A simple clinical scoring system to improve the sensitivity and standardization of the diagnosis of mycosis fungoides type cutaneous T-cell lymphoma: logistic regression of clinical and laboratory data

Evaluation of the International Society for Cutaneous Lymphoma Algorithm for the Diagnosis of Early Mycosis Fungoides

The International Society for Cutaneous Lymphoma (ISCL) proposes a diagnostic algorithm for early mycosis fungoides (MF) that includes clinical, histological, immunophenotypical, and molecular criteria. Here, we analyzed the immunologic markers and features of T-cell clonality in 38 early MF cases and 22 non-MF cases to validate the ISCL algorithm. We found that CD5 and CD7 expression differed significantly between early MF and non-MF cases, with epidermal discordance of CD7 expression more frequently identified in early MF. Notably, increasing the cut-off value for CD7 expression from 10% to 22.5% improved its sensitivity. Furthermore, TCR-γ and β chain rearrangements were more frequently detected in early MF than in non-MF cases. Based on these findings, we propose CD5 and CD7 deficiency as mandatory immunopathologic criteria and PCR-based testing for TCR-γ and β chains as required molecular/biologic criteria to improve the efficiency of early MF diagnosis using the ISCL algorithm.

Mycosis Fungoides: A Clinicopathological Study of 60 Cases from a Tertiary Care Center

Background:

Mycosis fungoides (MF) is the most common primary cutaneous lymphoma. It affects usually the covered areas of the body in elderly males in 6^th and 7^th decades of life. Atypical dermal lymphoid infiltrate is seen along with epidermotropism. Nuclei of neoplastic cells are convoluted. The neoplastic cells demonstrate positivity for CD3 (Pan T) immunohistochemical stain. Majority show increased CD4 to CD8 ratio. The present study was done to study the clinicopathological features, which might be of help in reaching a correct diagnosis in these cases.

Materials and Methods:

A retrospective descriptive study was conducted on 60 reported cases of MF. The retrieved slides were reviewed for clinical and histopathological features and immunohistochemical profile.

Results:

The ages ranged from 20–84 years, mean age was 47 years. Majority (75%) of patients were male. Trunk and extremities were the sites most commonly affected. There was significant inverse correlation between epidermal thickness and tumor stage (P = 0.02). Thickened epidermis was seen in patch stage and thickness reduced with progressing stage. The intensity of dermal infiltrate and cell size was also statistically significantly linked to stage progression (P < 0.001 each). In addition, proliferation index also correlated significantly with tumor stage (P = 0.002).

Conclusion:

Clinical information and histological features are equally important in the accurate diagnosis of MF. Papillary dermal fibrosis is a useful diagnostic clue. CD4:CD8 ratio is not increased in all cases; it may be decreased or remain unchanged.

Flow cytometric identification of immunophenotypically aberrant T-cell clusters on skin shave biopsy specimens from patients with mycosis fungoides

OBJECTIVES

To assess the ability of flow cytometry (FC) to detect putative neoplastic T-cell subsets on skin shave biopsy (SSB) specimens from patients with mycosis fungoides (MF) and to study the immunophenotype of skin-infiltrating tumor cells in MF.

METHODS

SSB specimens from patients with suspected MF were bisected and submitted for both FC and routine histopathology. Six-dimensional gating strategies were applied to identify putative neoplastic cells, independently from their expected immunophenotype.

RESULTS

Aberrant T cells were detected by FC in 18 of 33 SBB specimens, of which all had clinicomorphologic features of MF. Of the remaining 15 SSB specimens, six had clinicomorphologic features of MF and nine were diagnosed with benign inflammatory dermatoses. Unexpectedly, CD26 was aberrantly overexpressed in 11 (73%) and lost in three (20%) of 15 SSB specimens from patients with MF where this antigen was evaluated. Other detected aberrancies included CD3 dim- (13/18 [72%]), CD7 dim- (15/18 [83%]), and CD4-/CD8- (3/18 [17%]).

