Immunohistology of pityriasis lichenoides et varioliformis acuta and pityriasis lichenoides chronica. Evidence for their interrelationship with lymphomatoid papulosis

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.

Pityriasis Lichenoides: A Large Histopathological Case Series With a Focus on Adnexotropism

INTRODUCTION

Pityriasis lichenoides (PL) is an infrequent skin disorder. The clinical manifestations are usually specific enough for a reliable diagnosis, although the histopathological assessment of a biopsy is sometimes needed to differentiate between PL and a range of other diseases. The objectives of this study were to review cases of PL managed in our hospital, confirm the classical histopathological features of PL, and identify signs that may be of value in the diagnosis of PL.

MATERIALS AND METHODS

All cases of PL assessed in our pathology department between January 2007 and December 2017 were retrieved, and all slides were reviewed. Cases were selected only if a diagnosis of PL was initially suggested by a dermatologist and then confirmed by the histopathological assessment.

RESULTS

Seventy-one cases met the study criteria. The following features were almost always present: vacuolar changes or necrotic keratinocytes (100%), both superficial and deep lymphocytic infiltrates (99%), and the infiltration of lymphocytes into the adnexal epithelium (97%). The inflammatory cells were always small- to medium-sized lymphocytes. There were no eosinophilic infiltrates. Superficial perivascular and/or intraepidermal red blood cells were observed in 83% of cases.

DISCUSSION

We highlighted the presence of a deep dermal lymphocytic infiltrate, with a "T-shaped" periadnexal arrangement along the full length of the follicular and sudoral epithelia. This might be a feature that enables the differentiation of PL from other diseases. Our findings also prompted a number of physiopathological hypotheses for PL.

CONCLUSIONS

Our present results confirmed the classical histological aspects of PL and provided some useful new diagnostic features.

Febrile ulceronecrotic Mucha-Habermann disease

The Mucha-Habermann disease is an inflammatory disease of the skin and is a variant of pityriasis lichenoides et varioliformis acuta. We describe the case of a 64-years-old woman who was admitted for erysipelas of the face. Despite treatment, evolution was marked by the appearance of a necrotising ulcerative area in the centre of the erysipelas associated with local oedema and headache. A skin biopsy revealed a pityriasis lichenoides et varioliformis acuta. Corticosteroids led to a rapid stabilisation of lesions, and after 6 months the patient shows only a small area of frontal hypopigmentation. The aetiology remains uncertain. There is no established standard treatment. We would like to draw attention of the medical and surgical specialists to this rare disease. The diagnosis should be considered in a necrotic lesion associated with rapid expansion of systemic and peripheral cutaneous signs. Diagnosis must be considered to avoid unnecessary debridement and extensive scars.

Concordance between in vivo reflectance confocal microscopy and optical histology of lymphomatoid papulosis

BACKGROUND

Lymphomatoid papulosis is a primary cutaneous CD30+ T-cell lymphoma clinically characterized by a benign, chronic, recurrent course with self-limited papulo-nodular skin lesion eruption. In vivo Reflectance Confocal Microscopy is a non-invasive technique for real-time imaging of the superficial layers of the skin down to the superficial dermis with cellular-level resolution close to conventional histopathology. RCM has been previously reported to be useful in the in vivo evaluation of inflammatory diseases, skin tumours and also cutaneous lymphomas. Only two articles have been published on cutaneous lymphomas and none detailing confocal features of LyP. The aim of this manuscript was to describe the confocal features of LyP and their histological correlation to evaluate the possible application of this non-invasive tool in this T-cell lymphoma subtype clinical management.

METHODS

Five patients with histological diagnosis of LyP were imaged with RCM, followed by a skin biopsy on a clinically selected lesion.

RESULTS

High grade of correspondence between RCM and histopathology of LyP was observed, disclosing the potential rule of RCM at least for biopsy site selection.

CONCLUSION

Future studies on RCM for LyP vs. other cutaneous T-cells lymphomas and inflammatory skin diseases are needed to assess specificity and sensibility of our preliminary data.

