Lymphomatoid papulosis associated with mycosis fungoides: a study of 21 patients including analyses for clonality

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.

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.

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.

Patch/plaque mycosis-fungoides-like presentations of DUSP22-translocated T-cell lymphomas

The DUSP22-IRF4 gene rearrangement results in downregulation of DUSP22, a presumed tumor suppressor in T-cell lymphomagenesis. It has been described in some cases of primary cutaneous and systemic anaplastic large-cell lymphoma, lymphomatoid papulosis, and transformed mycosis fungoides. Here we describe two patients with clinical lesions resembling patch/plaque mycosis fungoides that did not meet WHO criteria for large-cell transformation on histopathology yet showed a DUSP22 translocation. One patient who had a history of systemic anaplastic large-cell lymphoma with DUSP22 translocation presented with cutaneous involvement by his systemic lymphoma along with lymphomatoid papulosis and mycosis-fungoides-like lesions, all showing an identical immunophenotype and T-cell clone. These cases expand the spectrum of DUSP22-rearranged lymphomas to include mycosis-fungoides-like presentations without large-cell transformation.

Spindle-cell (Sarcomatoid) Variant of Cutaneous Anaplastic Large-cell Lymphoma (C-ALCL): An Unusual Mimicker of Cutaneous Malignant Mesenchymal Tumors-A Series of 11 Cases

Cutaneous anaplastic large-cell lymphoma (C-ALCL) represents one of the entities within the group of CD30-positive lymphoproliferative disorders of the skin. Most cases are ALK-negative, though isolated cases of ALK-positive C-ALCL have also been reported. By definition, the diagnosis of C-ALCL requires the expression of CD30 in >75% of the cells. Histopathologically, C-ALCL shows a dermal-based nodular and circumscribed proliferation of large pleomorphic cells with vesicular nuclei, prominent nucleoli, and eosinophilic cytoplasm, including hallmark cells. Since 1990, isolated case reports of a so-called "sarcomatoid" variant have been published in the literature. Herein, we present a series of 11 cases of spindle (sarcomatoid) C-ALCL, with comprehensive histopathologic, immunophenotypic, and molecular data. Spindle C-ALCL represents a potential mimicker of malignant mesenchymal or hematopoietic tumors in the skin and should always be considered in the differential diagnosis when assessing cutaneous pleomorphic spindle cell neoplasms.

A Systematic Approach to the Cutaneous Lymphoid Infiltrates: A Clinical, Morphologic, and Immunophenotypic Evaluation

CONTEXT.—

The evaluation of cutaneous lymphoid infiltrates, both neoplastic and inflammatory, occurs very frequently in routine dermatopathologic examination and consultation practices. The "tough" cutaneous lymphoid infiltrate is feared by many pathologists; skin biopsies are relatively small, whereas diagnostic possibilities are relatively broad. It is true that cutaneous lymphomas can be difficult to diagnose and that in many circumstances multiple biopsies are required to establish a correct diagnostic interpretation. As a reminder, one should understand that low-grade cutaneous lymphomas are indolent disorders that usually linger for decades and that therapy does not result in disease cure. It is also important to remember that in most circumstances, those patients will die from another process that is completely unrelated to a diagnosis of skin lymphoma (even in the absence of specific therapy).

OBJECTIVE.—

To use a clinicopathologic, immunophenotypic, and molecular approach in the evaluation of common lymphocytic infiltrates.

DATA SOURCES.—

An in-depth analysis of updated literature in the field of cutaneous lymphomas was done, with particular emphasis on updated terminology from the most recent World Health Organization classification of skin and hematologic tumors.

CONCLUSIONS.—

A diagnosis of cutaneous lymphoid infiltrates can be adequately approached using a systematic scheme following the proposed ABCDE system. Overall, cutaneous T- and B-cell lymphomas are rare and "reactive" infiltrates are more common. Evaluation of lymphoid proliferations should start with a good sense of knowledge of the clinical presentation of the lesions, the clinical differential considerations, and a conscientious and appropriate use of immunohistochemistry and molecular tools.

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.

New Therapies and Immunological Findings in Cutaneous T-Cell Lymphoma

Primary cutaneous lymphomas comprise a group of lymphatic malignancies that occur primarily in the skin. They represent the second most common form of extranodal non-Hodgkin’s lymphoma and are characterized by heterogeneous clinical, histological, immunological, and molecular features. The most common type is mycosis fungoides and its leukemic variant, Sézary syndrome. Both diseases are considered T-helper cell type 2 (Th2) diseases. Not only the tumor cells but also the tumor microenvironment can promote Th2 differentiation, which is beneficial for the tumor cells because a Th1 environment enhances antitumor immune responses. This Th2-dominant milieu also underlies the infectious susceptibility of the patients. Many components, such as tumor-associated macrophages, cancer-associated fibroblasts, and dendritic cells, as well as humoral factors, such as chemokines and cytokines, establish the tumor microenvironment and can modify tumor cell migration and proliferation. Multiagent chemotherapy often induces immunosuppression, resulting in an increased risk of serious infection and poor tolerance. Therefore, overtreatment should be avoided for these types of lymphomas. Interferons have been shown to increase the time to next treatment to a greater degree than has chemotherapy. The pathogenesis and prognosis of cutaneous T-cell lymphoma (CTCL) differ markedly among the subtypes. In some aggressive subtypes of CTCLs, such as primary cutaneous gamma/delta T-cell lymphoma and primary cutaneous CD8⁺ aggressive epidermotropic cytotoxic T-cell lymphoma, hematopoietic stem cell transplantation should be considered, whereas overtreatment should be avoided with other, favorable subtypes. Therefore, a solid understanding of the pathogenesis and immunological background of cutaneous lymphoma is required to better treat patients who are inflicted with this disease. This review summarizes the current knowledge in the field to attempt to achieve this objective.

