Intraepidermal Lymphocytes Research Articles

CD4/CD8 double-negative epidermotropic cutaneous T-cell lymphoma: An immunohistochemical variant of mycosis fungoides

Mycosis fungoides (MF) is an epidermotropic cutaneous T-cell lymphoma in which the tumor cells express a mature T-helper memory phenotype, ie, CD3(+), CD4(+), CD8(-), CD45RO(+), with a T-cell receptor (TCR) of the alpha/beta heterodimer. A minority of patients have an unusual immunohistochemical profile consisting of a CD4(-), CD8(+) mature T-cell phenotype. An aberrant CD4/CD8 double-negative (DN) immunophenotype in patients with early MF has rarely been reported. We sought to evaluate the frequency of CD4/CD8 DN immunophenotype in patients with early MF, and to study their clinical, histopathologic, and immunohistochemical features, and the course of their disease. Our departmental archives were searched for patients with early-stage MF and CD4/CD8 DN immunophenotpye. Of the 140 patients with early MF immunophenotyped in our laboratory, 18 (12%) showed CD4 and CD8 expression in less than 10% of their intraepidermal T cells on fresh-frozen and paraffin-embedded samples. The group included 13 male and 5 female patients; 14 adults and 4 children; and 15 Jews and 3 Arabs. In all, 8 had classic MF and 10 had unusual clinical variants (5 hypopigmented, 3 localized, 1 ichthyosiform, 1 purpuric). All received skin-targeted therapies and all had an indolent course (mean follow-up 3.5 years). Histopathology revealed early MF. Results of immunohistochemical analysis of the intraepidermal lymphocytes were as follows: CD3(+), CD4(-), CD8(-) in all patients; CD7(-) in all of 17; CD45RO(+) in 15 of 16; T-cell-restricted intracellular antigen-1(+) in 11 of 15; CD30(+) in 2 of 16; and CD56(+) in 2 of 16. A betaF1(+)/delta(-) phenotype, indicating a TCR of the alpha/beta heterodimer, was found in 8 of 16; betaF1(-)/delta(+) phenotype, indicating a TCR of the gamma/delta heterodimer, in 1 of 16; betaF1(-)/ delta(-) in 5 of 16; and no determinable phenotype in 2 of 16. The TCR gamma gene was clonally rearranged in 10 of 16 patients. This was a single-center case series. There is a subgroup of patients with early MF that exhibit a CD4/CD8 DN immunophenotype. In our region, this aberrant immunophenotype is not as rare as reflected in the literature, is overrepresented in the unusual clinical variants of MF, and does not seem to have prognostic significance. Like CD4(+) MF, the tumor cells represent memory T cells and in many cases express alpha/beta TCR, but unlike CD4(+) MF, they have a mostly cytotoxic phenotype. We suggest that CD4/CD8 DN MF should be recognized as another immunohistochemical variant of this lymphoma.

CD1A Rich Inflammatory Stage of Lichen Sclerosus Et Atrophicans Mimicking Mycosis Fungoides and Extramammary Paget’S Disease

We report a case of inflammatory stage vulvar lichen sclerosus et atrophicans (LSA) with histopathologic features simulating both patch stage mycosis fungoides (MF) and extramammary Paget’s disease. The patient is a 79‐year‐old woman with an erythematous plaque on her vulva. A punch biopsy was performed that revealed mild psoriasiform hyperplasia of the epidermis with spongiosis, marked interface vacuolar alteration, scattered individual necrotic keratinocytes and Civatte bodies. A band‐like mixed inflammatory infiltrate was present in the papillary/upper dermis with prominent intraepidermal lymphocytes. Some intraepidermal lymphocytes showed atypical nuclear contours simulating the cells seen in MF. The presence of numerous intraepidermal epithelioid cells with a pagetoid distribution raised the possibility of extramammary Paget’s disease. A panel of immunohistochemical (IHC) stains showed a reactive lichenoid mixed population of lymphocytes with numerous intraepidermal Langerhans cells. This confirmed the diagnosis of the inflammatory stage of lichen sclerosus. The presence of prominent epithelioid Langerhans cells with activated small lymphocytes represents an immune response in LSA and could cause diagnostic confusion with neoplastic conditions. IHC staining can confirm cell type and rule out MF and extramammary Paget’s disease.

