The nosology of parapsoriasis

Critical Review-A Tribute to Louis Brocq Lymphomatoid Papulosis, the Key in Exploring the Relationship of Parapsoriasis and Mycosis Fungoides

ABSTRACT

Both parapsoriasis and LyP appear clinically as inflammatory dermatoses with a paradoxical link to cMF. A key element in addressing the relationship of parapsoriasis and MF were the results of the French and Dutch long-term registries tracking the emergence of lymphomas in the setting of LyP. Both cMF and cALCL emerged almost equally in these long-term studies. This ultimately supports that the stem cells in both cMF and cALCL are probably derived from a common stem cell shared by CD4+/CD8+ memory stem cells defining cMF and CD30+ stem cells defining cALCL. The discovery of inducible Skin Associated Lymphoid Tissue (iSALT) mesenchymal hubs incorporating Tregs, with their pleiotropic functions represents a paradigm shift and formed a translational tool in this analysis of the paradox. LyP can be recast as activated inhibitory lymphomatoid T-cell hubs derived from inducible iTregs in iSALT and the source of the common stem cell LyP line. iSALT Treg integrated mesenchymal hubs provided an emerging translational tool in redefining integrated lymphomatoid pathways. Brocq's complex scheme defining parapsoriasis as hybrid inflammatory dermatoses with a paradoxical link to cMF became a template to preserve parapsoriasis as a clinical diagnosis. Two major iSALT Treg generated inhibitory integrated lymphomatoid hubs emerged. The major CD30+TNF lymphomatoid hub has been linked to cALCL. Clinically defined chronic regressing and relapsing parapsoriasis with the histopathology of patch stage MF can be redefined as lymphomatoid parapsoriasis. This twin inhibited oncogenic memory based hub is defined by Treg modulated, CD4+/CD8+memory linked PD-1/DL-1 cytoxic complex and lichenoid histopathology.

The histopathological landscape of the major psoriasiform dermatoses

Psoriasiform dermatoses represent a wide spectrum of inflammatory conditions, with several major forms represented by psoriasis, as the prototype of this category, followed by pustular psoriasis, Reiter's syndrome, pityriasis rubra pilaris, lichen simplex chronicus and large-plaques parapsoriasis. They create a diagnostic challenge, both clinical and histopathological, because of their complexity and frequent overlapping of the microscopical features. The characteristic histopathological features of psoriasiform reaction comprise extensive hyperkeratosis, with horizontally confluent but vertically intermittent parakeratosis, which alternate with orthokeratosis, thin granular layer, with relative frequent mitoses, uniform elongated and fused rete ridges, edematous superficial papillary dermis, with dilated capillaries, perivascular lymphocytic infiltrate, Munro's microabscesses, and spongiform pustules of Kogoj. Our paper aims to review the histopathology of major form of psoriasiform dermatoses and to emphasize the characteristic microscopical differences between them, for a better approach of the diagnosis as an important key for clinical and therapeutical management. Using the clinicopathological correlations, a thoroughly evaluation of the microscopical features and compartments distribution or special stainings and techniques, the range of differential diagnosis can be decreased and a more accurate diagnostic can be usually achieved. The insights into the pathogenic mechanisms can lead to new therapeutic opportunities targeted to the specific type of inflammatory lesion.

[Clinical heterogeneity of poikilodermatous mycosis fungoides: A retrospective study of 12 cases]

INTRODUCTION

Poikilodermatous mycosis fungoides is a rare and indolent clinical variant of mycosis fungoides (MF). It can be difficult to distinguish from poikilodermatous parapsoriasis, a group of chronical dermatoses that may sometimes progress to MF. We aimed to specify the clinical, histopathological and developmental features of these entities by means of a retrospective study of 12 cases followed in our center.

PATIENTS AND METHODS

We identified cases of poikiloderma for which a diagnosis of MF or parapsoriasis was made by the physician. Photographs and histological slides were reviewed, and a final diagnosis of MF was made if the International Society for Cutaneous Lymphoma criteria for the diagnosis of early MF were fulfilled.

RESULTS

Twelve patients were included, 10 of whom met of the MF criteria. 5 patients had large poikilodermatous patches or thin, well-defined plaques ; 3 patients had the same lesions associated with classical MF lesions ; finally, 4 patients had widespread ill-defined erythematous lesions in a net-like pattern, described as parakeratosis variegata, including 3 MF. 2 patients with well-defined lesions (one associated with classical MF lesions) progressed to the tumoral stage whereas none of the patients with parakeratosis variegata presented such progression. A total of 5 patients had a high skin phototype (IV and V). Two patients had squamous cell carcinoma on poikilodermatous lesions.