Cutaneous Hematolymphoid and Histiocytic Proliferations in Children

This article focuses on cutaneous hematopoietic neoplasms that are more likely to be encountered in the pediatric age-group and includes both lymphoproliferative and histiocytic disorders. The cutaneous hematologic disorders in children have a different epidemiologic profile to what is seen during adulthood. Although mycosis fungoides is the most frequent form of cutaneous lymphoma in adults, it is very rare in children. Because lymphoblastic leukemias and lymphomas are more frequent in the pediatric setting, cutaneous leukemic infiltrates are relatively common in this age-group. Similarly, histiocytic disorders are more common in children, particularly Langerhans cell histiocytosis and juvenile xanthogranuloma. Notably, the histiocytic disorders have undergone significant modifications on their nomenclature in the basis of the molecular characteristics that are present in them. A summary of the most frequent cutaneous hematopoietic disorders in children will be discussed further in this review.

Cutaneous T-cell Lymphoma

Cutaneous T-cell lymphomas comprise a heterogeneous group of diseases characterized by monoclonal proliferations of T lymphocytes primarily involving skin, modified skin appendages, and some mucosal sites. This article addresses the basic clinical, histologic, and immunohistochemical characteristics of this group of diseases, with additional attention to evolving literature on dermoscopy, reflectance confocal microscopy, flow cytometry, and molecular data that may increasingly be applied to diagnostic and therapeutic algorithms in these diseases. Select unusual phenotypes or diagnostic examples of classic phenotypes are demonstrated, and flags for consideration while making a pathologic diagnosis of cutaneous T-cell lymphoma are suggested.

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.

Pathology of T-cell lymphomas: diagnosis and biomarker discovery

T-cell lymphomas are a group of predominantly rare hematologic malignancies that tend to recapitulate different stages of T-cell development, in a similar way that B-cell lymphomas do. As opposed to B-cell lymphomas, the understanding of the biology and the classification of T-cell lymphomas are somewhat rudimentary, and numerous entities are still included as 'provisional categories' in the World Health Classification of hematolopoietic malignancies. A relevant and useful classification of these disorders have been difficult to accomplish because of the rarity nature of them, the relative lack of understanding of the molecular pathogenesis, and their morphological and immunophenotypical complexity. Overall, T-cell lymphomas represent only 15 % of all non-Hodgkin lymphomas. This review is focused on addressing the current status of the categories of mature T-cell leukemias and lymphomas (nodal and extranodal) using an approach that incorporates histopathology, immunophenotype, and molecular understanding of the nature of these disorders, using the same philosophy of the most recent revised WHO classification of hematopoietic malignancies.

Papular mycosis fungoides: report of two patients, literature review, and conceptual re-appraisal

Recent reports of 10 patients have proposed a papular variant of mycosis fungoides (MF), characterized by the appearance of papules in the absence of patches and the presence of histopathologic features of classic patch/plaque stage MF. Given the overlapping clinical and pathologic features between this proposed entity and lymphomatoid papulosis (LyP)-type B, however, the optimal classification for such cases remains somewhat unclear. Herein, two patients are described who presented to the dermatology clinic with persistent erythematous papular eruptions on the trunk, upper and lower extremities and histopathology compatible with MF. Of note, these patients represent the oldest reported cases of papular MF, and one patient had documented peripheral blood involvement by atypical CD4+ cells. The clinicopathologic characteristics of this purported entity suggest that it may occupy the intersection between MF and CD30+ lymphoproliferative disorders. These two cases expand the clinicopathologic spectrum of papular MF to include older individuals, and further emphasize the importance of recognition of this morphology as a possible MF manifestation. Furthermore, consideration of our cases in conjunction with the previously documented 10 other patients in the literature, offers potential insight into the relationship between MF and CD30+ lymphoproliferative disorders.

