Diagnosis of mycosis fungoides with different algorithmic approaches

Mycosis Fungoides Exhibits the Features of Skin Tags: A Case Report

We present the case of a 37-year-old male diagnosed with Mycosis fungoides (MF) after gradually developing multiple skin tags and brownish lichenoid papules. The patient had pre-existing erythema over his entire body, especially his face, upper extremities, and trunk, for over 1.5 years. Microscopic examination of the papule and the skin tag (ST) exhibited similar features mainly characterized by superficial dense band-like lymphoid infiltrates and epidermotropism of atypical lymphocytes (Pautrier's micro-abscesses). Immunohistochemistry further revealed the lymphoid infiltrates predominantly expressed LCA, CD3, CD4, and CD45RO but lacked CD7, CD8, CD30, CD20, and CD79a. The finding of this study that reports MF characterized by unusual STs suggests that some causes and effects have not been previously described in MF.

Mycosis fungoides and Sézary syndrome: clinical presentation, diagnosis, staging, and therapeutic management

Mycosis fungoides (MF) and Sézary syndrome (SS) are cutaneous T-cell lymphomas. MF is the most common cutaneous lymphoma, and it is classified into classic Alibert-Bazin MF, folliculotropic MF, pagetoid reticulosis, and granulomatous slack skin, each with characteristic clinical presentation, histopathological findings, and distinct clinical behaviors. SS is an aggressive leukemic variant of cutaneous lymphoma, and it is characterized by erythroderma, lymphadenopathy, and peripheral blood involvement by malignant cells. There is a wide range of dermatological manifestations of MF/SS, and prompt recognition is essential for early diagnosis. Skin biopsy for histopathology and immunohistochemical analysis is imperative to confirm the diagnosis of MF/SS. Histopathology may also provide information that may influence prognosis and treatment. Staging follows the TNMB system. Besides advanced stage, other factors associated with poorer prognosis are advanced age, male gender, folliculotropism in histopathology of patients with infiltrated plaques and tumors in the head and neck region, large cell transformation, and elevated lactate dehydrogenase. Treatment is divided into skin-directed therapies (topical treatments, phototherapy, radiotherapy), and systemic therapies (biological response modifiers, targeted therapies, chemotherapy). Allogeneic bone marrow transplantation and extracorporeal photopheresis are other treatment modalities used in selected cases. This review discusses the main clinical characteristics, the histopathological/immunohistochemical findings, the staging system, and the therapeutic management of MF/SS.

Dysregulation of Plasma miR-146a and miR-155 Expression Profile in Mycosis Fungoides Is Associated with rs2910164 and rs767649 Polymorphisms

Diagnosis of Mycosis Fungoides (MF) may be challenging, due to its polymorphic nature. The use of miRNAs as biomarkers to assist in diagnosis has been investigated, mainly in skin lesion biopsies. The purpose of this study is to evaluate the plasma levels of miR-146a and miR-155 in MF patients and to investigate their association with SNPs of their genes. Plasma miRNAs were quantified by RT-qPCR. Genomic DNA was used for SNPs’ genotyping by Sanger sequencing. Plasma levels of miR-146a and miR-155 were significantly higher in patients vs. controls, in early MF patients vs. controls, and in advanced vs. early MF patients. Both miRNAs’ levels were significantly higher in stage IIB vs. early-stage patients. miR-155 plasma levels were significantly higher in patients with skin tumors or erythroderma. CC genotype (rs2910164 C>G) was significantly more frequent in healthy controls and associated with lower MF risk and lower miR-146a levels. The AA genotype (rs767649 T>A) was significantly more frequent in patients and correlated with increased MF risk and increased miR-155 levels. The combination of GG+AA was only detected in patients and was correlated with higher MF susceptibility. Increased mir-146a and mir-155 plasma levels in MF is an important finding to establish putative noninvasive biomarkers. The presence of SNPs is closely associated with miRs’ expression, and possibly with disease susceptibility.

PUVA-induced pityriasis lichenoides chronica-like papular lesions in patients with mycosis fungoides: a clinical, histopathological and immunohistochemical study

Mycosis fungoides (MF) is the most common form of cutaneous T cell lymphoma (CTCL) with many clinical variants including papular and pityriasis lichenoides chronica (PLC)-like variants. During psoralen and ultraviolet A (PUVA) treatment of MF, PLC-like papular lesions were observed to appear. The exact nature of these lesions is not fully understood. This work aimed to study PLC-like papular lesions arising in MF patients receiving PUVA therapy clinically, histopathologically and immunohistochemically (using monoclonal antibodies against CD4 and CD8) and to compare them with lesions in classic PLC patients. Fifteen MF patients with PLC-like papular lesions arising during PUVA treatment were included and 15 patients with classic PLC served as controls. While the extent of these lesions significantly correlated with their duration (p < 0.05), it showed no significant correlation with the TNMB stage of MF, number of phototherapy sessions or cumulative UVA dose at which they started to appear. The response status of MF to PUVA did not affect their development. Compared to classic PLC, these lesions showed significantly more acute onset (p = 0.003). None of these lesions showed histopathological features essential to diagnose papular/PLC-like MF and no significant difference existed with regard to their histopathological and CD4/CD8 phenotypic features compared to classic PLC. Papular lesions mimicking PLC in MF patients receiving PUVA mostly represent an upgrading reaction with possible good prognostic implication.