DISCUSSION

Our study suggests that poikilodermatous MF covers a heterogeneous clinical spectrum comprising on one hand a presentation of delimited lesions sharing classical MF risk of progression, and on the other, an entity similar to parakeratosis variegata, an entity overlooked in the French nomenclature, which was particularly benign in our small series, raising the question of its affiliation to the MF group. This question merits further investigation in a larger-scale study.

Poikilodermatous Mycosis Fungoides: Comparative Study of Clinical, Histopathological and Immunohistochemical Features

BACKGROUND

Poikilodermatous mycosis fungoides (pMF) is characterized by poikiloderma areas, typically involving the major flexural areas and trunk. Its presentation can be generalized or admixed with other forms of MF. Previous studies fail to correlate the clinical presentation with prognosis and laboratory findings. Some reports show pityriasis lichenoides chronica (PLC) preceding the poikiloderma.

OBJECTIVES

Correlate prognostic, histopathological and molecular aspects of pMF with its clinical presentation.

METHODS

Retrospective analysis of 14 cases of generalized pMF (GpMF), 22 of localized pMF (LpMF) and 17 of pMF admixed with other forms of MF (mix-pMF).

RESULTS

Female predominance and lower age at diagnosis was found in all groups compared to classic MF, a high prevalence of PLC-like lesions in the GpMF group and a high rate of hypopigmented lesions in the mix-pMF group. There were 2 deaths within the GpMF group. Histology was similar to previously reported findings, as was the prevalence of CD4 T-cell infiltrate, compared to CD8. The T-cell clonality positivity was lower in the GpMF group, compared to other groups (27% GpMF, 80% LpMF and 100% mix-pMF).

DISCUSSION

This is the first article to categorize the different forms of pMF and correlate them with clinical and laboratory findings. The dermatological presentation differs among the groups. There was a high frequency of PLC-like lesions within the GpMF group and of hypopigmented lesions in mix-pMF. The histological and immunohistochemical findings were similar to those previously reported. Aggressive treatments are not recommended due to the good prognosis of all pMF forms. The low positivity of T-cell clonality in the GpMF group should be investigated.

Risk of venous thromboembolism in patients with mycosis fungoides and parapsoriasis: A Danish nationwide population-based cohort study

BACKGROUND

Mycosis fungoides (MF) and parapsoriasis are characterized by malignant proliferation and chronic inflammation, which may affect the risk for venous thromboembolism (VTE).

OBJECTIVES

To examine the risk for VTE in patients with MF and parapsoriasis.

METHODS

We conducted a nationwide population-based cohort study in Denmark to examine the relative risk (RR) of VTE in 525 patients with MF and 634 patients with parapsoriasis compared with that in sex- and age-matched controls from the general population.

RESULTS

In patients with MF, the 10-year absolute risk for VTE was 3.4% (95% confidence interval [CI], 2.0-5.4). The adjusted RRs were 2.41 (95% CI, 1.49-3.90) for VTE and 4.01 (95% CI, 2.16-7.46) for pulmonary embolism. Notably, within the first 5 years after diagnosis with MF, the RR of pulmonary embolism was increased 6.7-fold (to 6.71 [95% CI, 2.86-15.72]). Patients with parapsoriasis had a 2.7-fold increased RR of VTE (to 2.67 [95% CI, 1.32-5.40]) in the absence of other established VTE risk factors.

LIMITATIONS

We had no information regarding disease stage of MF and prescribed drugs.

CONCLUSION

Patients with MF and parapsoriasis had an increased RR of VTE, although the absolute risk remained low. These findings should increase awareness of comorbidities in patients with MF and parapsoriasis.

Subsequent cancers, mortality, and causes of death in patients with mycosis fungoides and parapsoriasis: a Danish nationwide, population-based cohort study

BACKGROUND

Data on subsequent cancers, prognostic factors for mortality, and causes of death are limited in mycosis fungoides (MF) and parapsoriasis.

OBJECTIVES

To assess subsequent cancers, mortality, and causes of death in MF and parapsoriasis.

METHODS

Using the Danish nationwide population-based registries, we identified 368 MF patients and 582 parapsoriasis patients and compared them with the general Danish population for subsequent cancers, mortality, and causes of death.

