Histopathologic studies in Sézary syndrome and erythrodermic mycosis fungoides: a comparison with benign forms of erythroderma

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.

Sézary Syndrome: Different Erythroderma Morphological Features with Proposal for a Clinical Score System

Sézary syndrome is a rare subtype of cutaneous T-cell lymphoma characterized by erythroderma, peripheral lymphadenopathies, and circulating atypical cerebriform T-cells. To date, no definite staging system has been developed for these patients. In this retrospective analysis of the archive of the Dermatological Clinic of the University of Turin, Italy, erythrodermic SS patients were classified according to clinical records and photographs into three main presentations: erythematous, infiltrated, or melanodermic. The pattern of erythroderma was found to be associated with disease outcome, as better survivals were recorded in patients with erythematous and infiltrative erythroderma. Patients in the melanodermic group, though less represented in our investigation, seemed to show a worse trend in survival. According to this preliminary evidence, a new prognostic classification, with a revised score specific for Sézary syndrome patients, can be proposed to usefully integrate the current staging system. The correlation displayed in our research will be hopefully confirmed by prospective studies with larger cohorts, with the aim of identifying significant prognostic features in this subset of cutaneous T-cell lymphoma patients.

A histo-immunopathologic and prognostic study of erythrodermic cutaneous T-cell lymphoma

BACKGROUND

Sézary syndrome (SS) and erythrodermic mycosis fungoides (E-MF) represent two expressions of erythrodermic cutaneous T-cell lymphoma (E-CTCL).

METHODS

Histopathologic features were compared on skin specimens from 41 patients with SS and 70 patients with E-MF. Immunopathologic findings were compared on 42 SS and 79 E-MF specimens.

RESULTS

Specimens of SS usually showed band-like dermal infiltrates with intermediate-sized lymphoid cells and few plasma cells; on the other hand E-MF more often had a perivascular infiltrative pattern, predominance of small/mixed lymphoid cells and eosinophils. SS also had lower numbers of CD8+ cells and higher numbers of CD62L+ cells compared to E-MF. For E-MF patients, the presence of large Pautrier collections, infiltrates with intermediate-sized cells, increased number of mitotic figures and ≥50% CD62L+ cells in the dermal infiltrate correlated with a relatively poor disease-specific survival. However, only the presence of mitotic figures retained prognostic significance with clinical stage as a covariate.

CONCLUSIONS

Clinical stage provides the most important prognostic information for patients with E-CTCL. However, mitotic activity for E-MF and CD8+ cells <20% for SS have additional value. We hypothesize that observed differences in plasma cell and eosinophil numbers may reflect the influence of CD62L+ central memory T-cells in the microenvironment.

Prognostic Significance of Serum Copper in Patients With Cutaneous T-cell Lymphoma

BACKGROUND

Serum copper has been reported to be increased in various cancers, including lymphoma. The purpose of the present study was to investigate the clinical and prognostic importance of serum copper levels in patients with cutaneous T-cell lymphoma (CTCL).

PATIENTS AND METHODS

Serum copper was measured in 60 men and 38 women with mycosis fungoides (MF) and 14 men and 3 women with erythrodermic CTCL (6 with Sézary syndrome) consecutively evaluated from July 1980 to June 1985.

RESULTS

A greater than normal copper level was present in nearly 20% of patients and was associated with an increased risk of disease progression and shortened disease-specific survival for patients with patch or plaque phase MF, but not for those with tumor phase MF or erythrodermic CTCL. In contrast, the serum lactate dehydrogenase level and neutrophil/lymphocyte ratio were not significantly associated with prognosis in our patient cohort.

CONCLUSION

The reason for the association between the high serum copper levels and adverse prognosis is unknown. We hypothesized that interleukin-6 is secreted primarily by non-neoplastic cells at MF skin sites, leading to release of copper by the liver. Local production of interleukin-6 at the lesion sites might conceivably also promote neoplastic cell progression by stimulation of the STAT3 pathway. Further studies on the relationship between activated tumor-associated macrophages, serum copper levels, interleukin-6, or C-reactive protein and prognosis might be informative.

The role of histological presentation in erythroderma

BACKGROUND

Erythroderma is a serious medical condition characterized by inflamed red skin involving over 90% of the body. It can be the common presentation of different diseases, therefore clinical diagnosis can be problematic. Controversial data are reported regarding the diagnostic value of histological examination in erythroderma subjects.

METHODS

A retrospective study was performed, investigating histological skin specimens of patients with a clinical diagnosis of erythroderma admitted to the Department of Dermatology of State Pediatric Medical University, Saint Petersburg, from 2001 to 2014. Histopathology examination was performed in each case by a pathologist with a special interest in the skin disease who was blind to any clinical information as well as to final diagnosis.

RESULTS

Blinded histopathology examination alone was able to give the correct diagnosis in 61% (n = 50/82) of cases when compared to final diagnosis. A diagnosis of psoriasis was made in 23.2% (n = 19/82) of subjects, spongiotic dermatitis/eczema in 20.7% (n = 17/82), mycosis fungoides in 8.5% (n = 7/82), and drug eruption in 8.5%; histological diagnosis was inconclusive or not matching the final diagnosis when available in the remaining 39.1% of cases (n = 32/82).