CONCLUSIONS

FC is capable of identifying putative neoplastic cells on SSB specimens from patients with MF. Bright homogeneous CD26 expression is a common and previously undescribed immunophenotypic aberrancy on MF skin infiltrates.

Best practices in diagnostic immunohistochemistry: workup of cutaneous lymphoid lesions in the diagnosis of primary cutaneous lymphoma

CONTEXT

Primary cutaneous lymphoma is a common extranodal non-Hodgkin lymphoma. These lesions share common features with their nodal counterparts, but also have differences in morphology, unique clinical presentations, and immunohistochemical features.

OBJECTIVE

To review the 2008 World Health Organization (WHO) and 2005 consensus WHO-EORTC (European Organisation for Research and Treatment of Cancer) classifications, and address the immunohistochemical findings in the most common primary cutaneous T- and B-cell lymphomas. Since clonality testing is commonly used as an ancillary test in the evaluation of cutaneous lymphoma, a brief section in the use and pitfalls of clonality testing is included.

DATA SOURCES

The WHO and EORTC classification publications and the relevant recent literature were used to compile appropriate and practical guidelines in this review.

CONCLUSIONS

The practice of dermatopathology and hematopathology varies widely. Thus, while this review provides an overview and guideline for the workup of lymphoid lesions of the skin, the practitioner should understand the importance of clinical correlation as well as appropriate utility of available resources (such as clonality testing) in arriving at a diagnosis in cutaneous lymphoid lesions.

Defining early mycosis fungoides: validation of a diagnostic algorithm proposed by the International Society for Cutaneous Lymphomas

BACKGROUND

Mycosis fungoides (MF) is the most common subtype of cutaneous T-cell lymphoma and is often difficult to diagnose. Early-stage disease is particularly challenging and requires clinical and histopathologic correlation to make an accurate diagnosis. In order to facilitate the diagnosis of early MF, an algorithm has been proposed by the International Society for Cutaneous Lymphomas (ISCL) whereby clinical and histopathologic characteristics as well as immunohistochemistry and T-cell receptor gene rearrangement studies may be applied to suspected cases of MF. The diagnostic utility of this algorithm has not yet been validated. We sought to determine the validity of the proposed algorithm via an investigator-blinded, retrospective, case-control study.

METHODS

A total of 34 cases were randomly selected from the database of a clinic for cutaneous T-cell lymphomas and included patients with MF and patients with clinicopathologic mimics. The proposed diagnostic algorithm was systematically applied to the entire cohort. Each case was assigned a composite score based on the parameters in the proposed algorithm.

RESULTS

Among the 24 cases of MF, 21 cases achieved four or more points through application of the algorithm. Among the 10 cases of MF mimics, only four achieved four or more points. This difference was significant (Fisher's exact test, p = 0.009). The sensitivity of the 4-point threshold for a diagnosis of MF was 87.5% and the specificity was 60%.

CONCLUSIONS

The diagnostic algorithm proposed by the ISCL is a statistically valid method for defining cases of early MF and distinguishing these cases from other benign dermatoses. However, the clinical utility of the algorithm may be limited by its low specificity. Further refinement of the algorithm may improve its accuracy.

Mycosis Fungoides

This article is a comprehensive review of mycosis fungoides (MF), the most common type of cutaneous T-cell lymphoma. The first portion of the article introduces epidemiologic features of MF. Next, the clinical presentation is described, followed by the microscopic features. This article addresses how to establish a diagnosis of MF and includes a discussion of the utility of ancillary testing, such as immunohistochemistry and T-cell clonality testing. The differential diagnosis is also discussed, with attention to how to distinguish MF from histopathologic mimics. The final section of the article discusses prognosis and risk of disease progression in MF.

