CD8+ lymphomatoid papulosis and its differential diagnosis

We describe 5 cases (4 males, 14-43 years old; 1 female, 61 years old) of primary cutaneous T-cell lymphoproliferative lesions expressing a CD8/granzyme/CD30-positive phenotype. Four cases were compatible with lymphomatoid papulosis (LyP) based on the clinical course, which was recurrent asymptomatic papular nodular lesions over years responding to methotrexate; granulomatous inflammation and lack of other inflammatory cell elements were characteristic. In 1 case, an initial erroneous diagnosis was made of aggressive epidermotropic CD8+ T-cell lymphoma. The fifth case in this series was first interpreted as representing primary cutaneous anaplastic large cell lymphoma but was later recategorized as primary cutaneous aggressive epidermotropic CD8+ cytotoxic T-cell lymphoma owing to the extent of extracutaneous dissemination, including testicular involvement and disease progression despite chemotherapeutic intervention. Although all cases of LyP showed sharp cytoplasmic membrane staining with perinuclear Golgi accentuation with CD30, the recategorized case of aggressive epidermotropic CD8 cytotoxic T-cell lymphoma manifested only a weak cytoplasmic staining pattern. CD8 LyP defines a distinctive entity with characteristic light microscopic and phenotypic findings and has a predilection for young males. CD30 expression can occur in other forms of CD8 lymphoproliferative disease unrelated to primary cutaneous anaplastic large cell lymphoma or LyP.

Unusual histologic and clinical variants of melanoma: Implications for therapy

Unusual histologic variants of melanoma may prove problematic to the histopathologist. Several of these variants are sufficiently rare that their biological behavior remains obscure. Because identification of some of these melanoma subtypes has specific implications for the therapeutic approach and some may mimic other forms of epithelial or mesenchymal neoplasia, their recognition is key to patient management.

The future of dermatopathology

Of the major issues that dermatopathology will face in the immediate future, two powerful challenges loom large. The first is the application of novel nondestructive imaging technologies to in vivo diagnosis in humans. The second is the application of molecular technologies to a diagnostic arena which formerly belonged exclusively to the light microscopist. The first to be considered in this context is the application of near infrared spectroscopy to the noninvasive in vivo diagnosis of neoplastic skin disease. The second will be a discussion of application, methodology and the current state of the art in microarray technologies as they apply to neoplastic dermatopathology and, in particular, the diagnosis and prognostication of melanoma.

Prognosticators of melanoma, the melanoma report, and the sentinel lymph node

Since the 1960s, the clinical characteristics of melanoma, its histopathology and its biological basis have been the subject of intense study at pigmented lesion clinics in North America, Europe, and Australia. More recently, the immense database of the Melanoma Committee of the American Joint Committee on Cancer (AJCC) has been exploited through complex mathematical models to measure the impact of various histologic features of primary melanomas and of sentinel lymph node deposits and to correlate these parameters with patient survival. The wealth of modern information available to pathologists and clinicians has become of vital interest to the prognostication of the individual patient with melanoma. The purpose of this review is to bring to the attention of anatomic pathologists the essential characteristics of the pathology report for primary cutaneous melanoma in the modern era.

Medicolegal aspects of neoplastic dermatology

Medical malpractice litigation is rising at an explosive rate in the US and, to a lesser extent, in Canada. The impact of medical malpractice litigation on health care costs and the cost of insurance is dramatic. Certain specialist categories are becoming uninsurable in some parts of the US, while in others, clinicians are retiring early, restricting or changing practice or changing states of residence in consequence of medical malpractice claims and of the cost and availability of insurance. This, in turn, has had the real effect of denying care to patients in some communities in the US. Some 13% of all medical malpractice claims relate to one area of neoplastic dermatopathology, specifically, melanocytic neoplasia. Certain steps can be taken by pathology laboratories to reduce, but never completely eliminate, the risk of medical malpractice claims. In this review, attention is paid to the source of medical malpractice claims and an abbreviated approach to specific strategies for risk management is presented.

Basal cell carcinoma: biology, morphology and clinical implications

Basal cell carcinoma (BCC) is the most common malignant neoplasm of humans. Rising dramatically in incidence in North America, as likely reflects changing habits of the population and a move from more northerly climes to the sunbelt of the Southern and Southwestern United States, the incidence is surely to rise even higher in the future. The last decade has seen significant advances in our understanding of BCC biology and novel approaches to therapy, which hinge upon accurate diagnosis and subclassification by pathologists. The purpose of this review article is to summate the research advances in our understanding of BCC biology and to acquaint pathologists and clinicians to the practical issues in BCC diagnosis and subclassification which flow there from.

Unusual variants of malignant melanoma

A potential diagnostic pitfall in the histologic assessment of melanoma is the inability to recognize unusual melanoma variants. Of these, the more treacherous examples include the desmoplastic melanoma, the nevoid melanoma, the so-called 'minimal-deviation melanoma,' melanoma with prominent pigment synthesis or 'animal-type melanoma,' and the malignant blue nevus. Also problematic are the unusual phenotypic profiles seen in vertical growth phase melanomas; these include those tumors whose morphological peculiarities mimic cancers of nonmelanocytic lineage and those melanomas that express aberrant antigenic profiles not commonly associated with a melanocytic histogenesis. Metaplastic change in melanoma, balloon cell melanoma, signet-ring cell melanoma, myxoid melanoma, small cell melanoma and rhabdoid melanoma all have the potential to mimic metastatic and primary neoplasms of different lineage derivations. Abnormal immunohistochemical expression of CD 34, cytokeratins, epithelial membrane antigen, and smooth muscle markers as well as the deficient expression of S100 protein and melanocyte lineage-specific markers such as GP100 protein (ie HMB-45 antibody) and A103 (ie Melan-A) also present confusing diagnostic challenges. In this review, we will discuss in some detail certain of these novel clinicopathologic types of melanoma, as well as the abnormal phenotypic expressions seen in vertical growth phase melanoma.

Malignant adnexal neoplasms

Malignant cutaneous adnexal neoplasms are one of the most challenging areas of dermatopathology. Tumors of the pilosebaceous apparatus can occur as single-lineage neoplasms or may manifest as complex proliferations with multilineal differentiation patterns including not only the germinative component of the hair bulb, the inner or outer root sheath epithelium and the sebaceous gland and duct, but also the sweat duct components that relate to the apocrine secretory apparatus which empties into the follicle near the follicular bulge. Eccrine and apocrine neoplasms present a bewildering array of morphologies, which often defy precise classification. The purpose of this review is to discuss in detail the malignant neoplasms of the cutaneous adnexae and their benign and prognostically indeterminate mimics.