CONCLUSION

Erythroderma remains a condition difficult to study and treat. We showed that a correct judgment about its cause can be based on objective histopathological criteria in up to 60% of cases. More studies are needed to try to find out further histological and/or immunohistochemical markers that could help the clinician with the erythroderma etiology diagnostic process.

Histopathological and immunophenotypical criteria for the diagnosis of Sézary syndrome in differentiation from other erythrodermic skin diseases: a European Organisation for Research and Treatment of Cancer (EORTC) Cutaneous Lymphoma Task Force Study of 97 cases

BACKGROUND

Patients with erythrodermic disease are a diagnostic challenge regarding the clinical and histological differential diagnosis.

OBJECTIVES

To evaluate histopathological and immunohistochemical diagnostic markers for Sézary syndrome.

METHODS

Ninety-seven erythrodermic cases [Sézary syndrome (SS), n = 57; erythrodermic inflammatory dermatoses (EIDs), n = 40] were collected by the EORTC Cutaneous Lymphoma Task Force histopathology group. Evaluation criteria were (i) epidermal and dermal changes; (ii) morphology of the infiltrate; (iii) immunohistochemical analysis of marker loss (CD2, CD3, CD4, CD5 and CD7); (iv) bystander infiltrate by staining for CD8, FOXP3 and CD25; and (v) expression of Ki-67, CD30, PD-1 and MUM-1.

RESULTS

The workshop panel made a correct diagnosis of SS in 51% of cases (cutaneous T-cell lymphoma 81%) and of EID in 80% without clinical or laboratory data. Histology revealed a significantly increased degree of epidermotropism (P < 0.001) and more intraepidermal atypical lymphocytes (P = 0.0014) in SS biopsies compared with EID. Pautrier microabscesses were seen only in SS (23%) and not in EID (P = 0.0012). SS showed significantly more dermal cerebriform and blastic lymphocytes than EID. Immunohistochemistry revealed a significant loss of CD7 expression (< 50%) in 33 of 51 (65%) cases of SS compared with two of 35 (6%) EID (P < 0.001). The lymphocytic infiltrate in SS skin samples was found significantly to express PD-1 (P = 0.0053), MUM-1 (P = 0.0017) and Ki-67 (P < 0.001), and showed less infiltration of CD8(+) lymphocytes (P < 0.001). A multivariate analysis identified CD7 loss, increased numbers of small cerebriform lymphocytes, low numbers of CD8(+) lymphocytes and increased proliferation (Ki-67(+) lymphocytes) as the strongest indicators for the diagnosis of SS.

CONCLUSIONS

A number of different histological and immunophenotypical criteria are required to differentiate between SS and EIDs.

Differential expression of TOX by skin-infiltrating T cells in Sézary syndrome and erythrodermic dermatitis

BACKGROUND

The histopathologic differentiation between Sézary syndrome (SS) and erythrodermic dermatitis may be extremely difficult. In this immunohistochemical study, it was investigated if thymocyte selection-associated high mobility group box protein (TOX) and C-MYC can be used as additional diagnostic markers to differentiate between SS and erythrodermic dermatitis.

METHOD

Paraffin-embedded skin biopsies from 15 SS patients and 17 erythrodermic dermatitis patients were stained and scored for TOX or C-MYC expression.

RESULTS

Strong nuclear staining for TOX in more than 50% of skin-infiltrating T cells was observed in 13 of 15 (87%) SS cases, whereas erythrodermic dermatitis cases showed weak nuclear staining in 11-50% (median: 25%) of the T cells; strong nuclear staining as found in SS was never observed in erythrodermic dermatitis. No significant differences in C-MYC expression between SS and erythrodermic dermatitis were found. In most patients of both groups, percentages of C-MYC positive-cells varied between less than 10 and 25% of skin-infiltrating T cells.

CONCLUSION

Our results suggest that strong expression of TOX in more than 50% of skin-infiltrating T cells in erythrodermic skin is a useful marker in the differentiation between SS and erythrodermic dermatitis, whereas staining for C-MYC does not contribute to differential diagnosis.

Expression of programmed death-1 in skin biopsies of benign inflammatory vs. lymphomatous erythroderma

BACKGROUND

Histological differentiation between Sézary syndrome (SS) and erythrodermic inflammatory dermatoses (EID) can be very difficult. Recent studies show that programmed death-1 (PD-1) is strongly expressed by the neoplastic cells in skin biopsies of SS, while similar studies in EID are lacking.

OBJECTIVES

To determine whether the number and distribution of PD-1(+) T cells could be used as an adjunct in the differentiation between SS and EID.

METHODS

Expression of PD-1 and a panel of T-cell markers was investigated in skin biopsies from 30 patients with various types of EID (12 idiopathic, 10 atopic, six psoriatic and two paraneoplastic) and 25 patients with SS.

