Edematous, scarring vasculitic panniculitis: a new multisystemic disease with malignant potential

Oral manifestations of Hydroa vacciniforme-like lymphoproliferative disorder: a clinicopathological study of a Peruvian population

BACKGROUND

Hydroa vacciniforme-like lymphoproliferative disorder (HVLPD) is a chronic Epstein-Barr virus (EBV)-positive lymphoproliferative disease which may either present as an indolent condition or progress to a systemic T-cell lymphoma.

METHODS

All HVLPD diagnosed over a 10-year period were retrieved, and clinical data regarding sex, age, oral and systemic manifestations, and clinical follow-up were obtained. Immunohistochemistry was done in order to characterize the lymphoid cells, and in situ hybridization was used to demonstrate the presence of EBV.

RESULTS

Eleven cases were included, with a male predominance and a mean age of 25.1 years. Buccal mucosa and the lips were the most affected oral sites, appearing as painful ulcers. All patients exhibited facial oedema, usually affecting the lips, nose and periorbital region. The clinical course was gradual but progressive, with four patients having fever and 3 showing lymphadenopathies. All cases showed a moderate to severe lymphocytic infiltrate with angiotropism, angiocentricity and epidermotropism. Two cases affecting the lip skin exhibited a periappendageal lymphocytic infiltrate. Few large pleomorphic cells were found, surrounded by smaller and medium-sized lymphoid cells, as well as reactive plasma cells, macrophages, neutrophils and eosinophils. All lesions exhibited a cytotoxic T-cell (CD8+) phenotype with a variable proliferative index. All cases were associated with EBV, and all patients died due to complications of the disease.

CONCLUSIONS

HVLPD is a rare disease that may show oral involvement with a cytotoxic T-cell phenotype, and is strongly associated with EBV. As shown in this series, HVLPD may show aggressive clinical behaviour.

Epstein-Barr virus NK and T cell lymphoproliferative disease: report of a 2018 international meeting

Epstein-Barr virus (EBV) normally infects B cells, but in some persons the virus infects T or NK cells. Infection of B cells can result in infectious mononucleosis, and the virus is associated with several B cell malignancies including Hodgkin lymphoma, Burkitt lymphoma, and diffuse large B cell lymphoma. Infection of T or NK cells with EBV is associated with extranodal NK/T cell lymphoma, aggressive NK-cell leukemia, systemic EBV-associated T-cell lymphoma, and chronic active EBV disease, which in some cases can include hydroa vacciniforme-like lymphoproliferative disease and severe mosquito bite allergy. While NK and T cell lymphoproliferative disease is more common in Asia and Latin America, increasing numbers of cases are being reported from the United States and Europe. This review focuses on classification, clinical findings, pathogenesis, and recent genetic advances in NK and T cell lymphoproliferative diseases associated with EBV.

Recent Advances in Cutaneous T-cell Lymphoma: Diagnostic and Prognostic Considerations

This review describes the latest advances in the diagnosis of cutaneous T-cell lymphoma focusing on the most clinically useful features introduced since the publication of the World Health Organization revision in 2017. Clinical entities described include mycosis fungoides, Sézary syndrome, lymphomatoid papulosis, primary cutaneous anaplastic large cell lymphoma, primary cutaneous gamma delta T-cell lymphoma, primary cutaneous acral CD8⁺ T-cell lymphoma, primary cutaneous CD4⁺ small/medium T-cell lymphoproliferative disorder, and hydroa-vacciniforme-like lymphoproliferative disorder. Distinguishing histologic clues to diagnosis are discussed, and important molecular advances are described. Key prognostic indicators that may assist clinicians with timely and appropriate management options are presented.

Epstein-Barr Virus-Associated T and NK-Cell Lymphoproliferative Diseases

EBV-associated T and NK-cell lymphoproliferative diseases (EBV-T/NK LPDs) are characterized by the transformation and proliferation of EBV-infected T or NK cells. The 2016 revised World Health Organization classification recognizes the following EBV-positive lymphoproliferative disorders (LPD): chronic active EBV infection (CAEBV) of T- and NK-cell type (cutaneous and systemic forms), systemic EBV-positive T-cell lymphoma of childhood, aggressive NK-cell leukemia, extranodal NK/T-cell lymphoma, nasal type, and the new provisional entity primary EBV-positive nodal T/NK-cell lymphoma. EBV-associated hemophagocytic lymphohistiocytosis (HLH), although not included in the WHO classification because it is a reactive, inflammatory disease, is included in this review because it can be life-threatening and may have overlapping features with other EBV+ T/NK LPDs. EBV+ T/NK LPDs are rare diseases difficult to diagnose and manage properly, because some LPDs have unusual presentations, and discrepancies between clinical and histological findings might be encountered. Furthermore, EBV+ T/NK disorders share some clinico-pathological features, and may evolve into other categories during the clinical course, including malignant transformation of CAEBV. Here, we review the EBV+ T/NK LPDs in terms of their definitions, clinical features, histology, immunophenotype, molecular findings, and pathogenesis. This review aims to increase our understanding and awareness of the differential diagnosis among the different EBV+ T/NK LPDs. New insights into the genetic characteristics of these disorders will also be discussed.