RESULTS

Subsequent cancers were significantly increased in parapsoriasis patients (standardized incidence ratio [SIR], 2.0 [95% confidence interval {CI}, 1.6-2.5]), and a trend was observed in MF (SIR, 1.2 [95% CI, 0.9-1.5]). Mortality was significantly increased in MF (SIR, 2.0 [95% CI, 1.8-2.3]) and parapsoriasis (SIR, 1.3 [95% CI, 1.1-1.5]). Excess mortality from MF was highest during the first 5 years of follow-up, and causes of increased death included both malignant and nonmalignant diseases.

LIMITATIONS

We have no information regarding clinical stage, treatments, and patient lifestyles.

CONCLUSION

Patients with parapsoriasis had a significantly increased risk of subsequent cancers and increased mortality. In addition, the highest excess mortality in the MF group was observed during the first 5 years of follow-up, which suggests that MF exists in both an aggressive and a more indolent form.

Ichthyosiform large plaque parapsoriasis: report of a rare entity

Large plaque parapsoriasis (LPP) is an idiopathic, chronic scaly dermatosis classified within parapsoriasis group of diseases, occurring commonly in middle aged patients of all races and geographic regions. LPP and its variants are closely related to the patch stage of mycosis fungoides. The two types of LPP mostly described are the poikilodermatous and retiform parapsoriasis. We are reporting an ichthyosiform LPP for its rarity.

Parapsoriasis lichenoides/parapsoriasis variegata--a new concept

We present a new concept on the nosology of parapsoriasis lichenoides (= parakeratosis variegata) and show that this parapsoriasis type is not a separate entity. It represents different diseases: a large number of cases presenting as reticular parapsoriasis are mycosis fungoides, another group represents reticular variants of the parapsoriasis guttata group (pityriasis lichenoides acuta et chronica). Further, cases exist that can be classified as lichen planus reticularis or other diseases (e. g. keratosis lichenoides).

Parapsoriasis: a complex issue

Parapsoriasis is a peculiar reaction pattern of the skin that appears to have a spectrum with small plaque parapsoriasis at one end and large plaque at the other. The spectrum between is bridged by pityriasis lichenoides, pityriasis lichenoides chronica, pityriasis lichenoides et varioliformis acuta, and lymphomatoid papulosis. The highlights of the clinical pattern of these diseases has been succinctly elucidated here to facilitate their recognition in day-to-day dermatologic practice. Their possible etiopathogenesis has been brought to focus in the light of changing concepts reported in the literature. Further, possible future implications demand a meticulous follow-up because, in a few cases, true neoplasms may ultimately develop. Treatment modalities are briefly discussed.

Pityriasis lichenoides and its subtypes

Pityriasis lichenoides represents a unique group of inflammatory skin disorders that include pityriasis lichenoides et varioliformis acuta (PLEVA), febrile ulceronecrotic Mucha-Habermann disease (a subtype of PLEVA), and pityriasis lichenoides chronica. The history, epidemiology, clinical features, pathophysiology, and treatment of this group of conditions are reviewed in this manuscript.

Early-stage mycosis fungoides, parapsoriasis en plaque, and pregnancy

BACKGROUND

Non-Hodgkin's lymphoma (NHL) coincident with pregnancy is rare, and the literature regarding mycosis fungoides (MF), the most common primary cutaneous NHL, and pregnancy is strikingly sparse. The effect of pregnancy on MF, or on parapsoriasis en plaque (PPP), and the effect of these diseases on pregnancy, are still unknown.

OBJECTIVE

To study the effect of pregnancy on MF and PPP and the impact of these diseases on pregnancy.

METHODS

The files of the MF and PPP patients seen during the past 12 years in our department were reviewed to search for patients who had been pregnant during the course of their disease.

RESULTS

Nine women who met the study criteria were identified, seven with early-stage MF and two with PPP. A total of 12 pregnancies was recorded: nine in patients with MF and three in patients with PPP. In none of the patients was there any indication that pregnancy changed the course of MF or PPP. Of the 12 pregnancies, 11 were normal; one was naturally aborted. Two of the patients were treated with topical steroids during pregnancy. One patient was treated with narrow-band ultraviolet-B combined with topical steroids. The rest preferred to avoid any therapy.

CONCLUSIONS

Pregnancy appeared to have no impact on the course of early MF or PPP, and no adverse effect was noted on pregnancy. Further studies are needed to clarify the interplay between pregnancy and MF or PPP.

UVB therapy of pityriasis lichenoides - our experience with 29 patients

BACKGROUND

Pityriasis lichenoides comprises a clinical and pathological spectrum of disorders. So far no highly effective treatment has been reported. Previous small studies have suggested that ultraviolet B (UVB) is a good alternative.