RESULTS

Expression of PD-1 by > 50% of the infiltrating T cells was observed in 23 of 25 (92%) SS cases and in only four of 30 (13%) EID cases. PD-1 is expressed by neoplastic CD4(+) T cells in SS, while in contrast, PD-1 was predominantly expressed by dermal and epidermal CD8(+) T cells in EID. Expression of CD7 by ≤ 20% of the infiltrating T cells was observed only in SS (13 of 24; 54%), and not in any of the 30 cases of EID.

CONCLUSIONS

While PD-1 is expressed by CD4(+) neoplastic T cells in SS, our results suggest that PD-1 is expressed mainly by activated dermal and epidermal CD8(+) T cells in EID. Expression of PD-1 by > 50% of CD4(+) T cells and expression of CD7 by ≤ 20% of the infiltrating T cells strongly support a diagnosis of SS in skin biopsies of patients with erythroderma.

Histopathologic diagnosis of lymphomatous versus inflammatory erythroderma: a morphologic and phenotypic study on 47 skin biopsies

Erythroderma may be secondary to a cutaneous T-cell lymphoma (CTCL) and various other erythrodermic inflammatory dermatoses (EID), and their histopathologic distinction is often difficult. The aim of this study was to determine if morphological parameters, namely: the presence of b-catenin, and JunB (previously shown to be expressed by CTCL cells), the epidermal CD8:CD3 ratio, and CD30 expression may help in the histopathologic diagnosis of erythroderma, especially in differentiating CTCL and EID. We retrospectively reviewed a series of 47 skin biopsies from patients with erythroderma (18 CTCL and 29 EID). The diagnosis of each case was established using clinical, biological and histopathologic data. After a blind assessment of the hematoxylin--eosin--safran stained slides, a correct diagnosis of the underlying cause of erythroderma was made only in 31% of cases. A correct differential diagnosis between lymphoma and EID was done with certainty in 57% of cases. Various morphologic and phenotypic parameters were then recorded and we compared their frequency in the CTCL versus the EID group. With the exception of atypical lymphocytes, the moderate to high density of dermal infiltrates and Pautrier microabcesses, only found in CTCL, no morphologic parameter was found to be specific of CTCL, although single lymphocytes epidermotropism, telangiectasias, and slight lymphocytic dermal infiltrate were significantly more frequent in EID. A low (<10%) CD8:CD3 ratio in the epidermal lymphocytic infiltrate and dermal CD30+ lymphocytes were significantly more frequent in CTCL. JunB expression by lymphocytes was specific of CTCL, but was inconstant in our series (17%). We found β-catenin expression in a minority of cases from both the CTCL and EID groups. Among EID, dermal suprapapillary thinning was specific of psoriasis. Neutrophils exocytosis and edema of papillary dermis were significantly more frequent in psoriasis, and spongiosis was more frequent in eczema. In conclusion, few morphological and phenotypical parameters are helpful in making a differential diagnosis between erythrodermic CTCL and EID using paraffin embedded skin biopsies.

Flow Cytometric Assessment of T-cell Chronic Lymphoproliferative Disorders

Flow cytometry is frequently used in the evaluation of potential T-cell lineage lymphoproliferative disorders. Although flow cytometry is a useful tool, interpretation of the results can be challenging, because T-cells lack an easily analyzed structural element that can provide a surrogate marker of clonality such as immunoglobulin light chains on B-cells. Thus, routine T-cell phenotyping assays in the clinical laboratory require the comprehensive analysis of several T-cell-associated antigens. Although the detection of aberrant patterns of T-cell antigen expression can be helpful in establishing a diagnosis of T-cell malignancy, these patterns are not always disease specific, and some can overlap significantly with T-cell phenotypes observed in reactive conditions. Thus, arriving at an accurate diagnosis requires correlation of the flow cytometry results with the clinical, morphologic, and molecular results. Furthermore, the integration of these varied pieces of information into a cogent diagnosis requires an understanding of T-cell biology. In this review, the use of flow cytometry to identify T-cell lymphoproliferative disorders, particularly in peripheral blood and bone marrow specimens, is discussed, and a brief overview of T-cell biology to aid the reader in understanding the significance of the flow cytometry results is provided.

Revisions to the staging and classification of mycosis fungoides and Sezary syndrome: a proposal of the International Society for Cutaneous Lymphomas (ISCL) and the cutaneous lymphoma task force of the European Organization of Research and Treatment of Cancer (EORTC)

The ISCL/EORTC recommends revisions to the Mycosis Fungoides Cooperative Group classification and staging system for cutaneous T-cell lymphoma (CTCL). These revisions are made to incorporate advances related to tumor cell biology and diagnostic techniques as pertains to mycosis fungoides (MF) and Sézary syndrome (SS) since the 1979 publication of the original guidelines, to clarify certain variables that currently impede effective interinstitution and interinvestigator communication and/or the development of standardized clinical trials in MF and SS, and to provide a platform for tracking other variables of potential prognostic significance. Moreover, given the difference in prognosis and clinical characteristics of the non-MF/non-SS subtypes of cutaneous lymphoma, this revision pertains specifically to MF and SS. The evidence supporting the revisions is discussed as well as recommendations for evaluation and staging procedures based on these revisions.