Hydroa vacciniforme-like lymphoproliferative disorder in an elderly Chinese patient and a literature review of adult cases

Hydroa vaccinforme-like lymphoproliferative disorder (HVLPD) is a rare T-cell lymphoproliferative disorder driven by the Epstein-Barr Virus (EBV). It was initially designated under the 2008 WHO classification of tumors of hematopoietic and lymphoid tissues as a distinct entity but has been recently reclassified as a lymphoproliferative disorder under the 2016 revision of the 2008 WHO classification of lymphoid malignancies. HVLPD mainly affects Asian, Central, and South American children. It is rarely seen in adults. Although HVLPD may initially be limited to cutaneous involvement and run an indolent course, some patients may develop a rapidly aggressive course. We report a case of an elderly Chinese man with cutaneous-limited disease and a favorable course. A review of adult cases of HVLPD published in the English literature, with comparison to our case, is also presented in this paper.

EBV-Positive Lymphoproliferations of B- T- and NK-Cell Derivation in Non-Immunocompromised Hosts

The contribution of Epstein-Barr virus (EBV) to the development of specific types of benign lymphoproliferations and malignant lymphomas has been extensively studied since the discovery of the virus over the last 50 years. The importance and better understanding of the EBV-associated lymphoproliferative disorders (LPD) of B, T or natural killer (NK) cell type has resulted in the recognition of new entities like EBV+ mucocutaneous ulcer or the addition of chronic active EBV (CAEBV) infection in the revised 2016 World Health Organization (WHO) lymphoma classification. In this article, we review the definitions, morphology, pathogenesis, and evolving concepts of the various EBV-associated disorders including EBV+ diffuse large B-cell lymphoma, not otherwise specified (DLBCL, NOS), EBV+ mucocutaneous ulcer, DLBCL associated with chronic inflammation, fibrin-associated DLBCL, lymphomatoid granulomatosis, the EBV+ T and NK-cell LPD of childhood, aggressive NK leukaemia, extranodal NK/T-cell lymphoma, nasal type, and the new provisional entity of primary EBV+ nodal T- or NK-cell lymphoma. The current knowledge regarding the pathogenesis of B-cell lymphomas that can be EBV-associated including Burkitt lymphoma, plasmablastic lymphoma and classic Hodgkin lymphoma will be also explored.

Epstein-Barr Virus-associated Lymphoproliferative Disorders in the Skin

Epstein-Barr virus (EBV)-associated lymphoproliferations involving the skin are a rare but important group of diseases with a broad spectrum of behavior, ranging from self-limiting spontaneously resolving disorders to highly aggressive malignancies. They may be of B, T, or natural killer (NK) cell type and include EBV-positive mucocutaneous ulcer, lymphomatoid granulomatosis, EBV-positive diffuse large B-cell lymphoma, hydroa vacciniforme-like lymphoproliferative disorder, and extranodal NK/T-cell lymphoma of nasal type. Recognition and distinction of these entities is important in view of their differing prognoses and treatments. An association with EBV may be the first indication that a patient is immunosuppressed.

Clinical categories of exaggerated skin reactions to mosquito bites and their pathophysiology

Mosquito bites are skin irritating reactions, which usually resolve spontaneously without intensive medical care. However, in certain situations, mosquito bites may form a more vicious reaction, sometimes accompanying fever and systemic symptoms. In such cases, the presence of rare hematological disorders, abnormalities in eosinophils and/or association with Epstein-Barr virus (EBV) may underlie. Importantly, hypersensitivity to mosquito bites (HMB), which is characterized by necrotic skin reactions to mosquito bites with various systemic symptoms, is often observed in association with EBV infection and natural killer (NK) cell lymphoproliferative disorder. Exaggerated skin reaction to mosquito bites is also seen in Wells' syndrome. While strong Th2-skewing immune dysregulation is apparent in the patients, they also show robust CD4(+) T cell proliferation in response to mosquito salivary gland extracts, indicating close association between Wells' syndrome and mosquito bites. Similar skin reaction to mosquito bites is also noticed in certain types of B cell neoplasm, although the role of B cells in this peculiar reaction to mosquito bites is yet to be elucidated. In this review, we will discuss the current knowledge of exaggerated reaction toward mosquito bites seen in conjunction with these unique hematological disorders, and examine the scientific studies and observations reported in previous literatures to organize our current understanding of the pathogenesis of this distinct disorder.

