Primary CD30-positive cutaneous T-cell lymphomas and lymphomatoid papulosis frequently express cytotoxic proteins

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.

Lymphomatoid Papulosis "Type E" Affecting the Palate: A Detailed Case Report and Review of Literature

ABSTRACT

Lymphomatoid papulosis (LyP) belongs to the spectrum of primary cutaneous CD30 + lymphoproliferative disorders, characterized by chronic, recurrent, self-healing papules, small nodules, or ulcers. The clinicopathological features of LyP can mimic overt lymphomas. To date, about 27 intraoral LyP cases have been reported. Of them, only 2 cases were diagnosed as angioinvasive LyP (type E). Herein, we report a 24-year-old Brazilian man who presented a large ulcerated lesion on the hard palate with rapid evolution. Remarkably, there was no involvement of the skin or other mucous membranes. Microscopy revealed a lymphoid infiltrate constituted by medium-sized to large atypical cells, with angiocentric and angiodestructive features. The atypical cells showed immunopositivity for CD3, CD8, CD30, CD56, granzyme B, perforin, and focally for MUM1/IRF4. Ki-67 highlighted almost all atypical lymphoid cells, whereas EBER1/2 was negative. After 2 months of follow-up, the lesion healed completely. Although rare, LyP type E should be included in the differential diagnosis of oral ulcers.

Gamma/Delta Phenotype in Primary Cutaneous T-cell Lymphomas and Lymphoid Proliferations: Challenges for Diagnosis and Classification

Primary cutaneous T-cell lymphomas pose a diagnostic challenge for dermatopathologists, hematopathologists, and general surgical pathologists. Recognition of gamma/delta phenotype in cutaneous T proliferations has been enhanced by the availability of antibodies against TCRgamma and delta for immunohistochemistry. Thus, reporting gamma/delta phenotype in a cutaneous T-cell lymphoid proliferation may indicate a significant change in therapy and a challenge for dermatologists and oncologists who treat these patients. Herein, we discuss primary cutaneous gamma/delta T-cell lymphoma, its differential diagnosis, and other skin lymphoid proliferations that may show gamma/delta phenotype. Awareness of the occurrence of gamma/delta phenotype in both T-cell lymphomas and benign lymphoid proliferations involving skin is crucial for a better interpretation of histopathologic findings. Integration of clinical presentation, morphology, immunoprofile, and molecular findings is key for a correct diagnosis and appropriate therapy of lesions displaying gamma/delta T-cell phenotype.

How I Diagnose Anaplastic Large Cell Lymphoma

OBJECTIVES

This review describes our approach to the diagnosis of all 4 anaplastic large cell lymphoma (ALCL) entities.

METHODS

ALCLs are a group of CD30-positive mature T-cell lymphomas with similar morphologic and phenotypic characteristics but variable clinical and genetic features. They include systemic ALK-positive ALCL, systemic ALK-negative ALCL, primary cutaneous ALCL, and the recently described provisional entity breast implant-associated ALCL.

RESULTS

In cases with classic features, the diagnosis of ALCL is often straightforward. However, variant histology, the importance of clinical history, and multiple antigenic aberrancies all present challenges to accurate diagnosis and subclassification.

CONCLUSIONS

A systematic approach to the diagnosis of ALCL and awareness of potential mimics are critical to avoid misdiagnosis. It is also crucial to correctly identify localized forms of ALCL to avoid classification as systemic ALCL and subsequent overtreatment.

Perforins Expression by Cutaneous Gamma Delta T Cells

Gamma delta (GD) T cells are an unconventional T cell type present in both the epidermis and the dermis of human skin. They are critical to regulating skin inflammation, wound healing, and anti-microbial defense. Similar to CD8+ cytotoxic T cells expressing an alpha beta (AB) TCR, GD T cells have cytolytic capabilities. They play an important role in elimination of cutaneous tumors and virally infected cells and have also been implicated in pathogenicity of several autoimmune diseases. T cell cytotoxicity is associated with the expression of the pore forming protein Perforin. Perforin is an innate immune protein containing a membrane attack complex perforin-like (MACPF) domain and functions by forming pores in the membranes of target cells, which allow granzymes and reactive oxygen species to enter the cells and destroy them. Perforin-2, encoded by the gene MPEG1, is a newly discovered member of this protein family that is critical for clearance of intracellular bacteria. Cutaneous GD T cells express both Perforin and Perforin-2, but many questions remain regarding the role that these proteins play in GD T cell mediated cytotoxicity against tumors and bacterial pathogens. Here, we review what is known about Perforin expression by skin GD T cells and the mechanisms that contribute to Perforin activation.