Processos linfoproliferativos da pele: parte 2 - linfomas cutâneos de células T e de células NK

Os linfomas cutâneos de células T/NK constituem um grupo de doenças linfoproliferativas extranodais atualmente classificadas e subdivididas de acordo com o comportamento clínico segundo consenso da Organização Mundial de Saúde e da Organização Européia para Pesquisa e Tratamento do Câncer. Os linfomas cutâneos de células T/NK de comportamento clínico indolente compreendem a micose fungóide clássica, a micose fungóide foliculotrópica, a reticulose pagetóide, a cútis laxa granulomatosa, o linfoma cutâneo primário de grande célula anaplásica, a papulose linfomatóide, o linfoma subcutâneo de célula T paniculite-símile e o linfoma cutâneo primário de pequena e média célula T CD4+ pleomórfica. Os linfomas cutâneos de células T/NK de comportamento agressivo incluem a síndrome de Sézary, o linfoma extranodal de célula T/NK, tipo nasal, o linfoma cutâneo primário agressivo de célula T CD8+ epidermotrópica, o linfoma cutâneo de célula T <FONT FACE=Symbol>gd</FONT> e o linfoma cutâneo primário de célula T periférica, não especificado. O linfoma-leucemia de células T do adulto e a neoplasia hematodémica CD4+CD56+, embora considerados linfomas sistêmicos, são aqui abordados por apresentarem-se inicialmente na pele em significativo número de pacientes. O diagnóstico desses processos é realizado pelo exame histopatológico complementado pela análise do fenótipo das células neoplásicas, imprescindível no processo classificatório. O estadiamento para a avaliação da extensão anatômica da doença considera além do envolvimento cutâneo, o estado clínico e histológico dos linfonodos e das vísceras. Avaliação hematológica é fundamental na caracterização da síndrome de Sézary. Os tratamentos preconizados incluem terapêuticas dirigidas exclusivamente à pele, modificadores da resposta biológica e quimioterapia sistêmica.

On the diagnosis of erythrodermic cutaneous T-cell lymphoma

Erythrodermic cutaneous T-cell lymphoma (E-CTCL) is the cause of less than 5% of all cases of generalized erythroderma. A methodical evaluation of skin, blood, and lymph node samples using standard histology, immunohistochemistry (IHC), flow cytometry (FC), and molecular analysis for evidence of a dominant T-cell clone has been recommended in a recently published diagnostic algorithm. In this commentary, the author discusses available information regarding the role of these diagnostic methods for the diagnosis of E-CTCL with emphasis on personal observations regarding skin IHC and polymerase chain reaction (PCR)-based molecular studies as adjunct diagnostic studies on a series of 55 patients with erythrodermic mycosis fungoides and 50 patients with Sézary syndrome compared to 50 patients with extensive benign inflammatory skin disease. The conclusions are (1) IHC of the skin does not reliably differentiate E-CTCL from benign simulants, (2) presence of phenotypically abnormal T cells in the blood or expanded subsets of CD4+CD7- or CD4+CD26- cells by FC is particularly helpful as a diagnostic study, (3) the presence of an identical T-cell clone in the skin and blood also is a specific diagnostic criterion for E-CTCL, but exceptions may occur, and (4) the PCRgamma-denaturing gradient gel electrophoresis technique appears to be more reliable than PCRgamma-single-stranded conformational polymorphism for diagnostic purposes.

WHO/EORTC classification of cutaneous lymphomas 2005: histological and molecular aspects

The new WHO/EORTC classification for cutaneous lymphomas comprises mature T-cell and natural killer (NK)-cell neoplasms, mature B-cell neoplasms, and immature hematopoietic malignancies. It reflects the unique features of lymphoproliferative diseases of the skin, and at the same time it is as compatible as possible with the concepts underlying the WHO classification for nodal lymphomas and the EORTC classification of cutaneous lymphomas. This article reviews the histological, phenotypical, and molecular genetic features of the various nosological entities included in this new classification. These findings always have to be interpreted in the context of the clinical features and biologic behavior.

AIM

To review the histological, phenotypical and molecular genetic features of the various nosological entities of the new WHO/EORTC classification for cutaneous lymphomas.

METHODS

Extensive review of the literature cited in Medline and own data of the authors.

RESULTS

The WHO/EORTC classification of cutaneous lymphomas comprises mature T-cell and NK-cell neoplasms, mature B-cell neoplasms and immature hematopoietic malignancies. It reflects the unique features of primary cutaneous lymphoproliferative diseases.

CONCLUSION

This classification is as much as possible compatible with the concept of the WHO classification for nodal lymphomas and the EORTC classification of cutaneous lymphomas. The histological, phenotypical and molecular genetic features always have to be interpreted in the context of the clinical features and biologic behavior.

