Clinicopathological analysis of 34 Japanese patients with EBV-positive mucocutaneous ulcer

Diagnostic utility of cytology in a patient with Epstein-Barr virus-positive mucocutaneous ulcer in palatine tonsils: A case report

Epstein-Barr virus-positive mucocutaneous ulcer (EBVMCU) is a newly established immunodeficiency-related disease. Herein, we report a case of EBVMCU and focus on its cytological usefulness for diagnosis. An 82-year-old man manifested pharyngalgia, dysphagia, and oral pain. His medical history included rheumatoid arthritis that had been treated with methotrexate. Clinically, peritonsillar abscess was suspected, but since neoplastic lesions, including malignant lymphoma (ML), could not be excluded, a series of cytohistological examination was attempted. Despite some alarming findings (e.g., frequent mitoses), fine-needle aspiration and touch imprint cytology consistently revealed a heterogeneous population of lymphoid and plasmacytoid cells with mild nuclear atypia. The final diagnosis of EBVMCU was established based on the permanent histologic specimen; however, retrospectively, cytology was more representative of the benign nature of the lesion than histology, helping a great deal to differentiate it from ML. Cytology can be a useful tool for the correct diagnosis of EBVMCU.

Targeted mutational profiling of Epstein Barr virus-positive mucocutaneous ulcer: Implications for differential diagnosis with EBV-positive diffuse large B-cell lymphoma

Epstein Barr Virus-positive mucocutaneous ulcer (EBVMCU) can be difficult to distinguish from EBV-positive diffuse large B cell lymphoma (DLBCL). We used targeted next-generation sequencing (NGS) to explore genetic alterations in EBVMCU to aid in this diagnostic challenge. Ten cases of EBVMCU were evaluated by a targeted NGS panel of 164 genes. Targeted NGS identified 18 variants in 15 genes in eight cases of EBVMCU. Loss of function TET2 variants were most frequently identified (3 of 10 cases, 30 %). One TET2 variant occurred at low variant allele frequency (VAF) of 3 %, which may be suggestive of clonal hematopoiesis of indeterminate potential. One case harbored a loss of function DNMT3A variant at low VAF. Two cases demonstrated missense variants in the IRF8 gene. Both variants occurred at a VAF close to 50 % and with an estimated high burden of disease (75 %). Two cases of mucosal gastrointestinal involvement had no reportable variants. Mutational profiling of EBVMCU identified TET2 loss of function variants at an elevated frequency in our cohort; however, the findings are not specific and its clinical significance cannot be completely elucidated. Further studies are needed to confirm the findings in an independent and larger cohort of EBVMCU, to determine the cell of origin of the variants, and to further assess their significance in the pathogenesis of this disorder.

Update: The molecular spectrum of virus-associated high-grade B-cell non-Hodgkin lymphomas

The vast spectrum of aggressive B-cell non-Hodgkin neoplasms (B-NHL) encompasses several infrequent entities occurring in association with viral infections, posing diagnostic challenges for practitioners. In the emerging era of precision oncology, the molecular characterization of malignancies has acquired paramount significance. The pathophysiological comprehension of specific entities and the identification of targeted therapeutic options have seen rapid development. However, owing to their rarity, not all entities have undergone exhaustive molecular characterization. Considerable heterogeneity exists in the extant body of work, both in terms of employed methodologies and the scale of cases studied. Presently, therapeutic strategies are predominantly derived from observations in diffuse large B-cell lymphoma (DLBCL), the most prevalent subset of aggressive B-NHL. Ongoing investigations into the molecular profiles of these uncommon virus-associated entities are progressively facilitating a clearer distinction from DLBCL, ultimately paving the way towards individualized therapeutic approaches. This review consolidates the current molecular insights into aggressive and virus-associated B-NHL, taking into consideration the recently updated 5th edition of the WHO classification of hematolymphoid tumors (WHO-5HAEM) and the International Consensus Classification (ICC). Additionally, potential therapeutically targetable susceptibilities are highlighted, offering a comprehensive overview of the present scientific landscape in the field.

Epstein-Barr Virus-Positive Mucocutaneous Ulcer With Medication-Related Osteonecrosis of the Jaw Arising in the Mandible of a Rheumatoid Arthritis Patient: A Case Report

This study presents a rare case of an Epstein-Barr virus-positive mucocutaneous ulcer (EBVMCU) co-existing with medication-related osteonecrosis of the jaw (MRONJ) in the mandible of a 54-year-old Japanese man who complained of painful swelling of the left mandibular gingiva over the past three months. The patient had a history of methotrexate (MTX) and bisphosphonates (BPs) use. Intraoral examination revealed a 35 mm large ulcerative lesion with marginal gingival swelling and bone exposure on the left side of the mandible. A biopsy was performed, confirming the diagnosis of EBVMCU with MRONJ. Due to the enlargement of the bone exposure, marginal resection of the mandible was performed under general anesthesia as a treatment for residual MRONJ. At the two-year follow-up, no evidence of recurrence was observed.