METHODS

This is a retrospective analysis of 29 pityriasis lichenoides patients treated in our institution with broad- or narrow-band UVB during the period 1996-2002. Twenty-one of these patients had one or more previous unsuccessful treatments.

RESULTS

Complete response was achieved in 93.1% in both treatment groups, with 73% of them still relapse free after a mean follow-up of 58 and 38 months in broad- and narrow-band UVB treatment groups, respectively. Mild side-effects were observed in about one-third of the patients.

CONCLUSION

We believe both forms of UVB are a good option for pityriasis lichenoides and should be considered as the first line in generalized cases interested in treatment.

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.

Histopathology and genetics of cutaneous T-cell lymphoma

There is emerging evidence that genomic and chromosomal instability are features of CTCL, including variants such as MF, Sézary syndrome, and primary cutaneous CD30+ LCAL, and that specific chromosomal abnormalities are common. Additional resolution of specific regions of chromosomal loss and gain are required to define putative genes that may be of fundamental pathogenetic importance in CTCL. Inactivation of well-defined cell cycle and TSG are common as for other types of NHL. The prognostic significance of these abnormalities in CTCL has yet to be determined. The dysregulation of specific transcription factors is of interest, but requires further study. It is hoped that greater understanding of these molecular abnormalities will permit the development of CTCL-specific therapies that alleviate suffering and prolong survival.

Pityriasis lichenoides: a clonal T-cell lymphoproliferative disorder

Pityriasis lichenoides (PL) is a papulosquamous disorder often considered a form of reactive dermatosis and classified with small plaque parapsoriasis (digitate dermatosis). However, some patients with PL have developed large plaque parapsoriasis (LPP) and mycosis fungoides (MF), and lymphoid atypia and T-cell clonality have been reported in lesions of PL. We set out to explore the possibility that PL is a form of T-cell dyscrasia. Cases were selected by natural language search from an outpatient dermatopathology database; 35 cases were reviewed and clinicians and patients were contacted. Hematoxylin and eosin-stained sections were examined and immunophenotyping was carried out on paraffin-embedded, formalin-fixed tissue using antibodies to CD2, CD3, CD4, CD5, CD7, CD8, CD20, CD30, and CD56. In paraffin-embedded tissue, T-cell receptor (TCR)-gamma chain rearrangement was sought through polymerase chain reaction single stranded conformational polymorphism analysis. There were 14 males and 21 females with a mean age of 40 years held clinically to have PL chronica (PLC) (28 cases) and/or PL et varioliformis acuta (PLEVA) (7 cases). Five patients developed large atrophic poikilodermatous and/or annular plaques compatible with MF and/or LPP in a background of typical PLC. All biopsies showed tropism of lymphocytes to an epidermis manifesting psoriasiform hyperplasia, dyskeratosis, parakeratosis, and intraepithelial collections of Langerhans' cells and lymphocytes mimicking Pautrier's microabascesses. Epidermal atrophy, dermal fibroplasia, poikilodermatous alterations, and a dominance of intraepidermal cerebriform cells were seen only in patients with chronic persistent disease (i.e., PLC) and in some cases corresponded with clinical progression to MF. All cases had a T cell-dominant infiltrate, with a CD7 deletion in 21 of 32 biopsies examined; the CD7-negative cells were typically the largest and most atypical forms, often in a cohesive array within the upper layers of the epidermis. In 17 biopsies in which a CD4 stain was satisfactory for evaluation, 50% or more of the intraepidermal population was CD4 positive in 8 biopsies, whereas in 11 biopsies 50% or more of the dermal infiltrate was CD4 positive. The CD4-positive cells frequently had a cerebriform nuclear morphology and were CD7 negative. Most cases had an admixture of CD8-positive lymphocytes in excess of 40% or more of the intraepidermal and/or dermal infiltrate; it was the dominant intraepidermal infiltrate in 10 cases. The CD8-positive cells, typically small, round, and CD7 positive, showed a directed pattern of migration into acrosyringia and suprapapillary plates, with satellitosis around CD4-positive/CD8-negative/CD7-negative atypical lymphocytes. CD56 positivity was seen among the intraepidermal lymphoid cells and roughly paralleled the CD8 profile. In general, CD8-positive lymphocytes dominated in cases of PLEVA, whereas CD4-positive lymphocytes were very conspicuous and composed the dominant intraepidermal populace only in those biopsies of progressive PL/PLC. Clonality was shown in 25 of 27 biopsies in which amplifiable DNA was obtained. Intraepithelial atypical lymphocytes, phenotypic abnormalities, and TCR-gamma rearrangements suggest that PLC and PLEVA are a form of T-cell dyscrasia. Lesions may follow a recalcitrant course characteristic of MF and premycotic disorders such as LPP. The aberrant phenotype cell is similar to that defining MF: a CD4-positive T lymphocyte with a CD5 and CD7 deletion. Directed epidermal migration seen in biopsies procured from incipient lesions along with occasional temporal association to viral or drug exposure suggests that an abnormal immune response to an antigenic trigger may be the inciting event.