Facial swelling: an atypical presentation of cutaneous lymphoma

BACKGROUND

Cutaneous lymphomas (primary and secondary lymphomas involving the skin) are a heterogeneous group with various clinical manifestations, histological features, and prognoses.

METHODS

We describe eight cases of cutaneous lymphoma presenting with facial swelling.

RESULTS

Our case series included three cases of primary cutaneous extranodal natural killer/T-cell lymphoma, one case of secondary cutaneous extranodal natural killer/T-cell lymphoma, one case of subcutaneous panniculitis-like T-cell lymphoma, one case of cutaneous CD4+ small/medium pleomorphic T-cell lymphoma, and two cases of peripheral T-cell lymphoma (unspecified).

CONCLUSIONS

This collection of cases and literature review emphasizes the need for clinical suspicion of cutaneous lymphoma in the differential diagnosis of patients with refractory facial swelling.

Hydroa vacciniforme-like cutaneous T-cell lymphoma

A 14-year-old Chinese girl had a 6-year history of recurrent lesions on her head, face, and limbs. Epstein-Barr virus (EBV)-IgM was positive. Histopathological findings revealed focal lymphocyte invasion in subcutaneous panniculus adiposus, mainly surrounding the blood vessels. Immunohistochemistry showed CD3+, CD4+, CD5+, CD8+, TIA-1+, GrB+, CD56-, and L26-. In situ hybridization staining for EBV-encoded small nonpolyadenylated RNA (EBER)-1 was positive. The patient showed significant improvement in clinical symptoms after being treated with acyclovir and IFN-α in this patient.

Hydroa vacciniforme-like lymphoma: a chronic EBV+ lymphoproliferative disorder with risk to develop a systemic lymphoma

HVLL is a chronic EBV+ lymphoproliferative disorder of childhood with risk to develop systemic lymphoma. The disease shows favorable response to conservative therapy despite the presence of a T- or NK-cell monoclonal proliferation.

Chronic active Epstein-Barr virus infection-associated hydroa vacciniforme-like eruption and Behçet's-like orogenital ulcers

The cutaneous manifestations of chronic active Epstein-Barr virus (EBV) infection can be diverse. Among them, hydroa vacciniforme-like eruption is one of the best-known features. Although rare, mucosal ulcers have been reported to be associated with EBV as a result of primary infection or immune suppression. We describe a 65-year-old female with recurrent necrotic papulovesicles on the face and both arms for 2 years. She also complained of recurrent oral and genital mucosal ulcers developing simultaneously with skin eruptions. They appeared periodically during the spring and summer and were triggered or aggravated by sun exposure. Skin biopsies from the face and genitalia showed identical findings with dense lymphocytic infiltrations. In addition, in situ hybridization revealed EBV-positive lymphoid cells in both specimens. To our knowledge, this is the first case of serologically and pathologically proven chronic active EBV infection presenting hydroa vacciniforme-like eruption and orogenital ulcers at the same time in one patient.

Hydroa vacciniforme-like cutaneous T-cell lymphoma: clinicopathologic and immunohistochemical study of 12 cases

BACKGROUND

Hydroa vacciniforme (HV)-like lymphoma (HVL) is a rare and aggressive cutaneous T-cell lymphoma occurring mainly in children in Latin America and Asia. Chronic latent Epstein-Barr virus infection has been associated with both HV and HVL.

OBJECTIVE

We sought to evaluate the clinical presentation and histopathology of this rare cutaneous T-cell lymphoma.

METHODS

We reviewed the clinical, morphologic, and immunophenotypical features in 12 cases of HVL from Bolivia.

RESULTS

All 12 patients had skin lesions in both sun-exposed and nonsun-exposed areas, including edema, blistering, ulceration, and scarring, with a slowly progressive relapsing course. All 12 patients presented with systemic symptoms and showed a characteristic swelling of the nose and lips, and periorbital edema. Eight patients died an average of 5.3 months after initial diagnosis. Four patients remained alive with persistent disease. Histopathologic examination showed an atypical lymphocytic infiltrate with angiotropism and angiocentricity. The immunophenotype showed a cytotoxic T-cell (CD8(+)) profile. All cases were associated with Epstein-Barr virus infection and differed clinically from other forms of cutaneous T-cell lymphoma.

LIMITATIONS

Only a limited number of cases were studied.

CONCLUSIONS

This study confirms that HVL is a highly aggressive lymphoma, although some patients have a more indolent, chronic course.

