Frequency and Risk Factors for Associated Lymphomas in Patients With Lymphomatoid Papulosis

Clinical and Histologic Variants of CD8+ Cutaneous T-Cell Lymphomas

Although the vast majority of CTCL subtypes are of the CD4+ T-helper cell differentiation phenotype, there is a spectrum of CD8+ variants that manifest wide-ranging clinical, histologic, and phenotypic features that inform the classification of the disease. CD8, like CD4, and cytotoxic molecules (including TIA and granzyme) are readily detectable via IHC staining of tissue and, when expressed on the phenotypically abnormal T-cell population, can help distinguish specific CTCL subtypes. Nonetheless, given that the histopathologic differential for CD8+ lymphoproliferative disorders and lymphomas may range from very indolent lymphomatoid papulosis (LyP) to aggressive entities like CD8+ aggressive epidermotropic cytotoxic T-cell lymphoma (AECTCL), CD8 and/or cytotoxic molecule expression alone is insufficient for diagnosis and is not in itself an indicator of prognosis. We present a review of CTCL subtypes that can demonstrate CD8 positivity: CD8+ mycosis fungoides (MF), LyP type D, subcutaneous panniculitis-like T-cell lymphoma (SPTCL), primary cutaneous gamma/delta T-cell lymphoma (PCGDTL), CD8+ AECTCL, and acral CD8+ T-cell lymphoproliferative disorder (acral CD8+ TCLPD). These diseases may have different clinical manifestations and distinctive treatment algorithms. Due to the rare nature of these diseases, it is imperative to integrate clinical, histologic, and immunohistochemical findings to determine an accurate diagnosis and an appropriate treatment plan.

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.

Critical Review-A Tribute to Louis Brocq Lymphomatoid Papulosis, the Key in Exploring the Relationship of Parapsoriasis and Mycosis Fungoides

ABSTRACT

Both parapsoriasis and LyP appear clinically as inflammatory dermatoses with a paradoxical link to cMF. A key element in addressing the relationship of parapsoriasis and MF were the results of the French and Dutch long-term registries tracking the emergence of lymphomas in the setting of LyP. Both cMF and cALCL emerged almost equally in these long-term studies. This ultimately supports that the stem cells in both cMF and cALCL are probably derived from a common stem cell shared by CD4+/CD8+ memory stem cells defining cMF and CD30+ stem cells defining cALCL. The discovery of inducible Skin Associated Lymphoid Tissue (iSALT) mesenchymal hubs incorporating Tregs, with their pleiotropic functions represents a paradigm shift and formed a translational tool in this analysis of the paradox. LyP can be recast as activated inhibitory lymphomatoid T-cell hubs derived from inducible iTregs in iSALT and the source of the common stem cell LyP line. iSALT Treg integrated mesenchymal hubs provided an emerging translational tool in redefining integrated lymphomatoid pathways. Brocq's complex scheme defining parapsoriasis as hybrid inflammatory dermatoses with a paradoxical link to cMF became a template to preserve parapsoriasis as a clinical diagnosis. Two major iSALT Treg generated inhibitory integrated lymphomatoid hubs emerged. The major CD30+TNF lymphomatoid hub has been linked to cALCL. Clinically defined chronic regressing and relapsing parapsoriasis with the histopathology of patch stage MF can be redefined as lymphomatoid parapsoriasis. This twin inhibited oncogenic memory based hub is defined by Treg modulated, CD4+/CD8+memory linked PD-1/DL-1 cytoxic complex and lichenoid histopathology.

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.

Genetics Abnormalities with Clinical Impact in Primary Cutaneous Lymphomas

Simple Summary

The genetic landscape of cutaneous T-cell lymphomas analyzed by sequencing high throughput techniques shows a heterogeneous somatic mutational profile and genomic copy number variations in the TCR signaling effectors, the NF-κB elements, DNA damage/repair elements, JAK/STAT pathway elements and epigenetic modifiers. A mutational and genomic stratification of these patients provides new opportunities for the development or repurposing of (personalized) therapeutic strategies. The genetic heterogeneity in cutaneous B-cell lymphoma parallels with the specific subtype. Damaging mutations in primary cutaneous diffuse large B-cell lymphoma of the leg type, involving MYD88 gene, or BCL6 and MYC translocations or CDKN2A deletions are useful for diagnostic purposes. The more indolent forms, as the primary cutaneous lymphoma of follicle center cell (somatic mutations in TNFRSF14 and 1p36 deletions) and the cutaneous lymphoproliferative disorder of the marginal zone cells (FAS gene), present with a more restricted pattern of genetic alterations.