Epstein-Barr Virus-Positive Mucosal Skin Ulcer Resulting in Oral Lesions During Concomitant Use of Tacrolimus and Prednisolone

Epstein-Barr virus-positive mucocutaneous ulcer (EBVMCU) is a subtype of Epstein-Barr virus-positive lymphoproliferative disease with a favorable prognosis that can develop either due to medical interventions or as a consequence of aging. Medical-onset cases caused by immunosuppressive drugs may require a reduction or discontinuation of the causative drugs. However, specific methods for drug adjustment in cases where multiple immunosuppressive drugs are used have not yet been established. Herein, we present the case of a 63-year-old man with interstitial pneumonia who developed an EBVMCU on the right side of his tongue. He was on multidrug therapy with tacrolimus and prednisolone and was treated conservatively by discontinuation of the tacrolimus and switching to prednisolone monotherapy. The lesion resolved within two months following the adjustment. This case report provides evidence that conversion to monotherapy, rather than multiple immunosuppressive drugs, is a potentially effective treatment option for EBVMCU.

Epstein-Barr Virus-Positive Mucocutaneous Ulcer on the Gingiva of a Patient in Whom Immunosuppressive Drugs Could Not Be Withdrawn: A Case Report and Review of the Literature

Epstein-Barr virus-positive mucocutaneous ulcer (EBV-MCU) is characterized by ulcers confined to the skin and mucus membranes. EBV-MCU is an EBV-positive lymphoproliferative disorder that occurs during the use of immunosuppressive drugs such as methotrexate. We herein report a case of EBV-MCU in the maxillary gingiva. A 73-year-old woman was referred to our department in March 2021. During the initial examination, bone exposure and ulceration were observed in the extraction socket of the maxillary bilateral central incisors. The patient was taking methotrexate for rheumatoid arthritis and was unable to stop due to disease progression. In March 2021, curettage of the extraction socket of the maxillary anterior teeth and extraction of the maxillary right lateral incisor, which was difficult to preserve due to severe tooth mobility, was performed under local anesthesia. The extraction site epithelialized and healed well. Three months later, inflammation flared, and ulceration was observed. Extraction of the unsalvageable maxillary teeth and an excisional biopsy of the palatal gingiva were performed. The histopathological diagnosis was EBV-MCU. The postoperative course was uneventful, and no evidence of recurrence was found two years postoperatively; follow-up will be continued. There are many reports of EBV-MCU remission with the cessation of methotrexate treatment. In our patient, withdrawal was difficult because of the progression of rheumatoid arthritis, but remission was achieved by improving the oral cavity environment through an excisional biopsy and tooth extraction.

Importance of differential diagnosis of EBV mucocutaneous ulcer and EBV-positive diffuse large B-cell lymphoma: A case report

RATIONALE

Epstein-Barr virus mucocutaneous ulcers (EBVMCUs) were officially recognized as a clinicopathologic entity in the 2017 revision of the World Health Organization classification, which often occurs in the elderly or in immunosuppressive condition presented as an isolated ulcerative lesion. EBVMCUs are defined as "shallow, sharply circumscribed, mucosal or cutaneous ulcers with underlying polymorphous infiltration." It mostly involves oral mucosa, but some appear in skin or gastrointestinal tract. Typically, patients with EBVMCUs display a slow disease progression and may even undergo spontaneous regression.

PATIENT CONCERNS

This report describes the case of a 76-year-old woman who visited our outpatient clinic with the chief complaint of inflammation and ulceration on lower labial, lower right lingual gingiva seemed like acute necrotizing ulcerative gingivitis, and malignancy.

DIAGNOSES

She was diagnosed with EBVMCU after tissue biopsy.

INTERVENTIONS

Since most oral ulcerations usually appear in nonspecific form, it is important to check thoroughly for any underlying immunosuppressive systemic conditions and laboratory test results in case of viral infection. But she has no remarkable underlying immunosuppressive disorder.

OUTCOMES

For this patient, she was initially diagnosed with EBVMCU and showed spontaneous healing, but then relapsed after 4 to 6 months. The patient was re-diagnosed as EBV-positive diffuse large B-cell lymphoma (EBV-positive DLBCLs) after re-biopsy.

LESSONS

EBVMCU shows similar symptoms to malignant lesions or acute necrotizing ulcerative gingivitis but shows spontaneous healing. However, in case of EBV-positive DLBCLs, failing to detect and treat the disease in its early stages can lead to a fatal outcome. Thus, this case report highlights the differential diagnosis and appropriate treatment of EBVMCU and EBV-positive DLBCLs.

Non-neoplastic B-cell predominant lymphoid proliferations at the organs exposed to external environment mimicking lymphoma: A potential diagnostic pitfall