Pathology and genetics of anaplastic large cell lymphoma

Anaplastic large cell lymphomas are a rare subtype of peripheral/mature T-cell lymphomas which are clinically, pathologically and genetically heterogeneous. Both ALK-positive (ALK+) and ALK-negative (ALK-) ALCL are composed of large lymphoid cells with abundant cytoplasm and pleomorphic features with horseshoe-shaped and reniform nuclei. ALK+ ALCL were considered as a definite entity in the 2008 World Health Organization classification of hematopoietic and lymphoid tissues. ALK-ALCL was included as a provisional entity in the WHO 2008 edition and in the most recent 2017 edition, it is now considered a distinct entity that includes cytogenetic subsets that appear to have prognostic implications (e.g. 6p25 rearrangements at IRF4/DUSP22 locus). ALK+ ALCLs are distinct in epidemiology and pathogenetic origin and should be distinguished from ALK-ALCL, cutaneous ALCL and breast implant associated ALCL which have distinct clinical course and pathogenetic features. Breast implant-associated ALCL is now recognized as a new provisional entity distinct from other ALK-ALCL; notably that it is a noninvasive disease associated with excellent outcome. In this article, we will provide an overview of the salient themes relevant to the pathology and genetic mechanisms in ALCL.

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.

How I treat primary cutaneous CD30+ lymphoproliferative disorders

The primary cutaneous CD30+ lymphoproliferative disorders are a family of extranodal lymphoid neoplasms that arise from mature postthymic T cells and localize to the skin. Current classification systems recognize lymphomatoid papulosis (LyP), primary cutaneous anaplastic large cell lymphoma, and borderline cases. In the majority of patients, the prognosis of primary cutaneous CD30+ lymphoproliferative disorders is excellent; however, relapses are common, and complete cures are rare. Skin-directed and systemic therapies are used as monotherapy or in combination to achieve the best disease control and minimize overall toxicity. We discuss 3 distinct presentations of primary cutaneous CD30+ lymphoproliferative disorder and present recommendations for a multidisciplinary team approach to diagnosis, evaluation, and management of these conditions in keeping with existing consensus guidelines.

Successful experience in treating primary cutaneous anaplastic large cell lymphoma occuring with common lesions of the skin and lung tissue

The aim of the study is to present a successful case in treating primary cutaneous anaplastic large cell lymphoma (PCALCL) occurring with common lesions of the skin and lung tissue.Materials and methods. For the verification of the diagnosis in a patient with three types of skin elements (spot, thin plaque with and without ulceration), differential diagnosis was performed between ulcerative pyoderma gangrenosum, PCALCL, large-cell transformation of mycosis fungoides, and secondary skin lesions under the nodal ALK-negtaive ALCL. A complex of studies, including histological, immunohisto - chemical, cytogenetic studies of skin tumor biopsy, allowed the verification of the PCALCL diagnosis. For the treatment of the patient, intensive induction chemotherapy was used followed by high-dose consolidation and autologous transplantation of hematopoietic stem cells.Results. The selected treatment tactics allowed a long-term complete remission of the disease to be achieved in a patient from the poor prognosis group.Conclusion. An algorithm for the differential diagnosis and tactics of treating is presented for a patient with primary anaplastic large cell lymphoma with a widespread skin lesion and extradermal foci.

Cutaneous Lymphomas with Cytotoxic Phenotype

Primary cutaneous cytotoxic lymphomas are T-cell or natural killer-cell lymphomas that express 1 or more cytotoxic markers. These neoplasms constitute a spectrum of diseases. In this review, an overview of clinical, morphologic, and phenotypical features of each subtype is provided. Differential diagnosis is discussed with attention to scenarios in which diagnostic difficulties are most frequently encountered.

Primary cutaneous T-cell lymphomas: a review

Primary cutaneous T-cell lymphomas (CTCLs) represent a number of extranodal lymphomas arising from a malignant population of lymphocytes in the skin, with the most common type being mycosis fungoides (MF) representing half of all primary CTCLs. Despite advances in immunohistochemistry and molecular methodology, significant diagnostic challenges remain due to phenotypic overlap of primary CTCLs with several inflammatory dermatoses, secondary lymphomas, among other conditions. Clinical features such as presentation and morphology, staging, histology, immunophenotype and molecular features must be considered in detail before a diagnosis is made in order to minimise false-positive, false-negative and indeterminate diagnoses. Herein, we review primary CTCLs, including epidemiological data, a brief summary of clinical presentations, immunophenotype, molecular signatures and differential diagnoses.

CD68 expression is a discriminative feature of indolent cutaneous CD8-positive lymphoid proliferation and distinguishes this lymphoma subtype from other CD8-positive cutaneous lymphomas

BACKGROUND

Indolent cutaneous CD8+ lymphoid proliferation is a recently described rare entity among cutaneous T-cell lymphomas that typically presents with solitary skin lesions at acral sites. Separation from otherwise aggressive T-cell lymphomas bearing a cytotoxic CD8+ phenotype is fundamental to avoid unnecessary harmful treatment. However, up to now, no reliable discriminative marker has been identified.

OBJECTIVES

Motivated by these diagnostic quandaries, we have analyzed a large series of archived formalin-fixed paraffin-embedded (FFPE) specimens of atypical CD8+ cutaneous infiltrates with clear-cut diagnosis and clinical follow-up (n = 44) including five cases of indolent CD8+ lymphoid proliferation by using immunohistochemistry with the aim of obtaining markers predictive of subtype assignment.