Abstract

Primary cutaneous lymphomas comprise a heterogeneous group of extranodal non-Hodgkin lymphomas (NHL) that arise from skin resident lymphoid cells and are manifested by specific lymphomatous cutaneous lesions with no evidence of extracutaneous disease at the time of diagnosis. They may originate from mature T-lymphocytes (70% of all cases), mature B-lymphocytes (25–30%) or, rarely, NK cells. Cutaneous T-cell lymphomas (CTCL) comprise a heterogeneous group of T-cell malignancies including Mycosis Fungoides (MF) the most frequent subtype, accounting for approximately half of CTCL, and Sézary syndrome (SS), which is an erythrodermic and leukemic subtype characterized by significant blood involvement. The mutational landscape of MF and SS by NGS include recurrent genomic alterations in the TCR signaling effectors (i.e., PLCG1), the NF-κB elements (i.e., CARD11), DNA damage/repair elements (TP53 or ATM), JAK/STAT pathway elements or epigenetic modifiers (DNMT3). Genomic copy number variations appeared to be more prevalent than somatic mutations. Other CTCL subtypes such as primary cutaneous anaplastic large cell lymphoma also harbor genetic alterations of the JAK/STAT pathway in up to 50% of cases. Recently, primary cutaneous aggressive epidermotropic T-cell lymphoma, a rare fatal subtype, was found to contain a specific profile of JAK2 rearrangements. Other aggressive cytotoxic CTCL (primary cutaneous γδ T-cell lymphomas) also show genetic alterations in the JAK/STAT pathway in a large proportion of patients. Thus, CTCL patients have a heterogeneous genetic/transcriptional and epigenetic background, and there is no uniform treatment for these patients. In this scenario, a pathway-based personalized management is required. Cutaneous B-cell lymphoma (CBCL) subtypes present a variable genetic profile. The genetic heterogeneity parallels the multiple types of specialized B-cells and their specific tissue distribution. Particularly, many recurrent hotspot and damaging mutations in primary cutaneous diffuse large B-cell lymphoma of the leg type, involving MYD88 gene, or BCL6 and MYC translocations and BLIMP1 or CDKN2A deletions are useful for diagnostic and prognostic purposes for this aggressive subtype from other indolent CBCL forms.

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.

Two Histologic Patterns of Lymphomatoid Papulosis Occurring in a Child: A Matter of Timing?

There are several histologic patterns seen in lymphomatoid papulosis, with the possibility of different subtypes occurring in the same patient. We report a case of lymphomatoid papulosis presenting with 2 histologic subtypes (types A and B) occurring concomitantly in a 10-year-old child, and postulate that the different subtypes occur dependent on the age of the lesion biopsied. Incidentally, one of the biopsies also shows a rarely seen pattern of pseudoepitheliomatous hyperplasia in a pediatric lymphomatoid papulosis patient.

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.

Oncogenic Mutations and Gene Fusions in CD30-Positive Lymphoproliferations and Clonally Related Mycosis Fungoides Occurring in the Same Patients

The emergence of a common progenitor cell has been postulated for the association of CD30-positive lymphoproliferative disease (LPD) and mycosis fungoides (MF) within the same patient. Up to now, no comprehensive analysis has yet addressed the genetic profiles of such concurrent lymphoma subtypes. We aimed to delineate the molecular alterations of clonally related CD30-positive LPD and MF occurring in the same two patients. We analyzed the molecular profile of 16 samples of two patients suffering both from CD30-positive LPD and MF being obtained over a time course of at least 5 years. To detect oncogenic mutations, we applied targeted sequencing technologies with a hybrid capture-based DNA library preparation approach, and for the identification of fusion transcripts, an anchored multiplex PCR enrichment kit was used. In all samples of CD30-positive LPD and MF, oncogenic fusions afflicting the Jak/signal transducer and activator of transcription signaling pathway were present, namely NPM1‒TYK2 in patient 1 and ILF3‒JAK2 in patient 2. Additional signal transducer and activator of transcription 5A gene STAT5A mutations exclusively occurred in lesions of CD30-positive LPD in one patient. CD30-positive LPD and MF may share genetic events when occurring within the same patients. Constitutive activation of the Jak/signal transducer and activator of transcription signaling pathway may play a central role in the molecular pathogenesis of both entities.