Background: Typically, lymphatic tissue proliferative lesions include either benign lesions or lymphoma. However, not all lymphatic lesions can currently be accurately classified into one category, particularly in mucosal areas that are in contact with the external environment.Aims: To explore the morphology, immunophenotype, and molecular changes of Non-neoplastic B-cell predominant lymphoid proliferations (NBPLP) in pathological areas that are exposed to external surroundings which mimicked lymphoma.Methods and Results: 18 cases of Atypical lymphoid hyperplasia (AtLP)  were retrieved in this study. The biopsy samples were mucosal samples obtained from areas exposed to external surroundings, including intestines, urethra, cervix, tonsils, and tongue. Microscopically, there is a different level of B cell hyperplasia accompanied by morphological atypia. We categorized the morphology into 4 groups: type A (7/18), type B (3/18), type C (3/18), type D (5/18). Part of the AtLP was found positive for BCR gene rearrangement (6/15), and TCR gene rearrangement (1/4). The follow-up period ranged from 14.2 to 70 months. No evidence of lymphoma was found. Therefore, we diagnosed all of the presented cases as NBPLP. We illustrated the key differential points and provided valuable diagnostic experience on each subtype.Conclusions: Areas exposed to the external environment are commonly exposed to antigen and easily present with AtLP of NBPLP, accompanying with positive IGH rearrangement. Therefore, a comprehensive evaluation of macroscopic, morphology, immunophenotype, and molecular diagnostics is required to prevent the overdiagnosis of lymphoma.

Skin-Limited, Methotrexate-Associated Epstein-Barr Virus-Positive Mucocutaneous Ulcer-A Mimicker of High-Grade Lymphoma. A Report of 4 Cases and Review of the Literature

ABSTRACT

Immunodeficiency-associated lymphoproliferative disorders (IA-LPDs) constitute a diverse range of conditions including posttransplant lymphoproliferative disorders, other iatrogenic IA-LPDs, and lymphoproliferative disorders associated with an underlying primary immune disorder or HIV infection. IA-LPDs are clinically and pathologically heterogeneous, and there is a lack of standardization of diagnostic terminology. They can represent a potential serious diagnostic pitfall because the histological features of clinically indolent proliferations may mimic those of high-grade lymphoma. However, correct identification of these entities is essential given that complete remission may occur upon reversal of the underlying cause of immunosuppression without the need for systemic therapy. IA-LPDs presenting in the skin are rare but well documented. One form of iatrogenic IA-LPD, methotrexate-associated lymphoproliferative disorder (MTX-LPD), can present with cutaneous nodules, plaques, or ulcers. Predominantly, MTX-LPD develops in the context of long-term treatment of autoimmune conditions, such as rheumatoid arthritis, dermatomyositis, and Sjögren syndrome, and may be associated with underlying Epstein-Barr virus (EBV) infection. We present 4 cases of cutaneous EBV-positive B-cell MTX-LPD and describe their clinical and morphological findings. Comparison of our histological findings to the diagnostic criteria for EBV-positive mucocutaneous ulcer (EBVMCU) revealed significant overlap, highlighting the intersection between MTX-LPD and EBVMCU. Withdrawal of methotrexate resulted in healing of all lesions at a mean time of 2 months. In summary, close clinicopathological correlation is vital to identify MTX-LPD presenting as cutaneous EBVMCU given that the initial treatment strategy is that of withdrawal of methotrexate without the need for immediate systemic therapy.

Cutaneous B-cell lymphomas: 2023 update on diagnosis, risk-stratification, and management

DISEASE OVERVIEW

Approximately one-fourth of primary cutaneous lymphomas are B-cell derived and are generally classified into three distinct subgroups: primary cutaneous follicle center lymphoma (PCFCL), primary cutaneous marginal zone lymphoma (PCMZL), and primary cutaneous diffuse large B-cell lymphoma, leg type (PCDLBCL, LT).

DIAGNOSIS

Diagnosis and disease classification is based on histopathologic review and immunohistochemical staining of an appropriate skin biopsy. Pathologic review and an appropriate staging evaluation are necessary to distinguish primary cutaneous B-cell lymphomas from systemic B-cell lymphomas with secondary skin involvement.

RISK-STRATIFICATION

Disease histopathology remains the most important prognostic determinant in primary cutaneous B-cell lymphomas. Both PCFCL and PCMZL are indolent lymphomas that infrequently disseminate to extracutaneous sites and are associated with 5-year survival rates that exceed 95%. In contrast, PCDLBCL, LT is an aggressive lymphoma with an inferior prognosis.

RISK-ADAPTED THERAPY

PCFCL and PCMZL patients with solitary or relatively few skin lesions may be effectively managed with local radiation therapy. While single-agent rituximab may be employed for patients with more widespread skin involvement, multiagent chemotherapy is rarely appropriate. In contrast, management of patients with PCDLBCL, LT is comparable to the management of patients with systemic DLBCL.

EBV-positive mucocutaneous ulcer arising in methotrexate-treated rheumatoid arthritis patients: a clinicopathological study of 12 cases with analysis of PD-L1 expression