RESULTS

We identified exclusive expression of CD68 by lymphoma cells within the subgroup of indolent CD8+ lymphoid proliferation (5/5 cases). Specific CD68 expression in this entity was confirmed by the application of several monoclonal antibodies (KP1, PG-M1, KiM1P) against the CD68 molecule available for FFPE tissue. In contrast, none of the infiltrates of the other CD8+ cutaneous lymphoma entities stained positive for CD68 (0/39).

CONCLUSIONS

Based on these observations, we suggest CD68 as a new discriminative marker which is helpful in distinguishing indolent CD8+ lymphoid proliferation from other CD8+ cutaneous lymphomas in ambiguous cases.

Anaplastic large cell lymphomas: ALK positive, ALK negative, and primary cutaneous

Anaplastic large cell lymphomas (ALCLs) comprise a group of CD30-positive non-Hodgkin lymphomas that generally are of T-cell origin and share common morphologic and phenotypic characteristics. The World Health Organization recognizes 3 entities: primary cutaneous ALCL (pcALCL), anaplastic lymphoma kinase (ALK)-positive ALCL, and, provisionally, ALK-negative ALCL. Despite overlapping pathologic features, these tumors differ in clinical behavior and genetics. pcALCL presents in the skin and, while it may involve locoregional lymph nodes, rarely disseminates. Outcomes typically are excellent. ALK-positive ALCL and ALK-negative ALCL are systemic diseases. ALK-positive ALCLs consistently have chromosomal rearrangements involving the ALK gene with varied gene partners, and generally have a favorable prognosis. ALK-negative ALCLs lack ALK rearrangements and their genetic and clinical features are more variable. A subset of ALK-negative ALCLs has rearrangements in or near the DUSP22 gene and has a favorable prognosis similar to that of ALK-positive ALCL. DUSP22 rearrangements also are seen in a subset of pcALCLs. In this review, we discuss the clinical, morphologic, phenotypic, genetic, and biological features of ALCLs.

Multicenter case series of indolent small/medium-sized CD8+ lymphoid proliferations with predilection for the ear and face

We report 7 cases of a CD8 lymphoid proliferation of the ear and face with a cytotoxic T-cell phenotype, but an indolent clinical course. All patients presented with stable or slowly growing asymptomatic lesions on the ear, nose, or lower eyelid. Histopathology showed a dense diffuse dermal infiltrate of small- to medium-sized atypical lymphocytes without destructive features. The lymphocytes were positive for CD3, CD8, β-F1, and TIA-1 and negative for CD4, CD30, CD56, granzyme B, and PD-1. Of note, the proliferation index was low in available cases. All patients remained in complete remission at median follow-up of 14 months regardless of treatment modality. Staging was negative for extracutaneous disease in all patients. The clinically indolent behavior and histopathologic phenotype together with a low proliferation index (10%-15%) emphasize the importance of accurate diagnosis and appropriate clinical management to avoid overtreatment and complications of therapy.

Phenotypic variability in primary cutaneous anaplastic large T-cell lymphoma: a study on 35 patients

Primary cutaneous anaplastic large T-cell lymphoma (pcALCL) is a well-defined entity characterized by neoplastic cells expressing CD30, CD2, CD3, CD4, and CD5. Cases with different phenotype have been reported, including variable loss of CD2, CD3, and CD5, and expression of cytotoxic phenotype (CD8⁺) and/or of cytotoxic proteins. Aberrant phenotypes represent a diagnostic pitfall and may be the cause of misdiagnoses. We reviewed 35 cases of pcALCL (M:F = 19:16; mean age, 50.8 years; range, 14-92 years), to better characterize the immunophenotypic spectrum of the disease. Twelve cases (34%) had a T-helper phenotype (CD4⁺/CD8⁻), and TIA-1 was positive in 5 of 8 stained cases. Six cases (18%) had a T-cytotoxic phenotype (CD4⁻/CD8⁺) and were also positive for TIA-1. Positivity for both CD4 and CD8 was observed in 7 cases (20%), 4 of which were stained for TIA-1 and found to be positive, whereas both CD4 and CD8 were negative in 9 cases (26%, only 1/8 tested cases being TIA-1 positive). CD2 was positive in 21 of 27 tested cases (78%), CD3 in 21 of 34 cases (62%), and CD5 in 15 of 31 cases (48%). Interestingly, 11 cases (31%) showed a profoundly aberrant phenotype lacking simultaneously several T-cell markers. Our data allow a better characterization of pcALCL with aberrant phenotypes, showing the remarkable variability in expression of different markers.