Bone marrow histopathology in peripheral T-cell lymphomas

Peripheral T-cell lymphomas (PTCL) account for 10-15% of all lymphoproliferative disorders in the western hemisphere. In PTCL, bone marrow biopsy is performed to establish the diagnosis, rule out other pathology, assess the extent of disease and monitor treatment response. The frequency and histology of bone marrow involvement varies greatly between different clinicopathological entities recognized by the World Health Organisation (WHO) classification, reflecting the differences in the underlying biology. Some lymphomas, such as angioimmunoblastic T-cell lymphoma, show nodular and/or interstitial pattern of infiltration with accompanying reactive changes. Others, including hepatosplenic T-cell lymphoma and large granular lymphocyte leukaemia, are characterized by intrasinusoidal infiltration. In many instances the pathological features are subtle and immunohistochemical and molecular studies are required for the diagnosis. Histological appearances may overlap with a variety of reactive T-cell proliferations and other malignancies. Furthermore PTCL frequently induce secondary changes in the marrow that may obscure the neoplastic infiltrate. The diagnosis often requires critical integration of the information obtained from clinical features, peripheral blood, bone marrow aspirate and biopsy findings. In this article we review the histopathology of bone marrow biopsy in PTCL within the context of the new WHO classification.

Update on erythrodermic cutaneous T-cell lymphoma: report of the International Society for Cutaneous Lymphomas

Two conferences were sponsored by the International Society for Cutaneous Lymphomas (ISCL) to gain consensus on definitions and terminology for clinical use in erythrodermic cutaneous T-cell lymphoma (E-CTCL). Three subsets of E-CTCL were defined: Sézary syndrome ("leukemic phase" E-CTCL), erythrodermic mycosis fungoides (secondary E-CTCL that develops in patients with mycosis fungoides), and E-CTCL, not otherwise defined. The hematologic criteria recommended for Sézary syndrome are intended to identify patients with a worse prognosis compared with the other E-CTCL subsets and consist of one or more of the following: (1) an absolute Sézary cell count of 1000 cells/mm3 or more; (2) a CD4/CD8 ratio of 10 or higher caused by an increase in circulating T cells and/or an aberrant loss or expression of pan-T cell markers by flow cytometry; (3) increased lymphocyte counts with evidence of a T-cell clone in the blood by the Southern blot or polymerase chain reaction technique; or (4) a chromosomally abnormal T-cell clone. For staging purposes, it is proposed that these criteria define the B2 blood rating and that the B2 rating be considered equivalent to nodal involvement.

Diagnostic and prognostic importance of T-cell receptor gene analysis in patients with Sézary syndrome

BACKGROUND

Sézary syndrome (SS) is characterized by erythroderma, peripheral lymphadenopathy, and circulating Sézary cells and is clinically heterogeneous.

METHODS

T-cell receptor (TCR) gene analysis was performed using DNA extracted from peripheral blood mononuclear cells from 74 patients, and the results were correlated with a variety of other diagnostic parameters and patient outcomes.

RESULTS

Two groups were identified: 66 patients with clonal TCR gene rearrangement (clonal patients) detected with Southern blot analysis and/or polymerase chain reaction/single-strand conformational polymorphism analysis and 8 patients with no clonal rearrangement detected (nonclonal patients) using either technique. Clonal patients were compared with nonclonal patients. The following median blood parameters were significantly greater in the clonal group: total white cell count (13.7 10(9)/L vs. 9.6 10(9)/L), lymphocyte count (4.9 10(9)/L vs. 2.2 10(9)/L), absolute Sézary count (3.22 10(9)/L vs. 0.99 10(9)/L), CD4 count (3.17 10(9)/L vs. 1.36 10(9)/L), and CD4:CD8 ratio (15.86 vs. 3.21). An expanded population of T-cells of a specific TCR variable beta subset was detected in 7 of 36 clonal patients and in 1 of 4 nonclonal patients. Cytogenetic analysis of peripheral blood from 1 nonclonal patient and 6 clonal patients was normal. The median survival from the time of diagnosis was 45 months in the clonal group, and 40 of 49 deaths were cutaneous T-cell lymphoma (CTCL)-related, whereas 3 deaths in the nonclonal group were unrelated to CTCL (P < 0.01; log-rank test). Multivariate proportional hazards analysis showed that the absolute Sézary count and lymph node status were independent prognostic variables (P = 0.016 and P = 0.036, respectively).

CONCLUSIONS

TCR gene analysis defines a distinct clinicopathologic group of patients with SS. Clonal patients have a poor prognosis and are likely to die from leukemia/lymphoma, whereas nonclonal patients may have a reactive, inflammatory T-cell disorder. The authors suggest that the definitive diagnostic criteria for patients with SS should include the presence of a clonal TCR gene rearrangement.

Comparative analysis of histological and immunohistological features in mycosis fungoides and Sézary syndrome

Mycosis fungoides (MF) and Sézary syndrome (SS) are closely related cutaneous T-cell lymphomas, which differ in several clinical aspects. We compared histological and immunophenotypical features of these two entities, which could be implicated in the dermotropism and epidermotropism, characteristic for both of them. Thirteen biopsy specimens from patients with established plaque-stage MF and 13 from SS patients were examined retrospectively, and 21 histological criteria were assessed. Further, 9 cryosections from MF lesions and 9 from SS lesions were stained for LFA, ICAM1, CD40, CD40-ligand, CD28, CD80, CTLA-4, CD86, FAS, FAS-ligand, CLA and CD15s. The only histological criteria that showed persistent differences were acanthosis (in 12 of 13 SS and in 7 of 13 MF specimens) and Pautrier collections (detected in 6 SS and 11 MF biopsies). Patterns of staining with the antibodies mentioned above were found to be similar. Our results indicate that these interaction molecules seem to be involved in the pathogenesis of MF and SS, but their immunohistochemical distribution does not contribute to the differentiation between the two entities.