Epstein-Barr virus-associated hydroa vacciniforme-like cutaneous lymphoma in seven Chinese children

Hydroa vacciniforme-like cutaneous lymphoma is a rare type of Epstein-Barr virus-associated lymphoma. We analyze clinicopathologic features of seven Chinese child patients with hydroa vacciniforme-like cutaneous lymphoma and determine the pathogenic association of Epstein-Barr virus with this disorder. Clinical, histologic, and immunohistochemical features were reviewed. Skin lesions were subjected to Epstein-Barr virus-encoded RNA detection by in situ hybridization. Serologic assay and quantitation of Epstein-Barr virus DNA were performed. All seven patients presented with facial vesicles, papulovesicles, and atrophic scarring. Histologically, skin specimens showed epidermal blister formation, and dense lymphoid infiltration throughout the dermis and subcutaneous tissue. The infiltrate was composed of both small and large irregular lymphocytic cells expressing CD45RO or CD56. Tumor cells positive for Epstein-Barr virus-encoded RNA were detected in cutaneous infiltrates in all seven cases. Besides skin eruptions, all patients had systemic manifestations, such as intermittent fever, hepatosplenomegaly or lymph node enlargement. The amounts of Epstein-Barr virus DNA were increased in the peripheral blood in two detected cases, and antibody titers to Epstein-Barr virus revealed a chronic active Epstein-Barr virus infection in all cases. The diagnosis of hydroa vacciniforme-like cutaneous lymphoma was made. Four of seven patients were treated with interferon α intramuscularly, and the skin eruptions improved. Hydroa vacciniforme-like cutaneous lymphoma may present with severe facial edema, papulovesicular eruptions and permanent scars. The tumor cells often express natural killer- or T-cell markers. The disease is often preceded by chronic active Epstein-Barr virus infection.

A Case of Epstein-Barr Virus-associated Hydroa Vacciniforme

Hydroa vacciniforme (HV) is a photosensitivity disorder characterized by recurrent necrotic vesiculopapules on sun-exposed areas, which heal spontaneously during adolescence. Recently, an association has been reported between latent Epstein-Barr virus (EBV) infection and atypical HV-like eruption and malignant potential. However, latent EBV infection has also been reported in the setting of typical HV. An 11-year-old girl presented with recurrent, scattered, discrete vesicular eruptions with scarring on the face and the extensor surfaces of both forearms. In-situ hybridization was carried out to detect latent EBV infection. Based on the clinical and histopathological findings, typical EBV-associated HV was suspected.

Panniculitis in children

The panniculitides include a group of disorders of varied etiology that manifest as inflamed nodules in the subcutaneous tissue. They are rarely seen in infants and children. The panniculitides of the newborn represent a unique response of the infant's fat to different injuries, and are a specific type of panniculitis that is only seen in neonates and very young infants. These specific panniculitides of children include subcutaneous fat of the newborn, poststeroid panniculitis, sclerema neonatorum, and cold panniculitis. This article reviews in detail the specific types of panniculitis of the newborn and discusses the pediatric aspects of the panniculitis that is often seen in adults.

Emerging diseases in tropical dermatology

All dermatologists worldwide should have at least passing familiarity with various tropical maladies that generate cutaneous manifestions. In addition to the standard infectious ailments associated with tropical environs, the authors have described herein five "emerging" illnesses that are gaining increasing attention for their capacity to cause human disease in those immigrating from, or traveling to, the tropical and subtropical world.

Hydroa vacciniforme-like Epstein-Barr virus-associated monoclonal T-lymphoproliferative disorder in a child

Hydroa vacciniforme (HV) is a chronic photosensitivity disorder induced by ultraviolet radiation. Hydroa vacciniforme-like lymphoma is a rare cutaneous T-cell lymphoma occurring mainly in childhood. Recent studies have demonstrated an association between chronic latent Epstein-Barr virus (EBV) infection and both the benign skin disorder and the lymphoma. The authors report a 6-year-old boy with chronic EBV infection, HV-like skin eruptions, and chronic hepatitis. Histopathologic examination of a skin biopsy specimen demonstrated epidermal ballooning degeneration and dense superficial and deep perivascular and periappendageal lymphoid cell infiltrates extending to the fat lobules. Some blood vessels in the deep plexus were infiltrated by predominantly CD4+ and TIA-1+ cytotoxic T cells. The EBV genomes were found within tissue from three skin biopsies and peripheral blood cells. Monoclonal T-cell receptor gene rearrangement was present in skin biopsy specimens. Although no lymphoma has been found during 2 years of follow-up treatment, the possibility of lymphoma developing out of the current smoldering stage is of concern. The clinical manifestations of lymphoproliferative disorder and chronic active EBV infection are discussed.