Indolent CD8+ lymphoid proliferation of the face with eyelid involvement

In 2007, Petrella et al described a series of patients with clonally restricted, well-differentiated, nonepidermotropic, CD8-dominant lymphocytic infiltrates localized to the facial area. The clinical course described was indolent. A CD8 variant of primary cutaneous pleomorphic T-cell lymphoma has been proposed; however, there are many dissimilar features. The authors encountered 2 patients with CD8⁺ indolent lymphoid proliferation of the face, localized to the eyelid. Both patients were males in their 30s presenting with localized lesions of the eyelids. The biopsies showed an effacing lymphocytic infiltrate that spanned the sampled dermis. The lymphocytes were well differentiated, exhibiting mild nuclear contour irregularity. The infiltrate was predominated by CD8⁺ lymphocytes demonstrating TIA expression. There was a minimal B-cell component in 1 case, whereas another showed a significant degree of B-cell hyperplasia. They both underwent complete excision without recurrence. CD8⁺ indolent lymphoid proliferation has a reproducible clinical and morphologic presentation that warrants categorization as a distinct form of indolent lymphoproliferative disease, preferentially involving older adults with the most common site being the ear, recognizing that the nose, acral surfaces, and eyelids can also be involved.

Extrafacial indolent CD8-positive cutaneous lymphoid proliferation with unusual symmetrical presentation involving both feet

Indolent CD8+ cutaneous lymphoid proliferation represents a recently described entity among cutaneous T-cell lymphomas that typically presents with solitary skin lesions on the face or at acral sites and usually follows an indolent clinical course. Histopathologically, this entity is characterized by a dense dermal infiltrate of non-epidermotropic, small- to medium-sized pleomorphic CD8+ T-cells of the non-activated cytotoxic phenotype showing a clear-cut grenz zone and a low proliferation index. Distinction from otherwise aggressive T-cell lymphomas bearing a cytotoxic CD8+ phenotype is fundamental. We herein present an unusual case of indolent CD8+ cutaneous lymphoid proliferation presenting in bilateral symmetrical distribution on both feet and lacking the otherwise described grenz zone. Our case widens the spectrum of possible clinical and histomorphological variations of this entity. Taking into account the distinctive and unique clinical and microscopic features of all hitherto published cases of indolent CD8+ cutaneous lymphoid proliferation we suppose that this lymphoma subtype has to be included as a new and distinct entity in the World Health Organisation (WHO)-/European Organisation for Research and Treatment of Cancer (EORTC)-classification of cutaneous lymphomas.

Brentuximab vedotin in systemic T-cell lymphoma

INTRODUCTION

Brentuximab vedotin is an antibody-drug conjugate which consists of the anti-CD30 monoclonal antibody cAC10 conjugated with the cytotoxic agent monomethyl auristatin E (MMAE). Brentuximab vedotin has been approved by the US Food and Drug Administration for the treatment of relapsed or refractory Hodgkin's lymphoma (HL) and anaplastic large cell lymphoma (ALCL). The efficacy of brentuximab vedotin in other CD30(+) lymphomas is currently being investigated.

AREAS COVERED

In this paper, we review the currently available treatment options for systemic peripheral T-cell lymphomas (PTCL) and the role of brentuximab vedotin in relapsed or refractory ALCL. In addition, ongoing clinical trial of brentuximab vedotin in relapsed PTCL and combination therapy with other chemotherapies for initial treatment of CD30 lymphoma will also be reviewed.

EXPERT OPINION

Brentuximab vedotin has established its role in the treatment of relapsed or refractory HL and ALCL. In the next few years, the efficacy of this agent in other CD30(+) lymphomas will be described. The safety and efficacy of several brentuximab-based combination regimens, including use as frontline chemotherapy is under investigation.

Indolent CD8-positive lymphoid proliferation on the face: part of the spectrum of primary cutaneous small-/medium-sized pleomorphic T-cell lymphoma or a distinct entity?

We report two cases of a CD8-positive lymphoid proliferation presenting as solitary lesions on the ear and nose, respectively. Histopathologically, both cases were characterized by a diffuse non-epidermotropic dermal proliferation of clonal medium-sized CD8-positive T-lymphocytes with a lymphoblast-like appearance, having cells with large folded nuclei, prominent nucleoli and ample amphophilic or pale eosinophilic cytoplasm. Staging procedures excluded systemic involvement, and both lesions were successfully treated with localised radiotherapy without evidence of recurrence after 12 and 24 months' follow up, respectively. Previously reported cases on the ear had similar clinicopathological and immunophenotypical features, and together raise the possibility of a distinct entity, an indolent CD8-positive lymphoid proliferation.