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.

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.

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.

Lymphomatoid papulosis subtype C: A case report and literature review

Lymphomatoid papulosis (LyP) is a rare CD30⁺ lymphoproliferative primary skin disease with a benign clinical course and malignant histopathology. LyP is classified into seven subtypes based on histopathology: subtypes A through F and LyP with 6p25.3 chromosome rearrangement. We present here, a case report of a 51-year-old man, afflicted with multiple papules and nodules on his left arm for over 3 months and diagnosed with LyP subtype C. The patient refused treatment, and his lesions faded with no visible rash on the left arm 14 months after diagnosis.

Primary Cutaneous CD30+ Anaplastic Large Cell Lymphoma: A Rare Association With Large Plaque Parapsoriasis

Primary cutaneous CD30-positive lymphoproliferative disorders represent the second most common subgroup of cutaneous T-cell lymphomas and include lymphomatoid papulosis, primary cutaneous anaplastic large cell lymphoma, and borderline lesions. Primary cutaneous anaplastic large cell lymphoma is characterized by the presence of solitary or localized nodules or tumors located on the extremities or the cephalic or cervical region. Large plaque parapsoriasis is a chronic inflammatory disorder that associates a high risk of progression to mycosis fungoides. We report a case of CD30+ primary cutaneous anaplastic large cell lymphoma in a patient with a long history of large plaque parapsoriasis.

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.

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.

Pretibial Pruritic Papular Dermatitis: A Comprehensive Clinical and Pathologic Review of Cases at a Single Institution

BACKGROUND

Studies characterizing clinical and pathologic details of pretibial pruritic papular dermatitis (PPPD) are scarce. Several cases of PPPD at our institution have displayed lymphocyte atypia and CD30 positivity, resembling lymphomatoid papulosis (LyP). We explore the clinical and histological spectrum of PPPD, with emphasis on lymphocyte atypia.

METHODS

Retrospective observational study of 40 archived pathological specimens (hematoxylin/eosin, CD3, CD20, and CD30 immunohistochemistry) from 38 PPPD patients in an academic center. Clinical photographs were available in 22 cases.

RESULTS

Microscopic epidermal changes were focal, but common (spongiosis 75%, parakeratosis 90%, interface changes 43%, Langerhans cell microgranulomas 25%, multinucleated keratinocytes 55%, Civatte bodies 55%, erosion 20%, and more than focal irregular psoriasiform hyperplasia 37%) and certain dermal changes were universal (papillary dermal fibrosis 100%, stellate fibroblasts 100%, and multinucleated fibroblasts 93%). At least focal lymphocyte atypia was present in all cases. Lymphocytes were almost exclusively CD3 T cells with rare CD20 B cells. Up to 30% of lymphocytes exhibited weak CD30 staining. Clinically, all cases exhibited discrete papules, but plaques and erosions were not uncommon.

LIMITATIONS

As a retrospective series, clinical images were not available for all cases.

CONCLUSION

This study suggests a broader histological and clinical spectrum of PPPD than previously described. Epidermal changes are common in PPPD, as are atypical lymphocytes and focal CD30 positivity. Although the papular clinical appearance, lymphocyte atypia, and focal CD30 positivity may resemble LyP, the relatively low number of atypical lymphocytes, low intensity of CD30 staining, and absence of spontaneous resolution help to distinguish PPPD from LyP.

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.

Associated Hematolymphoid Malignancies in Patients With Lymphomatoid Papulosis: A Canadian Retrospective Study

BACKGROUND

Lymphomatoid papulosis is one of the primary cutaneous CD30+ T-cell lymphoproliferative disorders. Although considered a benign disease, lymphomatoid papulosis has been associated potentially with an increased risk of secondary hematolymphoid malignancies.