De novo intraepidermal epithelioid melanocytic dysplasia as a marker of the atypical mole phenotype - a clinical and pathological study of 75 patients

BACKGROUND

We encountered a distinctive pattern of dysplastic intraepidermal melanocytic proliferation, which defies classification as a dysplastic melanocytic nevus, but in which the morphologic features fall short of a diagnosis of melanoma in situ. We designate such lesions as de novo intraepidermal epithelioid melanocytic dysplasia.

METHODS

From 75 patients, 82 skin biopsies were encountered that showed this distinctive morphology. Hematoxylin- and eosin-stained histologic sections were studied and the features were correlated with personal and family histories of dysplastic nevi and melanoma.

RESULTS

The diagnosis of de novo melanocytic dysplasia was made in 27 male patients and 48 female patients (mean age: 44 years). The histologic hallmark was a pagetoid (single-cell) array of moderately to severely atypical epithelioid melanocytes within the epidermis. Seventy-three lesions were located on sun-exposed skin and nine on sun-protected skin. In 41 patients, there was an atypical mole phenotype, whereas 20 patients had a prior or subsequent diagnosis of melanoma with five of 16 patients questioned revealing a family history of melanoma.

CONCLUSIONS

De novo intraepidermal epithelioid melanocytic dysplasia is a distinct entity associated with an atypical mole phenotype and a personal and/or family history of melanoma.

Chondrodermatitis nodularis helicis as a marker of internal disease [corrected] associated with microvascular injury

Chondrodermatitis nodularis helicis (CNH) is held to be an idiopathic degenerative process involving the upper dermis of the auricular rim. Chondrodermatitis typically occurs in elderly men where associations with underlying trauma and sun exposure have been postulated as potential inciting triggers. Its association as a marker of systemic disease is not well established. We describe 24 patients with CNH, in whom there were also significant underlying diseases largely associated with vascular injury including those of immune-based etiology and/or conditions which have been previously linked with granuloma annulare, another necrobiotic process of collagen. These patients with concomitant systemic disease were characteristically younger compared to the classic demographics described for CNH. In some cases, chondrodermatitis may represent an ischemic necrobiotic disorder of collagen, potentially defining an important sign of underlying systemic disease in younger patients.

The application of a monoclonal antibody to CD62L on paraffin-embedded tissue samples in the assessment of the cutaneous T-cell infiltrates

BACKGROUND

A reduction in the expression of the pan T-cell markers CD7 and CD62L supports an endogenous T-cell dyscrasia. Previously, clone availability for CD62L restricted its application to frozen tissue sections.

MATERIALS AND METHODS

A nonavidin/biotin technique to examine CD3, CD62L, and CD7 in paraffin formalin-fixed tissue in non-neoplastic and neoplastic T-cell infiltrates.

RESULTS

In the reactive group, CD62L manifested a 15 and 22% reduction in epidermal and dermal staining, respectively; there was a 42 and 31% reduction in epidermal and dermal CD7 staining. In lymphomatoid hypersensitivity, CD62L showed a 24 and 9% reduction in epidermal and dermal staining, respectively; CD7 staining demonstrated reduced staining by 70 and 66% in the epidermis and dermis. In the non-lymphomatous endogenous T-cell dyscrasia and lymphoma categories, an 80% diminution in CD62L and CD7 expression was seen.

CONCLUSIONS

CD62L can be successfully applied in formalin-fixed tissue and exhibits enhanced specificity compared to CD7 in the evaluation of cutaneous T-cell infiltrates. Both CD62L and CD7 in paraffin-embedded, formalin-fixed tissue are useful diagnostic adjuncts, especially in regard to the discrimination of lymphomatoid hypersensitivity reactions from true endogenous T-cell dyscrasia.

Epstein-Barr virus- and human herpesvirus 8-associated primary cutaneous plasmablastic lymphoma in the setting of renal transplantation

BACKGROUND

Plasmablastic lymphoma (PBL) is a recently recognized entity most often reported in the oral cavity, mainly in the setting of underlying human immunodeficiency viral infection whereby a role for Epstein-Barr virus (EBV) and more recently human herpesvirus 8 (HHV8) has been described. Although EBV has been implicated in a variety of lymphoproliferative lesions, until recently HHV8 has only been associated with primary effusion lymphoma, multicentric Castleman's disease, and Kaposi's sarcoma. We describe a case of PBL occurring in the setting of renal transplantation.

METHODS

We encountered a case of PBL occurring in the setting of renal transplantation. We characterized the tumor by routine immunohistochemistry and evaluated for the presence of immunoglobulin light chain restriction and EBV RNA by in situ hybridization. We assessed for the presence of HHV8 RNA by reverse transcriptase in situ hybridization.

RESULTS

The tumor showed a histomorphology compatible with a PBL. In addition, there was strong RNA expression in the neoplastic cells for EBER-1, EBER-2, and HHV8.

CONCLUSION

This case suggests a possible role of both viruses in the pathogenesis of PBL in sites other than the oral cavity and expands the spectrum of post-transplantation lymphoproliferative disease to include PBL.

Assessment of T-cell Clonality via T-cell Receptor-γ Rearrangements in Cutaneous T-cell–Dominant Infiltrates Using Polymerase Chain Reaction and Single-stranded DNA Conformational Polymorphism Assay

Discerning the pathologic significance of cutaneous T-cell infiltrates can pose a diagnostic challenge for dermatopathologists. Reactive conditions such as drug-associated lymphomatoid hypersensitivity and lymphomatoid lupus erythematosus can demonstrate lymphoid atypia and a phenotype resembling cutaneous T-cell lymphoma (CTCL). Further, lymphoid dyscrasias such as pityriasis lichenoides chronica, large plaque parapsoriasis, and atypical pigmentary purpura confuse the picture because they not only mimic CTCL but also represent prelymphomatous states with inherent malignant potential. Although the emergence of a dominant clone has been considered a clue indicative of a T-cell dyscrasia, there are reports concerning the identification of monoclonality in biopsies of reactive lymphoid infiltrates. We have conducted a modified single-stranded DNA conformational polymorphism (SSCP) assay using paraffin-embedded, formalin-fixed tissue on 92 T-cell-rich biopsies to determine the relative specificity and sensitivity of this methodology. In addition, laser capture microdissection (LCM) was performed on 22 of the 92 samples to isolate the area of interest and to compare its specificity and sensitivity with those SSCP assays performed without LCM. We found that monoclonality or oligoclonality is 86% specific for preneoplastic and neoplastic states, whereas the finding of polyclonality appears to be relatively specific for a reactive process. Some cases of reversible T-cell dyscrasia produced a molecular profile mimicking lymphoma or prelymphomatous states by virtue of monoclonality or oligoclonality. Although LCM appears to improve the sensitivity for detecting preneoplastic conditions, the relative specificity appears to be the same as that encountered with routine SSCP.