Recurrent translocations involving the IRF4 oncogene locus in peripheral T-cell lymphomas

Oncogenes involved in recurrent chromosomal translocations serve as diagnostic markers and therapeutic targets in hematopoietic tumors. In contrast to myeloid and B-cell neoplasms, translocations in peripheral T-cell lymphomas (PTCLs) are poorly understood. Here, we identified recurrent translocations involving the multiple myeloma oncogene-1/interferon regulatory factor-4 (IRF4) locus in PTCLs. IRF4 translocations exist in myeloma and some B-cell lymphomas, but have not been reported previously in PTCLs. We studied 169 PTCLs using fluorescence in situ hybridization and identified 12 cases with IRF4 translocations. Two cases with t(6;14)(p25;q11.2) had translocations between IRF4 and the T-cell receptor-alpha (TCRA) locus. Both were cytotoxic PTCLs, unspecified (PTCL-Us) involving bone marrow and skin. Eight of the remaining ten cases were cutaneous ALCLs without TCRA rearrangements (57% of cutaneous ALCLs tested). These findings identified IRF4 translocations as a novel recurrent genetic abnormality in PTCLs. Cytotoxic PTCL-Us involving bone marrow and skin and containing IRF4/TCRA translocations might represent a distinct clinicopathologic entity. Translocations involving IRF4 but not TCRA appear to occur predominantly in cutaneous ALCLs. Detecting these translocations may be useful in lymphoma diagnosis. Further, due to its involvement in translocations, MUM1/IRF4 protein may play an important biologic role in some PTCLs, and might represent a possible therapeutic target.

Cutaneous T-cell and NK-cell lymphomas: the WHO-EORTC classification and the increasing recognition of specialized tumor types

Cases drawn from Session 5 of the 2005 Society for Hematopathology/European Association for Haematopathology Workshop on progress in T-cell and natural killer (NK)-cell malignancies are used as a framework to review the current classification of T-cell and NK-cell malignancies in skin. In comparison with the typical pattern and course of mycosis fungoides (MF), selected variants of MF that can be difficult to diagnose are discussed. Cutaneous CD30+ lymphoproliferative disorders are also presented in detail. Particular focus is placed on the recognition of rare but clinically more aggressive cytotoxic lymphomas in the skin. Overall, diagnostic pitfalls and new information regarding disease pathogenesis brought up by the Workshop cases are provided. In addition, a general approach to the diagnosis of cutaneous T-cell lymphomas is discussed.

Differential expression of TRAF1 aids in the distinction of cutaneous CD30-positive lymphoproliferations

Lymphomatoid papulosis (LyP), primary cutaneous anaplastic large T-cell lymphoma (cALCL), and cutaneous infiltrates of systemic anaplastic large cell lymphoma (sALCL) are CD30-positive lymphoproliferative disorders of the skin that overlap clinically, histopathologically, immunophenotypically, and genetically but differ considerably in their prognosis. In particular, lesions of LyP regress spontaneously, whereas those of cALCL and sALCL persist and may progress and spread to extracutaneous sites. In contrast to patients with cALCL, LyP patients do not benefit from an aggressive radio- and/or chemotherapeutic approach. We generated a novel tumor necrosis factor receptor (TNFR)-associated factor 1 (TRAF1) antibody that recognizes a formalin-resistant epitope (Ber-TRAF1A) and investigated the expression of TRAF1, an intracellular component of TNFR signaling, in LyP and ALCL. We could show a strong TRAF1 expression in the tumor cells of most LyP cases (42/49, 84%). In contrast, tumor cells of primary and secondary cALCL revealed TRAF1 expression in only a few cases (3/41, 7%) as shown for sALCL without skin manifestation. The data indicate that TRAF1 expression reliably distinguishes LyP from primary or secondary cALCL. This might be of crucial diagnostic importance and has a strong impact on the treatment decision for patients with cALCL and LyP.

Primary CD30+ve Cutaneous T-cell Lymphoma Associated with Chronic Burn Injury in a Patient with Longstanding Psoriasis

An increased incidence of lymphoma has been reported in psoriatic patients, but most cases are nodal B-cell lymphoma. We report a unique case of CD30-expressing cutaneous T-cell lymphoma arising from underlying psoriatic plaque after intractable caustic burns and cellulitis in the palm of a patient with generalized chronic plaque psoriasis. Molecular studies confirmed a localized clonal T-cell expansion, and the lesion responded dramatically to multiagent chemotherapy. The case highlighted the possible role of chronic systemic and local T-cell activation in the pathogenesis of primary CD30+ve cutaneous T-cell lymphoma, and the importance of histologic assessment in chronic nonhealing skin lesions.

Lymphomatoid Papulosis Histopathologically Simulating Angiocentric and Cytotoxic T-cell Lymphoma

We report a patient presenting with a 20-year history of recurrent papulonecrotic lesions in which skin biopsy shows extensive vascular destruction. Atypical lymphoid cells surrounding the dermal vessels had a CD3+, CD4-, CD5-, CD8+, CD20-, CD30+, CD56+, TIA-1+, and granzyme B immunophenotype implicating a natural killer/T origin. In situ hybridization was negative for Epstein-Barr virus transcripts. Analysis of T-cell receptor-gamma gene of 2 separate biopsy specimens detected an identical clone. The patient was treated with low-dose methotrexate and achieved complete resolution in a month. According to the clinical course, immunophenotype, clonality analysis and the excellent response to methotrexate, we conclude that this is an unusual case of lymphomatoid papulosis. We believe that this unusual presentation needs to be distinguished from other aggressive lymphomas, including the natural killer/T-cell and cytotoxic T-cell subsets.

