Lymphomatoid papulosis: Treatment response and associated lymphomas in a study of 180 patients

Paediatric-onset lymphomatoid papulosis: results of a multicentre retrospective cohort study on behalf of the EORTC Cutaneous Lymphoma Tumours Group (CLTG)

BACKGROUND

Lymphomatoid papulosis (LyP) is a rare cutaneous T-cell lymphoproliferative disorder. Comprehensive data on LyP in the paediatric population are scarce.

OBJECTIVES

To characterize the epidemiological, clinical, histopathological and prognostic features of paediatric LyP.

METHODS

This was a retrospective multicentre international cohort study that included 87 children and adolescents with LyP diagnosed between 1998 and 2022. Patients aged ≤ 18 years at disease onset were included. LyP diagnosis was made in each centre, based on clinicopathological correlation.

RESULTS

Eighty-seven patients from 12 centres were included. Mean age at disease onset was 7.0 years (range 3 months-18 years) with a male to female ratio of 2 : 1. Mean time between the onset of the first cutaneous lesions and diagnosis was 1.3 years (range 0-14). Initial misdiagnosis concerned 26% of patients. LyP was most often misdiagnosed as pityriasis lichenoides et varioliformis acuta, insect bites or mollusca contagiosa. Erythematous papules or papulonodules were the most frequent clinical presentation. Pruritus was specifically mentioned in 21% of patients. The main histological subtype was type A in 55% of cases. When analysed, monoclonal T-cell receptor rearrangement was found in 77% of skin biopsies. The overall survival rate was 100%, with follow-up at 5 years available for 33 patients and at 15 years for 8 patients. Associated haematological malignancy (HM) occurred in 10% of cases (n = 7/73), including four patients with mycosis fungoides, one with primary cutaneous anaplastic large cell lymphoma (ALCL), one with systemic ALCL and one with acute myeloid leukaemia. If we compared incidence rates of cancer with the world population aged 0-19 years from 2001 to 2010, we estimated a significantly higher risk of associated malignancy in general, occurring before the age of 19 years (incidence rate ratio 87.49, 95% confidence interval 86.01-88.99).

CONCLUSIONS

We report epidemiological data from a large international cohort of children and adolescents with LyP. Overall, the disease prognosis is good, with excellent survival rates for all patients. Owing to an increased risk of associated HM, long-term follow-up should be recommended for patients with LyP.

Primary Cutaneous CD30-Positive Lymphoproliferative Disorders-Current Therapeutic Approaches with a Focus on Brentuximab Vedotin

One of the most common subgroups of cutaneous T-cell lymphomas is that of primary cutaneous CD30-positive lymphoproliferative disorders. The group includes lymphomatoid papulosis (LyP) and primary cutaneous anaplastic large cell lymphoma (pcALCL), as well as some borderline cases. Recently, significant progress has been made in understanding the genetics and treatment of these disorders. This review article summarises the clinical evidence supporting the current treatment options for these diseases. Recent years have seen the introduction of novel agents into clinical practice; most of these target CD30, such as anti-CD30 monoclonal antibodies and conjugated antibodies (brentuximab vedotin), bispecific antibodies and cellular therapies, particularly anti-CD30 CAR-T cells. This paper briefly reviews the biology of CD30 that makes it a good therapeutic target and describes the anti-CD30 therapies that have emerged to date.

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.

Clinicopathological Factors Associated with the Prognosis and Chronicity of Lymphomatoid Papulosis: A Retrospective Cohort Study

BACKGROUND

The clinical and pathological features of lymphomatoid papulosis (LYP) are diverse. The objective of this study is to evaluate the clinical and pathological features associated with the prognosis and clinical course of LYP.

PATIENTS AND METHODS

The clinical and pathological features of LYP in a medical center database were retrospectively retrieved.

RESULTS

Overall, 58 LYP patients were included in the study. The mean age at diagnosis was 39.1 years and the female-to-male ratio was 1:1.2. More than two-thirds (40/58, 69.0%) of the patients showed a chronic and recurrent disease course. A longer pre-diagnosis duration (odds ratio (OR), 1.01; 95% confidence interval (CI), 1.00-1.03) was significantly associated with secondary lymphoma development. Lower extremity involvement (OR, 10.40; 95% CI, 1.17-92.28) and the absence of eosinophils in the lesions (OR, 11.28; 95% CI, 1.01-126.24) were found to be significantly associated with the chronic and recurrent course of LYP.

CONCLUSION

A longer pre-diagnosis duration is associated with secondary lymphoma, while a lower extremity involvement and the absence of lesional eosinophil infiltration are associated with the chronicity of LYP.