Cutaneous Immunocytoma

Immunocytomas represent low grade B cell lymphomas related to marginal zone lymphoma but with a predominance of cells having plasmacytic features. Eleven patients presented with lesions compatible with primary cutaneous immunocytoma. The expression of CD2, CD3, CD5, CD20, CD21, CD23, CD43, CD56, CD79, and bcl-2 was analyzed immunohistochemically and of lambda and kappa light chains by an in situ hybridization assay. There were 6 men and 5 women ranging in age from 43 to 76 years. The most common clinical presentation was as extremity based clustered erythematous brown papules. Therapy with local irradiation or Rituximab resulted in lesional resolution. Underlying illnesses included Sjögren's syndrome, hepatitis C, ulcerative colitis, autoimmune thyroid disease, and rheumatoid arthritis. Four patients were taking medications previously associated with immune dysregulation. In two patients in whom a paraproteinemia was uncovered. The most common pattern light microscopically was perivascular small lymphocytic and plasmacellular infiltrates mimicking architecturally a reactive process. Phenotypic studies revealed a marginal zone (MZL) phenotype amid the small atypical lymphocytic infiltrate and highlighted a reactive background population of non-neoplastic T and B cells; light chain restriction was seen amid the plasma cells. In one case there was EBER staining of plasma cells while in another case in whom there was hepatitis C seropositivity staining of plasma cells for hepatitis C associated RNA transcripts was observed. Primary cutaneous immunocytoma appears to arise from a pre-existing state of reactive lymphoid hyperplasia. latrogenic and endogenous immune dysregulation including in the context of lymphotropic viral infections is implicated.

Parvoviral infection of endothelial cells and stromal fibroblasts: a possible pathogenetic role in scleroderma

BACKGROUND

Systemic sclerosis (SSc) is a connective tissue disease (CTD) which differs from other CTDs by progressive irreversible fibrosis in lung, kidney, skin, and heart. It has a worse prognosis compared to several other CTDs. The pathogenesis may reflect a humorally mediated microangiopathy in concert with the overproduction of collagen triggered by immune-mediated cytokine production. Having previously demonstrated parvovirus B19 (B19) DNA in bone marrow and skin biopsies of SSc patients in the absence of B19 viremia, we sought to further elucidate a role for B19 in the pathogenesis of SSc.

DESIGN

Twelve patients who fulfilled American College of Rheumatology criteria for a diagnosis of SSc were encountered. Ten were serologically screened for B19 infection. Solution phase polymerase chain reaction (PCR) for B19 DNA was performed on skin tissue from six patients, and in all biopsies, reverse transcriptase in situ PCR (RT in situ PCR) for B19 and tumor necrosis factor (TNF)-alpha mRNA was performed. B19 viral protein (VP2) expression was sought by immunohistochemistry and correlated to PCR findings and to light microscopy of hematoxylin and eosin-stained sections. Frozen tissue was also available on five of the patients. Two control groups were assessed for B19 and TNF expression comprising one with irrelevant primers and the other representing 18 cases of inflammatory skin lesions where the etiology was known and unrelated to B19 infection. In addition, frozen and paraffin-embedded tissues procured from skin lesions unrelated to B19 infection were assessed for B19 genome. In all cases, pretreatment with RNase was also performed to verify that any positive signal was indeed RNA based.

RESULTS

Diffuse SSc was seen in seven patients, and limited disease in five. All patients had an antinuclear antibody--specifically, an antinucleolar, anticentromere, and/or anti-Scl 70 antibody. Eleven of the 12 had lung involvement, whereas eight patients had myocardial disease. Of 12 patients tested serologically, nine had B19-specific antibodies, which included immunoglobulin M (IgM)-specific antibodies in two cases. Solution phase PCR showed B19 DNA in the skin in three cases and in the bone marrow in three cases, including two in whom skin-based B19 DNA was observed. In all cases, RT in situ PCR demonstrated B19 and TNF-alpha mRNA in endothelia, fibroblasts, mast cells, and perivascular inflammatory cells. Immunohistochemistry to assess VP2 was either negative or equivocal. Immunofluorescent studies revealed prominent deposition of C5b-9 within the cutaneous vasculature from biopsies of all patients tested. The control samples were negative for B19 and TNF RNA and DNA.

CONCLUSIONS

Parasitism of endothelia and fibroblasts by B19 with resultant enhanced TNF-alpha expression may be of pathogenetic importance in SSc even in the absence of demonstrable viremia. The vascular deposition of C5b-9 suggests a role for humoral immunity possibly induced by a state of endothelial neoantigenicity evoked by virally mediated cell injury. Treatment strategies include anti-viral therapy, including in the context of intravenous gamma-globulin and anti-TNF therapy.

Atrophying tinea versicolor: a clinical and histological study of 12 patients

BACKGROUND

We describe 12 patients with an atrophying dermatitis in whom the biopsy findings were compatible with tinea versicolor.

DESIGN

We encountered 12 skin biopsies from 12 patients in whom a clinically atrophying dermatosis was associated with light microscopic (LM) evidence of atrophy and epidermal colonization by Pityrosporum sp. Formalin-fixed, paraffin-embedded tissue sections were cut at 5 microns and stained with H&E, alcian blue-PAS and PAS-diastase preparations.

RESULTS

Five men and seven women aged 17-73 years in whom lesions characterized as atrophic plaques, patches or macules prompted clinical differential diagnoses including parapsoriasis or mycosis fungoides (MF), anetoderma, lupus erythematosus, and steroid atrophy. A LM examination showed epidermal colonization with pityrosporum hyphae and spores accompanied by variable epidermal and dermal atrophy characterized by rete-ridge effacement, subepidermal fibroplasia, pigment incontinence and elastolysis.

CONCLUSIONS

Atrophying cutaneous lesions comprise part of the clinical spectrum of tinea versicolor for which we propose the term 'atrophying tinea versicolor'. The pathogenetic basis is unclear but could be the sequela of delayed type hypersensitivity and the release by T-helper lymphocytes of leukotrienes which perturb collagen metabolism and/or keratinocyte growth. Lesions may be mistaken clinically for MF or other atrophying dermatoses.

Docetaxel (taxotere) induced subacute cutaneous lupus erythematosus: report of 4 cases

OBJECTIVE

We describe 4 patients who developed subacute cutaneous lupus erythematosus (SCLE)-like photodistributed eruptions after ingestion of docetaxel (Taxotere). The development of SCLE-like cutaneous eruptions has been associated with the intake of drugs including thiazide diuretics, calcium channel blockers, angiotensin converting-enzyme inhibitors, phenytoin, etanercept, antihistaminics, interferons, statins, and terbinafine. Docetaxel, a chemotherapeutic drug used in breast cancer therapy, has not to our knowledge been reported to cause SCLE.

METHODS

Skin biopsies were obtained from 4 patients with photodistributed rashes while taking docetaxel.

RESULTS

In all patients, skin biopsies were remarkable for an atrophying interface dermatitis associated with mucin deposition. Immunofluorescent testing revealed the characteristic pattern of SCLE, namely, granular epidermal keratinocyte deposition of IgG and C5b-9. The eruptions resolved following cessation of the drug.

