Controversies and Discussion on Early Diagnosis of Cutaneous T-Cell Lymphoma: Phenotyping

Cutaneous T Cell Lymphoma: A Difficult Diagnosis Demystified

Cutaneous T cell lymphoma (CTCL) represents a heterogeneous group of extranodal non-Hodgkin lymphomas in which monoclonal T lymphocytes infiltrate the skin. The mechanism of CTCL development is not fully understood, but likely involves dysregulation of various genes and signaling pathways. A variety of treatment modalities are available, and although they can induce remission in most patients, the disease may recur after treatment cessation. Owing to relatively low incidence and significant chronicity of disease, and the high morbidity of some therapeutic regimens, further clinical trials are warranted to better define the ideal treatment option for each subtype of CTCL.

Primary cutaneous T-cell lymphoma presenting as mycosis fungoides with a T-/null-cell phenotype: report of two cases

Variations in the clinical and histological presentation of cutaneous T-cell lymphoma (CTCL) can hamper diagnosis. We report two cases of a novel presentation of CTCL characterized by an aberrant immunophenotype with complete loss of pan T-cell antigens including T-cell receptor β chain and showing the clinical and histopathological appearance of erythrodermic and plaque-stage mycosis fungoides.

CD4/CD8 double negative mycosis fungoides with PD-1 (CD279) expression--a disease of follicular helper T-cells?

CD4/CD8 double negative mycosis fungoides (MF) is a rare phenotypic variant of this epidermotropic cutaneous T-cell lymphoma. Clinically, this MF form manifests with unusual appearances such as annular lesions confined to one body region as in our patient in whom the lesions were found on the left lower leg. The cellular origin of CD4/CD8 double negative MF is unknown. In our case, the intraepidermal CD4/CD8 double negative clonal T-lymphocytes (CD2+, CD4-, CD8-, CD30-, beta-F1+) expressed programmed death-1 but were negative for CXCL-13 and cytotoxic molecules (TIA-1, granzyme B, perforin). Our observation may give an insight into the histogenesis of this unique MF variant and may also be of therapeutic significance because programmed death-1 may serve as a target for therapeutic intervention.

Improved polymerase chain reaction-based method to detect early-stage epitheliotropic T-cell lymphoma (mycosis fungoides) in formalin-fixed, paraffin-embedded skin biopsy specimens of the dog

In the dog, early-stage epitheliotropic T-cell lymphoma (ETCL) can clinically and histologically mimic a large range of inflammatory dermatoses and often progresses rapidly to a more aggressive tumor stage. Early diagnosis of ETCL is essential to proceed with a specific oncologic therapy that is favorable for the prognosis. In the present study, an improved method for the detection of T-cell receptor gamma (TCRgamma) rearrangement was developed by designing a new set of consensus primers to amplify the different forms of rearranged canine TCRgamma gene sequences by polymerase chain reaction. The amplicons were analyzed by conventional polyacrylamide gel electrophoresis, which requires minimal specific equipment and may be performed in almost every pathology laboratory at low costs. The method proved to be highly specific and sensitive to detect early ETCL in formalin-fixed, paraffin-embedded biopsy specimens, providing an efficient tool for veterinary pathologists to distinguish early neoplastic from reactive cutaneous T-cell infiltrates (tumor-specific marker) or to discriminate T-cell lymphoma from B-cell lymphomas or nonlymphoid neoplasms (T-cell lineage marker). By direct sequencing analysis of amplified TCRgamma gene sequences, ETCL was found to rearrange exclusively the joining (J) 4 region, which suggests specific biology for primary cutaneous T-cell lymphomas. Also, a novel (seventh) functional J region in the TCRgamma gene, localized approximately 2.3 kb upstream of J5, was identified.

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.

Usefulness of Cutaneous T-Cell Clonality Analysis for the Diagnosis of Cutaneous T-Cell Lymphoma in Patients With Erythroderma

Context.—Demonstration of a dominant T-cell clone in skin biopsy specimens by a molecular assay constitutes an additional diagnostic criterion to differentiate cutaneous T-cell lymphomas (CTCLs) from inflammatory dermatoses.