Efficacy of brentuximab vedotin in patients with CD30-positive lymphoproliferative skin diseases: results of the first prospective study in the Russian Federation

Background. Primary cutaneous lymphomas are the second most common group of extranodal lymphomas. Unlike nodal lymphomas, where B-cell proliferations dominate, primary cutaneous T-cell lymphomas account for 6575% of all cutaneous lymphomas. Among T-cell lymphomas of the skin, about 50% of cases are mycosis fungoides (MF), the second place in frequency of occurrence is occupied by CD30-positive lymphoproliferative skin diseases (CD30 LPD), about 10% are rare nosological forms, such as primary cutaneous peripheral T-cell lymphoma, unspecified, Sezari syndrome (SS), etc. During the initiating treatment of patients with MF and Szary syndrome (SS), carried out on the territory of the Russian Federation, for about 30% of patients are resistant to various therapeutic effects, especially in the later stages. The problem of the treatment of CD30+ LPD is extracutaneous dissemination in case of primary cutaneous anaplastic large cell lymphoma (pcALCL), steadily relapsing course of lymphomatoid papulosis (LyP) without symptom-free intervals. These characteristics of the therapy of cutaneous lymphomas demand for the need to search for new treatment options. Brentuximab vedotin, according to the results of the international randomized ALCANZA trial, has shown high efficiency in the treatment of cutaneous T-cell lymphoproliferative diseases. Aim. To evaluate the efficacy of brentuximab vedotin application in patients with cutaneous T-cell lymphomas in adverse risk group received at least one line of systemic therapy. Materials and methods. The study included 21 patients: 16 men and 5 women. The diagnosis of MF was verified in 8 patients, SS in 5 patients, cutaneous CD30+ LPD in 6 patients (5 patients pcALCL, 1 patient LyP) and a primary cutaneous peripheral T-cell lymphoma, unspecified in 2 patients. The diagnosis of cutaneous T-cell lymphoma was verified on the basis of the anamnesis of the disease, on the character of cutaneous lesions, on histological, immunohistochemical and in some cases on molecular genetic testing of the skin biopsy (the assessment of T-cell receptor gene rearrangement). Results. The late stages of the disease were diagnosed in 12 of 13 patients with MF/SS. Extracutaneous lesions were diagnosed in 57% of cases. The median of prior lines therapy was 3 (18 variants of treatment). The overall response to the treatment was achieved in 91% of cases (in 19 of 21 patients): the complete remission was obtained in 53% of cases, very good partial remission in 31% of cases and partial remission in 16% of cases. The progression of the disease was determined in 2 patients (after the first and fourth cycles). Some patients with partial remission as a result of therapy using brentuximab vedotin had the additional therapy (radiation therapy, interferon , the cycles of systemic therapy) and these acts gave an option of achieving deeper antitumor response. The early relapse was diagnosed in 2 of 19 patients who had responded to the treatment. The treatment tolerability was acceptable, and the toxicity did not exceed the already known one described in earlier studies. Thus, the stable overall antitumor response had been persisting in 89% of patients (the median of the observation was 10 months). Conclusion. The use of targeted therapy with brentuximab vedotin gave an option of achieving high treatment results in group of patients with advanced stages of the disease and inefficiency of several lines of therapy.

Oral manifestation of lymphomatoid papulosis: systematic review

Introduction: Lymphomatoid Papulosis (LyP) is a lymphoproliferative disorder with typical histopathological criteria and a spontaneous regression. Only few cases of oral involvement have been reported. We wondered about their clinical characteristics and their association with lymphoma. Method: This systematic review is conducted according to the PRISMA statement. The Oxford Centre for Evidence Based Medicine table (OCEBM) and the scoring from the National Agency for Accreditation and Assessment in Health (ANAES) was assigned to each study. Results: We have included 16 references. LyP can occur at any age with a female predilection. Oral lesions were unique ulcer and tongue was mostly affected. Histological types A, and C were dominant and LyP resolved spontaneously. 1 case was associated with a lymphoma. Discussion: Cutaneous LyP more affects men and are mostly classified as type A while those orals are type A or C. Oral LyP is probably a progressive lesion whose evolution is not illustrated by the histological aspect which often reflects only the initial acute period. Conclusion: Our literature review has shown that the epidemiological aspects between oral and cutaneous LyP are not the same. LyP may be associated with an increased risk of developing systemic lymphoproliferative disorders.