Epstein-Barr virus-positive mucocutaneous ulcer (EBVMCU) is a newly recognized disease entity characterized by EBV-positive atypical B-cell proliferation. EBVMCU is a localized self-limited disease that affects mucosa and skin, especially the oral cavity. EBVMCU develops in immunosuppressive patients, such as those with methotrexate (MTX)-administrated rheumatoid arthritis (RA). Here we clinicopathologically analyzed 12 EBVMCU patients in a single institution. All cases were administrated MTX for RA, and five cases occurred in the oral cavity. All cases except one had demonstrated spontaneous regression after withdrawal of the immunosuppressive agent. We found 4 of 5 cases in the oral cavity had preceding traumatic events in the same site within a week before the onset of EBVMCU. Although there is no detailed and large study that has analyzed the trigger of EBVMCU, a traumatic event would indeed be a significant trigger for EBVMCU in the oral cavity. The cases were histologically classified; six cases were diffuse large B-cell lymphoma-type, five were polymorphous-type, and one was Hodgkin-like lesion type due to morphological appearance and immunophenotype. The PD-L1 expression was also examined by two antibodies for PD-L1 (E1J2J and SP142). Both antibodies revealed identical results for PD-L1 expression, and three cases were positive for PD-L1. The application of SP142 for evaluating the immune status of lymphomagenesis has also been proposed. Nine of 12 cases were negative for PD-L1, which implies that most EBVMCU cases may be caused by an immunodeficiency, rather than an immune-evasion, mechanism. However, as three cases were positive for PD-L1, immune escape may underly the pathogenesis in a subset of EBVMCU cases.

Top Ten Lymphoproliferative Lesions Not to Miss When Evaluating Oral Ulcer Biopsies

BACKGROUND

Oral ulcers represent a full thickness loss of the mucosal epithelium leading to exposure of the submucosal connective tissue. These are common and usually self-limited lesions, although they may sometimes result from neoplasms, most commonly squamous cell carcinoma. Lymphoproliferative disorders may be difficult to diagnose in apthous ulcers since they mimic reactive inflammation.

METHODS

This review presents ten rare oral lymphoid proliferations which should not be missed when assessing oral ulcer biopsies.

RESULTS

The ten lesions include several with diagnostic cells which look similar to the histiocytes of a reactive inflammatory ulcer, including Rosai-Dorfman disease, reticulohistiocytoma, Langerhans cell histiocytosis, and traumatic ulcerative granuloma. Other lesions, such as EBV-positive mucocutaneous ulcer, extranodal marginal zone lymphoma of mucosal-associated lymphoid tissue, and plasmablastic lymphoma have lymphoid and/or plasma cell differentiation that mimic the reactive lymphocytes and plasma cells found in reactive ulcers. Two dendritic cell lesions, follicular dendritic cell sarcoma and blastic plasmacytoid dendritic cell neoplasm, both have distinct phenotypes which are required to make an accurate diagnosis.

CONCLUSION

Each of these lesions are diagnosed by evaluating their histology, along with their phenotypic profile, which is sometimes enhanced by pertinent molecular findings.

How I Diagnose EBV-Positive B- and T-Cell Lymphoproliferative Disorders

OBJECTIVES

Epstein-Barr virus (EBV)-associated lymphoproliferative disorders (LPDs) encompass a group of well-defined entities of B-, T-, and natural killer (NK)-cell derivation. The diagnosis of these disorders is challenging because of clinical and morphologic features that may overlap with other benign and malignant EBV+ lymphoproliferations. This review describes our approach to the diagnosis of EBV-associated LPDs.

METHODS

Two cases are presented that illustrate how we diagnose EBV-associated LPDs. The first case represents a systemic EBV+ T-cell lymphoma of childhood and the second case an EBV+ mucocutaneous ulcer. The clinicopathologic features that help distinguish these entities from biological and morphologic mimickers are emphasized.

RESULTS

The accurate diagnosis of EBV-associated LPDs requires the incorporation of histologic and immunophenotypic features, the assessment of the EBV latency program, and, most important, complete clinical findings. Clonality analysis is not helpful in distinguishing benign from malignant EBV+ LPDs.

CONCLUSIONS

The better understanding of EBV-associated LPDs has resulted in the recognition of well-defined entities of B-, T-, and NK-cell derivation and consequently improvement of their treatment with curative intent. It is critical to distinguish benign from malignant EBV+ LPDs to avoid overtreatment.

Epstein-Barr Virus-positive Mucocutanous Ulcer of the Uterine Cervix: Report of a Rare and Evolving Entity

Epstein-Barr virus (EBV)-positive mucocutaneous ulcer (EBVMCU) is a newly described lymphoproliferative lesion characterized by the proliferation of EBV-positive atypical B cells in a variable inflammatory background associated with mucosal or cutaneous ulcers. Commonly involved sites include the oropharyngeal tract, skin, and gastrointestinal tract, with emerging reports describing EBVMCU of genitalia. To date, no lesions have been described of the uterine cervix. Herein, we report the first cervical EBVMCU incidentally discovered at large loop excision of the transformation zone performed for treating human papillomavirus induced high-grade squamous intraepithelial lesion. The patient was a 35-yr-old, human immunodeficiency virus-positive woman with a history of pulmonary tuberculosis. Histologic and immunohistochemical findings showed classic Hodgkin lymphoma-like features. Systemic lymphoproliferative disease was excluded by appropriate clinical and imaging modalities. This case report highlights the prototypical histologic features of cervical EBVMCU. We emphasize the importance of clinicopathologic correlation to avoid overtreatment of a lesion that can otherwise meet histologic criteria for a lymphoma. Clinicians and pathologists should familiarize themselves with this entity, as this indolent, pseudomaligant lesion typically occurs in immunocompromised patients and spontaneously regresses when the cause for the immunosuppression is addressed.