Primary cutaneous CD30-positive lymphoproliferative disorders

Primary cutaneous CD30-positive (anaplastic) large T-cell lymphoma and lymphomatoid papulosis have many overlapping clinical, histologic, and immunophenotypic features. These entities are currently considered as parts of a spectrum of primary cutaneous CD30-positive lymphoproliferative disorders. We provide the clinician with practical guidelines for the diagnosis, management, and treatment of patients within this spectrum of primary cutaneous CD30-positive lymphoproliferative disorders. Most patients within this spectrum of disease have an excellent prognosis. Multi-agent chemotherapy should be reserved for patients who have extracutaneous disease.

Phenotypic analysis of peripheral T/NK cell lymphoma: study of 408 Japanese cases with special reference to their anatomical sites

The World Health Organization (WHO) classification of malignant lymphoma presented a list of disease entities well defined by clinical, immunological and genetic features. Therefore, the current diagnosis of peripheral T/NK-cell lymphomas (PTNKLs) essentially requires the inclusion of anatomical sites of disease and phenotypical features. We analyzed 408 Japanese cases of PTNKLs in order to clarify the relationship between anatomical sites of disease and phenotypical features and to translate the functional subsets of T and NK cells into their diagnoses for further understanding lymphomatic biology. The T/NK-cell lymphoma entities were allocated into three categories: (i) cytotoxic memory T-cell and/or NK-cell lymphoma (n = 151) consisting of extranodal NK/T-cell tumors other than mycosis fungoides (MF); (ii) non-cytotoxic memory T-cell lymphoma (n = 142) consisting of nodal and cutaneous tumors such as angioimmunoblastic T-cell lymphoma, adult T-cell lymphoma/leukemia and MF; and (iii) anaplastic lymphoma kinase positive anaplastic large cell lymphoma (n = 110) that has unique features and might be regarded as cytotoxic 'naive' T-cell lymphoma. Overall, these three categories were significantly correlated with age of onset, anatomical sites, the level of expression of cytotoxic molecules and CD45RO, and association with Epstein-Barr virus. This concept might provide a new insight enabling further understanding of the interrelationships among WHO T/NK-cell disease entities.

Liposomal daunorubicin in tumor stage cutaneous T-cell lymphoma: report of three cases

PURPOSE

Advanced cutaneous T-cell lymphoma (CTCL) is a hard-to-treat condition. Complete response is rare even with polychemotherapy. The use of liposomal formulation anti-cancer drugs can improve the efficacy and the risk-benefit ratio. Liposomal doxorubicin was shown to be effective as a second-line treatment in CTCL. There is no data available on another classical anthracycline, daunorubicin, when given in liposomal formulation as a monotherapy.

METHODS

Monotherapy with liposomal-encapsulated daunorubicin (DNX) was given as a monotherapy once a month at 20 mg/m(2) three times to achieve a clinical response. In the case of limited response the drug was given once every 3 weeks and a dose increase was performed. Three patients were treated.

RESULTS

A complete response was achieved in one patient (dosage 20 mg/m(2 )once per month). Two other patients achieved a partial response. The final outcome was disease-free survival of more than 10 months in the patient with a complete response and survival of >8 months and 6 months in those with a partial response. Adverse effects were grade 4 anemia in one patient, lymphopenia grade 2 with grade 1 anemia, and grade 1 lymphopenia in the other patients.

CONCLUSION

This is the first report on DNX monotherapy in CTCL. In a small group of three patients a response rate of 100% was achieved with one complete response. DNX seems to be another option in advanced cases of CTCL.

Killer cell immunoglobulin-like receptor expression delineates in situ Sézary syndrome lymphocytes

p140/KIR3DL2 has been identified in malignant cell lines isolated from the skin and blood of patients with transformed mycosis fungoides (MF) and Sézary's syndrome (SS). For the first time, the expression of a cell membrane structure appeared to be able to distinguish CD4+ tumour lymphocytes from reactive lymphocytes in these small cutaneous T-cell lymphomas (CTCLs). This study has examined the in vivo expression of this receptor in various CTCL subtypes, which constituted a heterogeneous group. Tumour cells diffusely expressed KIR in SS, in lymphomatoid papulosis (LyP) and in CD4+CD30+ as well as CD8+ large cell pleomorphic CTCL. In contrast, the infiltrating lymphocytes did not express KIR in MF at the patch/plaque stage or in CD4+CD30- large cell pleomorphic CTCL, except for scattered small cells. One quarter of the transformed MF tested exhibited KIR+ tumour cells, suggesting heterogeneity in this subtype. KIR expression was also examined in inflammatory lesions characterized by a dense infiltrate of T cells, such as lupus erythematosus and lichen planus. Only scattered CD8+ cells in lichen planus expressed a significant amount of KIR3DL2. Taken together, these results show for the first time that KIR molecules are expressed in distinct subtypes of malignant CTCL. It is also shown for the first time that SS and MF, which are frequent variants of CTCL with similar histological features, can be distinguished by their KIR3DL2 expression analysis. The identification of this KIR also differentiates between lupus erythematosus and lichen planus, which are both diseases with dense benign lymphocytic infiltrates.