Modern possibilities of therapy for primary cutaneous T-cell lymphomas: the first results of the use of brentuximab vedotin in the Russian Federation

Background. Primary cutaneous T-cell lymphomas are rare heterogeneous group of lymphoproliferative diseases characterized by primarily involving skin and subcutaneous adipose tissue. Half of these cases are mycosis fungoides (MF), for about 25% are cutaneous CD30+ lymphoproliferative diseases (CD30+ LPD): primary cutaneous anaplastic large cell lymphoma (pcALCL) and lymphomatoid papulosis (LyP). During the initiating treatment of patients with MF and Szary syndrome (SS), carried out on the territory of the Russian Federation, for about 30% of patients are resistant to various therapeutic effects, especially in the later stages. The problem of the treatment of CD30+ LPD is extracutaneous dissemination in case of pcALCL, steadily relapsing course of LyP without symptom-free intervals. These characteristics of the therapy of cutaneous lymphomas demand for the need to search for new treatment options. Brentuximab vedotin, according to the results of the international randomized ALCANZA trial, has shown high efficiency in the treatment of cutaneous T-cell lymphoproliferative diseases. Aim. To evaluate the efficacy of brentuximab vedotin application in patients with cutaneous T-cell lymphomas in adverse risk group received at least one line of systemic therapy. Materials and methods. The study included 21 patients: 16 men and 5 women. The diagnosis of MF was verified in 8 patients, SS in 5 patients, cutaneous CD30+ LPD in 6 patients (5 patients pcALCL, 1 patient LyP) and a primary cutaneous peripheral T-cell lymphoma, unspecified in 2 patients. The diagnosis of cutaneous T-cell lymphoma was verified on the basis of the anamnesis of the disease, on the character of cutaneous lesions, on histological, immunohistochemical and in some cases on molecular genetic testing of the biopted sample of the skin (the assessment of T-cell receptor gene rearrangement). Results. The late stages of the disease were diagnosed in 12 of 13 patients with MF/SS. Extracutaneous lesions were diagnosed in 57% of cases. The median of prior lines therapy was 3 (18 variants of treatment). The overall response to the treatment was achieved in 91% of cases (in 19 of 21 patients): the complete remission was obtained in 53% of cases, very good partial remission in 31% of cases and partial remission in 16% of cases. The progression of the disease was determined in 2 patients (after the first and fourth cycles). Some patients with partial remission as a result of therapy using brentuximab vedotin had the additional therapy (radiation therapy, interferon , the cycles of systemic therapy) and these acts gave an option of achieving deeper antitumor response. The early relapse was diagnosed in 2 of 19 patients who had responded to the treatment. The treatment tolerability was acceptable, and the toxicity did not exceed the already known one described in earlier studies. Thus, the stable overall antitumor response had been persisting in 89% of patients (the median of the observation was 10 months). Conclusion. The use of targeted therapy with brentuximab vedotin gave an option of achieving high treatment results in group of patients with advanced stages of the disease and inefficiency of several lines of therapy.

An unusual case of cluster of differentiation 30-positive T-cell lymphoproliferative disorder manifesting as mandibular gingival ulceration: A case report

BACKGROUND

Primary cutaneous cluster of differentiation 30-positive (CD30+) T-cell lymphoproliferative disorders are the second most common type of skin T-cell lymphoma. The lesions exhibit an indolent course, with a morphology resembling high-grade T-cell lymphoma.

CASE DESCRIPTION

A 67-year-old healthy man sought treatment for a large nonhealing ulcer on the buccal gingiva of the mandibular right premolars. He reported a history of recurrent cutaneous lesions, for which he was seen 1 year earlier at a hospital. Results of incisional biopsy showed a dense lymphoid cell infiltrate composed of atypical CD30+ T-cells intermixed with eosinophils. The diagnosis was updated to CD30+ T-cell lymphoproliferative disorder, which was similar to the cutaneous lesion diagnosis. The lesion area healed completely, and there were no signs of recurrence at 18-month follow-up.

PRACTICAL IMPLICATIONS

Oral CD30+ T-cell lymphoproliferative disorder has a favorable outcome, but it is commonly misdiagnosed. Biopsy is crucial and should be combined with clinical examination to avoid chemotherapeutic treatments intended for high-grade lymphoma.

Lymphomatoid Papulosis Development in Acute Lymphoblastic Leukemia

Lymphomatoid papulosis (LyP) is a chronic, recurrent benign skin disease characterized by histological features of a CD 30-positive cutaneous T-cell lymphoproliferative disorder. It is rare, with an annual, worldwide incidence of 1.2 - 1.9 per million, and accounts for 16-47% of pediatric cutaneous lymphoproliferative disorders. It often occurs on the extremities or the trunk and rarely affects the face or genitals. Its onset may be triggered by irradiation therapy, immunomodulating agents, infection or atopic dermatitis. It has a benign course but is associated with certain hematological malignancies. Mycosis fungoides and primary cutaneous anaplastic large cell lymphoma are the most commonly associated hematological malignancies. The incidence of lymphoma in children with LyP has been reported to be 8.5% at most. Most patients who develop lymphomas do so within 4 years of the LyP onset; therefore, patients with LyP should be carefully followed up. Herein, we report a case in which tumors appeared in the left scrotum and under the left lip during maintenance therapy for precursor B-cell acute lymphoblastic leukemia. We needed to distinguish the tumor from extramedullary recurrence of ALL or de novo other cutaneous lymphoma; however, the histological findings of a tumor biopsy resulted in a diagnosis of LyP.