[Mycosis fungoides or inflammatory dermatitis: differential diagnosis between early lymphoma and inflammation in skin biopsies]

Mycosis fungoides is a cutaneous T-cell lymphoma with protracted clinical course and progression in different stages with increasing aggressiveness. The clinical picture as well as the histopathology of mycosis fungoides within the early patch and plaque phase is difficult to delineate from some inflammatory skin diseases. Thus, the diagnosis of these early stages of the lymphoma is only possible when clinical, histopathological, and molecular features are integrated into the diagnosis, especially as none of the individual disease criteria is specific. Important clues towards the diagnosis of mycosis fungoides are cytologically abnormal epidermotropic CD4-positive T-cells causing only minor epidermal alterations, the formation of Pautrier-abscesses and basal alignment of the epidermotropic T-cells. The findings of an aberrant T-cell immunophenotype of the intraepidermal lymphoid component as well as the molecular proof of T-cell clonality are important further features. In the differential diagnosis between early stage mycosis fungoides and parapsoriasis, there remains nevertheless a diagnostic and maybe also a true biological grey zone.

A naïve approach for deriving scoring systems to support clinical decision making

RATIONALE, AIMS AND OBJECTIVES

Scoring systems are frequently proposed in medicine to summarize a set of qualitative and quantitative items by means of a numeric score. Their design often requires modelling ability and subjective judgments. This can make it difficult to adapt a scoring system to a clinical setting different from that in which the system was developed. The objective of this study was to discuss an approach to derive scoring systems, which can be easily modified and matched to any scenario.

METHODS

A naïve Bayes approach was used to develop a scoring system that is completely defined by descriptive tables obtained by frequency counts from the training set. The approach was implemented to build a locally customized scoring system for planning transfusion requirements after cardiac surgery. The performance of this system was evaluated and compared with that of a logistic regression model designed using the same predictors. The working sample was a set of 3182 consecutive patients undergoing cardiac surgery at the University Hospital of Siena, Italy.

RESULTS

The area under the receiver operating characteristic curve was equal to 0.811 and 0.824 for the scoring system and for the logistic regression model, respectively. This result proves that this global index of discrimination capacity was virtually identical and very good for both models. The values of sensitivity, specificity and overall correct-classification percentage obtained by the leave-one-out method were practically the same for the two models (73.9% versus 75.3%).

CONCLUSIONS

An easy-fitting and trustworthy scoring system can be directly developed using a naïve Bayes approach. The simplicity of its design allows the system to be customized to any specific institution and updated regularly. This aspect has important practical implications because it can encourage the use of scoring systems among clinicians, enabling their performance to be properly assessed in a wider clinical context.

Origin Use of CD4, CD8, and CD1a Immunostains in Distinguishing Mycosis Fungoides from its Inflammatory Mimics: A Pilot Study

Patch-stage/early mycosis fungoides (MF) is difficult to differentiate from benign dermatoses, despite several robust histologic criteria. Most studies include advanced lesions and data about early disease is limited.

Objectives:

(1) To compare the CD4:CD8 ratio in patch-stage MF versus inflammatory mimics. (2) To study patterns of CD1a expression in the epidermis and dermis in the two groups.

Materials and Methods:

Twenty cases each of early MF and inflammatory dermatoses were selected. The diagnoses were established after clinicopathologic correlation, repeat biopsies, and follow-up. The inflammatory group included pityriasis lichenoides chronica, actinic reticuloid, lichenoid purpura, and various psoriasiform dermatoses. Immunohistochemistry was done for CD4, CD8, and CD1a. Epidermal CD4, CD8 cells were quantified and CD1a was graded semi-quantitatively in the epidermis and dermis.

Results:

The average CD4:CD8 ratio was 4.2 in MF (range: 1-16.8), and 0.9 in inflammatory diseases (range: 0.43-5), which was statistically significant (P < 0.0001). None of the MF cases had a ratio <1. Four cases of pityriasis lichenoides chronica had a ratio >1. CD1a cells had a continuous or confluent epidermal pattern in almost all cases of MF, while they occurred as small or large groups in the dermis. In inflammatory dermatoses, there were either isolated or scattered CD1a+ cells in both epidermis and dermis.