Objective.—To determine which patients, depending on their clinical presentations, could most benefit from a cutaneous T-cell clonality analysis in addition to histopathologic analysis for the diagnosis of CTCL.

Design.—Comparison of sensitivity and specificity of histopathologic analysis and a combination of this method and the detection of a T-cell receptor γ chain gene rearrangement by polymerase chain reaction denaturing gradient gel electrophoresis performed on skin biopsy specimens obtained at initial presentation.

Patients.—One hundred forty consecutive patients were classified into 4 groups, depending on their clinical presentation: (1) eczematous patches suggestive of early-stage mycosis fungoides (MF) (IA and IB of the TNM classification) (n = 42); (2) plaques, nodules, or tumors that arise on or are associated with plaques suggestive of late-stage MF (IIB and III of the TNM classification) (n = 16); (3) erythroderma (n = 50); and (4) nodules or tumors that arise in normal skin, suggestive of non-MF CTCL (n = 32).

Results.—When compared with histopathologic examination, the addition of clonality analysis increased the sensitivity of CTCL diagnosis in all groups of patients except those with cutaneous lesions suggestive of late-stage MF, because the diagnosis was made based on histopathologic analysis alone in 100% of these cases. The main increase in sensitivity of CTCL diagnosis was observed in patients with erythroderma: 62% with histopathologic analysis alone to 87% with the combination of both methods (P = .04). Diagnostic specificity of molecular assays decreased from 100% to 76% (P = .01) in patients with patch lesions and from 100% to 70% (P = .04) in patients with nodules that occurred in normal skin due to the detection of a T-cell clone in 6 patients with follicular mucinosis without a histologic pattern of MF and in 5 of 20 cases of T-cell pseudolymphoma (25%), respectively. In contrast, a T-cell clone was not detected in the 34 patients with erythroderma of inflammatory origin.

Conclusion.—Polymerase chain reaction analysis of cutaneous T-cell clonality could be useful for the diagnosis of CTCL in patients who present with erythroderma.

Practical evaluation and management of cutaneous lymphoma

Accurate evaluation of patients with suspected or known cutaneous lymphoma requires the integration of many sources and types of information, including clinical evaluation, microscopic analysis of tissue, immunophenotyping, gene rearrangement studies, clinical staging, and longitudinal observation. Diagnoses should be based on knowledge of specific lymphoma types as described in modern classification systems. Management of patients with cutaneous lymphoma requires collaboration among dermatologists, dermatopathologists, hematopathologists, and medical, surgical and radiation oncologists. (J Am Acad Dermatol 2002;46:325-57.)

LEARNING OBJECTIVE

At the conclusion of this learning activity, participants should better understand how to evaluate and manage patients for suspected or established lymphoma of the skin. Components include the clinical history and physical examination, optimal biopsy and tissue handling, interpretation of pathology and adjunctive test results, clinicopathologic correlation, and therapy. Participants should also understand the basis for establishing a specific diagnosis of cutaneous lymphoma based on current classification and staging.

Efficacy of Histologic Criteria for Diagnosing Early Mycosis Fungoides

The correct classification of lymphoproliferative disorders provides valuable information regarding subsequent clinical evolution of the disease. The ability of pathologists to distinguish such lesions is generally low, especially when dealing with minimal lymphoid infiltrates. To improve the efficacy of histopathology in the diagnosis of early lesions of mycosis fungoides (MF), we reviewed 24 skin biopsies from 18 patients with patch stage lesions of MF early in the course of their disease and 13 slides of lichenoid, spongiotic, or psoriasiform simulators of MF as a control series. A series of cytoarchitectural features was assessed, and differences in the distribution of histopathologic parameters between the two groups (early MF lesions and MF simulators) were evaluated by the chi-square test and Fisher's exact test. For these parameters, sensitivity and specificity also were calculated. A multivariate log-linear analysis was performed to estimate which of the morphologic parameters yielded independent diagnostic information. We found that the most important feature for the diagnosis of lymphoma was the presence of lymphocytes with extremely convoluted, medium-large (7-9 microm in diameter) nuclei (medium-large cerebriform cells), singly or clustered in the epidermis and in small sheets in the dermis. Additional significant histologic features were epidermotropism as single cells lined up along the basal keratinocytes of the dermal-epidermal junction, absence of significant papillary dermis fibrosis, and absence of significant numbers of dermal blastlike cells. We conclude that the efficacy of single histopathologic features in the diagnosis of early MF is generally poor. Only the presence of medium-large cerebriform cells in the epidermis or in clusters in the dermis proved to be a highly reliable feature. However, the histopathologic diagnosis of early MF lesions and their discrimination from inflammatory simulators can be achieved using the constellation of cytoarchitectural parameters proposed.