Hypersensitivity to mosquito bites: A unique pathogenic mechanism linking Epstein-Barr virus infection, allergy and oncogenesis

Hypersensitivity to mosquito bites (HMB) is characterized by intense local skin reactions and systemic symptoms, such as high fever, lymphadenopathy and hepatosplenomegaly. Half of the patients reported died of hemophagocytic syndrome or lymphocyte proliferative disorders. Clinical and laboratory studies have revealed that HMB occurs in association with natural killer (NK) cell lymphocytosis related to chronic Epstein-Barr virus (EBV) infection. Recent studies have clarified the unique pathogenic mechanism of this mysterious disease, and demonstrated the close relationship between HMB and EBV-carrying NK cell lymphocytosis; i.e., CD4(+) T cells from the patients markedly responded to mosquito salivary gland extracts, and the CD4(+) T cells stimulated by mosquito bites may play a key role in the development of HMB and NK cell oncogenesis via the induction of EBV reactivation and EBV-oncogene expression, respectively.

Mosquito Salivary Gland Extracts Induce EBV-Infected NK Cell Oncogenesis Via CD4+ T Cells in Patients with Hypersensitivity to Mosquito Bites

Severe hypersensitivity to mosquito bites (HMB) is characterized by intense local skin reactions and systemic symptoms such as high fever, lymphadenopathy, and hepatosplenomegaly. Patients with HMB often have natural killer (NK) cell lymphocytosis associated with Epstein-Barr virus (EBV) infection. Here we investigated whether mosquito bites have any influence on the oncogenesis of EBV-infected NK cells. We examined six HMB patients with EBV-infected NK cell lymphocytosis. We first demonstrated that CD4+ T cells, but not NK cells, proliferated well in response to mosquito salivary gland extracts (SGE), especially to SGE of Aedes albopictus. When NK cells were cocultured with autologous CD4+ T cells stimulated by mosquito SGE, the expression of viral oncogene latent membrane protein 1 (LMP1) was remarkably enhanced. Next, we stimulated mononuclear cells of the patients with mosquito SGE, and NK cell counts were monitored for 28 d. The counts changed little from initial levels in the culture with mosquito SGE, whereas they decreased steadily in the culture without the extracts. Furthermore, we detected LMP1 mRNA in the skin lesion induced by mosquito SGE. These results suggest that mosquito bites can induce expression of the viral oncogene LMP1 in NK cells via mosquito antigen-specific CD4+ T cells, which is involved in the oncogenesis of NK cells in vivo.

Enhanced T-cell response to mosquito extracts by NK cells in hypersensitivity to mosquito bites associated with EBV infection and NK cell lymphocytosis

Hypersensitivity to mosquito bites is characterized by severe systemic as well as local symptoms, and associated with chronic active EBV infection and NK cell lymphocytosis. In this HEN disease, we investigated the response of PBMC to MSG extracts. PBMC were taken from three defined cases of HEN disease, three borderline cases, five individuals with simple exaggerated reactions to mosquito bites without systemic symptoms (simple responders), and eight healthy donors. PBMC, or purified CD4+, CD8+ or CD56+ cells, were cultured with MSG extracts prepared from each of five mosquito species to examine their proliferation and cytokine secretion. The patients with HEN disease had high stimulation indices with variations in responses to the extracts from Aedes albopictus, Aedes aegypti, Anopheles sinensis and Culex pipiens pallens. However, a non-Japan-habitant species Anopheles stephensi did not stimulate the patients' PBMC. Some borderline or simple responders showed moderate proliferation, and healthy donors had no reactive PBMC. In HEN disease, both CD56+ NK cells (producing IFN-gamma) and CD4+ Th0 cells (producing IL-4 and IFN-gamma) were increased in the blood. CD4+ cells, but not CD56+ NK cells or CD8+ cells, propagated in response to MSG extracts. However, this response of CD4+ cells and their IL-4 production were strongly enhanced by coexisting CD56+ cells. We suggest that the CD4+ T cell serving as the primary responder to MSG antigen and the NK cell functioning as the enhancer are both pathogenic in the development of HMB.

Epstein-Barr virus-associated lymphoproliferative lesions presenting as a hydroa vacciniforme-like eruption: an analysis of six cases

BACKGROUND

There are many reports of patients with a severe hydroa vacciniforme (HV)-like eruption in which cutaneous lesions occur in both sun-exposed and non-exposed areas, unlike in true HV. Several patients have died from a malignant haematological neoplasm. In most cases, a latent Epstein-Barr virus (EBV) infection has been detected in the skin lesions.

OBJECTIVES

To describe the clinical and laboratory features of six additional patients with an EBV-associated HV-like eruption.

METHODS

The clinical, histological and immunohistochemical features were reviewed. T-cell receptor gamma gene rearrangements were studied using polymerase chain reaction (PCR) and heteroduplex analysis. In-situ hybridization was performed to detect mRNA for EBV in skin biopsy specimens. PCR was performed to screen for EBV infection in the skin lesions of three patients and blood of two patients. Photoprovocation with repeated ultraviolet (UV) A exposure was performed in three patients.

RESULTS

The severity of the skin lesions and the clinical course varied among the patients. Skin lesions were induced by repeated UVA exposure in three patients and a latent EBV infection was demonstrated in the photoprovoked lesions.