Cutaneous T‐cell lymphoma presenting as disseminated, pigmented, purpura‐like eruption

A 48-year-old man with a history of psoriasis, who had received no oral pharmacologic treatment, presented in March 2000 with a progressive, cutaneous, pruritic eruption that began on his arms and legs, and became generalized. Examination revealed discrete, purpuric elements disseminated over the entire cutaneous surface, and in some areas confluent, large, erythematous, purpuric patches (1, 2). The palmoplantar surfaces and mucous membranes were spared. No lesions suggesting parapsoriasis or the usual presentation of cutaneous T-cell lymphoma (CTCL) were present. Figure 1Open in figure viewerPowerPoint Confluent, large, erythematopurpuric patches with sharply pointed purpuric elements on the buttocks Figure 2Open in figure viewerPowerPoint Similar lesions on the lower limbs Histopathologic examination of a cutaneous specimen showed numerous atypical lymphocytes in the superficial dermis, slight changes at the dermo-epidermal junction, and an intense epidermotrophism, with atypical lymphocytes in the epidermis. These intraepidermal atypical lymphocytes were present both isolated and forming aggregates of 4-7 cells (Fig. 3). Immunohistochemical studies demonstrated that these lymphocytes were T-helper cells. Figure 3Open in figure viewerPowerPoint Atypical lymphocytes in the superficial dermis, slight changes at the dermo-epidermal junction, and intense epidermotrophism, with atypical lymphocytes. Intraepidermal lymphocytes were present both isolated and forming small cellular aggregates Routine laboratory tests were normal, except for slight hypercholesterolemia. Direct examination of peripheral blood, coagulation, antinuclear antibody (ANA) immunofluorescent test, body scanner, and bone marrow study were normal. CTCL stage IB was diagnosed and psoralen plus UVA (PUVA) therapy was initiated.

Monoclonality of Intraepidermal T Lymphocytes in Early Mycosis Fungoides Detected by Molecular Analysis after Laser-Beam-Based Microdissection

The identification of neoplastic lymphocytes in early lesions of mycosis fungoides is difficult because of the scarcity of the infiltrate and the presence of reactive T lymphocytes admixed with neoplastic cells. Molecular analysis of the T cell receptor gene rearrangement using the polymerase chain reaction technique demonstrates monoclonality only in a proportion of these cases. The exact location of the malignant clone is unknown, and at present it is not clear whether neoplastic cells in early lesions reside within the epidermis, the superficial dermis, or both. We analyzed skin lesions from five patients with early mycosis fungoides using the polymerase chain reaction technique after microdissection of the specimens. In each case the epidermis was separated from the dermis using a laser-beam microdissection technique. Three samples were prepared from each lesion: one containing only the epidermis, one only the superficial dermis, and one the entire specimen. A distinct band could be observed in the epidermal sample in four cases, indicating the presence of an intraepidermal monoclonal population of T lymphocytes. The dermal sample revealed a monoclonal pattern in two cases (both of them showing clonality also within the epidermis). Analysis of the entire specimen revealed a monoclonal pattern only in two cases. Our results demonstrate that intraepidermal lymphocytes in early mycosis fungoides often show a monoclonal pattern of T cell receptor gene rearrangement. Microdissection of biopsy specimens may enhance the sensitivity of the polymerase chain reaction technique.