Lymphomatoid Papulosis With a Unique T Follicular Helper-Like Phenotype

Lymphomatoid papulosis (LyP) is a benign skin condition that typically presents with grouped or scattered lesions on the body that self-resolve within weeks or months of onset. LyP belongs to the group of CD30-positive lymphoproliferative disorders. Several histological variants of LyP exist, and the histological features of LyP can overlap with other lymphoproliferative disorders; therefore, both histological and clinical correlations are needed for a proper diagnosis of LyP. We report an unusual case of LyP displaying a T follicular helper cell-like phenotype and histopathologically resembling the primary cutaneous CD4-positive small-sized to medium-sized T-cell lymphoproliferative disorder.

Self-regressing oral CD30-positive, EBV-negative, T-cell lymphoproliferative lesions. A poorly understood process highlighted by ominous clinicopathologic features and indolent behavior

OBJECTIVE

Intraoral, primary, CD30-positive (CD30⁺) T-cell lymphoproliferative disorders (TLPDs) are uncommon, and their clinicopathologic presentation and management can vary and may be challenging. Herein, we present a retrospective study of 4 examples of self-regressing primary CD30⁺ TLPD affecting the gingiva.

STUDY DESIGN

Archived files were retrospectively reviewed for oral CD30⁺ TLPDs featuring (1) proper immunohistochemical documentation, (2) Epstein-Barr virus negativity, (3) adequate follow-up information corroborating regression, and (4) no history of hematopoietic malignancy or related-mucocutaneous disease.

RESULTS

Three women and 1 man (age range, 55-82 years; mean, 68.3 years) presented with rapidly growing gingival ulcers. Microscopic evaluation revealed diffuse infiltration by sheets of large, atypical cells admixed with lymphocytes and eosinophils, showing angiocentric distribution, focal neurotropism, and muscle infiltration. The lesional cells consistently stained for CD3 and CD30 and were variably immunoreactive against CD2, CD4, CD5, CD7, and CD8, but were negative for ALK1 and EBV-encoded small RNA. TCR-γ gene rearrangement studies revealed a monoclonal T-cell population in 1 case. All lesions showed complete regression 2 to 8 weeks postoperatively (mean follow-up, 4.5 weeks).

CONCLUSIONS

Notwithstanding their alarming clinicopathologic appearance, there are CD30⁺ TLPDs confined to the oral cavity that have an indolent course. However, clinical staging is essential to exclude aggressive systemic malignancy.

Secondary skin involvement in classic Hodgkin lymphoma: Results of an international collaborative cutaneous lymphoma working group study of 25 patients

BACKGROUND

Cutaneous involvement by classic Hodgkin lymphoma (CHL) is an extraordinarily rare phenomenon in the current era. To date, no single large case series of cutaneous involvement by Hodgkin lymphoma has ever been reported in the literature.

METHODS

A comprehensive search for cases designated "skin" and "Hodgkin" was performed at different institutions between 1990 and 2020. Twenty-five cases were identified, and each case was independently reviewed by at least three board-certified dermatopathologists and/or hematopathologists.

RESULTS

All cases represented examples of systemic CHL with secondary skin dissemination. A single lesion, usually a tumor, nodule or infiltrative plaque was observed in 56% of cases and multiple lesions were present in 28% of cases. Most patients (86%-12/14) had a diagnosis of stage IV disease at first diagnosis. The interval between the clinical (first) diagnosis of HL and the development of skin lesions ranged between 6 and 108 months (average 33.75 months). Comprehensive histopathologic evaluation of these cases (at the initial diagnosis) revealed a diagnosis of classic HL not otherwise specified (NOS) in 60% of cases (15/25), nodular sclerosis type in 24% (6/25), mixed cellularity in 12% (3/25), and lymphocyte depleted in 4% (1/25).

CONCLUSIONS

We provide documentation of a large series of CHL with secondary skin involvement in association with CHL with additional clinical, morphologic, and immunophenotypic features.

Lymphomatoid papulosis types D and E: a multicentre series of the French Cutaneous Lymphomas Study Group

BACKGROUND

Lymphomatoid papulosis (LyP) type D (LyP D) and type E (LyP E) have recently been described in small series of cases or isolated case reports.

AIM

To further describe the clinical and histological features of LyP D and E based on a retrospective multicentre study.

METHODS

The clinical and histopathological features of 29 patients with an initial diagnosis of LyP D or LyP E were retrospectively assessed using standardized forms.

RESULTS

After exclusion of 5 cases, 24 patients (14 LyP D, 10 LyP E) were enrolled in the study. The median follow-up was 2.5 years (range 1 month to 13 years). LyP D was characterized by multiple recurrent self-regressing small papules that developed central erosion or necrosis, whereas LyP E presented as papulonodular lesions that rapidly evolved into necrotic eschar-like lesions > 10 mm in size. Epidermal changes were more frequent in LyP D, whereas dermal infiltrates were deeper in LyP E. Anaplastic cytology was rare and the DUSP22 rearrangement was never observed. Two patients (8%) had an associated cutaneous lymphoma.