Childhood pityriasis lichenoides and oral erythromycin

Pityriasis lichenoides (PL) is not uncommon in childhood, but current knowledge about the efficacy of oral erythromycin therapy for its treatment in children is limited. To investigate the role of oral erythromycin therapy in the treatment of PL in children, the records of 24 children with PL who had been started on oral erythromycin treatment at our institution between 2005 and 2008 were retrospectively reviewed. The study included 24 patients (14 male, 10 female) with a median age of 7 years (range 2-14) of whom 15 (62.5%) had PL chronica (PLC), six (25%) PL et varioliformis acuta (PLEVA), and three (2.5%) PLEVA-PLC overlap. History of upper respiratory tract infection was reported in 33% (n = 8) of the patients. History of drug intake and vaccination was noted in 20% (n = 5) and 20% (n = 5), respectively. The disease began during spring (30%, n = 7) or fall (30%, n = 7) in the majority of patients. The median duration of the disease was 11 months (range 1-48 months). Fifteen (68.2%) patients had more than 100 lesions. Distribution was diffuse in 82% (n = 18) of the cases and peripheral in the remainder (n = 6). Oral erythromycin was started at a dosage of 30 to 50 mg/kg per day in three to four divided dosages for 1 to 4 months. Good response was recorded in 64% and 73% of patients in the first and second months of therapy, respectively. Response rate rose to 83% in the third month. In those for whom follow-up data were available (n = 16), relapse was recorded in 12.5% (n = 3). Oral erythromycin may be an effective and well-tolerated treatment option for PL in children and should be continued for at least 3 months.

The use of synchrotron infrared microspectroscopy in the assessment of cutaneous T-cell lymphoma vs. pityriasis lichenoides chronica

BACKGROUND

The diagnosis of cutaneous lymphomas remains a challenge for both the clinician and dermatopathologist.

OBJECTIVES

To differentiate between frank malignant and premalignant lymphocytes within the skin.

METHODS

This study was performed on 20 patients with a mean age of 50 years. They were divided into two groups: mycosis fungoides (MF) (stage IA, IB and IIA) and pityriasis lichenoides chronica (PLC). Immunophenotyping using antibodies CD3, CD4, CD8, CD20 and CD30 was performed. Synchrotron Fourier transform infrared microspectroscopy (S-FTIRM) was performed on cell nuclei to assess chemical differences between MF and PLC cases as a potential complementary screening tool. Dermal spectra of both MF and PLC were compared using principal components analysis (PCA) of the S-FTIRM data.

RESULTS

All PLC spectra was clustered together. However, the MF spectra formed two clusters, one that grouped with the PLC and the other grouped separately. Moreover, protein and nucleic acids showed highly significant differences between MF (IIA and IB), MF (IA) and PLC.

CONCLUSIONS

The malignant transformation within lymphocytes was identifiable through the spectroscopic analysis of protein, RNA and DNA with S-FTIRM, making it a promising tool for classifying the progression of cutaneous T-cell lymphoma.

Narrowband UVB (311 nm, TL01) phototherapy for pityriasis lichenoides

BACKGROUND/PURPOSE

Narrowband (NB) UVB (NB-UVB) phototherapy has recently demonstrated high levels of efficacy and tolerability in a variety of skin diseases. The purpose of the present study was to assess the efficacy of NB-UVB phototherapy in the management of pityriasis lichenoides (PL).

METHODS

The therapeutic response in 31 PL patients (23 pityriasis lichenoides et varioliformis acuta; PLEVA, eight pityriasis lichenoides chronica; PLC) treated with NB-UVB phototherapy between 2000 and 2007 was assessed.

RESULTS

NB-UVB treatment led to a complete response (CR) in 15 out of 23 PLEVA patients (65.2%) with a mean cumulative dose of 23 J/cm(2) after a mean number of 43.4 exposures and a partial response (PR) in eight patients (34.8%) with a cumulative dose of 15.6 J/cm(2) after a mean number of 32.3 exposures. NB-UVB treatment led to CR in seven out of eight PLC patients (87.5%) with a mean cumulative dose of 18.4 J/cm(2) after a mean number of 45.8 exposures and PR in one patient (12.5%) with a cumulative dose of 9.1 J/cm(2) after a mean number of 19 exposures. Relapses occurred in four PL patients within a mean time period of 6 months.