Emerging Treatment Options for Advanced-Stage Mycosis Fungoides

A 72-year-old man with a 3-year history of hypersensitivity skin reaction managed with topical steroids and ultraviolet B (UVB) radiation develops skin tumors chiefly involving his face. After a diagnosis of stage IIB mycosis fungoides (MF), he begins oral low-dose weekly methotrexate with partial response lasting 5 months. Subsequently, he receives six cycles of weekly gemcitabine and achieves a partial response with resolution of skin tumors but persistence of scattered patches and plaques ( Fig 1 ). He begins daily bexarotene and interferon alfa (IFN-α) three times per week while continuing topical steroids. When scattered patches and plaques progress 7 months later, UVB radiation is added to his regimen. His disease remains well controlled until 17 months later, when he develops pneumonia complicated by pericarditis, requiring discontinuation of IFN-α. Over the next year, he continues bexarotene maintenance therapy and topical steroids but requires localized radiation therapy to isolated patch and tumor lesions. When patch lesions become more extensive, he receives total-skin electron beam therapy (TSEBT). Nearly 4 years after diagnosis of stage IIB MF and 5 months after completion of TSEBT, two tumor lesions redevelop on his face and scalp. The scalp tumor has overlying epidermal change with ulceration; the face tumor is subdermal with minimal overlying epidermal change and obstructs the right external auditory meatus ( Fig 1 D). You consider management options.

[Clinical course and therapy of lymphomatoid papulosis. Experience with 17 cases and literature review]

Lymphomatoid papulosis is a rare disease with a worldwide incidence of 1.2 to 1.9 per 1 million. It affects all age groups with a peak incidence between 30 and 40 years and an apparent male predominance. Occurrence in childhood has also been described. Both the etiology and pathogenesis of the disease are unknown. The clinical presentation is extremely variable and frequently uncharacteristic. A papulonodular eruption, characterized by self-healing skin lesions appearing in crops can often be seen, particularly on extremities. We report on 17 patients, including 2 children. By detailing 6 cases we point out the variable morphologic manifestations, the different courses of disease and therapeutic options.

CD30+ large cell transformation of mycosis fungoides after psoralen plus ultraviolet A photochemotherapy

Psoralen plus ultraviolet A (PUVA) photochemotherapy is widely used for the therapy of mycosis fungoides (MF). Clinical progression of MF is often associated with an increase in the size of tumour cells known as transformation. We report two patients with CD30+ large cell transformation that appeared after low-dose PUVA therapy for MF. Clinical data, histopathology, immunohistopathology and T-cell receptor gene rearrangement were studied. Nodules consisted of atypical large cells that expressed CD30. Monoclonal rearrangement of T-cell receptors was observed in one case. Low-dose PUVA therapy may be associated with CD30+ large cell transformation in patients with MF.

Pathobiology of CD30+ cutaneous T-cell lymphomas

CD30+ cutaneous lymphoproliferative disorders include lymphomatoid papulosis (LyP) and anaplastic large cell lymphoma (ALCL). LyP is associated with development of lymphoma in nearly 20% of patients. Herein is reviewed the clonal relationship of LyP to malignant lymphoma, the concept of a common stem cell for LyP and associated lymphomas, and the role of genetic instability in lymphomagenesis. The possible role of the CD30+ cell as a regulatory T-cell is introduced and a model for progression of LyP to ALCL is illustrated.

T-cell clonality of peripheral blood lymphocytes in patients with lymphomatoid papulosis

Six patients with lymphomatoid papulosis demonstrated a clonal T-cell population in skin lesions by polymerase chain reaction methods. Two of these patients showed identical T-cell clones in their peripheral blood T cells as well. In one case, the clone persisted in the blood despite clearing of skin lesions with methotrexate.

Death Receptor Apoptosis Signaling Mediated by FADD in CD30-Positive Lymphoproliferative Disorders Involving the Skin

BACKGROUND

The CD30-positive lymphoproliferative disorders lymphomatoid papulosis (LyP), primary cutaneous anaplastic large cell lymphoma (C-ALCL), and systemic anaplastic large cell lymphoma (S-ALCL) are lesions that overlap clinically, histopathologically, and immunophenotypically. Their biologic behaviors, however, vary considerably. In particular, lesions of LyP regress spontaneously while those of S-ALCL persist and often progress. Apoptosis has been suggested as the mechanism by which the lesions of LyP regress, but the underlying signaling pathways remain unclear. In this study, we used newly developed activation state-specific antibodies to demonstrate apoptosis signaling through the death receptor-mediated pathway regulated by FADD and caspase 3.

METHODS

Dual immunohistochemistry for CD30 and activated forms of FADD and caspase 3 was performed on cutaneous biopsy specimens from 27 patients with CD30-positive lymphoproliferative disorders involving the skin. The patients included 18 with primary cutaneous CD30-positive LPDs (15 with LyP and 3 with C-ALCL) and 9 with S-ALCL.

RESULTS

The proportion of CD30-positive cells expressing activated FADD was significantly different between primary cutaneous CD30-positive lymphoproliferative disorders and S-ALCL (36.4% vs. 14.5%, P = 0.0083). Expression of cleaved caspase 3 was also significantly different between primary cutaneous lesions and S-ALCL (9.2% vs. 1.9%, P = 0.048).

CONCLUSIONS

Although a larger number of cases should be studied to validate these results, these data provide evidence that differences in signaling through the death-receptor apoptosis pathway mediated by FADD may be responsible for the varying biologic behaviors of CD30-positive lymphoproliferative disorders involving the skin.