OBJECTIVE

The aim of this study was to assess the clinical characteristics and histologic subtypes of lymphomatoid papulosis, identify the prevalence and types of secondary hematolymphoid malignancies, and determine the potential risk factors for development of these hematolymphoid malignancies.

METHODS AND MATERIALS

A retrospective chart review was performed for all histologically confirmed cases of lymphomatoid papulosis between 1991 and 2016.

RESULTS

Seventy patients with lymphomatoid papulosis were identified. Thirty patients (43%) experienced a secondary hematolymphoid malignancy. Twenty-four (80%) of the hematolymphoid malignancies occurred after the onset of lymphomatoid papulosis. Older age at diagnosis of lymphomatoid papulosis, male sex, histology type B, and the presence of T-cell receptor gene rearrangement are associated with higher risk of developing hematolymphoid malignancy.

CONCLUSION

Lymphomatoid papulosis is associated with increased risk of developing secondary hematolymphoid malignancies, particularly mycosis fungoides and cutaneous anaplastic large cell lymphoma.

CD30+ Lymphoproliferative Disorders of the Skin

Primary cutaneous CD30⁺ lymphoproliferative disorders encompass lymphomatoid papulosis (LyP), primary cutaneous anaplastic large cell lymphoma (pcALCL), and indeterminate cases. LyP is a benign disorder characterized by recurrent crops of red or violaceous papulonodules. Patients with LyP are at an increased risk of a secondary malignancy. pcALCL is characterized by a solitary red to violaceous nodule or tumor larger than 20 mm. LyP is benign, is limited to the skin, and self-resolves, with a 5-year survival rate of 100%; pcALCL is limited to the skin and responsive to directed therapies, with a 5-year survival rate of over 95%. Aggressive chemotherapeutic regimens should be avoided.

Adult T-cell leukemia/lymphoma in South and Central America and the Caribbean: systematic search and review

Adult T-cell leukemia/lymphoma (ATL) is caused by the human T-cell lymphotropic virus type 1 (HTLV-1) which is endemic in countries of Caribbean and Central and South America. We performed a systematic search and review to identify publications on ATL in these countries to verify if this disease was getting recognition in these regions as well as the characteristics of the observed cases. The median age of 49.4 years was lower than that referred to in Japan. According to our findings in most Brazilian states and in some other countries, ATL is not being recognized and should be strongly considered in the differential diagnosis of T-cell leukemias/lymphomas. Failure to identify these cases may be due to the unsystematic realization of serology for HTLV-1 and phenotypic identification of non-Hodgkin lymphomas that may result from lack of resources. Detection of ATL cases has been more feasible with cooperation from foreign research centers. A huge effort should be made to improve the surveillance system for ATL diagnosis in most of the South- and Central-American and Caribbean countries, and this attitude should be embraced by public organs to support health professionals in this important task.

A new era for cutaneous CD30-positive T-cell lymphoproliferative disorders

Cutaneous CD30+ T-cell lymphoproliferative disorders (CD30+ T-LPD) represent a spectrum encompassing lymphomatoid papulosis (LyP), primary cutaneous anaplastic large-cell lymphoma (pcALCL) and borderline lesions. They share the expression of CD30 as a common phenotypic marker. They differ however in their clinical presentation, the histological features and clinical course. Moreover, LyP and PcALCL show numerous clinical, histological and phenotypic variants. Overlapping features of LyP and pcALCL with themselves and with other cutaneous and systemic lymphomas emphasize the importance of careful clinicopathologic correlation and staging in the diagnosis of CD30+ T-LPD. Furthermore, an increasing number of inflammatory and infectious skin disorders harboring medium-sized to large CD30+ cells have to be considered in the differential diagnosis. Whereas the expression of CD30 in cutaneous CD30+ T-LPD stands for a favourable prognosis, its expression in other cutaneous and systemic lymphomas has a divergent impact. The assessment of CD30 expression does not only provide prognostic information, but is of potential therapeutic relevance as CD30 can serve as a therapeutic target. This review focuses on the clinicopathological and phenotypic spectrum of CD30+ T-LPD, its differential diagnoses and the role of CD30 as a diagnostic, prognostic and therapeutic marker.