Clonal T cell receptor gamma-chain gene rearrangement by PCR-based GeneScan analysis in the skin and blood of patients with parapsoriasis and early-stage mycosis fungoides

Cutaneous T cell lymphoma (CTCL) and reactive T cell skin diseases represent opposite ends of a spectrum of diseases ranging from overtly malignant to persistently benign. Within this spectrum, the parapsoriasis group is not clearly defined regarding malignant potential. In contrast to consistent findings in advanced-stage CTCL, clonality analysis of parapsoriasis has produced conflicting results in previous studies. As T cell receptor gamma-chain polymerase chain reaction GeneScan analysis (TCR-gamma-PCR-GSA) stands out by its sensitivity, its accuracy in size determination of PCR products, its capacity to identify false positives by repeated analysis and its easy applicability, this approach was used to analyse the clonality status of 41 patients with borderline T cell lymphoproliferative skin diseases, including parapsoriasis (n=27) and early-stage mycosis fungoides (MF) (n=14). A monoclonal T cell infiltrate was demonstrated by repeated TCR-gamma-PCR-GSA in lesional skin specimens in 19.2% of parapsoriasis patients and in 66.6% of early-stage MF cases (p=0.013). In peripheral blood, a monoclonal T cell population was found in a similar percentage of parapsoriasis and of early-stage MF patients (26.7% versus 12.5%; p=0.611). A detailed analysis of parapsoriasis subentities, namely small and large plaque parapsoriasis, and parapsoriasis lichenoides, revealed monoclonality in 2(6)/2(5), 3(14)/2(8) and 0(6)/0/(3) of the skin and peripheral blood specimens, respectively. The high detection rate of false positive cases by repeated analysis (20-37.5%) provides a corrected perspective for the high rates of dominant T cell clones found by others in the peripheral blood of such patients. From the results obtained, three major conclusions can be drawn: firstly, CTCL is clearly associated with detection of monoclonality, even in its early stages; secondly, monoclonality is not a prerequisite for potential CTCL precursor entities; and thirdly, recirculating malignant T cells identical to the skin clone are not readily detected in parapsoriasis or early-stage MF, but may rather indicate disease progression.

Cutaneous T-cell lymphoproliferative disorders: approach for the surgical pathologist: recent advances and clarification of confused issues

Cutaneous T-cell lymphoproliferative disorders (CTCLs) remain a subject of confusion and controversy. In this review, the authors discuss diagnostic criteria and classification, including the role of immunohistochemistry and gene rearrangement studies. In addition, cutaneous T-cell pseudolymphomas, the current status of parapsoriasis and other premalignant syndromes, and the clinicopathological variants of mycosis fungoides are discussed. CD30-positive lymphoproliferative disorders and a number of rare variants of CTCL including granulamatous slack skin, subcutaneous (panniculitic) T-cell lymphoma, gamma-delta cutaneous lymphoma, NK/NK-like T-cell lymphoma, and primary cutaneous CD8-positive epidermotropic cytotoxic T-cell lymphoma are also considered.

Primary cutaneous T-cell lymphoma: review and current concepts

PURPOSE

Primary cutaneous T-cell lymphomas (CTCLs) encompass a wide variety of lymphomas that are characterized by the localization of the malignant lymphocytes to the skin at presentation. Advances in molecular biologic techniques, including immunophenotyping and gene rearrangement studies to determine clonality, have led to more frequent diagnosis of CTCL as well as more consistent subclassification of these entities. However, there continues to be confusion in the classification, prognosis, and management of patients with CTCL. The purpose of this review is to present a summary of the diagnosis, prognosis, and treatment of CTCL, with specific emphasis on mycosis fungoides (MF) and Sézary syndrome (SS). We also present a detailed discussion of the entities that make up the differential diagnosis of CTCL.

DESIGN

We reviewed the medical literature on CTCL and other diseases that make up the differential diagnosis of CTCL.