Histologic criteria for the diagnosis of erythrodermic mycosis fungoides and Sézary syndrome: a critical reappraisal

It is often difficult to make a clinical or histologic diagnosis of erythrodermic mycosis fungoides (MF) and Sezary syndrome (SS). Whereas the histologic parameters for making a diagnosis of MF with well-developed patch and plaque stage lesions are clearly defined, the same criteria appear to be less relevant for diagnosing MF in patients with erythroderma secondary to the disease. In order to better define the histologic features of erythrodermic MF and SS, we studied 28 routine histologic sections of 17 patients with known erythrodermic MF or SS. Sections were reviewed independently by 2 dermatopathologists. Each of 24 parameters was scored semi-quantitatively and the data were compared to data previously reported from a group of 64 patients with limited patch and plaque stage lesions of MF. When compared to biopsies from patients with limited patch/plaque lesions, biopsies taken from erythrodermic patients displayed more parakeratosis (p=0.0492) and acanthosis (p=0.0046), less disproportionate epidermotropism, fewer lymphocytes aligned within the basal layer (p=0.0045), fewer hyperconvoluted cells in the epidermis, more dermal hyperconvoluted cells (p=0.0191), more papillary dermal fibrosis (p=0.0002), more prominent teleangiectasias (p=0.0028) and more mitotic figures. The histologic features of erythrodermic MF and Sezary syndrome are even more subtle than the features of patch and plaque stage MF, thus rendering the histologic diagnosis more difficult.

Cutaneous histopathology of Sézary syndrome: a study of 41 cases with a proven circulating T-cell clone

Sezary syndrome is an uncommon variant of cutaneous T-cell lymphoma (CTCL) characterized by erythroderma, pruritus, adenopathy, and circulating atypical T-lymphocytes with cerebriform nuclei. The definition of Sezary syndrome can be further refined by including only patients with a circulating peripheral blood population of clonal T-cells. We have evaluated 79 skin biopsies from such a group of 41 erythrodermic patients with circulating Sezary cells and a clonal population of T-cells detected by T-cell receptor-beta gene rearrangement on Southern analysis of peripheral blood mononuclear cells. Histopathologic features consistent with chronic dermatitis were observed in 26/79 (33%) skin biopsy specimens, emphasizing that a non-specific histologic appearance is common. Evidence of CTCL was lacking in 11/41 patients on biopsy of their erythrodermic skin. The survival of these patients was not significantly different from 30/41 patients in whom skin biopsies revealed changes diagnostic of CTCL, such as a dermal lymphocytic band with atypical lymphocytes (18/79, 23%) or a mycosis fungoides-like infiltrate (30/79, 38%). This study confirms that non-specific cutaneous histopathologic findings are common in Sezary syndrome, even when a circulating T-cell clone is present. This stresses the need for peripheral blood genetic analysis and for multiple or repeat skin biopsies in erythrodermic patients when there is high clinical suspicion of CTCL.

Histopathology in erythroderma: review of a series of cases by multiple observers

This study examines the utility of objective histopathological studies in the evaluation of adult patients with erythroderma. A series of 56 skin biopsies, from 40 erythrodermic patients, was reviewed sequentially by 4 Canadian dermatopathologists who were unaware of clinical details of the cases. The final diagnosis (gold standard), in each instance, had already been determined by others, based on clinicopathologic data and response to therapy. Direct comparison revealed that the mean accuracy of the histopathological diagnoses was 53% (range: 48-66%), a favorable result in view of the difficulty of the task at hand. Additional points of information which evolved from the study are as follows: (i) identification, by microscopy alone, of spongiotic dermatitis, cutaneous T-cell lymphoma and psoriasis, as underlying causes of erythroderma was more successful than that of drug eruptions and pityriasis rubra pilaris; (ii) the epidermotropism which characterizes cutaneous T-cell lymphoma may be mistaken for inflammatory interface changes seen in drug eruptions and vice versa, thus constituting a pitfall in diagnosis; (iii) finally, it appears that submission of multiple simultaneous biopsies, rather than a single specimen, from patients with erythroderma would be likely to enhance the accuracy of histopathological diagnosis.

