrolling 252 patients with LyP. RESULTS: Topical steroids, methotrexate and phototherapy were the most common first-line treatments, prescribed for 35%, 20% and 14% of the patients, respectively. Complete response (CR) was achieved in 48% of treated patients. Eczematous lesions significantly increased relative risk (RR) of not achieving CR (RR = 1.76; 95% CI 1.16-2.11). Overall median time to CR was 10 months (95% CI 6-13 months), and 78% of complete responders showed cutaneous relapse; both results were similar for all treatment groups (P > 0.05). Overall estimated median disease-free survival (DFS) was 11 months (95% CI 9-13 months) but DFS for patients treated with phototherapy was 23 months (95% CI 10-36 months; P < 0.03). Having the Type A LyP variant (RR = 2.04; 95% CI 0.96-4.30) and receiving a first-line treatment other than phototherapy (RR = 5.33; 95% CI 0.84-33.89) were significantly associated with cutaneous early relapse. Of the 252 patients, 31 (13%) had associated mycosis fungoides unrelated to therapeutic approach, type of LyP or T-cell receptor clonality. CONCLUSIONS: Current epidemiological, clinical and pathological data support previous results. Topical steroids, phototherapy and methotrexate are the most frequently prescribed first-line treatments. Although CR and cutaneous relapse rates do not differ between them, phototherapy achieves a longer DFS. Presence of Type A LyP and use of topical steroid or methotrexate were associated with an increased risk of early relapse.