RESULTS AND CONCLUSION

MF and SS are the most common forms of CTCL. The etiology of this disease is still unknown. Patients may go for months to years with skin abnormalities before being diagnosed. MF/SS is an indolent disease and patients with T1 disease have a normal life expectancy. Patients who undergo transformation to large-cell lymphoma (8% to 23% of patients) have a poor prognosis, with mean survival ranging from 2 to 19 months. Treatment for MF/SS continues to be palliative. There are many new therapies that are currently being investigated in clinical trials, and the DAB(389)IL-2 fusion protein was recently approved for the treatment of refractory MF/SS.

Demonstration of Frequent Occurrence of Clonal T Cells in the Peripheral Blood But Not in the Skin of Patients With Small Plaque Parapsoriasis

Clinical, immunohistological, and molecular biological data suggest the chronic dermatosis small plaque parapsoriasis (SPP) to be a precursor of mycosis fungoides (MF). However, most data are contradictory and confusing due to inexact definition of SPP. Recently, clonal T cells were detected in skin and blood samples of early MF. Because demonstration of identical T-cell clones in skin and blood of SPP patients would indicate a close relationship of SPP to MF, we investigated the clonality of skin and blood specimens from 14 well-defined SPP patients. By a polymerase chain reaction (PCR) amplifying T-cell receptor γ rearrangements and subsequent high-resolution electrophoresis, clonal T cells were detected in 9 of 14 initial and 32 of 49 follow-up blood samples, but in 0 of 14 initial skin specimens. Even a clone-specific PCR showing the persistence of the initial blood T-cell clone in 20 of 20 follow-up samples, failed to detect the T-cell clone in the skin. In 2 patients, the clonal T cells were shown to be CD4+. For the first time, the majority of SPP patients was shown to carry a T-cell clone in the peripheral blood. Although a relation between circulating clonal T cells and SPP cannot directly be proven by the applied techniques, our results indicate blood T-cell clonality to be a characteristic feature of SPP and CTCL because analysis of multiple controls and clinical workup of our SPP patients excluded other factors simulating or causing a clonal T-cell proliferation. A sufficient cutaneous antitumor response but also an extracutaneous origin of the T-cell clones might explain the failure to detect skin infiltrating clonal T cells.

Demonstration of Frequent Occurrence of Clonal T Cells in the Peripheral Blood But Not in the Skin of Patients With Small Plaque Parapsoriasis

Clinical, immunohistological, and molecular biological data suggest the chronic dermatosis small plaque parapsoriasis (SPP) to be a precursor of mycosis fungoides (MF). However, most data are contradictory and confusing due to inexact definition of SPP. Recently, clonal T cells were detected in skin and blood samples of early MF. Because demonstration of identical T-cell clones in skin and blood of SPP patients would indicate a close relationship of SPP to MF, we investigated the clonality of skin and blood specimens from 14 well-defined SPP patients. By a polymerase chain reaction (PCR) amplifying T-cell receptor γ rearrangements and subsequent high-resolution electrophoresis, clonal T cells were detected in 9 of 14 initial and 32 of 49 follow-up blood samples, but in 0 of 14 initial skin specimens. Even a clone-specific PCR showing the persistence of the initial blood T-cell clone in 20 of 20 follow-up samples, failed to detect the T-cell clone in the skin. In 2 patients, the clonal T cells were shown to be CD4+. For the first time, the majority of SPP patients was shown to carry a T-cell clone in the peripheral blood. Although a relation between circulating clonal T cells and SPP cannot directly be proven by the applied techniques, our results indicate blood T-cell clonality to be a characteristic feature of SPP and CTCL because analysis of multiple controls and clinical workup of our SPP patients excluded other factors simulating or causing a clonal T-cell proliferation. A sufficient cutaneous antitumor response but also an extracutaneous origin of the T-cell clones might explain the failure to detect skin infiltrating clonal T cells.

Atypical lymphoid infiltrates arising in cutaneous lesions of connective tissue disease

Atypical lymphoid infiltrates occurring in the setting of connective-tissue disease (CTD) comprise malignant neoplasms of B-cell or T-cell phenotypes and various reactive lymphoid hyperplasias, such as myoepithelial sialadenitis, lymphocytic thyroiditis, and lymphocytic interstitial pneumonitis. We describe 17 patients with atypical lymphoid infiltrates arising in cutaneous lesions of CTD, the spectrum of which included lupus erythematosus, dermatomyositis, relapsing polychondritis, and lichen sclerosus et atrophicus. There were two principal categories, pseudolymphoma and malignant lymphoma, the former representing 15 of the 17 cases. The clinical and histologic features and possible pathogenetic mechanisms are discussed.