The specificity of histopathology in erythroderma

Conflicting views about the diagnostic value of skin biopsy in the investigation of erythrodermic patients are extant. The objective of the present study was to establish the frequency with which a correct diagnosis can be based on histopathological assessment alone. This was achieved by comparison of the "blinded" microscopic diagnosis with the final diagnosis (based on combined clinico-pathologic parameters and response to therapy). In a retrospective review of 56 skin biopsies from 40 patients with erythroderma, we found a positive correlation between the pathological diagnosis and the final diagnosis in 66%; furthermore, when the microscopic characteristics observed in different diagnostic categories were assessed, these proved to simulate those seen in conventional manifestations of the various underlying diseases but tended to be subtle in the setting of erythroderma. We conclude that, despite the homogeneity of the clinical expression of erythroderma, diagnostic histopathological features of the underlying disease are retained in the majority of cases.

Expression and Role of Integrin Receptors in Sézary Syndrome

The potential role of integrins in the epidermotropism of the atypical lymphocytes of Sézary syndrome was studied by monitoring the expression of alpha and beta chains and their major ligands in skin biopsies and peripheral blood cells in patients at different progression stages. Most mononuclear cell integrins were also detected on infiltrating cells including the leukocyte complex CD11/CD18, alpha 4 beta 1, and their ligands, ICAM-1 and VCAM-1. Conversely, alpha 6 and beta 4 were present only in epidermal basal cells. Mononuclear infiltrates of SS were positive for both alpha 3 and alpha 5 chains, whereas in inflammatory cutaneous diseases only alpha 5 was expressed, indicating that a major feature of Sézary cells is the unique expression of alpha 3 beta 1. Significant changes of alpha 3 beta 1 were monitored in the follow-up of Sézary patients and correlated with the results of the therapy. The heterodimer alpha 1 beta 1 was absent from mononuclear cells except in one case. Among matrix molecules, laminin and type IV collagen displayed a pattern similar to that of the controls, whereas fibronectin and tenascin deposition were apparently increased. Circulating Sézary cells, both at diagnosis and during follow-up, were alpha 3 and alpha 5 negative and failed to acquire these adhesion molecules after mitogenic stimulation. We propose that the expression of alpha 3 beta 1 is a distinguishing feature of skin-infiltrating Sézary cells and may be related to their epidermotropism. It could also be adopted as an additional parameter of the progression and therapeutic stage of Sézary syndrome.

Diagnostic value of T-cell receptor beta gene rearrangement analysis on peripheral blood lymphocytes of patients with erythroderma

Differentiation between Sézary's syndrome (SS) and benign forms of erythroderma may be extremely difficult. In this study T-cell receptor beta (TCR beta) gene rearrangement analysis was performed on peripheral blood lymphocytes (PBL) from 32 patients with erythroderma, including 10 patients with SS, three patients with another type of cutaneous T-cell lymphoma, and 19 patients with a benign form of erythroderma. The aim of this study was to define the sensitivity and specificity of this technique in the diagnosis of SS. Clonal TCR beta gene rearrangements were found in eight of 10 patients with SS, one T-CLL patient, one of two patients with erythrodermic mycosis fungoides, and only one of 19 patients from the benign group. In the two "false-negative" cases of SS clonal TCR beta gene rearrangements were detected in PBL obtained during follow-up. The results indicate that TCR beta gene rearrangement analysis on PBL is a sensitive and highly specific technique, that may contribute significantly to the differential diagnosis of patients with erythroderma. However, because both "false-positive" and "false-negative" results may occur, the results of gene-rearrangement analysis should always be considered in conjunction with clinical, histologic, and immunophenotypical data.

Mycosis fungoides and the Sézary syndrome: pathology, staging, and treatment

Mycosis fungoides and the Sézary syndrome are forms of cutaneous T-cell lymphoma. Mycosis fungoides is an uncommon disease: only about 500 new cases are diagnosed in the United States annually. The median age of onset is 55 years and there is a 2:1 male predominance. The etiology of mycosis fungoides is unknown. Although occupational exposures have been implicated, case control studies fail to support this hypothesis. Mycosis fungoides is typified by cutaneous plaques which may evolve into tumors over the course of time. It is often preceded by a lengthy pre-mycotic phase prior to the time of definitive diagnosis. In its earliest diagnostic phase, there may only be slightly scaling patches with a limited distribution. Indurated lesions evolve into plaques, which may become more generalized in their distribution. As the severity of skin involvement increases, there is an increasing likelihood of spread to extracutaneous sites. The pathology of this disease is marked by involvement of the epidermis (Pautrier microabscesses). Immunologic studies characterize these cells as belonging to the helper T-cell subset. Genotypic analysis demonstrates monoclonal rearrangements of the T-cell receptors of the infiltrating cells. The staging system for mycosis fungoides considers the extent of skin involvement, presence of lymph node or visceral disease, and detection of abnormal cells in the peripheral blood. Patients with disease limited to the skin (90% of newly diagnosed cases) are treated best with topical or cutaneous therapies. Common modalities include psoralen photochemotherapy (PUVA), topical chemotherapy (nitrogen mustard) and total skin electron beam therapy. Both topical nitrogen mustard and electron beam therapy have good initial response rates (73% and 100%) and may achieve long-term disease-free survival, especially in patients with initially limited disease. Even if the response is incomplete or relapse occurs, substantial and very important palliation is generally achieved with topical therapy. Recurrent or resistant cutaneous disease will require the use of sequential topical treatment. The median survival time of patients who present with disease limited to the skin is greater than 10 years, and many deaths in this group are from intercurrent causes, especially in patients with limited or generalized plaque disease. If cutaneous tumors are present, the majority of these patients will eventually die from disease-related causes. The prognosis of patients who develop extracutaneous disease is exceedingly poor (median survival time, approximately 1 year).(ABSTRACT TRUNCATED AT 400 WORDS)