CONCLUSION

NB-UVB therapy is an effective, safe and practical alternative treatment modality for the management of PLEVA and PLC.

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.

Lichenoid eruptions in children

Lichenoid eruptions are quite common in children and can result from many different origins. In most instances the precise mechanism of disease is not known, although it is usually believed to be immunologic in nature. Certain disorders are common in children, whereas others more often affect the adult population. Lichen striatus, lichen nitidus, Gianotti-Crosti syndrome, and lichen spinulosus are examples of lichenoid lesions that are more common in children than adults. Distinguishing these diseases is necessary for prediction of the course of the eruption and for optimal management. In most cases, certain clinical characteristics enable the clinician to reach a diagnosis, whereas in other cases biopsy is required for a definitive answer. Many of these lesions are self-limited and only require symptomatic treatment, although corticosteroids can hasten resolution in certain disorders. Discontinuation of the medication is often sufficient for resolution of lichenoid drug eruptions.

Pityriasis lichenoides: a cytotoxic T-cell-mediated skin disorder. Evidence of human parvovirus B19 DNA in nine cases

BACKGROUND

Pityriasis lichenoides et varioliformis acuta (PLEVA) and pityriasis lichenoides chronica (PLC) probably represent the polar ends of the same pathologic process, i.e. pityriasis lichenoides (PL), with intermediate forms in between. Previous studies have demonstrated that the inflammatory infiltrate in PLEVA is composed of cytotoxic suppressor T cells, whereas in PLC the helper/inducer T-cell population drives the immunological answer. Furthermore, monoclonal rearrangement of the T-cell receptor-gamma (TCR-gamma) genes was repeatedly found both in PLEVA and PLC.

METHODS

Forty-one formalin-fixed, paraffin-embedded tissue specimens of 40 cases of PL were retrieved from the files of the authors. Immunophenotyping for cytotoxic granular proteins (Tia-1/GMP-17 and Granzyme B) and T-cell-related antigens (n = 41), TCR-gamma chain gene analysis (n = 30) and molecular investigations for parvovirus B19 (PVB19) DNA (n = 30) were performed.

RESULTS

Overlapping immunophenotypes were observed in PLEVA and PLC. The dermal and epidermal T cells predominantly expressed CD2, CD3, CD8, and Tia-1 with a variable positivity for CD45RA, CD45RO, and Granzyme B. A monoclonal rearrangement pattern of the TCR-gamma genes was detected in three cases (10%). PVB19 DNA was found in nine cases (30%). T-cell monoclonality in conjunction with genomic PVB19 DNA was present in one case.

CONCLUSIONS

Our results demonstrate that PL is a skin disorder mediated by the effector cytotoxic T-cell population. The identification of PVB19 DNA in nine cases may be interpreted ambiguously: PVB19 as a true pathogen or as an innocent bystander.

Parakeratosis

The diagnostic value of parakeratosis is reviewed, with special emphasis on associated inflammatory tissue reaction patterns and the geometric pattern of the scale. Parakeratosis may also occur in disorders not primarily inflammatory in nature and those associations are addressed. Topics are divided into 6 categories: parakeratosis in the settings of spongiotic and interface dermatitis, disorders in which neutrophils are a prominent feature, "patterned" parakeratosis, parapsoriasis, and disorders of keratinization. The entities considered are diverse and major diagnostic features of each are reviewed.

Diagnostic role of tests for T cell receptor (TCR) genes

Rapid advances in molecular biological techniques have made it possible to study disease pathogenesis at a genomic level. T cell receptor (TCR) gene rearrangement is an important event in T cell ontogeny that enables T cells to recognise antigens specifically, and any dysregulation in this complex yet highly regulated process may result in disease. Using techniques such as Southern blot hybridisation, polymerase chain reaction, and flow cytometry it has been possible to characterise T cell proliferations in malignancy and in diseases where T cells have been implicated in the pathogenesis. The main aim of this article is to discuss briefly the process of TCR gene rearrangement and highlight the disorders in which expansions or clonal proliferations of T cells have been recognised. It will also describe various methods that are currently used to study T cell populations in body fluids and tissue, their diagnostic role, and current limitations of the methodology.