CONCLUSION

Pathogenetically, docetaxel may evoke a lupus-like eruption through its proapoptotic effects on replicating cells, which could in turn provoke the release of nucleosomes postulated to be target antigens in LE. It seems reasonable to postulate that the rapidly replicating keratinocyte, when subjected to the cytotoxic effects of docetaxel, would also manifest nucleosome release followed by a local autoimmune reaction in a genetically predisposed host.

Atypical lymphocytic lobular panniculitis

BACKGROUND

Although subcutaneous T-cell lymphoma (SCTCL) is considered an aggressive form of lymphoma, some patients manifest a long waxing and waning phase unaccompanied by constitutional symptoms.

METHODS

Twelve patients were prospectively encountered, presenting with a lymphocytic panniculitis accompanied by lymphoid atypia, although not fulfilling criteria for SCTCL. Clinical, histologic, phenotypic, and genotypic analyses were conducted.

RESULTS

There were five men, one boy, and six women; none had symptoms compatible with lupus erythematosus or aggressive SCTCL. All but two had a waxing and waning course of years. Four patients had periodic cytopenias accompanied by fevers. While responding somewhat to prednisone, the lesions relapsed. In one patient, treatment with alemtuzumab (CAMPATH-1) led to complete lesional resolution with no recurrence. Light microscopy showed expansion of the interstices of the fat lobule by mildly atypical lymphocytes of the CD4 subset in 10 biopsies from eight patients; in the other four patients, there was an increase in CD8 lymphocytes. There was diminished expression of CD5 and/or CD7 in the majority of biopsies. Ten of 13 biopsies showed clonal T-cell receptor-gamma rearrangements.

CONCLUSIONS

We apply the term atypical lymphocytic lobular panniculitis to this distinctive form of lymphocytic panniculitis manifesting this light microscopic, phenotypic, and genotypic profile.

The data warehouse as a foundation for population-based reference intervals

The volume of data contained in a data warehouse represents a potential resource to provide the basis for detailed and specific reference intervals. Routine chemistry panel testing data were derived from an outreach laboratory patient population of 438,180 people and then screened by multiple data filters to identify a large and demographically diverse reference population. Reference intervals were determined for 4 common analytes: aspartate aminotransferase, alanine aminotransferase, total bilirubin, and alkaline phosphatase. Each derived reference population contained more than 60,000 people with sex- and age-specific subgroups comprising between 495 and 4,949 persons. These intervals are particularly representative of the aging patient population and demonstrate a degree of age and sex diversity not reflected commonly in routine laboratory reference intervals. Warehouse data also can yield other interpretative data, such as percentile ranking of results or disease-specific reference intervals. As the warehouse accumulates data from other disciplines (such as from clinical notes or pharmacy), there is increasing potential for the laboratory to enhance the clinician's ability to diagnose and treat disease.

Cutaneous manifestations of Crohn's disease, its spectrum, and its pathogenesis: intracellular consensus bacterial 16S rRNA is associated with the gastrointestinal but not the cutaneous manifestations of Crohn's disease

The classic pathology of skin disease discontinuous from the inflamed gastrointestinal (GI) tract in patients with Crohn's disease (CD) includes pyoderma gangrenosum (PG), erythema nodosum (EN), and so-called metastatic Crohn's disease. The purpose of this study was two-fold: First, we explored the full spectrum of cutaneous lesions associated with Crohn's disease, and second, we sought to explore a potential molecular basis of the skin lesions in patients with CD. In this regard, we analyzed skin and GI tract biopsies from affected patients for the consensus bacterial SrRNA to determine whether direct bacterial infection was associated with either condition. Formalin-fixed, paraffin-embedded sections were studied and correlated to clinical presentation and histories from 33 patients with CD. Consensus bacterial RNA sequences were analyzed using an RT in situ PCR assay on both skin biopsy and GI biopsy material. The GI tract material included biopsies from 3 patients who had skin lesions and from 7 patients in whom there were no known skin manifestations. There were 8 cases of neutrophilic dominant dermal infiltrates, including pyoderma gangrenosum, 6 cases of granuloma annulare/necrobiosis lipoidica-like lesions, 5 cases of sterile neutrophilic folliculitis, 5 cases of panniculitis, 4 cases of vasculitis, 2 cases of psoriasis, 2 cases of lichenoid and granulomatous inflammation, and 1 case of classic metastatic CD. Intracellular bacterial 16S rRNA was detected in 8 of 10 tissues of active CD in the GI tract, of which 3 of the cases tested were from patients who also developed skin lesions at some point in their clinical course; in contrast, none of the skin biopsies had detectable bacterial RNA. The dermatopathological manifestations of CD discontiguous from the involved GI tract mucosa have in common a vascular injury syndrome, typically with a prominent extravascular neutrophilic and/or histiocytic dermal infiltrate. In addition, this study, the first to document in situ intracellular consensus bacterial SrRNA in the GI tract in CD, suggests that hematogenous dissemination of viable microbes is not associated with the cutaneous manifestations of this disease. Bacteria do, however, appear to play a role in bowel lesions of patients with CD.

Progress in the understanding of the pathology and pathogenesis of cutaneous drug eruptions : implications for management

Cutaneous drug eruptions are among the most common adverse reactions to drug therapy. The etiology may reflect immunologic or nonimmunologic mechanisms, the former encompassing all of the classic Gell and Combs immune mechanisms. Cumulative and synergistic effects of drugs include those interactions of pharmacokinetic and pharmacodynamic factors reflecting the alteration by one drug of the effective serum concentration of another and the functions of drugs and their metabolites that interact to evoke cutaneous and systemic adverse reactions. Recent observations include the role of concurrent infection with lymphotropic viruses and drug effects that, through the enhancement of lymphoid blast transformation and/or lymphocyte survival and the contribution of intercurrent systemic connective tissue disease syndromes, promote enhanced lymphocyte longevity and the acquisition of progressively broadening autoantibody specificities. The latter are particularly opposite to drug-induced lupus erythematosus and to drug reactions in the setting of HIV infection. Specific common types of cutaneous drug eruptions will be discussed in this review. Successful management of cutaneous drug eruptions relies upon the prompt discontinuation of the causative medication; most drug eruptions have a good prognosis after this is accomplished. Oral or topical corticosteroids can be administered to aid in the resolution of some types of eruptions. Antihistamines or anti-inflammatory agents may also be administered for some eruptions.