CONCLUSIONS

Three different clinical courses were found in six patients with an HV-like eruption associated with chronic EBV infection: (i) spontaneous remission; (ii) clearing after photoprotection; and (iii) continuous recurrence irrespective of sun exposure. It is possible that there are two patterns of HV-like eruption associated with chronic EBV infection. One is characterized by recurrent necrotic papulovesicles of the face and the other by nodules and facial swelling. It was demonstrated that the skin lesions could be triggered by repeated UVA exposure in the patients showing recurrent necrotic papulovesicles of the face.

Characterization of Epstein-Barr virus (EBV)-positive NK cells isolated from hydroa vacciniforme-like eruptions

Recently, the involvement of Epstein-Barr virus (EBV) in hydroa vacciniforme (HV)-like eruptions has been suggested. To elucidate the role of EBV in this disease, we isolated EBV-infected cell clones from peripheral blood mononuclear cells (PBMC) and the skin lesions of a patient with HV-like eruptions; cells isolated from PBMC were designated SNK-12, and those from the eruption SNK-11. Both cells expressed CD16, CD56, and HLA-DR and had germline configurations of the T-cell receptor and the immunoglobulin genes, indicating that the cell clones were of NK cell lineage. The analysis of EBV terminal repeats indicated that the cells were monoclonal, had identical clonality, and originated from EBV-positive cells in the PBMC and eruption. Both clones expressed EBNA-1, but not EBNA-2. Although LMP-1 was weakly detected in SNK-11, no LMP-1 was detected in SNK-12. Interestingly, EBV-infected cells required less IL-2 for in vitro growth in the later phase of this disease and this appeared to correlate with the expression of LMP-1, suggesting that the proliferative capacity of the EBV-positive NK cells increased during the time course of the disease, and LMP-1 expression might be responsible for that. This is the first report of the isolation of EBV-infected cells from the skin lesions of HV-like eruptions and strongly suggests that the HV-like eruption in the patient was caused by clonal NK cells with latent EBV infection.

Common cytological and cytogenetic features of Epstein-Barr virus (EBV)-positive natural killer (NK) cells and cell lines derived from patients with nasal T/NK-cell lymphomas, chronic active EBV infection and hydroa vacciniforme-like eruptions

In this study, we describe the cytological and cytogenetic features of six Epstein-Barr virus (EBV)-infected natural killer (NK) cell clones. Three cell clones, SNK-1, -3 and -6, were derived from patients with nasal T/NK-cell lymphomas; two cell clones, SNK-5 and -10, were isolated from patients with chronic active EBV infection (CAEBV); and the other cell clone, SNK-11, was from a patient with hydroa vacciniforme (HV)-like eruptions. An analysis of the number of EBV-terminal repeats showed that the SNK cell clones had monoclonal EBV genomes identical to the original EBV-infected cells of the respective patients, and SNK cells had the type II latency of EBV infection, suggesting that not only the cell clones isolated from nasal T/NK-cell lymphomas but also those isolated from CAEBV and HV-like eruptions had been transformed by EBV to a certain degree. Cytogenetic analysis detected deletions in chromosome 6q in five out of the six SNK cell clones, while 6q was not deleted in four control cell lines of T-cell lineage. This suggested that a 6q deletion is a characteristic feature of EBV-positive NK cells, which proliferated in the diseased individuals. The results showed that EBV-positive NK cells in malignant and non-malignant lymphoproliferative diseases shared common cytological and cytogenetic features.

Hydroa vacciniforme-like eruptions in a patient with chronic active EB virus infection

We report a case of chronic active Epstein-Barr (EB) virus infection (CAEBV) associated with skin eruptions mimicking hydroa vacciniforme (HV) in a 4-year-old boy. The patient had repeated episodes of vesiculo-necrotic eruptions on the face, scalp, and bilateral forearms one year before the first visit to our department. General symptoms including fever, hepatosplenomegaly, abnormal liver function, and cervical lymph node swelling were noted three months before the first visit. At the first visit, small, bean-sized, erythemic papules with central necrosis were observed on the face and anterior chest wall. Thumb-sized ulcers with crust were present on the bilateral forearms. Histopathological examination of an erythematous lesion in the submandibular area revealed parakeratosis with a thick crust, mild spongiosis in the epidermis, and a dense infiltration of lymphoid cells into the dermis and perivascular space. Laboratory examination showed EBNA x 40, EBV VCA IgG x 1,280, and EBV DNA (PCR) 8 x 10(4). EBV-encoded small nuclear RNA (EBER) positive cells were detected in the dermis by an in situ hybridization (ISH) method. Large granular lymphocytes (65%) with the NK cell phenotype were found in the peripheral blood. A real time PCR method showed 171,741 copies/ micro g DNA in CD 16 positive cells. Although latent EBV infection-associated eruptions have been documented, detailed skin manifestations in CAEBV are less well known.