CONCLUSION

LyP D and E have distinct clinical findings and may be associated with other cutaneous lymphomas.

Article Topic/Title: Primary cutaneous T-cell lymphomas other than Mycosis Fungoides and Sezary Syndrome. Part II: Prognosis and Management

Primary cutaneous T-cell lymphomas (CTCLs) other than Mycosis Fungoides (MF) and Sézary syndrome (SS) encompass a heterogenous group of non-Hodgkin lymphomas with variable clinical course, prognoses, and management. With morphologic and histologic overlap among the CTCL subtypes and other T-cell lymphomas with cutaneous manifestations, thorough evaluation with clinicopathologic correlation and exclusion of systemic involvement are essential prior to initiating therapy. Staging and treatment recommendations vary depending on the subtype, clinical behavior, and treatment response. Generally, for subtypes where staging is recommended, Ann Arbor or TNM staging specific to CTCL other than MF or SS are used. For many subtypes, there is no standard treatment to date. Available recommended treatments range widely from no active or minimal intervention with skin-directed therapy to aggressive systemic therapies including multiagent chemotherapy with consideration for hematopoietic stem cell transplant. Emerging targeted therapies, such as brentuximab, a chimeric antibody targeting CD30, show promise in altering the disease course of non-MF/SS CTCLs.

Primary cutaneous T-cell lymphomas other than Mycosis Fungoides and Sezary Syndrome - Part I: Clinical and histologic features and diagnosis

Primary cutaneous T-cell lymphomas (CTCLs) are defined as lymphomas with a T-cell phenotype that present in the skin without evidence of systemic or extracutaneous disease at initial presentation. CTCLs other than Mycosis Fungoides (MF) and Sézary syndrome (SS) account for approximately one-third of CTCLs and encompass a heterogenous group of non-Hodgkin lymphomas ranging from indolent lymphoproliferative disorders to aggressive malignancies with a poor prognosis. The spectrum of CTCLs continues to broaden as new provisional entities are classified. Given the morphologic and histologic overlap among CTCLs and other diagnoses, a thorough clinical history, physical evaluation, and clinicopathologic correlation are essential in the workup and diagnosis of these rare entities. This article will summarize the epidemiologic, clinical, pathologic, and diagnostic features of CTCLs other than MF and SS.

Is immunohistochemical expression of GATA3 helpful in the differential diagnosis of transformed mycosis fungoides and primary cutaneous CD30-positive T cell lymphoproliferative disorders?

Mycosis fungoides with large cell transformation (MFLCT) can be difficult to distinguish from primary cutaneous CD30+ T cell lymphoproliferative disorders (PC CD30+ LPD), especially primary cutaneous anaplastic large cell lymphoma (PC-ALCL). This diagnostic distinction is critical for appropriate patient management. GATA3 has been proposed to be useful in the discrimination between these two entities. We identified 25 cases of MFLCT and 24 cases of PC CD30+ LPDs (including lymphomatoid papulosis (n=14), PC-ALCL (n=6), and CD30+ LPD, not otherwise specified (n=4)) diagnosed at our institution from 2002 to 2019. Sections from archived specimens were stained to evaluate for GATA3 expression by immunohistochemistry and compared among cutaneous CD30+ T cell LPDs. The majority of the MFLCT cohort had strong, diffuse expression of GATA3 ranging from 0 to 100% of dermal T cells (mean 53.20%) with 15/25 cases (60%) showing GATA3 expression greater than 50%, while the PC CD30+ LPD group showed variable, moderate GATA3 labeling ranging from 0 to 60% of dermal T cells (mean 23.26%), with 5/6 cases (83%) showing GATA3 expression less than 40% (p =0.003). The calculated sensitivity and specificity were 56% and 74%, while positive and negative predictive values were 70% and 61%, respectively. Based on the percent staining of positive cells, using 50% as a cutoff value for expression, GATA3 might be a useful immunohistochemical marker to discriminate MFLCT from PC CD30+ LPDs, including PC-ALCL.

A case of lymphomatoid papulosis type E in a young adult: An uncommon entity

Lymphomatoid papulosis (LyP) type E is a rare variant of the primary cutaneous CD30+ lymphoproliferative disorders, characterized clinically by large necrotic eschar-like lesions and histopathologically by angiodestructive and angioinvasive infiltrates of CD30+ lymphocytes. As in other forms of lymphomatoid papulosis, type E lesions may undergo spontaneous regression after weeks, with frequent recurrences. We report a 21-year old male with an angiodestructive infiltrate of CD30+ lymphocytes manifesting as a papular eruption rather than ulceration, and suggest that this clinical phenotype might be related to the presence of CD4+ lymphocytes in the inflammatory cell infiltrate.