The Ectopic Expression of Meiosis Regulatory Genes in Cutaneous T-Cell Lymphomas (CTCL)

Cancer testis (CT) antigens, under normal circumstances are uniquely expressed in testicular germ cells. Recent research has shown that meiosis-specific CT (meiCT) antigens are ectopically expressed in cutaneous T-cell lymphoma (CTCL) and may contribute to increased genomic instability. The aberrant activation of meiosis genes in a mitotic cell is now recognized as a distinctive process, “meiomitosis.” We have previously demonstrated the ectopic expression of several meiCT antigens in nine patient-derived CTCL cell lines and in expanded peripheral T lymphocytes isolated from Sézary Syndrome patients. In this study we analyzed the transcriptional expression of meiCT genes in Sézary Syndrome patients and healthy controls using publicly-available RNA sequencing (RNA-Seq) data. We corroborated our in silico analysis by examining the expression of 5 meiCT proteins in formalin-fixed, paraffin-embedded (FFPE) lesional samples from CTCL patients. Our results show significant differential gene expression of STAG3, SGO2, SYCP3, and DMC1 in a cohort of Sézary Syndrome patients when compared to healthy controls. Additionally, our study demonstrates a heterogenous expression of meiCT genes involved in initiation (STRA8), sister chromatin cohesion (STAG3, SGO2), homologous chromosome synapsis (SYCP3) and homologous recombination (DMC1) in atypical lymphocytes in FFPE samples. Our results further confirm the ectopic expression of meiCT genes in CTCL which indicates that CTCL malignant cells likely undergo the process of cancer meiomitosis, as opposed to a typical mitotic division. The ectopic expression of meiCT genes together with investigations into the functional mechanisms of cancer meiomitosis will help provide a foundation to develop novel diagnostic tests to distinguish CTCL from benign inflammatory dermatoses and may enable us to develop additional targeted therapies for patients with this malignancy.

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.

A review of survival in mycosis fungoides

OBJECTIVES

The objectives of this study are to review prior publications of survival for patients with mycosis fungoides (MF), to perform some analyses on the consolidated data, and then to consider the implications of the results.

METHODS

The data for this study comprise 18 survival curves derived from seven prior publications of long-term survival in relatively large series of patients with MF. Altogether, the study uses results from over 5,000 patients. To examine fatality, the study uses hazard functions derived from the survival curves.

RESULTS

The analyses demonstrate significant variability in survival between different groups who have studied MF, and the results document that for most patients the diagnosis of MF has little impact on fatality.

CONCLUSIONS

Although MF is considered a cutaneous lymphoma, that is, a malignancy, it may be time to reconsider low stages of MF as precursors to malignancy analogous to the precursors to malignancies of other types or organs.

Cutaneous T-Cell Lymphoma–Like Drug Eruption in an HIV-Positive Patient Taking Vancomycin and Rifampin

Background:

Cutaneous T-cell pseudolymphoma (CTPL) is a benign reactive T-cell lymphoproliferative subtype of pseudolymphoma. Some variants of CTPL can resemble the plaques of mycosis fungoides (MF). The vast majority of drug-induced cases have been associated with anticonvulsants. There is only one report in the literature documenting a case of vancomycin-induced CTPL.

Methods:

We report a cutaneous T-cell lymphoma–like eruption in a human immunodeficiency virus (HIV)-positive patient recently started on vancomycin and rifampin.

Results:

A skin biopsy showed several histologic features of MF with immunohistochemical and T-cell receptor gene rearrangement studies suggestive of CTPL. This atypical T-cell reaction mimicking MF completely resolved on cessation of rifampin followed by vancomycin.

Conclusion:

Considering drug-induced causes of MF-like histologic changes is crucial to prevent unnecessary treatment for MF.

Mycosis fungoides and Sézary syndrome: clinical, histopathological and immunohistochemical review and update

This paper reviews the diagnostic and classificatory concepts of mycosis fungoides and Sézary syndrome in light of the latest normative publications. It describes the great variability of the clinical expression of mycosis fungoides in its early stages as well as the histopathological and immunohistochemical aspects that help with diagnosis. The diagnostic criteria required for characterizing Sézary syndrome and the staging system used for both mycosis fungoides and Sézary syndrome are described.