Hydroa vacciniforme-like primary cutaneous CD8-positive T-cell lymphoma

An 8-year-old Taiwanese girl had a 6-month history of a relapsing papulovesicular eruption on her face that resembled hydroa vacciniforme (HV). Histologically, there was a dense infiltration of large atypical lymphocytic cells expressing CD8. TCR-gamma gene rearrangement study revealed a monoclonal band present in the DNA extracted from the specimen. A diagnosis of CD8+ cutaneous T-cell lymphoma (CTCL) was made. The patient was treated with Chinese herbal drugs and her skin lesions waxed and waned. At this writing, 11 months after establishment of the diagnosis, the skin lesions have been limited to the facial area and no definite evidence of systemic involvement is noted. To our knowledge, this is the first case of CD8+ primary CTCL with clinical features resembling HV.

Hydroa-like cutaneous T-cell lymphoma: a clinicopathologic and molecular genetic study of 16 pediatric cases from Peru

Hydroa-like cutaneous T-cell lymphoma (hydroa-like CTCL) is an unusual pediatric malignancy with a poor prognosis. An impressive cutaneous rash characterized by edema, blisters, ulcers, crusts, and scars, resembling hidroa vacciniforme, is seen mainly on the face and sometimes on the extremities. The lesion consists of lymphomatous T-cell infiltration of the skin and subcutis with variable exocytosis and angiocentricity. It has been also called edematous, scarring vasculitic panniculitis and hydroa-like lymphoma. An association with Epstein-Barr virus has been suggested. The differential diagnosis includes other cutaneous lymphomas, particularly the cutaneous nasal type T/natural killer-cell lymphoma, mycosis fungoides, precursor T-cell lymphoblastic lymphoma, nonspecific peripheral T-cell lymphoma, cutaneous anaplastic large cell lymphoma, and subcutaneous panniculitic T-cell lymphoma. Other differential diagnoses are inflammatory dermatopathies and panniculitides. Based on a series of 16 such cases referred to the Institute of Neoplastic Diseases, the objective of this report is not only to provide a better clinicopathologic understanding of this entity but also a reappraisal of it as a malignancy. The male/female frequency ratio was 1:1. The median age was 10 years old. All cases showed predominant facial involvement with edema, blisters, ulcers, crusts, and scars. Chemotherapy and/or radiotherapy had little or no benefit. The prognosis was usually dismal. The lymphoma extended from the epidermis to the subcutis, with frequent angiocentric and periadnexal array. Lymphoma cells were mostly of intermediate size with dense hyperchromatic nuclei, inconspicuous nucleoli, and infrequent mitosis. A scanty and variable inflammatory background was found. The lymphoma cells displayed T-cell cytotoxic phenotype. In addition, they were negative for the natural killer cell antigens CD56 and CD57. Epstein-Barr virus in situ hybridization was positive in the six cases in which it was assayed. T-cell receptor gamma (TCRgamma) displayed monoclonal-type rearrangement in four cases studied. Our findings indicate that hydroa-like CTCL is an independent clinicopathologic entity that affects children. Consequently, it should be considered an independent subset of CTCLs and be included as such in the classification of neoplastic diseases of the lymphoid tissues.

Hypersensitivity to mosquito bites as the primary clinical manifestation of a juvenile type of Epstein-Barr virus-associated natural killer cell leukemia/lymphoma

Hypersensitivity to mosquito bites or mosquito allergy is a mysterious disorder that has been reported mainly in Japanese patients (at least 58 patients) in the first two decades of life. The skin lesion at bite sites is typically a bulla that develops into necrosis. Patients simultaneously exhibit a high temperature and general malaise and subsequently may experience lymphadenopathy and hepatosplenomegaly. Recent studies have revealed that this mosquito hypersensitivity is associated with chronic Epstein-Barr virus infection and natural killer cell leukemia/lymphoma. The natural killer cell, infected with monoclonal (or oligoclonal) Epstein-Barr virus, seems to be involved in the pathogenesis of the hypersensitivity. Half of the patients reported died of hemophagocytic syndrome (or malignant histiocytosis), granular lymphocyte proliferative disorder, or lymphomas. We propose that this disease, defined as the triad of hypersensitivity to mosquito bites, chronic Epstein-Barr virus infection, and natural killer cell leukemia/lymphoma, is a clinical entity mostly seen in Asians.