Evaluation of Associated Lymphomas and Their Risk Factors in Patients with Lymphomatoid Papulosis: A Retrospective Single-Center Study from Turkey

Objective:

Lymphomatoid papulosis (LyP) is an indolent skin disease with variable clinical features classified among the primary cutaneous CD30+ T-cell lymphoproliferative disorders. It may show association with cutaneous and systemic lymphomas. We aimed to identify the frequency and characteristics of associated lymphomas among Turkish patients with LyP and to determine the risk factors for secondary lymphomas.

Materials and Methods:

The files of patients diagnosed with LyP between 1998 and 2018 in a tertiary dermatology clinic were retrospectively analyzed. Univariate and multivariate models were used to assess the possible risk factors for secondary lymphomas, such as demographic and clinical characteristics of the patients.

Results:

Among 61 patients (47 adults, 14 children) with LyP, a total of 22 secondary lymphomas were observed in 20 patients. Nineteen of them were adults. Mycosis fungoides (MF) was the major associated lymphoma (n=19) followed by systemic anaplastic large cell lymphoma (ALCL) (n=2) and primary cutaneous ALCL (n=1). The most common stage in patients with accompanying MF was stage IB (n=11). While 18 patients showed the classical type of MF, one patient had folliculotropic MF. When the risk factors for association between LyP and other lymphomas were evaluated, only older age was found to be a significant risk factor and existence of ulcerated lesions was found to be a negative indicator.

Conclusion:

LyP is not rare in the pediatric population. MF is the most common associated lymphoma in patients with LyP. Adult LyP patients are more commonly associated with secondary lymphomas than pediatric patients. Older age at the time of diagnosis of LyP is a significant risk factor for associated lymphomas.

A deep dive into UV-based phototherapy: Mechanisms of action and emerging molecular targets in inflammation and cancer

UV-based phototherapy (including psoralen plus UVA (PUVA), UVB and UVA1) has a long, successful history in the management of numerous cutaneous disorders. Photoresponsive diseases are etiologically diverse, but most involve disturbances in local (and occasionally systemic) inflammatory cells and/or abnormalities in keratinocytes that trigger inflammation. UV-based phototherapy works by regulating the inflammatory component and inducing apoptosis of pathogenic cells. This results in a fascinating and complex network of simultaneous events-immediate transcriptional changes in keratinocytes, immune cells, and pigment cells; the emergence of apoptotic bodies; and the trafficking of antigen-presenting cells in skin-that quickly transform the microenvironment of UV-exposed skin. Molecular elements in this system of UV recognition and response include chromophores, metabolic byproducts, innate immune receptors, neurotransmitters and mediators such as chemokines and cytokines, antimicrobial peptides, and platelet activating factor (PAF) and PAF-like molecules that simultaneously shape the immunomodulatory effects of UV and their interplay with the microbiota of the skin and beyond. Phototherapy's key effects-proapoptotic, immunomodulatory, antipruritic, antifibrotic, propigmentary, and pro-prebiotic-promote clinical improvement in various skin diseases such as psoriasis, atopic dermatitis (AD), graft-versus-host disease (GvHD), vitiligo, scleroderma, and cutaneous T-cell lymphoma (CTCL) as well as prevention of polymorphic light eruption (PLE). As understanding of phototherapy improves, new therapies (UV- and non-UV-based) are being developed that will modify regulatory T-cells (Treg), interact with (resident) memory T-cells and /or utilize agonists and antagonists as well as antibodies targeting soluble molecules such as cytokines and chemokines, transcription factors, and a variety of membrane-associated receptors.

Outlines of the Japanese guidelines for the management of primary cutaneous lymphomas 2020

Since the publication of the Japanese "Guidelines for the management of cutaneous lymphomas" in 2011, the World Health Organization (WHO) classification of hematolymphoid neoplasms and the WHO-European Organisation for Research and Treatment of Cancer classification for primary cutaneous lymphomas were updated and a number of novel systemic drugs for cutaneous T-cell lymphoma had been approved in Japan. In 2020, we revised the Japanese guidelines for the management of cutaneous lymphomas with consideration of the recent advances in the understanding of the pathophysiology and classification of cutaneous lymphomas together with the update of treatment strategies reflecting the advent of novel drugs. In addition to a brief explanation of epidemiology, diagnosis, staging system, prognosis and management of each subtype of cutaneous lymphomas, the recommendations for nine clinical questions regarding treatment options that can vary even among experts are also described. A systematic review process and determination of recommendations in answer to each clinical question have been performed in accordance with the Grading of Recommendations, Assessment, Development and Evaluation scheme by a multidisciplinary expert panel consisting of dermatologists, a hematologist and a radiation oncologist. In this article, we present the outlines of the revised Japanese "Guidelines for the management of cutaneous lymphomas".