Conclusions:

Elevated CD4:CD8 ratio favors MF. But there is an overlap in the lower range with pityriasis lichenoides chronica. These cases require good clinicopathologic correlation and follow-up. Patterns of CD1a expression are more reliable. Immunostains buttress morphology and are a valuable addition.

Diagnostic significance of TCR gene clonal rearrangement analysis in early mycosis fungoides

Mycosis fungoides (MF), the most common type of cutaneous T-cell lymphoma, has various unspecific clinical and histological characteristics. Its early diagnosis is challenging. The application of T-cell receptor (TCR) gene clonal rearrangement to the diagnosis of MF has been widely studied. In this study, we used polymerase chain reaction (PCR) to investigate the diagnostic significance of detecting TCR-γ and -β gene clonal rearrangement in the early diagnosis of mycosis fungoides. PCR for TCR-γ and TCR-β gene rearrangement was performed on 19 patients with suspected early MF, 6 with typical MF, and 6 with chronic dermatitis. Of the 19 patients with suspected early MF, 13 had TCR-γ gene clonal rearrangement, whereas none had TCR-β gene clonal rearrangement. All patients with typical MF had TCR gene clonal rearrangement, in which 4 showed TCR-γ clonal rearrangement, 1 showed TCR-β gene clonal rearrangements, and 1 showed both. No patients with chronic dermatitis had TCR gene clonal rearrangement. These results indicate that TCR gene clonal rearrangement analysis is a useful tool in diagnosing early MF. TCR-γ gene is recommended to the routine analysis, whereas TCR-β gene has potential in combination toward intractable cases.

The role of immunohistochemical analysis in the diagnosis of parapsoriasis

Parapsoriasis is a chronic dermatosis whose biological distinction from early mycosis fungoides, the most frequent form of cutaneous T-cell lymphoma, is still not clearly defined. Two types of parapsoriasis have been delineated: large-plaque parapsoriasis and small-plaque parapsoriasis. The lack of clinical and histological features, which may allow distinguishing parapsoriasis from early mycosis fungoides has prompted several investigations to assess the role of immunohistochemistry in establishing a conclusive diagnosis of these conditions. However, the additional data obtained by immunohistochemical analysis concerning the CD4/CD8 ratio, the aberrant expression of T-cell antigens and the expression of proliferation markers has not generally helped establish a more definitive diagnosis. This review critically discusses these immunohistochemical markers and their use in diagnosis of parapsoriasis.

Usefulness of flow cytometry in the diagnosis of mycosis fungoides

BACKGROUND

The pathologic evaluation of mycosis fungoides (MF) is a challenging area in dermatopathology.

OBJECTIVE

We sought to determine the usefulness of flow cytometry for the diagnosis of MF from skin biopsy specimens.

METHODS

Skin biopsy specimens from 22 patients with a clinical suggestion for MF were evaluated by 4-color flow cytometry. The results were correlated with the International Society for Cutaneous Lymphoma (ISCL) MF diagnostic score and molecular studies for T-cell receptor gene rearrangement.

RESULTS

A T-cell abnormality by flow cytometry was identified in all 11 patients with diagnostic ISCL scores whereas the 7 patients with either subdiagnostic ISCL scores or reactive histology showed no phenotypic abnormality by flow cytometry. In all, 10 of 11 patients with diagnostic skin biopsy specimens for MF had T-cell receptor gene rearrangements by polymerase chain reaction. Gene rearrangements were not detected in the subdiagnostic group.

LIMITATIONS

Small study size was a limitation.

CONCLUSION

Flow cytometry of skin biopsy specimens is a sensitive method for detecting abnormalities in MF and should be considered part of the routine workup of patients with a clinical suggestion of MF.

UVB in the management of early stage mycosis fungoides

BACKGROUND

Several options for treatment of early mycosis fungoides (MF) offer similar success rates. Previous small studies have shown UVB to be at least as effective as PUVA.

OBJECTIVE

To summarize our experience with UVB treatment of early MF.