A case of febrile ulceronecrotic Mucha-Habermann disease requiring debridement of necrotic skin and epidermal autograft

We report a case of febrile ulceronecrotic Mucha-Habermann disease (FUMHD) in a 21-year-old man. This disease is a severe form of pityriasis lichenoides et varioliformis acuta (PLEVA) and is characterized by the sudden onset of diffuse ulcerations associated with high fever and systemic symptoms. It is sometimes lethal especially in elderly patients. In the present case, intense generalized maculopapular erythematous plaques with central necrosis developed progressively in association with a high fever. Initial treatment with systemic betamethasone had been unsuccessful and the skin lesions, which covered about 50% of the body surface, became severely ulcerated. Although the development of new lesions had ceased spontaneously, widespread ulceration of the skin remained. Debridement of the necrotic skin and skin grafting using cultured epidermal autografts and meshed allografts of cadaver skin led to prompt reepithelization.

Pityriasis lichenoides in a girl with the granulomatous form of common variable immunodeficiency

Pityriasis lichenoides (PL) is a cutaneous disease of unknown origin. In our 8-year-old female patient with the granulomatous form of common variable immunodeficiency (CVID), PL occurred together with massive splenomegaly and intra-abdominal lymphadenopathy. Prednisone was efficient for treatment of her splenomegaly and autoimmune cytopenias. However, PL was resistant to both topical and systemic steroid treatment. Healing of PL was achieved with the use of a super-potent topical steroid, clobetasol propionate. A defect of T-cell function in CVID may contribute to development of PL. In the granulomatous form of CVID, sarcoid-like granulomas are the most commonly reported cutaneous lesions. PL has not been previously reported.

Lymphomatoid papulosis

Lymphomatoid papulosis is a chronic disease of cutaneous lymphoid infiltration characterized clinically by involuting and recurring papules, plaques, and nodules. The intriguing combination of a usually benign clinical course, a cytologically malignant lymphoid infiltrate on histologic examination, and a clear, but sporadic association with extracutaneous lymphomas has stimulated significant investigation. Application of recent technical advances to research in lymphomatoid papulosis prompts this review.

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.

Pityriasis lichenoides in children: a long-term follow-up of eighty-nine cases

Pityriasis lichenoides is usually classified into an acute and a chronic form. From a review of 89 cases of the disease seen since 1974 it seems that a more realistic classification into three main groups, according to the distribution of pityriasis lichenoides lesions, could be made, namely, a diffuse, a central, and a peripheral form, each characterized by a different clinical course. Conversely, no correlations were detected in our series between the severity of skin lesions and their distribution or the overall course of the disease. None of our cases suggests the possible evolution of pityriasis lichenoides into lymphomatoid papulosis. Although no infectious causative agent has been identified, a viral origin seems likely in some cases. Most patients responded favorably to UVB irradiation. Our conclusions are (1) that pityriasis lichenoides is probably a clinical disorder with a diverse etiology and (2) that its classification by distribution seems more useful than its subdivision into an acute and a chronic form.

Leu-8/CD7 antigen expression by CD3+ T cells: comparative analysis of skin and blood in mycosis fungoides/Sézary syndrome relative to normal blood values