Sézary syndrome: diagnosis, prognosis, and critical review of treatment options

Sézary syndrome is a form of leukemia-lymphoma characterized clinically by erythroderma, pruritus, adenopathy, and circulating atypical cells with cerebriform nuclei. Histologically, atypical lymphocytes in the dermis and Pautrier's microabscesses are often present in skin biopsy specimens. Immunologic findings that support a diagnosis of Sézary syndrome include a predominance of CD4+ lymphocytes in both skin biopsy specimens and peripheral blood. Cytogenetic studies that demonstrate aneuploidy and DNA probe analysis that shows gene rearrangement for the beta-subunit of the T cell receptor are the latest, most sensitive, and specific methods for identifying the clonal nature of the disease. Various staging systems are used. We review the various treatments for Sézary syndrome, including the newer, biologically based investigational therapies, (e.g., antithymocyte globulin, monoclonal antibodies and other immunostimulants, retinoids, cyclosporine, interferon, and extracorporeal photopheresis). Extracorporeal photopheresis and some chemotherapeutic agents appear to produce the best results in terms of response and remission duration with minimal toxicity. However, more multicenter controlled clinical trials are needed to determine the most effective single or combined therapeutic regimen.

Low-dose methotrexate for the Sézary syndrome

Seventeen patients with Sézary syndrome were treated with low-dose methotrexate for periods of up to 5 years (median follow-up 22 months). Seven patients (41%) achieved a complete response, and six patients (35%) achieved a partial response (more than 50% improvement). As of their latest evaluation, 10 of 17 (59%) were in a state of either complete or partial response. The estimated 5-year survival rate was 71% (standard error 13%). Toxicity was minor and self-limiting in only one patient. Clinical improvement was accompanied by a decrease in the circulating Sézary cell count.

Detection of clonal T-cell receptor gene rearrangements in the peripheral blood of patients with mycosis fungoides/Sezary syndrome

Involvement of the peripheral blood in mycosis fungoides/Sezary syndrome (MF/SS) has a significant impact upon prognosis, but it is often difficult to distinguish circulating cells of MF/SS from atypical reactive lymphocytes. We compared the standard morphologic method of identifying leukemic cells, the Sezary preparation, to a genotypic method using Southern blot analysis of T-cell receptor gene rearrangements in concurrent blood samples. We studied 26 MF/SS patients, five of them in remission, together with five controls from cases of various non-MF/SS skin diseases. Six of 26 MF/SS patients had morphologically atypical circulating leukocytes (3%, 4%, 5%, 14%, 16%, 19%). Seven of 26 MF/SS patients had clonal T-cell receptor gene rearrangements, including the four patients with the greatest percentages of atypical cells and three patients lacking atypical cells. Six of seven patients had skin disease at the time of sampling, including three with erythroderma, two with generalized thick plaques, and one with generalized patches, while one patient was in clinical remission. All five controls lacked morphologic and genotypic evidence of atypical or clonal T-cells. Relative to genotyping, in our series the Sezary preparation was less sensitive and less specific. There were three apparent false negative results in the Sezary preparations, and two potential false positive (patients with 3% and 4% atypical leukocytes); however, there was agreement between the two techniques in most cases. We conclude that gene rearrangement studies may provide an effective test with which to assess the peripheral blood of MF/SS patients.

Benign and malignant forms of erythroderma: cutaneous immunophenotypic characteristics

In order to determine if immunohistologic features are useful in distinguishing benign from malignant types of erythroderma, we studied the immunophenotype of lesional T cells in 20 patients (8 mycosis fungoides/Sézary syndrome, 12 benign) and found them to be generally similar. In all cases, the majority of T cells were Leu-1+, Leu-4+, and Leu-5+, as is typical of mature T cells. Although in most cases a majority of Leu-3+ (helper/phenotype) T cells were present, in 2 there was a majority of the Leu-2+ (cytotoxic/suppressor) subset and in 12 others, a significant minority (20%-40%) of these cells. Low percentages of Leu-2+ cells (less than or equal to 10%), resulting in high Leu-3+/Leu-2+ ratios, did not distinguish benign from malignant erythroderma. Leu-8 antigen deficiency was common in both mycosis fungoides/Sézary syndrome and benign cases (62% vs 75%, respectively). In contrast, Leu-9 antigen deficiency was present in only one patient in each group. The lack of combined Leu-8/9 antigen deficiency in our patients may be due to a heavy inflammatory T cell component, obscuring the antigen deficiencies seen in most nonerythrodermic mycosis fungoides cases. We conclude that immunophenotypic studies with the use of the current antibody panel show many similarities between benign and malignant forms of erythroderma, as well as some minor differences that may prove diagnostically useful if corroborated by future studies.