METHODS

A retrospective analysis of early-stage MF patients treated by narrow band (NB) or broad band (BB) UVB in our institution between 1996 and 2002. Most patients achieving complete response (CR) were put on maintenance until natural sun exposure was possible and followed up every 3-6 months. The results were compared to those previously reported regarding PUVA.

RESULTS

Sixty-eight and 43 patients were treated by NB and BB UVB, respectively. Eighty-six per cent (84 and 89% in NB and BB UVB groups, respectively) of IA and 71% (78 and 44% in NB and BB UVB groups, respectively) of IB patients achieved CR within a mean of 12.8 and 10.6 weeks, respectively. When maintenance was stopped, 65 and 30% had not relapsed after an average follow up of 27 and 222 weeks, respectively. Non-relapse rate was 33 and 48% for those having had vs. those not having had maintenance, respectively.

CONCLUSIONS

Our results are comparable to all previously reported for skin-targeted treatments, including PUVA and, to our belief, reflect the nature of early MF, in which CR can probably be achieved in most of the patients. Among the responding patients there is no relapse during prolonged follow-up in about one third of the cases. Thus, we believe treatment should be stopped completely following first CR induction and maintenance treatment should be considered for relapsing patients only. Both broad and narrow UVB options are good and future choices should be made on the basis of short- and long-term side-effects.

The New World Health Organization–European Organization for Research and Treatment of Cancer Classification of Cutaneous Lymphomas

The WHO-EORTC classification of cutaneous lymphomas is a good start to unifying nomenclature, a necessity before coherent consensus diagnoses can be made. There are three provisional diagnoses in this new classification that are not covered in detail in this review because they are rare diseases that still require further study for definitive classification. Much remains to be elucidated about cutaneous lymphomas, but understanding of the major entities within the new classification is an important first step in understanding these diverse diseases.

Defining early mycosis fungoides

This editorial review summarizes the results of 5 meetings sponsored by the International Society for Cutaneous Lymphoma at which the clinicopathologic and ancillary features of early mycosis fungoides were critically examined. Based on this analysis, an algorithm was developed for the diagnosis of early mycosis fungoides involving a holistic integration of clinical, histopathologic, immunopathologic, and molecular biological characteristics. A novel aspect of this algorithm is that it relies on multiple types of criteria rather than just one, for example, histopathology. Before its finalization, the proposed diagnostic algorithm will require validation and possibly further refinement at multiple centers during the next several years. It is anticipated that a more standardized approach to the diagnosis of early mycosis fungoides will have a beneficial impact on the epidemiology, prognostication, treatment, and analysis of clinical trials pertaining to this most common type of cutaneous lymphoma.

Evidence for Restricted Vβ Usage in the Leukemic Phase of Cutaneous T Cell Lymphoma

Antibodies directed against the beta chain of the T cell receptor (anti-Vbeta antibodies) are useful to identify the Vbeta repertoire of T cells in various diseases and to quantify numbers of Vbeta-bearing T cells. The goals of this study were to identify Vbeta+ cases of leukemic phase cutaneous T cell lymphoma (CTCL) and to compare the percentage of positive calls with other measures of blood tumor burden, i.e., lymphocyte subsets with a CD4+CD7- and CD4+CD26- phenotype and Sezary cell counts. Thirty-three of 49 (67%) cases of leukemic CTCL reacted with an anti-Vbeta antibody. When combined with reports from the literature, the frequency of Vbeta5 (probably Vbeta5.1) usage was relatively high when compared with Vbeta2 that is also frequently expressed by normal CD4+ T cells. The percentage of Vbeta+ cells correlated to the percentage of CD4+CD7- and CD4+CD26- cells for cases in which the neoplastic cells were deficient in expression of CD7 and CD26, respectively, but not the Sezary cell count. We hypothesize that the increased Vbeta5.1 usage in CTCL may be the result of depletion of Vbeta2 and other Vbeta-bearing T cells by staphylococcal superantigens prior to neoplastic transformation, resulting in a relative increase in the frequency of Vbeta5.1 usage in CTCL.