Atypical pigmentary purpura: A clinical, histopathologic, and genotypic study

Background: The pigmentary purpuras (PPs) are a heterogeneous group of dermatoses defined by specific clinicopathologic features but sharing, at the light microscopic level, superficially disposed dermal lymphocytic infiltrates and hemorrhage. The term atypical pigmentary purpura (APP) is used by the authors in reference to cases of PP in which individual lesions, although clinically presenting as PP, show morphological features typically associated with mycosis fungoides (MF) including Sezary cells and epidermotropism. The integrated concept of lymphocyte atypia and PP is a confusing and enigmatic one to which reference in the literature has been previously made. Specifically, there are reports of PP presaging fully evolved MF, lymphoid atypia has been identified in lesions of routine PP and MF with purpuric features has been described. The clinical, light microscopic, and genomic features of biopsied lesions showing pathological features of APP and which clinically were consistent with PP is explored. Design: The light microscopy of skin biopsy specimens from 34 patients with a pathological diagnosis of APP was correlated to medical and drug histories. In 14 cases, adequate tissue was present in the paraffin blocks to allow DNA extraction. The polymerase chain reaction (PCR) was used in these 14 cases to explore for rearrangement of the T-cell receptor. Fisher's exact test and pair wise exact tests were used to assess the significance of histological differences between cases determined by clinical features to be of MF- or drug-related origin, or to be idiopathic in nature. Results: Of 34 patients, 7 were held to have MF related PP; specifically these patients had violaceous, infiltrative, variably purpuric plaques on trunk, buttocks, and thighs accompanied by typical PP lesions which occurred either concomitant to or preceded the MF lesions. In 10 cases, a diagnosis of idiopathic PP was made whereby the clinical presentation was characteristic of PP; there were no concomitant lesions suspicious for MF and a drug-based origin was excluded. A drug-based origin was established in 17 patients based on lesional onset related to initiation (5 patients) and/or resolution after discontinuation (12 patients) of drugs including calcium channel blockers, lipid-lowering agents, β-blockers, angiotensin-converting enzyme (ACE) inhibitors, antihistamines, antidepressants, or analgesics. There was considerable overlap histologically between all 3 groups including the degree of lymphoid atypia in the dermis, the presence of dermal-based Sezary cells, the degree and pattern of epidermotropism, the paucity of other inflammatory cell elements, and the presence of laminated dermal sclerosis. Morphological features predictive of MF related APP over the other 2 groups were intraepidermal lymphocytes which were more atypical than the dermal-based infiltrate. Intraepidermal Sezary cells were less frequent in biopsies of drug-related APP relative to idiopathic PP (IPP) and MF related PP. PCR studies conducted in 14 cases (2 cases of MF, 6 cases of drug-related APP, and 6 cases of IPP) revealed clonality in 2 cases of drug-related APP and 2 cases of IPP; the 2 studied MF-related cases did nor show clonal restriction. Conclusion: APP should not be equated with purpuric MF; it is not necessarily a precursor lesion of MF, and may be of drug-based origin. Clinical features are critical to the final assessment because there is overlap pathologically in the 3 clinical subtypes of APP.

Intraepidermal lymphocytes in psoriatic lesions are activated GMP-17(TIA-1)+CD8+CD3+ CTLs as determined by phenotypic analysis.

The onset and persistence of psoriatic lesions are linked to the presence of an inflammatory infiltrate of CD3+ lymphocytes that includes CD4+ and CD8+ subsets. Since a primary susceptibility factor for psoriasis is the Class I HLA-Cw6 molecule, we set out to learn more about the features of the epidermal CD8+ lymphocytes. The markers tested were GMP-17, a cytotoxic granule protein found in activated cytotoxic lymphocytes (CTLs), and the alpha chain of the IL-2 receptor (CD25), a plasma membrane molecule found on activated T cells. Lymphocytes in lesional skin expressed the GMP-17 protein, whereas lymphocytes in non-lesional skin, resolving lesional skin and normal skin had little or no GMP-17. By flow cytometry analysis, lesional epidermal GMP-17+ cells were CD8+CD3+, with a subpopulation expressing the activation marker CD25+. Due to the abundance of activated GMP-17+CD8+CD3+ lymphocytes (the phenotype of activated cytotoxic cells) in psoriatic lesions compared to non-lesional and normal skin, we hypothesize that they are contributing directly to the psoriatic phenotype.

Reassessment of histologic parameters in the diagnosis of mycosis fungoides.