The utility of the in situ detection of T-cell receptor Beta rearrangements in cutaneous T-cell-dominant infiltrates

The diagnostic assessment of cutaneous T-cell infiltrates is problematic for dermatopathologists. A variety of conditions, including lymphomatoid hypersensitivity reactions and lymphomatoid lupus erythematosus, can demonstrate lymphoid atypia and phenotypic changes that can mimic cutaneous T-cell lymphoma (CTCL). A similar issue revolves around lymphoid dyscrasias, which includes parapsoriasis, atypical pigmentary purpura, pityriasis lichenoides chronica, indeterminate lymphocytic lobular panniculitis, and lymphomatoid papulosis, which can progress to CTCL. A reverse transcription (RT) in situ PCR assay for T-cell receptor beta rearrangements (TCRbeta) was used to assess T-cell clonality in formalin-fixed, paraffin-embedded tissues. In 7 of 8 cases of classic CTCL, the RT in situ PCR assay for TCRbeta rearrangement showed monoclonality; the other was biclonal. Further, in cases with multiple lesions over time, the same T-cell clone could be detected including in those patients whose biopsies showed large-cell transformation. Monoclonality was also demonstrated in each of 2 cases of cutaneous lymphomatoid papulosis. Demonstration of oligoclonality (and one case of biclonality) by RT in situ PCR was confined to those cases that either represented prelymphomatous conditions such as large plaque parapsoriasis or pityriasis lichenoides or lesions of drug-induced lymphomatoid hypersensitivity that all demonstrated clinical regression. In conclusion, RT in situ PCR for TCRbeta, which can be done on formalin-fixed biopsies and allows direct correlation of the molecular data with the histology, is a useful adjunctive test in the differentiation of CTCL from its mimics.

Automated kappa and lambda light chain mRNA expression for the assessment of B-cell clonality in cutaneous B-cell infiltrates: its utility and diagnostic application

INTRODUCTION

Primary cutaneous B-cell lymphoma (1 degrees CBCL) accounts for 25% of all lymphomas. The difficulty in distinction of reactive from neoplastic B-cell infiltrates prompts the use of molecular diagnostic adjuncts. While T-cell clonality can be seen in various reactive states, clonal B-cell infiltrates are often neoplastic; standard assays employed include polymerase chain reaction (PCR) or Southern blot analysis to assess heavy chain rearrangement. We sought to assess the utility of kappa (kappa) and lambda (lambda) mRNA expression using the Ventana automated assay (Ventana Medical Systems, Tucson, AZ, USA) in the analysis of atypical cutaneous B-cell lymphoid infiltrates.

MATERIALS AND METHODS

Multiple 4 micro m sections of paraffin-embedded, formalin-fixed skin biopsies from 31 patients with CBCL were placed on silane-coated slides, deparaffinized, then digested in pepsin (5 mg/ml) for 30 min at 37 degrees C. Fluorescein-tagged oligoprobes and tissue mRNA were denatured at 80 degrees C for 5 min, hybridized for 2 h at 37 degrees C, and incubated with antifluorescein alkaline phosphatase conjugates. Detection of the probe target complex employed nitroblue tetrazolium and bromochloroindolyl phosphate conjugates with a nuclear fast red counterstain. A kappa : lambda ratio > 3 : 1 was held to represent kappa light chain restriction and a kappa : lambda ratio </= 1 : 1 to indicate lambda light chain restriction.

RESULTS

The diagnosis in each case was determined by careful integration of clinical, histologic, and phenotypic data. The diagnoses included: pseudolymphoma (PL), marginal zone lymphoma (MZL), 1 degrees CBCL of the trunk, scalp or leg, 2 degrees lymphoma, and plasma cell dyscrasia. All but one case of lymphoma were light chain restricted. All cases of PL were proven to be polyclonal by this methodology. In non-plasmacytic small cell lymphomas, only 5-10% of the infiltrate expressed kappa or lambda, with clonality established through the abnormal kappa : lambda ratio. Interpretations were most difficult in the 2 degrees small cell-dominant follicular center cell lymphomas and easiest in cases with significant plasmacytic differentiation (i.e. MZL, immunocytomas, or plasma cell dyscrasias).

CONCLUSION

The Ventana kappa/lambda assay is a reliable, quick, and inexpensive way to determine B-cell clonality in cutaneous lymphoid infiltrates in paraffin-embedded formalin-fixed tissue.

The dermatopathologic manifestations of hepatitis C infection: a clinical, histological, and molecular assessment of 35 cases

Cutaneous eruptions related to hepatitis C virus (HCV), a major cause of hepatitis in the setting of blood transfusion, intravenous drug abuse, organ transplantation, and hemodialysis, are typically reported as isolated cases. We encountered 35 cases of HCV infection associated with cutaneous eruptions. The present study evaluates paraffin-embedded, formalin-fixed tissue sections stained with hematoxylin and eosin from biopsy specimens of skin lesions from 35 patients seropositive for HCV. In 20 cases, reverse transcriptase polymerase chain reaction (RT-PCR) was performed using a probe for HCV RNA; the RNA was detected through the action of alkaline phosphatase on the chromogen nitroblue tetrazolium and bromochloroindolyl phosphate. The clinical spectrum comprised dermatomyositis-like photodistributed eruptions, palpable purpura, folliculitis, violaceous and perniotic acral lesions, ulcers, nodules, and urticaria. Lesions were also classified histopathologically by the dominant reaction pattern: vasculopathies of neutrophilic, lymphocytic, and granulomatous vasculitis and pauci-inflammatory subtypes (15 patients); palisading granulomatous inflammation (3 patients); sterile neutrophilic folliculitis (5 patients); dermatitis herpetiformis (1 patient); lobular panniculitis composed of neutrophilic lobular panniculitis in 2 patients and benign cutaneous polyarteritis nodosa in 1 patient; neutrophilic dermatoses, including neutrophilic urticaria, neutrophilic eccrine hidradenitis, and pyoderma gangrenosum (3 patients); interface dermatitis (3 patients); and low-grade lymphoproliferative disease of B-cell lineage representing marginal zone lymphoma in 1 patient and a clonal plasmacellular infiltrate in another patient. In most cases, whereas 1 of the aforementioned disorders defined the dominant reaction pattern, there was an accompanying secondary reaction pattern, defining a hybrid picture. Endothelial changes including endothelial cell enlargement and effaced heterochromatin with margination of the chromatin to the nuclear membrane were seen in several cases; in some cases similar cytopathic changes also involved the supporting pericytes, eccrine ductular cells, or keratinocytes. The RT-PCR analyses in 8 of 20 cases examined revealed HCV RNA expression in a focal, weak fashion in endothelia and perivascular inflammatory cells in those cases showing vasculopathic changes. Viral parasitism of endothelia may be important in cutaneous lesional propagation in the setting of HCV infection. Cross-reactivity between endogenous and viral antigens, leading to cellular and/or type II immune reactions; viral tropism to B lymphocytes, resulting in B cell expansion with resultant autoantibody production; and circulating immune complexes containing monoclonal cryoglobulins may also be of pathogenetic importance. Tropism of the virus to B lymphocytes provides a mechanism for the development of low-grade clonal B cell lymphoproliferative disease in this setting.