Chromosomal abnormalities in cutaneous T-cell lymphoma and in its premalignant conditions as detected by G-banding and interphase cytogenetic methods

The etiology of cutaneous T-cell lymphomas (CTCL) is unknown. We studied the pattern of chromosomal abnormalities with G-banding and interphase in situ hybridization methods in blood mononuclear cells in 17 patients representing the different phases of CTCL or the premalignant condition, parapsoriasis en plaque, and in 10 control persons. We used biotinylated centromere-specific probes with fluorescent detection (FISH) for chromosomes 1, 11, 8, and 17 and similar, enzymatically detectable, digoxigenin-labeled probes for chromosomes 1, 6, 12, 17, and 18. In G-banding, all patients showed numerical and structural chromosome aberrations. Numerical aberrations of chromosomes 6, 13, 15, and 17, marker chromosomes, and structural aberrations of chromosomes 3, 9, and 13 were increased in mycosis fungoides (MF) compared with healthy controls. In four of five patients the detection of a chromosomal clone preceded relapse or progression of the disease. In FISH of interphase cells, the cells abnormal for chromosomes 8 or 11, and for all four chromosomes collectively, were increased in MF and in Sezary Syndrome (SS). FISH and G-banding methods agreed statistically significantly for the detection of monosomy. Also, digoxigenin-labeled probes hybridized to interphases or mitoses detected aberrations corresponding to those observed with G-banding. Thus, chromosomally abnormal cells can be found in the peripheral blood of both parapsoriasis en plaque and CTCL patients. They can be detected with interphase cytogenetical methods, which obviates the need for dividing cells, often difficult to accomplish in CTCL.

Immunoperoxidase techniques in the evaluation of cutaneous lymphocytic infiltrates

The widespread availability of immunoperoxidase technology and antibody probes over the past 15 years has changed the discipline of dermatopathology. In no aspect is this more evident than in the microscopic study of cutaneous lymphoid infiltrates. In the following review, the discussion focuses on some of the ways in which immunophenotyping is used to enhance the diagnosis of cutaneous lymphoproliferative disorders. A strategy for the use of immunophenotyping in some common clinical situations is forwarded. The immunopathologic findings can be helpful in resolving problems in the differential diagnosis of lymphoma and mimics of lymphoma.

Th2 cytokine mRNA expression in skin in cutaneous T-cell lymphoma

We have previously demonstrated that peripheral blood mononuclear cells from patients with Sézary syndrome, the leukemic form of cutaneous T-cell lymphoma which is accompanied by erythroderma and lymphadenopathy, have a Th2 cell cytokine [interleukin 4 (IL-4) and interleukin 5] production pattern. In this study, we extend these observations to demonstrate a correlation of the presence of a Th2 cytokine pattern with a malignant T-cell clone in different stages of cutaneous involvement among patients with cutaneous T-cell lymphoma (CTCL). Skin biopsies were obtained from 12 CTCL patients with various disease stages (three patch, three plaque, six tumor), three patients with parapsoriasis, four patients with inflammatory dermatoses, including two psoriasis and two lichen planus, and 12 normal controls. Total RNA was extracted, reverse transcribed, and PCR amplified with IL-2, IL-4, IL-5, interferon gamma (IFN-gamma), and beta-actin oligonucleotide primers. Although all skin specimens tested had detectable IL-2 and IFN-gamma mRNA, only specimens from patients with CTCL or parapsoriasis had demonstrable IL-4 and/or IL-5 mRNA. Specifically, IL-5 mRNA was detected in skin biopsies from five of six tumor-stage CTCL, two of three plaque-stage CTCL, one of three patch-stage CTCL, and 1 of 3 parapsoriasis patients, whereas IL-4 mRNA was demonstrated to be present in five of six tumor-stage, one of three plaque stage, none of three patch-stage CTCL, and none of three parapsoriasis patients. These results indicate that in all stages of cutaneous involvement of CTCL, encompassing patch stage through tumor stage, IL-4 and IL-5 mRNA is variably detectable. In tumor-stage skin lesions, typically characterized by a dense dermal infiltrate of malignant T cells, Th2 cytokine mRNA is virtually always detectable. The ability to detect Th2 cytokine mRNA in the skin of patients with CTCL supports our previous findings that the malignant T cells in CTCL possess a Th2-helper cell phenotype.

Impact of non-CTCL dermatologic diagnoses and adjuvant therapies on cutaneous T-cell lymphoma patients treated with total skin electron beam radiation therapy

PURPOSE

To evaluate the impact of pre-cutaneous T-cell lymphoma dermatologic diagnoses and adjuvant therapies on the relapse-free and overall survivals of patients treated with total skin electron beam therapy.