The histologic diagnosis of mycosis fungoides (MF) can be difficult to establish and is based on interpretation of numerous subtle changes, most of which may be present to some degree in many inflammatory and neoplastic cutaneous conditions. To reassess the diagnostic criteria for making a histologic diagnosis of MF, we retrospectively reviewed histologic sections from 64 patients with mycosis fungoides (MF+) and compared the findings with sections from 47 patients who were biopsied to exclude MF and were shown not to have the disease (MF-). Patients were selected as MF+ or MF- independent of histologic findings based on the clinical course with at least 3 years of follow-up and immunophenotyping results. Following patient selection, at least two observers reviewed each slide without knowledge of final diagnosis and graded the intensity of approximately 25 histologic parameters. On univariate analysis, the following parameters were significant at beyond the p = 0.01 level: Pautrier's abscesses, haloed lymphocytes, exocytosis, disproportionate epidermotropism, epidermal lymphocytes larger than dermal lymphocytes, hyperconvoluted intraepidermal lymphocytes, and lymphocytes aligned within the basal layer. Haloed lymphocytes proved to be the most robust discriminator of MF from non-MF on multivariate analysis. These findings show that whereas many previously described features do discriminate between MF and inflammatory mimics, others are much less specific. Furthermore, few cases demonstrate all histologic features; for example, Pautrier's microabscesses were seen in only 37.5% of our cases. We conclude that a combination of specific histologic parameters can be used to establish a microscopic diagnosis of MF without the necessity of confirmatory immunophenotyping in the vast majority of cases.

Differential expression of adhesion molecules on infiltrating cells in inflammatory dermatoses

Adhesion molecules and their ligands are involved in coordination of the activities of the immune system. To evaluate whether adhesion molecules are relevant in the pathogenesis of inflammatory dermatoses, we analyzed the expression pattern of many of these molecules. The expression of 10 members of the integrin and immunoglobulin superfamilies was mapped by means of immunohistochemical techniques in biopsy specimens of psoriasis (n = 15), pityriasis lichenoides (n = 11), parapsoriasis en plaques (n = 11), contact dermatitis (n = 7), and lichen planus (n = 5). In all investigated skin diseases, almost every infiltrating cell expressed lymphocyte function-associated antigens 1 and 3 as well as very late activation (VLA) antigens 4 and 5. The subepidermal infiltrate differed with regard to the expression of VLA-1, VLA-3, and VLA-6, which was high in lichen planus and moderate or absent in the other dermatoses. The intraepidermal lymphocytes in psoriasis and pityriasis lichenoides were VLA-1 positive, whereas the subepidermal infiltrate lacked this marker. The differential upregulation of adhesion molecules in the mononuclear infiltrate and on keratinocytes demonstrates their importance in the pathogenesis of cutaneous inflammation.

Characterization of intercellular adhesion molecule-1 and HLA-DR expression in normal inflamed skin: Modulation by recombinant gamma interferon and tumor necrosis factor

Lymphocytes bind to cultured keratinocytes that are treated with interferon gamma (IFN-γ) and tumor necrosis factor (TNF). When the lymphocytes are preincubated with antibody to lymphocyte function associated antigen—1 (LFA-1), this adherence is inhibited. Because intercellular adhesion molecule—1 (ICAM-1) is a ligand for LFA-1, we studied the cellular expression of ICAM-1, as well as two other IFN-γ-inducible antigens, (HLA) human lymphocyte antigens DR and DQ, in both normal and diseased skin. The modulation of these cell surface antigens by IFN-γ and TNF with the use of short-term organ cultures of skin was compared with isolated keratinocytes grown in a conventional tissue culture system. While in normal skin, keratinocytes did not express HLA-DR, DQ, or ICAM-1, when organ cultures were supplemented with IFN-γ, rapid induction of keratinocyte ICAM-1 expression occurred after 24 hours; HLA-DR but not DQ expression occurred after 48 hours. TNF also induced keratinocyte ICAM-1 expression (although to a lesser degree than IFN-γ) but did not induce either keratinocyte HLA-DR or DQ expression. There was good correlation of keratinocyte expression of ICAM-1 and HLA-DR by IFN-γ and TNF when the epidermis of the organ culture system was compared with the isolated keratinocytes grown in tissue culture. The presence of intraepidermal lymphocytes correlated extremely well with keratinocyte ICAM-1 expression but not with keratinocyte HLA-DR expression in psoriasis, atopic dermatitis, lichen planus, and mycosis fungoides. The intensity of endothelial cell expression of ICAM-1 correlated with the degree of dermal inflammation. We conclude that IFN-γ, once produced by activated T lymphocytes in the dermis, may be of importance in lymphocyte trafficking in the epidermis by the induction of keratinocyte ICAM-1 expression. The use of the short-term organ culture system, in which there is inducible ICAM-1 expression, provides an experimental bridge between purely in vitro and in vivo investigations to further our understanding of the molecular basis for lymphocyte apposition to keratinocytes in the skin.