Granulomatous eccrinotropic lymphomatoid papulosis

We describe 9 patients with a novel variant of lymphomatoid papulosis characterized by prominent localization of the infiltrate around the eccrine coil, resulting in nodular expansion of the coil accompanied by variable granulomatous inflammation. Light microscopy, immunohistochemical analysis using antibodies to CD2, CD3, CD4, CD5, CD7, CD8, and CD30 in 6 cases, and polymerase chain reaction--single-stranded conformational polymorphism analysis for T-cell receptor gamma chain gene rearrangement in 5 cases revealed 2 cytomorphologic patterns (large cell dominant with polymorphous inflammation, small cell lymphocyte--rich with an inconspicuous large cell component [phenotypes, CD30+/CD3+/CD4+/CD7-for large atypical cells; reactive for small lymphocytes]) and clonal restriction in 4 and polyclonality in 1 of the lymphocyte-dominant cases. During an average 6-year follow-up, no lymphomas developed. Recognition of this variant is important--accentuation of the infiltrate around the eccrine coil and cutaneous nerves, presence of granulomatous inflammation, dominance of small lymphocytes in the dermis, and variable extension into the panniculus may lead to diagnostic confusion with entities such as discoid lupus erythematosus, Jessner lymphocytic infiltrate of skin, subcutaneous T-cell lymphoma, and persistent arthropod bite reaction. Our findings suggest that pruritus, a younger age at diagnosis, and a more indolent course are defining clinical features.

Cutaneous vasculitis: a review

As the skin is commonly involved in systemic vasculitic disorders as well as those hypersensitivity states whose expression is largely skin-confined, cutaneous vasculitic lesions offer a window to diagnosis and a ready source of accessible tissue for biopsy. In this review, we discuss the pathologic manifestations of chronic vasculitic syndromes such as granuloma faciale and erythema elevatum diutinum; IgA-associated vasculitis including Henoch-Schonlein purpura; vasculitis seen in the setting of cryoglobulinemia and hypergammaglobulinemia of Waldenstrom, hereditary deficiencies of complement, and IgA deficiency; those leukocytoclastic vasculitides resulting from hypersensitivity reactions to drug, chemical and foodstuff ingestion; and those vasculitides seen in patients with systemic diseases such as polyarteritis nodosa, rheumatoid arthritis, mixed connective tissue disease, systemic lupus erythematosus, Sjogren's syndrome, relapsing polychondritis, Behcet's disease, Wegener's granulomatosis, and allergic granulomatosis of Churg and Strauss.

Drug-induced reversible lymphoid dyscrasia: a clonal lymphomatoid dermatitis of memory and activated T cells

Certain systemic conditions predispose patients to excessive lymphocyte responses to immune-perturbing drugs, which may progress to malignant lymphoma. Many pathologists and clinicians believe that differentiation of pseudolymphoma from cutaneous T cell lymphoma (CTCL) can be reliably made through phenotypic and molecular analysis. We encountered 15 cases of atypical cutaneous T-cell lymphoid hyperplasia in the setting of drug therapy. We explored phenotypic anomalies using antibodies to CD2, 3, 4, 7, 8, 20, 30 and CD62 K and sought T-cell receptor gene rearrangements by a polymerase chain reaction methodology. The lymphoid infiltrates showed reproducible CD7 and/or CD62 K deletion in concert with T cell clonality and variable CD30 positivity-findings similar to those of CTCL-but the rashes resolved or improved substantially after drug modulation. We hypothesize that the infiltrates represent an unrepressed expansion of CD7- and CD62 K-negative activated memory T lymphocytes in response to antigenic triggers. We propose the term "drug-induced reversible lymphoid dyscrasia" to describe this entity.

Pyoderma gangrenosum: a review

Since its first description in 1930, the pathogenesis of pyoderma gangrenosum (PG) has remained obscure even as an ever-widening array of systemic diseases has been described in association with it. The histopathologic distinction of PG from other ulcerative processes with dermal neutrophilia is challenging and at times impossible. In consequence, when confronted with a biopsy from such a lesion, the pathologist has an obligation to obtain a full and detailed clinical history. In short, as a diagnosis of PG does not hinge exclusively upon the biopsy findings in isolation from other studies, a solid knowledge of the clinical features, the systemic disease associations and the differential diagnosis will help the pathologist to avoid diagnostic pitfalls or the generation of a report which is non-contributory to patient care. In this review, we describe in detail the different clinicopathologic forms of PG, summarize the diseases associated with this process in the literature and in our experience, and briefly review the treatment options.

The spectrum of cutaneous lesions in rheumatoid arthritis: a clinical and pathological study of 43 patients

INTRODUCTION

Rheumatoid arthritis (RA) is an idiopathic arthropathy syndrome that has a propensity to affect the small joints of the hands and feet with extra-articular manifestations comprising skin lesions, neuropathy, pericarditis, pleuritis, interstitial pulmonary fibrosis and a systemic polyarteritis nodosa (PAN)-like vasculitic syndrome. The most widely recognized skin lesion is the rheumatoid nodule. Other skin manifestations are poorly defined.

MATERIALS AND METHODS

Using a natural language search of the authors' outpatient dermatopathology databases, skin biopsies from 43 patients with RA were selected for retrospective analysis in an attempt to define the dermatopathological spectrum of RA and its clinical correlates.

RESULTS

The biopsies were categorized by the dominant histologic pattern, recognizing that in most cases there were additional minor reaction patterns. Palisading and/or diffuse interstitial granulomatous inflammation was the dominant pattern seen in 21 patients; the lesions included nodules, plaques and papules with a predilection to involve skin over joints. Besides interstitial histiocytic infiltrates and variable collagen necrobiosis, these cases also showed interstitial neutrophilia, vasculitis and pauci-inflammatory vascular thrombosis. The dominant morphology in 11 other patients was vasculopathic in nature: pauci-inflammatory vascular thrombosis, glomeruloid neovascularization, a neutrophilic vasculitis of pustular, folliculocentric, leukocytoclastic or benign cutaneous PAN types, granulomatous vasculitis, and lymphocytic vasculitis and finally occlusive intravascular histiocytic foci for which the designation of "RA-associated intravascular histiocytopathy" is proposed. Rheumatoid factor (RF) positivity and active arthritis were common in this group, with anti-Ro and anticardiolipin antibodies being co-factors contributing to vascular injury in some cases. Immunofluorescent testing in three patients revealed dominant vascular IgA deposition. In nine patients, the main pattern was one of neutrophilic dermal and/or subcuticular infiltrates manifested clinically as urticarial plaques, pyoderma gangrenosum and panniculitis.