Mycosis fungoides involving an acrochordon: a case report

We present the case of a 77-year-old male undergoing treatment for mycosis fungoides (MF) who presented for removal of an acrochordon on his mid back. Histopathologic examination of the acrochordon revealed a dense, band-like lymphocytic inflammatory infiltrate in the dermis with epidermotropism of single lymphocytes and small nests of lymphocytes into the lower epidermis. Immunohistochemical staining characterized the dermal and epidermal lymphocytic population as CD3-positive T lymphocytes with a predominance of CD4-positive over CD8-positive lymphocytes. These findings were consistent with the patient's known MF and molecular identification of a clonal T-cell receptor gene rearrangement further supported the diagnosis. Our unusual case reports MF involving an acrochordon and provides evidence to support the importance of submitting acrochordons for histopathologic examination.

Molecular markers of early-stage mycosis fungoides

The lack of a specific marker differentiating early mycosis fungoides (eMF) from benign inflammatory dermatitis presents significant difficulties in the assessment and management of suspected MF patients, which often leads to delayed diagnosis and improper medical approaches. To address this, an investigation was carried out to characterize positive identification markers for eMF by comparing eMF lesions with healthy skin and benign inflammatory dermatitis, using high-throughput genomic transcription profiling. A total of 349 genes were differentially expressed in eMF lesions compared with normal skin. These genes belong to pathways associated with inflammation, immune activation, and apoptosis regulation. Most of them (N=330) also demonstrated significant upregulation in chronic dermatitis, making them nonideal markers for eMF. Among them, 19 genes with specific enrichment in eMF lesions were identified that showed no significant upregulation in chronic dermatitis. Two of them, TOX and PDCD1, showed high discrimination power between eMF lesions and biopsies from benign dermatitis by RNA expression. Furthermore, TOX demonstrated highly specific staining of MF cells in eMF skin biopsies in immunohistochemistry and immunofluorescence, including the early epidermotropic cells in Pautrier's microabscesses. This study demonstrates the potential of eMF-enriched genes, especially TOX, as molecular markers for histological diagnosis of eMF, which currently is a major diagnostic challenge.

Comments on cutaneous lymphomas: since the WHO-2008 classification to present

The last classification of lymphomas of the World Health Organization in 2008 made a few changes from the preceding classification. Although useful, at the same time, it has posed new questions, concerns, and dilemmas which have been raised in the literature. The current report highlights some of these controversies, of each of these primary cutaneous entities, going through cutaneous mature T-cell and NK-cell neoplasms, mature B-cell neoplasms, precursor neoplasms, and other entities, which for several reasons do not fit in the previous categories. It also reviews some advances on many of these lymphomas published in the last 2 years.

The role of molecular and genetic methods to determine theТ-cell and В-cell clonality in diagnosing malignant cutaneouslymphomas

The article presents the data on the studies contributing to improving the differential diagnostics of T-cell and B-cell cutaneous lymphomas including large-plaque parapsoriasis and T-cell and B-cell cutaneous pseudolymphomas as well as frequency of their transformation into malignant cutaneous lymphomas. There was a study of 101 patients using the polymerase chain reaction method to determine the T-cell and B-cell lymphocyte clonality by genes of g and ƒ chains in the T-cell receptor and immunoglobulin heavy chain genes. Monoclonality was determined in 40 of 46 cases in patients with T-cell cutaneous lymphomas and in three of four cases in patients with B-cell cutaneous lymphomas. Monoclonality was revealed in one of 14 cases of large-plaque parapsoriasis and one of two cases of T-cell cutaneous pseudolymphoma. In all of the 24 cases of chronic benign dermatoses, five cases of small-plaque parapsoriasis and ten skin tissue samples obtained from healthy donors, polyclonal lymphocytes were revealed. So, the obtained results make it possible to consider the method to be an important addition in the field of diagnosing lymphoproliferative skin diseases.

Immunophenotypic correlation between skin biopsy and peripheral blood findings in mycosis fungoides

In mycosis fungoides (MF) with blood involvement, T-cell immunophenotypes in skin and blood have not been compared. Our aim was to evaluate T-cell immunophenotypes in skin by immunohistochemical analysis and compare results with flow cytometric (FC) findings in blood. Of 20 patients with MF with blood involvement, the immunophenotype was discrepant in 11 (55%). Compared with FC findings in blood, immunohistochemical analysis of skin samples failed to detect partial deletion of CD2 (5/11 [45%]), CD3 (3/11 [27%]), and CD5 (3/11 [27%]) and overrepresented deletion of CD7 in 2 (18%) of 11 patients. In addition, CD8+ MF was missed by immunohistochemical analysis in 2 (18%) of 11 patients. Identical T-cell populations were demonstrated by T-cell gene polymerase chain reaction in skin and blood in 8 of the 11 patients who had a discrepant immunophenotype. Awareness of the limitations of immunohistochemical analysis of skin samples is of practical value for pathologists interpreting skin biopsies in MF patients. In addition, our findings suggest CD8+ MF to be more common than previously reported.