Peripheral T-cell lymphoma

Peripheral (post-thymic) T-cell lymphoma consists of a wide spectrum of disorders with marked differences in biology and behavior. Proper classification is pivotal for evaluating treatment results, and most studies performed a decade ago lump together different disease entities and cannot be interpreted. With improved use of immunophenotyping and molecular methods for these disorders, their exact nature is better defined in the Revised European-American Lymphoma and subsequent World Health Organization (WHO) classifications. The WHO classification of post- thymic T/natural killer (NK)-cell lymphoma consists of 15 entities, including about 30% that are unclassified cases. A wide range in incidence exists between different populations, but it is likely to be lower than previously estimated. Certain entities, like nasal/nasal-type T/NK-cell lymphoma and human T-cell leukemia/lymphoma virus 1, are much more prevalent in certain racial groups and show exquisite viral association. In these entities as a group, prognosis and treatment seem inferior to those of their B-cell counterparts, but treatment must be tailored to the exact pathologic diagnosis and prognostic index. Aggressive combination chemotherapy appears to be curative for certain entities (eg, anaplastic lymphoma kinase-positive), whereas purine analogues may be useful for low-grade entities. The role of autologous and allogeneic stem cell transplantation is still poorly defined. Specific antibody-based therapy is also on the horizon.

Single-cell analysis of CD30+ cells in lymphomatoid papulosis demonstrates a common clonal T-cell origin

Lymphomatoid papulosis (LyP) represents an intriguing cutaneous T-cell lymphoproliferative disorder with a histologic appearance resembling malignant lymphoma. This finding strongly contrasts with the benign clinical course of the disease. However, in 10% to 20% of cases, LyP can precede, coexist with, or follow malignant lymphoma. In these cases, the same T-cell population has been shown to be present in the LyP as well as in the associated lymphoma. In most LyP cases, there is-despite the sometimes extremely long course of the disease-no evolution of a secondary lymphoma. The investigation of these uncomplicated LyP cases for the presence of clonal T-cell receptor rearrangements has produced heterogeneous results. This might be explained by biologic or technical reasons arising from analyzing whole tissue DNA extracts. To definitively clarify whether the large atypical CD30(+) cells in LyP without associated lymphoma all belong to the same clone or represent individually rearranged T cells, we analyzed the T-cell receptor-gamma rearrangements of single CD30+ as well as of single CD30- cells isolated from 14 LyP lesions of 11 patients. By using this approach we could demonstrate that the CD30+ cells represent members of a single T-cell clone in all LyP cases. Moreover, in 3 patients the same CD30+ cell clone was found in anatomically and temporally separate lesions. In contrast, with only a few exceptions, the CD30- cells were polyclonal in all instances and unrelated to the CD30+ cell clone. Our results demonstrate that LyP unequivocally represents a monoclonal T-cell disorder of CD30+ cells in all instances.

Large atypical cells of lymphomatoid papulosis are CD56-negative: a study of 18 cases

BACKGROUND

Histologically, diffuse dermal infiltrates of large atypical lymphocytes can be seen in lesions as indolent as type C lymphomatoid papulosis (LyP) to ones as aggressive as NK/T-cell lymphoma. While lesions of lymphomatoid papulosis are definitionally positive for CD30, their ability to express CD56 has not been formally studied. The objective of the current study was to determine whether or not the large atypical cells of LyP express the natural killer cell marker, CD56.

METHODS

Biopsies from 18 patients with LyP were studied with monoclonal antibodies to CD30, CD56, CD8, and TIA-1. These included four type C LyP lesions. Clinical information was obtained by chart review and included extent of LyP lesions, presence/absence of disease at follow-up, and any associated hematologic malignancies,.

RESULTS

None of the biopsies exhibited CD56 positivity within the large atypical cells of LyP. While some biopsies demonstrated CD56-positive, small, presumably reactive, lymphocytes within the infiltrate, their presence did not correlate with extent of disease, persistence of disease, or propensity for an associated non-LyP hematologic malignancy.

CONCLUSIONS

The large atypical cells of types A and C LyP do not exhibit positivity for CD56, and thus a panel of antibodies that includes CD30 and CD56 can readily distinguish between the benign end of the spectrum of CD30-positive lymphoproliferations and aggressive NK/T-cell lymphoma.

Proapoptotic and antiapoptotic markers in cutaneous T-cell lymphoma skin infiltrates and lymphomatoid papulosis

BACKGROUND

In cutaneous T-cell lymphoma (CTCL) lesions, both reactive T cells and malignant T cells intermingle. The disease progression is mostly slow. Recent evidence suggests that even if clinical remission is reached, malignant cells persist and a relapse follows sooner or later. To wha extent tumour cell apoptosis occurs in the skin lesions either due to the reactive T cells or t therapeutic efforts is not known.