A comparison of the International Consensus and 5th World Health Organization classifications of mature B-cell lymphomas

Several editions of the World Health Organization (WHO) classifications of lympho-hemopoietic neoplasms in 2001, 2008 and 2017 served as the international standard for diagnosis. Since the 4th WHO edition, here referred as WHO-HAEM4, significant clinico-pathological, immunophenotypic and molecular advances have been made in the field of lymphomas, contributing to refining diagnostic criteria of several diseases, to upgrade entities previously defined as provisional and to identify new entities. This process has resulted in two recent classifying proposals of lymphoid neoplasms, the International Consensus Classification (ICC) and the 5th edition of the WHO classification (WHO-HAEM5). In this paper, we review and compare the two classifications in terms of diagnostic criteria and entity definition, with focus on mature B-cell neoplasms. The main aim is to provide a tool to facilitate the work of pathologists, hematologists and researchers involved in the diagnosis and treatment of lymphomas.

Extraordinary Case: Unique Presentation of an Aggressive Epstein-Barr Virus-Positive Mucocutaneous Ulcer

ABSTRACT

Epstein-Barr virus-positive mucocutaneous ulcer is a recent and unusual type of lymphoproliferation, mostly associated with various forms of immunosuppression. In most cases, they regress spontaneously, but an increasing number of reports describe a spectral behavior of the lesion, which ranges from a simple ulcer with eosinophilia to aggressive ulcers. In these cases, Epstein-Barr virus-related lymphomas are the main differential diagnosis. We report a unique observation of this rare disease with mandibular involvement. Due to bone erosion, the patient was treated with 6 cycles of R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone) with complete healing of the ulcer on clinical examination and PET-scan control.

The International Consensus Classification of Mature Lymphoid Neoplasms: a report from the Clinical Advisory Committee

Since the publication of the Revised European-American Classification of Lymphoid Neoplasms in 1994, subsequent updates of the classification of lymphoid neoplasms have been generated through iterative international efforts to achieve broad consensus among hematopathologists, geneticists, molecular scientists, and clinicians. Significant progress has recently been made in the characterization of malignancies of the immune system, with many new insights provided by genomic studies. They have led to this proposal. We have followed the same process that was successfully used for the third and fourth editions of the World Health Organization Classification of Hematologic Neoplasms. The definition, recommended studies, and criteria for the diagnosis of many entities have been extensively refined. Some categories considered provisional have now been upgraded to definite entities. Terminology for some diseases has been revised to adapt nomenclature to the current knowledge of their biology, but these modifications have been restricted to well-justified situations. Major findings from recent genomic studies have impacted the conceptual framework and diagnostic criteria for many disease entities. These changes will have an impact on optimal clinical management. The conclusions of this work are summarized in this report as the proposed International Consensus Classification of mature lymphoid, histiocytic, and dendritic cell tumors.

Primary Epstein-Barr Virus-Positive Mucocutaneous Ulcer of Esophagus: A Rare Case Report

Primary EBV-positive mucocutaneous ulcer (EBVMCU) is a rare and indolent disorder occurring in the oropharynx, skin, and gastrointestinal tract, with remission after removal of the immunosuppressive causes. We present a 69-year-old woman with heartburn, regurgitation of gastric acid, enlarged lymph nodes, and parotid glands. The endoscopic examination showed a circumscribed ulcer in the lower esophagus. A biopsy pathology indicated an esophageal EBV-associated lymphoproliferative disorder and a parotid gland/lymph node indolent B-cell lymphoma. Interestingly, the patient did not undergo any treatment, but the endoscopic ulcer improved significantly after more than 2 months. The last pathology showed EBV negativity, and EBVMCU was considered in combination with clinical and endoscopic manifestations. We followed up with the patient at 6 months, and the symptoms of acid reflux and heartburn had disappeared. Our case demonstrates that EBVMCU may occur in the esophagus with spontaneous regression.

Epstein-Barr virus-positive mucocutaneous ulcer, plasmablastic type, associated with nodal CD4+ angioimmunoblastic T-cell lymphoma and generalised pruritus: a self-limiting lymphoproliferative disorder resembling cutaneous plasmablastic lymphoma

A woman in her 80s reported of generalised pruritus, which was treated with phototherapy and steroid administration. Two months after onset, lymph node biopsy revealed CD4+ angioimmunoblastic T-cell lymphoma with systemic superficial nodal involvement. Intractable prurigo was judged as T-cell lymphoma related. After effective chemotherapy (7 months later), skin nodules appeared multifocally, including on the lip, thumb and lower leg. The biopsied infiltrative lesion on the right lower leg microscopically revealed subcutaneous growth of atypical plasmablasts with nearly 100% Ki-67 labelling and Epstein-Barr virus (EBV)-encoded small nuclear RNA positivity. Plasmablastic lymphoma (CD45/CD19/CD38/CD138/MUM1+, CD20/CD79a/PAX5-) was suspected. Immunoglobulin light-chain restriction and nuclear expression of c-myc protein were undetectable, and the ulcers were spontaneously epithelialised by the cessation of steroid administration. After 10 months, non-progressive prurigos persisted on the extremities, but without regrowth of nodal T-cell lymphoma and cutaneous lymphoproliferative lesion. Reactive nature of the EBV-induced mucocutaneous plasmablastic growth (EBV-positive mucocutaneous ulcer, plasmablastic type) is discussed.