Panniculitis. Part II. Mostly lobular panniculitis

The second part of our review of panniculitis summarizes the clinicopathologic features of the mostly lobular panniculitides. Erythema induratum of Bazin (nodular vasculitis) represents the most common variant of lobular panniculitis with vasculitis, although controversy persists about the nature of the involved vessels. Mostly lobular panniculitides without vasculitis comprise a series of disparate disorders. These include sclerosing panniculitis that results from chronic venous insufficiency of the lower extremities; panniculitis with calcification of the vessel walls such as calciphylaxis and oxalosis; and inflammatory diseases with crystals within the adipocytes such as sclerema neonatorum, subcutaneous fat necrosis of the newborn, and poststeroid panniculitis. Connective tissue diseases, such as systemic lupus erythematosus and dermatomyositis, pancreatic diseases, and alpha(1)-antitrypsin deficiency may also show a mostly lobular panniculitis with characteristic histopathologic features. Lobular panniculitis may also be an expression of infections, trauma, or factitial causes involving the subcutaneous fat. Lipoatrophy refers to a loss of subcutaneous fat due to a previous inflammatory process involving the subcutis, and it may be the late-stage lesion of several types of panniculitis. In contrast, lipodystrophy means an absence of subcutaneous fat with no evidence of inflammation and often the process is associated with endocrinologic, metabolic, or autoimmune diseases. Finally, cytophagic histiocytic panniculitis is the term that has been used to describe two different processes: one is inflammatory, a lobular panniculitis, and the other one is neoplastic, a subcutaneous T-cell lymphoma. The only common feature of these two different processes is the presence of cytophagocytosis in the lesions. (J Am Acad Dermatol 2001;45:325-61.)

LEARNING OBJECTIVE

At the completion of this learning activity, participants should be familiar with the pathogenesis, clinical manifestations, histopathologic findings, and treatment options for the most frequent variants of the lobular panniculitides.

Epstein-Barr virus-associated recurrent necrotic papulovesicles with repeated bacterial infections ending in sepsis and death: consideration of the relationship between Epstein-Barr virus infection and immune defect

The disease of Epstein-Barr virus (EBV) -associated recurrent necrotic papulovesicles is a distinct clinicopathologic entity different from classic hydroa vacciniforme (HV). A few patients have been reported as atypical HV with systemic involvement, development of lymphoma, and poor prognosis. We describe a patient with recurrent necrotic papulovesicles and multiple varioliform scars in both sun-exposed and covered areas. In contrast to cases of previously reported atypical HV, our patient suffered from repeated bacterial infections on various sites ending in sepsis and death, but without malignant transformation. EBV was detected in the lymphoid cells from the skin lesions by anti-latent membrane protein (LMP) antibody and in situ hybridization. We suggest that the repeated bacterial infections in this case raise the possibility of an association of EBV infection with increased susceptibility to bacterial infections.

Epstein-Barr virus-associated peripheral T-cell lymphoma in adults with hydroa vacciniforme-like lesions

We describe two Korean adult patients who had necrotizing papulovesicles mainly on their faces. Skin biopsy specimens showed perivascular and periadnexal infiltrate of atypical lymphoid cells with vasculitis in the dermis and subcutaneous tissue. In situ hybridization demonstrated a latent infection of Epstein-Barr virus in the majority of lymphoid cells in the dermis. These patients were diagnosed as having T-cell lymphoma. Interestingly, large granular lymphocytosis was found in the peripheral blood of Case 2.

Skin is the frequent site for involvement of peripheral T-cell and natural killer cell lymphomas in Korea

We have studied the clinicopathological features of 19 Korean cases of peripheral T-cell and natural killer (NK) cell lymphomas, not including mycosis fungoides. Primary cutaneous involvement was demonstrated in eight of these 19 cases, and we recognized four clinicopathologic subtypes among these eight patients: nasal type NK/T cell lymphoma, three cases; primary cutaneous CD30 positive anaplastic large cell lymphoma, two cases; subcutaneous panniculitis-like T-cell lymphoma, one case; lymphoma with hydroa vacciniforme-like cutaneous lesions, two cases. We did not, however, encounter any cases of HTLV-associated adult T-cell lymphoma/leukemia, which is common in Taiwan and Japan. EBV-associated lymphoma is the most prominent type of peripheral T-cell and NK cell neoplasm involving the skin in Korea.

Cutaneous lymphoproliferative disorders associated with Epstein-Barr virus infection: a clinical overview

Epstein Barr virus (EBV) infection is implicated in various kinds of neoplasms including certain types of cutaneous T or natural killer (NK) cell proliferative disorders. Although a pathogenic role of EBV infection is not clear, some EBV gene products expressed during a latency phase were found to have biological properties leading to cellular gene expression and immortalization. Furthermore, EBV can use an array of strategies to evade host immune responses, and maintain the latent infection. EBV-associated cutaneous lymphoproliferative disorders are prevalent in Asia, and less frequent in western countries where infectious mononucleosis is common in adolescents and young adults. This review introduces recent advances on the mechanism of EBV infection, highlighting unique clinicopathologic manifestations of EBV-associated cutaneous lymphoproliferative disorders.