A case of pediatric lymphomatoid papulosis treated with photodynamic therapy and narrowband ultraviolet B

We report a case of a 13-year-old boy with extensive lymphomatoid papulosis (LyP) involving his elbows, forearms, proximal thighs, and right hip, with treatment-resistant nodules on his right forearm. He was treated with full-body narrowband ultraviolet B and targeted photodynamic therapy (PDT) with 20% aminolevulinic acid (ALA). After two months, there was complete resolution of the right forearm nodules. Due to its minimal toxicity, PDT offers unique advantages and may be considered for pediatric LyP patients with symptomatic, localized disease resistant to conventional treatments.

Practical Approaches on CD30 Detection and Reporting in Lymphoma Diagnosis

While our understanding of the biology of CD30 in lymphoma continues to evolve, our need to detect and measure its expression at the protein level remains critically important for diagnosis and patient care. In addition to its diagnostic and prognostic utility, CD30 has emerged as a vehicle for drug targeting through the antibody-drug conjugate brentuximab-vedotin (BV). Given the numerous ways that CD30 is utilized and its emergence as a predictive/prognostic biomarker, pathologists must come to a general consensus on the best reporting structure and methodology to ensure appropriate patient care. In this manuscript, we review the indications for testing, various modalities for testing, technical challenges, pitfalls, and potential standards of reporting. The following questions will try to be addressed in the current review article: What defines a "POSITIVE" level of CD30 expression?; How do we evaluate and report CD30 expression?; What are the caveats in the evaluation of CD30 expression?

Primary cutaneous peripheral T-cell lymphoma, not otherwise specified, associated with lymphomatoid papulosis after a 9-year follow up: A case report

Lymphomatoid papulosis (LyP) is a self-limiting cutaneous T-cell lymphoproliferative disorder that may progress into malignant lymphoma. Most of the previously reported associated lymphomas are primary cutaneous anaplastic large-cell lymphoma and mycosis fungoides with a low mortality rate. We report a case of primary cutaneous peripheral T-cell lymphoma, not otherwise specified (pcPTCL-NOS), associated with LyP after long-term follow up. The patient was a 79-year old Japanese man followed up for 9 years. He suddenly developed a 3-cm ulcerated lesion on his forehead, which was diagnosed as an exacerbation of LyP. The lesion regressed after conservative treatment, but the patient soon developed multifocal pcPTCL-NOS. Thereafter, the patient developed pneumonia and cerebral infarction and died within a few months of the onset of malignant lymphoma. Aggressive cutaneous lymphoma may develop in LyP patients. The present case re-emphasizes the need for careful follow up of patients with persistent LyP.

Lymphomatoid papulosis in children and adolescents: A clinical and histopathologic retrospective cohort

BACKGROUND, AIMS AND OBJECTIVES

Lymphomatoid papulosis (LyP) is a CD30+ lymphoproliferative disorder that is rare and not well described within the pediatric subpopulation. We sought to review the literature and characterize clinical and pathologic features among pediatric and adolescent patients diagnosed with LyP at a tertiary care center.

MATERIALS AND METHODS

A retrospective cohort of 27 pediatric and adolescent patients (defined as <20 years old) diagnosed with LyP at the Weill Cornell Medicine Dermatopathology division from 2006 to 2016 was identified. Subsequently, we reviewed the histopathologic characteristics and collected clinical follow-up data from patients and their providers. The parameters assessed included the pathological LyP subtype including the immunohistochemical staining pattern, the development of secondary lymphoma, disease duration and rate of remission.

RESULTS

While type A was the most prevalent subtype, B and C subtypes were also frequently observed. CD8 predominance was a common finding, especially among type B LyP patients and those with eccrinotropic granulomatous features. None of the patients with clinical follow-up have developed secondary lymphoma, and some patients experienced remission of their disease.

CONCLUSION

While type A appears to be the dominant variant described in children, types B, C, and even the newly described variants E and F may occur more often than previously reported. Pediatric LyP may be more indolent than the adult variant, but close clinical follow-up is still warranted.

Lymphomatoid papulosis

Lymphomatoid papulosis (LyP) is characterized by a varied clinical presentation that includes erythema, papules, pustules, vesicles, plaques, nodules and ulcerations. While its biological course is typically marked by spontaneous regression, the histopathological findings of LyP are consistent with cutaneous T-cell lymphoma. Provided patients do no develop a secondary lymphoma, they exhibit unusually high 10-year survival rates (> 90 %), which is a typical feature of LyP. To date, the etiology and pathogenesis of LyP have not been elucidated. One particular subtype of LyP is known to be associated with chromosome 6p25.3 rearrangement (DUSP22-IRF4 translocation). Treatment is guided by the clinical presentation. In addition to a wait-and-see approach, recommended options include topical corticosteroids and PUVA therapy.