Co-Occurrence of EBV-Positive Mucocutaneous Ulcer (EBV-MCU) and CLL/SLL in the Head and Neck Region

EBV-positive mucocutaneous ulcer (EBV-MCU) was classified as a rare new entity of the lymphoproliferative B-cell diseases by the WHO in 2017 and must be distinguished from head and neck squamous cell carcinoma by early biopsy. The aim of the study is to raise awareness of the disease and to give a review of the current literature and a recommendation for EBV-MCU management. All EBV-MCU cases of the head and neck region published so far were included. We also report a case of a pharyngeal EBV-MCU in an 89-year-old patient who was immunosuppressed by chronic lymphatic leukaemia/small lymphocytic lymphoma (CLL/SLL). In contrast to all previously described cases, histopathology showed a co-infiltration of EBV-MCU and CLL/SLL. A total of 181 cases were identified on PubMed and summarised. EBV-MCU was predominantly caused by immunosuppressive drug therapy. Complete remission could be achieved in 68% of cases and was mainly attributed to a reduction of the immunosuppressive therapy alone (72%). However, some severe cases require more aggressive treatment. Regarding the various histopathologic similarities to other lymphoproliferative disorders, the diagnosis of EBV-MCU can be misleading, with a great impact on patient care and treatment. This diagnosis must be made with caution and requires a combination of clinical, morphological and immunophenotypic features.

The Grey Zones of Classic Hodgkin Lymphoma

Simple Summary

Classic Hodgkin lymphoma (CHL) is a well-defined lymphoid neoplasm with a minority of characteristic neoplastic cells of B cell origin, namely Hodgkin and Reed–Sternberg cells immersed in a rich reactive inflammatory infiltrate in the background. Although CHL has always been set apart from non-Hodgkin lymphomas, cases with morphological and phenotypic features intermediate between CHL and other lymphomas have been described. Whereas some of these lymphomas only represent morphological mimics, others exhibit mutational and gene expression profiles which overlap with CHL, indicating that these cases, frequently termed grey zone lymphomas, reside on the biological boundary between CHL and large B-cell lymphomas. In the present review, we aim to describe the current knowledge of these rare lymphomas, address diagnostic issues and summarize today’s concepts on the classification of grey zone lymphomas and related tumors.

Abstract

Classic Hodgkin lymphoma (CHL) is a well-defined neoplasm characterized by the presence of a minority of pathognomonic Hodgkin and Reed–Sternberg (HRS) cells in a reactive inflammatory background. Although genotypically of B cell origin, HRS cells exhibit a downregulated B cell program and therefore are set apart from other B cell lymphomas in the current WHO classification. However, cases with morphological and phenotypic features overlapping with CHL have been recognized, and the category of B cell lymphoma—unclassifiable—with features intermediate between diffuse large B cell lymphoma (DLBCL) and CHL, also termed grey zone lymphoma, was first introduced into the WHO classification in 2008 as provisional entity. These cases, as well as others raising a differential diagnosis of CHL can present diagnostic problems, as well as therapeutic challenges. Whereas some of these lymphomas only represent biologically unrelated morphological mimics, others, especially mediastinal grey zone lymphoma, exhibit genetic and gene expression profiles which overlap with CHL, indicating a true biological relationship. In this review, we address areas of diagnostic difficulties between CHL and other lymphoma subtypes, discuss the biological basis of true grey zone lymphoma based on recent molecular studies and delineate current concepts for the classification of these rare tumors.

Multifocal Oral Epstein-Barr Virus-Positive Mucocutaneous Ulcers Associated with Dual Methotrexate and Leflunomide Therapy: A Case Report

Epstein-Barr virus (EBV)-positive mucocutaneous ulcer (EBVMCU) is a unique clinicopathologic entity of lymphoproliferative disorder, occurring in immunosuppressed patients. Due to its rarity, EBVMCU may be under-recognized by clinicians as well as pathologists. In addition, its clinical and histopathologic features overlap with other benign and malignant conditions, making a diagnosis challenging. This report presents an unusual case of multifocal oral EBVMCUs in a 52-year-old female patient with rheumatoid arthritis, receiving the combination of methotrexate and leflunomide for 5 years. The patient presented with persistent multiple large painful ulcers involving her palate and gingiva for 6 months. The histopathologic examination revealed extensive ulceration with diffuse polymorphic inflammatory infiltrate admixed with scattered atypical lymphoid cells showing occasional Hodgkin and Reed/Sternberg-like cell features. These atypical cells showed immunoreactivity for CD20, CD30 and MUM1/IRF4. EBV-encoded small RNA in situ hybridization was positive, validating the presence of EBV-infected cells. Two months after discontinuation of both immunosuppressive medications, oral lesions gradually regressed. At 9-month follow-up, no evidence of relapsing oral EBVMCU has been observed. The multifocal presentation of EBVMCU is rare and could be resulted from the overwhelming immune suppression by long-term use of dual immunosuppressants. Its diagnosis requires comprehensive correlation of patient history, clinical findings, histopathologic, and immunophenotypic features. The ability of EBVMCU to regress following removal of immunosuppressive causes is in drastic contrast to a variety of its potential clinical and histopathologic mimics. Therefore, accurate diagnosis is crucial to avoid unnecessary patient management and achieve optimal patient outcomes.