Cytotoxic T lymphocytes and phenotypically abnormal epidermal dendritic cells in fixed cutaneous eruptions

Fixed cutaneous eruptions are erythematous plaques or bullae that recur, often after drug ingestion, at precisely the same cutaneous sites. The study of this condition may provide insight into the mechanisms responsible for regionally localized, immunologically mediated dermatoses. Biopsy specimens from both advancing borders and established centers of fixed eruptions were studied by immunofluorescence microscopy, light microscopy (1-micron sections), and transmission electron microscopy, and with a panel of monoclonal antibodies to Langerhans cells and subsets of T lymphocytes. The dermal inflammatory infiltrates of the advancing edges of the lesions were composed predominantly of OKT4/Leu-3a-positive lymphoid cells in perivascular array. In more established regions (the centers of the lesions), the majority of mononuclear cells were OKT8-positive lymphocytes disposed along the dermal-epidermal junction and migrating into the epidermis through focal defects in the basement membrane. In these areas, keratinocyte reactivity for anti-HLA-DR antibody and the apposition of intraepidermal lymphocytes to degenerating keratinocytes were observed. T6-positive epidermal dendritic cells were observed in normal numbers in the epidermis, although extensive study failed to reveal characteristic Langerhans cell granules within these cells. It is concluded that fixed cutaneous eruptions are characterized by an early vascular phase involving lymphocytes with helper/inducer phenotypes, and a later epidermal phase involving cytotoxic/suppressor cells. Potential effector cells with the phenotypic characteristics of cytotoxic T cells appear to represent important mediators of the epidermal damage characteristic of fixed cutaneous eruptions. Morphologically abnormal epidermal dendritic cells may contribute to regionally altered antigen presentation and may thus be relevant to the recurrence of lesions at identical cutaneous sites.

Verrucous lupus erythematosus: Ultrastructural studies on a distinct variant of chronic discoid lupus erythematosus

Ten patients with classic discoid lupus erythematosus of the face associated with verrucous, papulonodular lesions on the arms and hands were studied by electron microscopy. The ultrastructural findings on the verrucous lesions included apoptotic keratinocytes, intraepidermal lymphocytes, and gapping, detachment, and reduplication of the basal lamina. Also, tubuloreticular inclusion bodies were present in the endothelial cells. These observations, together with the clinical, histopathologic, and immunofluorescence findings, suggest that the verrucous lesions represent a rare, but distinct, variant of chronic discoid lupus erythematosus.

Histopathologic Diagnosis of Pityriasis Lichenoides et Varioliformis Acuta and Its Clinical Correlation

To assess the specificity of the histopathologic features in the diagnosis of pityriasis lichenoides et varioliformis acuta (PLEVA), we reviewed the clinical manifestations and courses of 42 patients for whom this diagnosis was suggested in the pathology report. The histologic diagnosis of PLEVA was clinically substantiated in 16 of these 42 cases. Of the 26 cases in which PLEVA was erroneously diagnosed histologically, the correct clinical diagnosis was suggested before biopsies were done in 21 instances. In the five remaining cases, both the prebiopsy clinical diagnosis and the pathologic diagnosis proved to be incorrect. Pityriasis rosea, insect bites, and eczematous dermatitis accounted for the majority of the cases that histologically mimicked PLEVA. The constellation of histologic findings described in PLEVA (presence of intraepidermal lymphocytes and erythrocytes, dermal hemorrhage, and so-called lymphocytic vasculitis) is not specific and may be seen in a variety of dermatologic disorders.

Fine structure of lymphoid cells in the nasal skin of primates.

Electron microscopy of the nasal skin of primates shows that lymphoid cells are normally present in this region. No degeneration or mitosis of these cells or their transformation into other cell types was seen. These intraepidermal lymphocytes contained cytoplasmic fibrils. There was no evidence that they were phagocytic in the epidermis. The present study suggests that these lymphoid cells migrate into the lamina propria but not into the epidermis.