CONCLUSIONS

The cutaneous manifestations of RA are varied and encompass a number of entities, some of which define the dominant clinical features, such as the rheumatoid papule or subcutaneous cords, while others allude to the histopathology, i.e. rheumatoid neutrophilic dermatosis. We propose a more simplified classification scheme using the adjectival modifiers of "rheumatoid-associated" and then further categorizing the lesion according to the dominant reaction pattern. Three principal reaction patterns are recognized, namely extravascular palisading granulomatous inflammation, interstitial and/or subcuticular neutrophilia and active vasculopathy encompassing lymphocyte-dominant, neutrophil-rich and granulomatous vasculitis. In most cases, an overlap of the three reaction patterns is seen. Co-factors for the vascular injury that we believe are integral to the skin lesions of RA include RF, anti-endothelial antibodies of IgA class, anti-Ro and anticardiolipin antibodies.

The precursors of malignant melanoma

The precursors to melanoma are generally considered to be related to nevi of different types. Here we emphasize the dysplastic nevus, the congenital nevus, and lentigo maligna as specific lesions. The dysplastic nevus is discussed not only as a formal precursor but also as a marker of cutaneous melanoma. The clinical and histologic characteristics are outlined, as well as evidence of progression in dysplastic nevi. The congenital nevus is briefly reviewed and emphasis is placed upon clues to malignant degeneration. The concept of lentigo maligna as a precursor as distinct from an in situ phase is detailed.

Immunoglobulin A-associated lymphocytic vasculopathy: a clinicopathologic study of eight patients

INTRODUCTION

Cutaneous IgA-associated vasculitis can be a clue to Henoch-Schönlein purpura (HSP), which typically comprises renal and gastrointestinal tract disease and arthritis, whereby prominent and predominant IgA deposits within the cutaneous vasculature provoke a pustular leukocytoclastic vasculitis.

DESIGN

We describe eight patients with a novel expression of a cutaneous IgA vascular injury syndrome, namely a lymphoid vasculopathy which clinically and light microscopically resembled a pigmentary purpura (PP) in six, and correlate direct immunofluorescence (DIF) and clinical features to light microscopy.

RESULTS

Among associated diseases were prior viral infection, an HSP symptom complex, an undifferentiated connective tissue disease syndrome, lupus erythematosus profundus (LEP), Degos' disease and Berger's disease. Skin lesions comprised non-palpable petechial lesions involving lower extremities in all cases and also the upper extremities in two. A superficial perivascular lymphocytic infiltrate unaccompanied by vascular fibrin deposits was associated with prominent erythrocyte extravasation including into the epidermis. Mural and extravascular fibrin deposition was seen in one biopsy from a PP-like lesion and mural fibrinoid necrosis was seen in the cases of LEP and Degos' disease; in biopsies from these three cases, the presence of fibrin deposition warranted use of the appellation 'lymphocytic vasculitis'. In all patients, DIF showed prominent and predominant IgA deposits.

CONCLUSIONS

A non-necrotizing lymphocytic purpuric vascular reaction is one manifestation of vascular IgA deposition in the skin. A subpopulation of human lymphocytes bear surface Fc receptor and/or C3 receptors ('complement receptor lymphocytes') which can bind circulating immune complexes (ICs) or C3 generated via activation of the alternative complement cascade. Thus, circulating ICs are a potential pathogenic basis of this eruption, the histologic differential diagnosis of which is idiopathic PP and PP of drug or viral etiology.

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.

Clear cell atypical fibroxanthoma:a clinicopathologic study

INTRODUCTION

The atypical fibroxanthoma (AFX) is considered by most authorities to represent a superficial or minimally invasive variant of malignant fibrous histiocytoma that most often presents as a solitary nodule on the sun-exposed skin of the elderly. Among the rarest variants is the clear cell AFX, a lesion which raises consideration to a differential diagnosis encompassing a variety of neoplastic and non-neoplastic clear cell proliferations.

METHODS

We describe three cases of a distinctive cutaneous neoplasm arising in the sun-exposed skin of elderly patients. In all cases, formalin-fixed, paraffin-embedded tissue was available for analysis. The histology in concert with the immunophenotype was held to be diagnostic of the clear cell variant of AFX.

RESULTS

All tumors comprised sheets of large cells with foamy cytoplasms and hyperchromatic, polyploid nuclei manifesting frequent and atypical mitoses. The critical cells in our cases expressed CD68 but none of CD3, CD20, CD34, S-100 protein, muscle-specific actin, factor XIIIa, Melan-A, carcinoembryonic antigen, or cytokeratin.

CONCLUSION

Although typical examples of AFX provoke diagnostic consideration of spindle cell cancers of the skin (most often spindle cell melanoma, spindle cell squamous cell carcinoma, and leiomyosarcoma), the clear cell variant raises other differential diagnostic considerations instead. These include balloon cell melanoma, sebaceous carcinoma, pleomorphic liposarcoma, chordoma, parachordoma, tricholemmal carcinoma and clear cell squamous cell carcinoma. A diagnosis of AFX is one of exclusion; one must employ immunohistochemical markers to rule out the aforementioned differential diagnostic considerations. By reporting the fifth, sixth and seventh cases of clear cell AFX, we hope to alert dermatopathologists to this distinctive and unusual neoplasm, recognition of which is essential to avoid under- or over-diagnosis and inappropriate therapy.

Parvoviral infection of endothelial cells and its possible role in vasculitis and autoimmune diseases

OBJECTIVE

To analyze a series of biopsies from 16 patients who, on the basis of clinical and dermatopathologic findings, had a spectrum of connective tissue diseases (CTD), autoinflammatory or CTD-like syndromes for parvoviral DNA, RNA, and protein.

METHODS

Most of the patients were initially screened for parvoviral-related IgG and IgM antibodies. Parvoviral DNA was analyzed by solution phase polymerase chain reaction (PCR). In situ localization of viral VP1 RNA was accomplished by in situ reverse transcriptase (RT) PCR; viral protein (VP2) was detected by immunohistochemistry and these results correlated with the histologic findings. (J Rheumatol 2002;29:xxxx)

RESULTS

Of 11 people tested, 10 had either IgG or IgM specific antibodies against parvovirus. Common histologic features of the 16 cases included an interface dermatitis, interstitial histiocytic infiltration with variable collagen necrobiosis, a mononuclear cell dominant vasculitis, and interstitial neutrophilia. Detection of parvoviral RNA by in situ RT-PCR in 14 of 16 cases corroborated solution phase PCR data and demonstrated that the endothelial cells and surrounding mononuclear cells were the viral target. Viral protein as revealed by immunohistochemisty showed an equivalent histologic distribution. Anti-tumor necrosis factor-alpha (TNF-alpha) therapy (etanercept) yielded dramatic improvement after worsening of symptoms with traditional immunosuppressive therapy in the 3 patients in whom this drug was administered; TNF-alpha mRNA was detected by in situ RT-PCR in the area of parvoviral infected cells.

CONCLUSION

Parvoviral induced endothelialitis may be responsible for cases of "idiopathic" CTD.