Deficiencies of Leu-8 and CD7 antigens are exhibited by CD3+ T cells in the skin lesions of most patients with mycosis fungoides/Sézary syndrome. To determine whether these antigenic abnormalities are limited to involved skin, we studied Leu-8/CD7 expression in 21 skin lesions of mycosis fungoides/Sézary syndrome obtained from 16 patients and compared them with their peripheral blood leukocytes obtained concurrently. There was no correlation between Leu-8/CD7 values in skin lesions versus blood. Blood values were relatively uniform; most patients had 50% or greater of CD3+, Leu-8+ T cells and CD3+, CD7+ T cells. In contrast, skin values were highly heterogeneous; most patients lacked expression of Leu-8 or CD7 by the majority of lesional CD3+ T cells. Furthermore, Leu-8/CD7 antigen deficiency was present in lesional skin in one patient with mycosis fungoides but not in her concurrently sampled pityriasis lichenoides chronica or blood. These findings suggest that Leu-8/CD7 antigen deficiencies in skin lesions of mycosis fungoides/Sézary syndrome do not represent generalized antigenic abnormalities of CD3+ T cells in other body compartments and that within the skin, these deficiencies are disease specific within individual patients with more than one dermatosis. Comparative peripheral blood immunophenotyping of the patients with mycosis fungoides/Sézary syndrome and of the control subjects indicated that the control ranges of CD3+/Leu-8+ and CD3+/CD7+ T cells (33% or greater) extend lower than reported previously (60% or greater) and suggested that leukemic involvement in patients with mycosis fungoides/Sézary syndrome may correlate with percentages of CD3+, Leu8+ and/or CD3+, CD7+ T cells that fall below the revised control range.

Lymphomatoid papulosis with antigen deletion and clonal rearrangement in a 4-year-old boy

Lymphomatoid papulosis (LyP) is rarely seen in children. We report a case of LyP in a 4-year-old boy in whom immunopathologic studies demonstrated T cell antigen deletions. In contrast to all but two previous reports, a T suppressor (CD-8) phenotype was predominant. Southern blot analysis of DNA isolated from a typical skin lesion indicated a clonal rearrangement of the T cell receptor beta gene. Because of a 10% frequency of malignant lymphomas in patients with LyP, long-term observation is crucial, especially in children. We recommend routine clonal rearrangement studies for aid in diagnosis and follow-up, and as possible prognostic indicators in children with this condition.

A case of lymphomatoid papulosis and Hodgkin's disease

Lymphomatoid papulosis is a unique paradoxic entity characterized by recurrent self-healing papulonodular lesions with histologic features of malignancy. Usually the disease has a protracted benign course; however, it can be associated with or evolve to a lymphoproliferative disorder. Thus "lymphoma-associated papulosis" represents the malignant end of a wide spectrum. We describe a case of a patient with lymphomatoid papulosis who developed Hodgkin's disease 8 years after the onset of skin lesions. Systemic chemotherapy achieved complete remission of Hodgkin's disease, but recurrent papulonodular lesions continued to form in the subsequent 18 months.

Actinic reticuloid: immunohistochemical analysis of the cutaneous infiltrate in 13 patients

An immunohistological study on cryostat sections of skin biopsies in 13 patients with actinic reticuloid has been performed using a panel of 21 monoclonal antibodies against lymphoid and non-lymphoid infiltrate cells. The infiltrate consisted of activated T cells, numerous histiocytes and macrophages, and small numbers of B cells. In 10 out of 13 patients the majority of the lymphocytes expressed the phenotype of suppressor cells. The number of Leu 8+ cells was inversely proportional to HLA-DR expression by the dermal infiltrate, which suggested a negative correlation between a state of activation and the concentration of Leu 8+ cells. There was a striking number of IgE bearing dendritic cells in the dermis associated with elevated serum IgE levels.

What's new in dermatopathology

This article reviews the recent English language literature on dematopathology, with an emphasis on publications appearing between January 1986 and July 1987. Immunohistochemistry continues to grow in importance as a diagnostic as well as a research technique. The advent of in situ deoxyribonucleic acid hybridization technology has raised diagnostic accuracy to a new level; it has already proved valuable in the diagnosis of certain viral infections. Areas that have received particular attention include phenotypic characteristics of lymphomas and lymphoma-like conditions, congenital melanocytic nevi and malignant melanoma, neuroendocrine carcinoma and other small cell tumors of the skin, sweat gland carcinomas, and eosinophil and its associated diseases, and unusual infectious diseases involving the skin.