Cardiac involvement and molecular staging in a fatal case of mycosis fungoides

Polymerase chain reaction (PCR) amplification of T-cell receptor-gamma gene rearrangement was used for molecular staging in a case of primary cutaneous T-cell lymphoma (CTCL) with fatal evolution. Although initial evaluation was negative for systemic involvement, the patient died due to heart failure. Autopsy findings revealed lymphomatous myocardial infiltration, but other tissues and organs examined, including lymph nodes, liver, spleen, lung and bone marrow, appeared to be free of disease. Molecular analysis from frozen samples obtained during the initial evaluation, as well as paraffin-embedded material obtained during autopsy, revealed the presence of clonal rearranged bands in all tissues examined except the bone marrow. Subsequent hybridization of PCR products with a tumour-specific oligoprobe confirmed the PCR results, suggesting widespread dissemination of the lymphomatous process. The use of molecular analysis can add significant information about the extent of disease in patients with CTCL and may be helpful in the establishment of therapeutic options.

Role of histology in providing prognostic information in mycosis fungoides

Many patients who present with patch and early plaque stage mycosis fungoides follow an indolent course and survive for many years following diagnosis. A certain subset of patients, however, have rapidly progressive disease leading to accelerated demise. We examined 21 histologic sections from initial biopsies taken from patients with stable disease and 26 from patients with rapidly progressive disease in order to evaluate the role of histology in predicting the disease course. Two or three authors examined each case and scored each of 24 histologic parameters using a previously described four-point scale with no knowledge of the patients' clinical courses. Interobserver agreement was quite high. The only histologic parameter that demonstrated statistical differences between the two groups of patients was degree of acanthosis. The degree of spongiosis, number of eosinophils, amount of hyperconvolution of dermal lymphocytes and density of the dermal infiltrate approached statistical significance but did not attain this level. All of these differences were quite small. No differences were seen for the other 19 parameters. Patients with rapidly progressive disease tended to have more acanthosis, a few more hyperconvoluted dermal lymphocytes, a slightly greater number of eosinophils and perhaps a slightly more dense dermal infiltrate than patients who had stable disease. However, as all of these changes were very slight, it appears unlikely that evaluation of any single biopsy specimen for the histologic parameters we studied is helpful in predicting the prognosis for a specific patient.

Understanding and evaluating clinical trials

In this review, we attempt to provide the basic knowledge necessary to understand and evaluate clinical trials because properly conducted, randomized clinical trials are the best sources for determining the best available treatment. Other commonly used sources rarely provide sufficient detail necessary to determine the efficacy and safety of any treatment, and they often contain biases or pitfalls that make them unacceptable or unreliable. Our method for reviewing clinical trials allows a busy clinician to use his or her time most efficiently by deciding not to read the majority of poorly conceived, designed, executed, or reported trials and those trials with insignificant results. It provides a means to determine the quality of the trials that one does decide to read and to retain and retrieve the information when it is needed. The method involves recognizing and evaluating the features that strengthen clinical trials and help validate their conclusions. These features include proper selection and allocation of patients, inclusion of an appropriate control group, randomization, prior selection of clinically and biologically important outcome variables, blinding of assessment, consideration of patient compliance and drop out, and proper presentation and statistical analysis of results.