Melanocytic proliferations associated with lichen sclerosus

OBJECTIVES

To describe the clinicopathologic features of melanocytic proliferations associated with lichen sclerosus (LS) and to compare these findings with those in controls.

DESIGN

Cohort study.

SETTING

Academic and private practice dermatology and dermatopathology services.

PATIENTS

Cases of melanocytic proliferations associated with LS and consecutive controls with persistent (recurrent) melanocytic nevi, persistent malignant melanomas, and compound melanocytic nevi.

MAIN OUTCOME MEASURES

Diagnostic criteria and disease recurrence.

RESULTS

Eleven patients, all female, with a mean age of 40 years (range, 8-83 years), presented with pigmented lesions clinically suspected to be malignant melanoma or atypical melanocytic nevi affecting the vulva (7 patients), perineum (3 patients), or chest (1 patient). Lichen sclerosus was first identified in the biopsy specimen and subsequently confirmed clinically. In 10 cases, a melanocytic nevus was superimposed on LS (overlying or entrapped by sclerosis), whereas LS was found at the periphery of vulvar malignant melanoma. After complete excision, no recurrences have been reported for the melanocytic nevi in LS (mean follow-up, 29 months; range, 4-60 months). Compared with control lesions, the LS melanocytic nevi most closely resembled persistent melanocytic nevi and could be distinguished from persistent malignant melanoma histologically. Melanocytes, nevoid or malignant, proliferating contiguously with fibrotic or sclerotic collagen, contained abundant melanin, diffusely expressed HMB-45, and had a higher Ki-67 labeling index than ordinary melanocytic nevi. However, persistent malignant melanoma exhibited mitotic figures, significantly higher Ki-67 labeling index, and deep dermal HMB-45 expression compared with LS melanocytic nevi and persistent melanocytic nevi.

CONCLUSIONS

Melanocytic nevi occurring in LS have features in common with persistent melanocytic nevi and can mimic malignant melanoma. An "activated" melanocytic phenotype is seen in LS melanocytic nevi, implicating a stromal-induced change.

Lupus profundus, indeterminate lymphocytic lobular panniculitis and subcutaneous T-cell lymphoma: a spectrum of subcuticular T-cell lymphoid dyscrasia

INTRODUCTION

The diagnosis and classification of lymphocytic lobular panniculitis (LLP) has historically proven to be a difficult challenge. We encountered 32 cases of primary LLP which could be categorized as: 1) lupus erythematosus profundus (LEP) (19 patients); 2) an indeterminate group termed indeterminate lymphocytic lobular panniculitis (ILLP) (6 patients); and 3) subcutaneous T-cell lymphoma (SCTCL) (7 patients).

OBJECTIVE

We attempted to better define the subtypes of LLP by morphologic, phenotypic and genotypic features and to correlate those features to clinical presentation and outcome.

METHOD

Skin biopsy material was studied by conventional light microscopy, through immunophenotyping performed on sections from paraffin-embedded, formalin-fixed tissue and in some cases on sections of tissue frozen after receipt in physiological (Michel's) medium, and by polymerase chain reaction single-stranded conformational polymorphism analysis to assess for clonality of T-lymphocytes. Clinical features were correlated to histologic, phenotypic, and genotypic analyses.

RESULTS

Patients with LEP had a prior diagnosis of LE or overlying skin changes which light microscopically were characteristic of LE. Patients with ILLP had no concurrent or prior history of LE, no systemic symptoms or cytopenias, and a clinical course not suggestive of lymphoma. Cases of SCTCL showed hemophagocytic syndrome and/or lesional progression with demise attributable to the disease. Lesions in all groups showed proximal extremity predilection. Females predominated in the LEP group. The average age of onset was 38, 40 and 55 years in the LEP, ILLP and SCTCL groups, respectively. Cytopenia was seen in 4 LEP patients; 1 also developed fever. In LEP and ILLP, lesions resolved with hydroxychloroquine and/or steroid therapy, with recurrences following cessation of therapy. In the SCTCL group 4 developed hemophagocytic syndrome, 4 died within 2 years of diagnosis, and 3 went into remission following chemotherapy. The LEP and SCTCL groups manifested histological similarities: dense perieccrine and lobular lymphocytic infiltration, lymphoid atypia, histiocytes with ingested debris, eosinophilic necrosis of the fat lobule and thrombosis. The atypical lymphocytes although pleomorphic did not have a cerebriform morphology. The infiltrate in ILLP had a similar cytomorphology and distribution with variable angioinvasion which in all save one case was of lesser intensity and was not associated with significant fat necrosis or vasculitis. Germinal centers, dermal/subcuticular mucin deposition and an atrophying interface dermatitis with hyperkeratosis and follicular plugging were largely confined to the LEP group. Erythrophagocytosis, characteristic of SCTCL, usually indicated a supervening subcuticular lymphoid dyscrasia when encountered in ILLP and LEP. SCTCL showed a selective loss of CD5 expression with or without diminution in CD7 and monoclonal CD3 expression. Of 4 cases studied, 3 showed a CD8 dominant infiltrate while 2 others exhibited CD56 and CD30 positivity, respectively. All cases of SCTCL with amplifiable DNA showed T-cell clonality. Similar molecular and phenotypic features indicative of subcuticular lymphoid dyscrasia were encountered in cases of LEP and ILLP including a reduction in CD5, CD7, and/or monoclonal CD3 expression, a preponderance of CD8 lymphocytes within the subcutaneous fat and T-cell clonality. These cases showed lymphoid atypia with variable erythrophagocytosis. Cases of phenotypically abnormal and/or clonal LEP showed one or more of local destruction, lesional size progression, fever, and cytopenias, but lesions responded to hydroxychloroquine and/or prednisone therapy and death attributable to panniculitis could not be documented. Cases that were phenotypically normal and without clonality had none of the aforesaid atypical clinical features.

CONCLUSION

Lymphoid atypia, erythrophagocytosis, loss of certain pan T-cell markers, a reduced CD4/8 ratio and TCR rearrangement define subcuticular T-cell lymphoid dyscrasia, including a subset of LEP and ILLP. The subcuticular lymphoid infiltrates represent a spectrum of histologic, immunophenotypic, and molecular abnormalities which range from those which are clearly benign to those which are clearly neoplastic, and also encompasses those cases which defy precise classification into the two aforesaid poles.

The cutaneous neutrophilic vascular injury syndromes: a review

The skin manifestations of vasculitis reflect injury by all of the classic immune reactions of Gell and Coombs. As the skin affords a window of opportunity for the clinician to obtain tissue for diagnostic purposes in patients with systemic vasculitic syndromes, a thorough understanding of the dermatopathologic manifestations of those systemic diseases is a considerable asset to the practicing pathologist. This review focuses on those systemic diseases that can provoke a small vessel neutrophilic injury pattern in the skin and provides clues by which these diseases can be separated from each other and from their innocuous mimics in which cutaneous vascular injury is the only significant consequence.