Two Cases of Epstein-Barr Virus-Positive Mucocutaneous Ulcer Mimicking Head and Neck Cancers in 18F-FDG PET/CT

ABSTRACT

Epstein-Barr virus-positive mucocutaneous ulcer is a newly recognized clinicopathological entity among mature B-cell neoplasms according to the 2016 revision of the World Health Organization diagnostic criteria. Here, we present FDG PET/CT images of 2 Epstein-Barr virus-positive mucocutaneous ulcer cases. Both cases shown in the images mimicked head and neck cancers, which are similar to carcinomas of the tonsil and gingiva, respectively, and both lesions showed intense FDG uptake on PET scan.

EBV-Driven Lymphoproliferative Disorders and Lymphomas of the Gastrointestinal Tract: A Spectrum of Entities with a Common Denominator (Part 3)

EBV is the first known oncogenic virus involved in the development of several tumors. The majority of the global population are infected with the virus early in life and the virus persists throughout life, in a latent stage, and usually within B lymphocytes. Despite the worldwide diffusion of EBV infection, EBV-associated diseases develop in only in a small subset of individuals often when conditions of immunosuppression disrupt the balance between the infection and host immune system. EBV-driven lymphoid proliferations are either of B-cell or T/NK-cell origin, and range from disorders with an indolent behavior to aggressive lymphomas. In this review, which is divided in three parts, we provide an update of EBV-associated lymphoid disorders developing in the gastrointestinal tract, often representing a challenging diagnostic and therapeutic issue. Our aim is to provide a practical diagnostic approach to clinicians and pathologists who face this complex spectrum of disorders in their daily practice. In this part of the review, the chronic active EBV infection of T-cell and NK-cell type, its systemic form; extranodal NK/T-cell lymphoma, nasal type and post-transplant lymphoproliferative disorders are discussed.

EBV-Driven Lymphoproliferative Disorders and Lymphomas of the Gastrointestinal Tract: A Spectrum of Entities with a Common Denominator (Part 1)

EBV is the most common persistent virus in humans. The interaction of EBV with B lymphocytes, which are considered the virus reservoir, is at the base of the life-long latent infection. Under circumstances of immunosuppression, the balance between virus and host immune system is altered and hence, EBV-associated lymphoid proliferations may originate. These disorders encompass several entities, ranging from self-limited diseases with indolent behavior to aggressive lymphomas. The virus may infect not only B-cells, but even T- and NK-cells. The occurrence of different types of lymphoid disorders depends on both the type of infected cells and the state of host immunity. EBV-driven lymphoproliferative lesions can rarely occur in the gastrointestinal tract and may be missed even by expert pathologists due to both the uncommon site of presentation and the frequent overlapping morphology and immunophenotypic features shared by different entities. The aim of this review is to provide a comprehensive overview of the current knowledge of EBV-associated lymphoproliferative disorders, arising within the gastrointestinal tract. The review is divided in three parts. In this part, the available data on EBV biology, EBV-positive mucocutaneous ulcer, EBV-positive diffuse large B-cell lymphoma, not otherwise specified and classic Hodgkin lymphoma are discussed.

EBV-Driven Lymphoproliferative Disorders and Lymphomas of the Gastrointestinal Tract: A Spectrum of Entities with a Common Denominator (Part 2)

Epstein-Barr virus (EBV) is a common pathogen infecting people primarily early in life. The virus has the ability to persist throughout a person's life, usually in B lymphocytes. Conditions of immunodeficiency as well as the introduction of immunosuppressive therapies and the advent of transplant technologies has brought immunodeficiency-associated lymphoproliferative disorders into view, which are often driven by EBV. The group of EBV-associated lymphoproliferative disorders includes different entities, with distinct biological features, ranging from indolent disorders, which may even spontaneously regress, to aggressive lymphomas requiring prompt and adequate treatment. These disorders are often diagnostically challenging due to their overlapping morphology and immunophenotype. Both nodal and extra-nodal sites, including the gastrointestinal tract, may be involved. This review, divided in three parts, summarizes the clinical, pathological, molecular features and treatment strategies of EBV-related lymphoproliferative disorders occurring in the gastrointestinal tract and critically analyzes the major issues in the differential diagnosis. In this part of the review, we discuss plasmablastic lymphoma, extra-cavitary primary effusion lymphoma and Burkitt lymphoma.

EBV-positive B-cell lymphomas and lymphoproliferative disorders: Review from the perspective of immune escape and immunodeficiency

Background

Epstein‐Barr virus (EBV) is detected in a variety of B‐cell lymphomas (BCLs) and B‐cell lymphoproliferative disorders (B‐LPDs). Immunodeficiency has been considered to play a key role in the pathogenesis of these diseases. In addition, immune escape of tumor cells may also contribute to the development of EBV⁺ BCLs and B‐LPDs. The PD‐1/PD‐L1 pathway is particularly important for immune escape of tumor cells that contribute to development of lymphoma through suppression of cytotoxic T‐cell function. We now consider PD‐L1 immunohistochemistry (IHC) a very useful method for predicting whether tumor cells of lymphoid malignancies are characterized by the immune escape mechanism.