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.

Comorbidities in Mycosis Fungoides and Racial Differences in Co-Existent Lymphomatoid Papulosis: A Cross-Sectional Study of 580 Patients in an Urban Tertiary Care Center

Background: Mycosis fungoides (MF) is a cutaneous T-cell lymphoma. Previous reports have suggested MF is associated with inflammatory conditions such as psoriasis, increased cardiovascular risk factors as well as secondary neoplasms. Methods: A cross-sectional study of MF patients seen from 2013 to 2019 was performed. Comorbidities were selected based on the 2015 Medicare report highlighting the most common chronic medical illnesses in the United States. Lifetime comorbidity occurrence in patients with MF were compared with that in patients with atopic dermatitis, psoriasis and patients without MF. Additional analyses were performed with patients sub-stratified by race. Results: Compared to control groups, MF was strongly associated with lymphomatoid papulosis and Hodgkin's disease, but not significantly associated with lung, breast or colon cancer. Interestingly, the association with lymphomatoid papulosis was observed in Caucasians (CI 1062-4338; p < 0.001) and not African Americans (p = 0.9). Patients with MF had a greater association with congestive heart failure, hypertension (HT) and hyperlipidemia (HLD) compared with the general population. However, they were significantly less likely to have HT and HLD when compared with psoriasis patients (HT CI: 0.6-0.9; p < 0.001, and HLD CI: 0.05-0.07; p < 0.001). MF patients were also significantly less likely to have concomitant vitamin D deficiency compared with atopic dermatitis (AD) and psoriasis (p < 0.001). Conclusions: Our results suggest that the association of MF with lymphomatoid papulosis varies by race. Compared to the general population, hypertension and hyperlipidemia were positively associated with MF, however, these were significantly less likely on comparison to psoriasis. Unlike previously described, vitamin D deficiency was found to be significantly less in patients with MF.

Frequency and prognosis of associated malignancies in 504 patients with lymphomatoid papulosis

Background

Lymphomatoid papulosis (LyP) can be associated with other haematological malignancies (HM), but reported percentages vary from 20% to over 50%.

Objective

To evaluate the frequency and prognostic significance of associated HM and non‐HM in LyP patients.

Methods

In this multicentre cohort study, the complete Dutch LyP population was included from the Dutch Cutaneous Lymphoma Registry between 1985 and 2018. Clinical and histopathological information was retrieved from every individual patient.

Results

After a median follow‐up of 120 months (range, 6–585), an associated HM was observed in 78/504 (15.5%) patients. Most common associated HM were mycosis fungoides (MF; n = 31) and anaplastic large‐cell lymphoma (ALCL; n = 29), while 19 patients had another HM of B‐cell (n = 14) or myeloid origin (n = 5). Even after a 25‐year follow‐up period, percentages of associated HM did not exceed 20%. Thirty‐nine of 465 patients (8.4%) without a prior or concurrent associated HM developed an associated HM during follow‐up, after a median of 68 months (range of 3–286 months). Nine of 78 patients died of associated HM, including 6/22 patients developing extracutaneous ALCL, while all patients with associated MF or skin‐limited ALCL had an excellent prognosis. Compared with the general population, LyP patients showed an increased risk (relative risk, 2.8; 95% confidence intervals, 2.4–3.3) for non‐HM, in particular cutaneous squamous cell carcinoma, melanoma and intestinal/lung/bladder cancer.

Conclusions

An associated HM was reported in 15.5% of the LyP patients, particularly MF and ALCL. Although the frequency of associated HM is lower than suggested and the prognosis of most patients with associated HM is excellent, a small subgroup will develop aggressive disease, in particular extracutaneous ALCL. Furthermore, LyP patients have a higher risk of developing other malignancies. Clinicians should be aware of these risks, and LyP patients require close monitoring.

Linked article: F. Rongioletti. J Eur Acad Dermatol Venereol 2020; 34: 216–217. https://doi.org/10.1111/jdv.16157.

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.

Recent Advances in Cutaneous T-cell Lymphoma: Diagnostic and Prognostic Considerations

This review describes the latest advances in the diagnosis of cutaneous T-cell lymphoma focusing on the most clinically useful features introduced since the publication of the World Health Organization revision in 2017. Clinical entities described include mycosis fungoides, Sézary syndrome, lymphomatoid papulosis, primary cutaneous anaplastic large cell lymphoma, primary cutaneous gamma delta T-cell lymphoma, primary cutaneous acral CD8⁺ T-cell lymphoma, primary cutaneous CD4⁺ small/medium T-cell lymphoproliferative disorder, and hydroa-vacciniforme-like lymphoproliferative disorder. Distinguishing histologic clues to diagnosis are discussed, and important molecular advances are described. Key prognostic indicators that may assist clinicians with timely and appropriate management options are presented.