OBJECTIVES

To determine the extent of tumour cell apoptosis and the expression of proapoptotic an antiapoptotic markers in serial skin lesion samples from patients with CTCL, and to compare th findings with those in patients with lymphomatoid papulosis (LyP).

METHODS

Thirty-four skin samples were obtained from 12 patients with CTCL at the time o diagnosis and at a mean of 1.6, 3 and 6 years later. The patients received psoralen plus ultraviolet (PUVA), electron beam or cytostatic treatments. In addition, fresh post-treatment samples fro three patients with CTCL undergoing PUVA therapy were obtained. For comparison, skin biopsies o five patients with LyP were studied. Immunohistochemical demonstration of the expression of th following markers was performed on formalin-fixed skin sections: Fas (CD95), Fas ligand (FasL) bcl-2, granzyme B, the tumour-suppressor protein PTEN and the effector caspase, caspase-3. Th malignant cells were identified morphologically, and apoptotic cells were identified with th terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labelling method on parallel sections.

RESULTS

In untreated CTCL lesions, apoptotic lymphocytes were extremely rare, and no increase in the number of apoptotic cells was observed after any of the treatments used. In LyP, apoptotic cell were more frequent, comprising on average 5% of the infiltrate. The apoptosis-associated marker Fas, FasL, caspase-3 and granzyme B were expressed by morphologically neoplastic cells in CTCL and by large atypical cells in LyP, with no significant differences. However, only a few reactive cell in CTCL infiltrates expressed granzyme B while about 10% of the corresponding cells were positive in LyP. The expression of antiapoptotic bcl-2 was more frequent in CTCL than in LyP, while PTE expression was high in both instances. The number of bcl-2 + cells tended to decrease after therapy When comparing the findings between the first and the last samples, a decrease in the number of bcl-2+ cells and an increase in Fas+ cells was associated with disease progression, despite therapy, while the opposite was true for remissions.

CONCLUSIONS

Apoptosis was found to be a rare event in CTCL lesions irrespective of precedin therapy During patient follow-up, no significant differences in the expression of apoptotic marker was observed while in most cases a lower level of antiapoptotic bcl-2 expression was observed after all types of therapies and in association with disease progression when compared with high expression in the untreated lesions. The absence of apoptosis and high expression of bcl-2 together with a low expression of apoptosis-inducing granzyme B in the reactive lymphocytes in CTC could explain the chronic nature of the disease and the poor response to therapy, while th more frequent occurrence of granzyme B and apoptosis together with a lower level of expressio of bcl-2 by the large atypical cells in LyP could contribute to the favourable outcome of the latter.

Expression of cutaneous lymphocyte-associated antigen and TIA-1 by lymphocytes in pityriasis lichenoides et varioliformis acuta and lymphomatoid papulosis: immunohistochemical study

BACKGROUND

Pityriasis lichenoides et varioliformis acuta (PLEVA) and lymphomatoid papulosis (LyP) are benign self-healing cutaneous eruptions that may be clinically and histologically similar. The purposes of this study were to evaluate immunohistological characteristics of PLEVA and LyP and to investigate whether Epstein-Barr virus (EBV) may be present in PLEVA and LyP.

METHODS

We performed an immunohistochemical staining in 12 cases of PLEVA and 8 cases of LyP using nine antibodies for CD3, CD4, CD8, CD30, CD45RO, CD56, CD79, cutaneous lymphocyte-associated antigen (CLA), and TIA-1. In situ hybridization was performed using fluorescein-conjugated oligonucleotide probes for EBV early regions (EBER).

RESULTS

In PLEVA, immunohistochemical studies revealed that infiltrated lymphocytes consisted of mainly CD3-positive (5+), CD8-positive (4+ to 5+), CLA-positive (4+ to 5+) T cells and partly CD79 positive (+ to 2+) B cells. CD4-positive T cells were less than 25%. In LyP, immunohistochemical studies revealed that infiltrated lymphocytes consisted of partly CD3-positive (5+), CD8-positive (2+ to 3+), CLA-positive (3+ to 4+) T cells and partly CD79-positive (2+ to 3+) B cells. CD4-positive T cells were less than 10%. CD8 and CLA were more strongly expressed in PLEVA than in LyP. CD30 was strongly expressed in LyP but not expressed in PLEVA. CD79 was more expressed in LyP than in PLEVA. TIA-1 was not expressed in any cases. In situ hybridization using antisense EBER probe showed negative reaction in all cases.

CONCLUSIONS

Immunohistochemical stains for CD8, CD30, CD79 and CLA may be valuable tools in the differential diagnosis between PLEVA and LyP. TIA-1 was negative in LyP, which means cytotoxic cells may not be implicated in the pathogenesis of LyP. It was a contradictory result to the previous results. The absence of EBV in PLEVA and LyP suggests that this virus may not be operative in the pathogenesis of these diseases. These results suggest that LyP and PLEVA are separate disorders, thus accounting for their variable prognosis.