METHODS AND MATERIALS

Between 1974 and 1990, 164 patients were evaluated by members of Yale University School of Medicine departments of Dermatology and Therapeutic Radiology and treated with total skin electron beam therapy to a total dose of 3600 cGy. Patients who achieved a clinical complete response were offered doxorubicin/cyclophosphamide chemotherapy, extracorporeal photopheresis, or no systemic adjuvant therapy. The effects of TNM stage, antecedent non-T-cell lymphoma dermatologic diagnoses, and systemic adjuvant therapies were analyzed for their impact on relapse-free and overall survival.

RESULTS

In this cohort of patients, an antecedent dermatologic diagnosis of follicular mucinosis or lymphomatoid papulosis was significantly associated with a shorter relapse-free survival for T1 and T2 patients, while antecedent "non-specific" dermatitides were associated with a somewhat better relapse-free survival. When the impact of systemic adjuvant therapies was analyzed, neither systemic doxorubicin/cyclophosphamide chemotherapy nor systemic extracorporeal photopheresis were found to delay cutaneous relapse.

CONCLUSION

Our results suggest that antecedent follicular mucinosis and lymphomatoid papulosis may be associated with short relapse-free survival in T1 and T2 patients treated with total skin electron beam therapy. They also imply that neither adjuvant chemotherapy nor extracorporeal photopheresis delay cutaneous relapse after total skin electron beam therapy.

Parapsoriasis en plaques: its potential for progression to malignant lymphoma

BACKGROUND

Parapsoriasis en plaques (large-plaque type) is a premalignant condition capable of developing into cutaneous T-cell lymphoma (CTCL). However, it is not known whether the early stage of CTCL can be distinguished from parapsoriasis en plaques.

OBJECTIVE

Our purpose was to determine whether parapsoriasis en plaques can develop into CTCL.

METHODS

The clinical appearance, histopathologic features, immunophenotype, DNA rearrangements, and clinical course were analyzed in 20 cases.

RESULTS

T-cell receptor beta-chain gene rearrangement was detected in four of the 20 cases. No clinical, histopathologic, or immunohistochemical differences were found between patients with and without gene rearrangement.

CONCLUSION

The early stage of CTCL cannot be differentiated from parapsoriasis en plaques by clinical features, histopathologic characteristics, or immunophenotype. Patients with parapsoriasis en plaques exhibit heterogeneous findings, which may include monoclonal proliferation. Patients with long-standing parapsoriasis-like lesions resistant to conventional treatment require careful monitoring for the possible development of cutaneous lymphoma.

T-cell receptor gene rearrangement studies as a diagnostic tool in lymphoproliferative skin diseases

The growth of our knowledge in T-cell biology, in particular the molecular biology of the T-cell receptor (TCR), has provided a means to molecularly characterize lymphoproliferative diseases of the skin based on the presence or absence of a clonal population of T lymphocytes. TCR gene rearrangement studies, by Southern blot analysis, have aided the investigative dermatologist in gaining insights into the pathogenesis and clonal evolution of lymphoproliferative skin diseases. In addition, the application of TCR gene rearrangement studies as a diagnostic aid in the evaluation of lymphoproliferative skin diseases has been introduced into clinical dermatology. Despite its enormous research value, TCR gene rearrangement studies presently have limited applications as an independent diagnostic tool. However, as our knowledge and experience grows and as the application of new techniques provides us with greater detection sensitivity and specificity, the diagnostic utility of TCR gene rearrangement studies will be enhanced.

T-cell receptor gene rearrangement analysis: cutaneous T cell lymphoma, peripheral T cell lymphoma, and premalignant and benign cutaneous lymphoproliferative disorders

T-cell receptor gene rearrangement analysis is a useful technique to detect clonality and determine lineage of lymphoid neoplasms. We examined 103 patients with mycosis fungoides, Sézary syndrome, peripheral T cell lymphoma, potentially malignant lymphoproliferative disorders including pre-Sézary syndrome, large plaque parapsoriasis, lymphomatoid papulosis and follicular mucinosis, and various benign inflammatory infiltrates. A clonal rearrangement was detected in skin samples in 20 of 24 patients with mycosis fungoides and in peripheral blood samples in 19 of 21 patients with Sézary syndrome. A clonal population was also detected in seven of eight cases classified as peripheral T cell lymphoma. The potentially malignant dermatoses tended to have clonal rearrangement, with the exception of large plaque parapsoriasis, and further follow-up is needed to correlate clonality with the disease course. These studies demonstrate the value of molecular genetics as an adjunct to morphology in the examination of patients with cutaneous lymphoproliferative disease.