Methods

We reviewed articles of EBV⁺ BCLs and B‐LPDs from the perspective of immune escape and immunodeficiency, particularly focusing on PD‐L1 IHC.

Results

Based on PD‐L1 IHC, we consider that EBV⁺ BCL and B‐LPD can be classified into three types: “immunodeficiency”, “immune escape”, and “immunodeficiency + immune escape” type. The immunodeficiency type includes EBV⁺ diffuse large BCL (DLBCL) of the elderly, EBV⁺ sporadic Burkitt lymphoma, EBV⁺ mucocutaneous ulcer, and methotrexate (MTX)‐associated B‐LPD. The immune escape type includes EBV⁺ classic Hodgkin lymphoma (CHL) and EBV⁺ DLBCL of the young. The immunodeficiency + immune escape type includes CHL type MTX‐associated LPD and a minor subset of EBV⁺ DLBCL of the elderly.

Conclusions

Recently, good results have been reported for immune check‐point inhibitors in treating lymphoma. Lymphomas and LPDs characterized by immune escape are regarded as good candidates for PD1/PD‐L1 blockade therapy. Therefore, from both the clinical and pathological perspective, we suggest that lymphoma diagnosis should be made considering immune escape and immunodeficiency.

Epstein-Barr Virus Positive B-Cell Lymphoproliferative Disorder of the Gastrointestinal Tract

Epstein-Barr virus positive B-cell lymphoproliferative disorder (EBV+ B-LPD) encompasses a broad clinicopathological spectrum and distinct clinical behavior that relatively favors the gastrointestinal (GI) tract. In this review, we provide an update on the clinicopathological features and biological behavior of EBV-positive mucocutaneous ulcer (EBVMCU) and primary EBV+ diffuse large B-cell lymphoma (DLBCL) of the GI tract. EBVMCU is a newly recognized entity but well known as an indolent and self-limited EBV+ B-LPD occurring in various immunodeficiencies. In contrast, EBV+ DLBCL constitutes the largest group of EBV+ B-LPDs and is regarded as an aggressive neoplasm. These two distinct diseases have historically been distinguished in the reappraisal of age-related EBV-associated B-LPDs but are challenging in routine practice regarding their differential diagnostic and therapeutic approaches. An increasing number of reports indicate that they are epidemiologically prevalent beyond western and eastern countries, but their comprehensive analysis is still limited. We also describe the PD-L1 positivity of tumorous large cells and non-malignant immune cells, which is relevant for the prognostic delineation among patients with primary DLBCL of the GI tract with and without EBV on tumor cells.

Classical Hodgkin Lymphoma Presenting as a Sigmoid Mass

Primary classical Hodgkin lymphoma (CHL) in the colon is exceedingly rare and shares many histologic features with other lymphoproliferative disorders in the gastrointestinal tract. Here we report a case of CHL forming a sigmoid mass. An elderly man with a past medical history of mantle cell lymphoma presented with constipation. Imaging revealed an ulcerated, circumferential mass in the sigmoid colon. Endoscopic biopsy of the mass showed ulcerated colonic mucosa with an underlying diffuse mixed inflammatory infiltrate admixed with Hodgkin and Reed-Sternberg cells. Immunohistochemistry was performed to characterize these cells. They were weakly positive for Pax-5, strongly positive for CD30, variably positive for CD15, and negative for CD45, CD20, CD3, and SOX-11. In situ hybridization was positive for Epstein-Barr virus (EBV) and negative for cytomegalovirus or herpes simplex virus. This immunophenotype is diagnostic for CHL in the clinical context of a large mass. It is not possible in this case to determine whether this is de novo CHL or progression from a precursor lesion like EBV-positive mucocutaneous ulcer. Since diagnosis, this patient underwent colectomy followed by chemotherapy and has remained in complete remission.

Secondary skin involvement in classic Hodgkin lymphoma: Results of an international collaborative cutaneous lymphoma working group study of 25 patients

BACKGROUND

Cutaneous involvement by classic Hodgkin lymphoma (CHL) is an extraordinarily rare phenomenon in the current era. To date, no single large case series of cutaneous involvement by Hodgkin lymphoma has ever been reported in the literature.

METHODS

A comprehensive search for cases designated "skin" and "Hodgkin" was performed at different institutions between 1990 and 2020. Twenty-five cases were identified, and each case was independently reviewed by at least three board-certified dermatopathologists and/or hematopathologists.

RESULTS

All cases represented examples of systemic CHL with secondary skin dissemination. A single lesion, usually a tumor, nodule or infiltrative plaque was observed in 56% of cases and multiple lesions were present in 28% of cases. Most patients (86%-12/14) had a diagnosis of stage IV disease at first diagnosis. The interval between the clinical (first) diagnosis of HL and the development of skin lesions ranged between 6 and 108 months (average 33.75 months). Comprehensive histopathologic evaluation of these cases (at the initial diagnosis) revealed a diagnosis of classic HL not otherwise specified (NOS) in 60% of cases (15/25), nodular sclerosis type in 24% (6/25), mixed cellularity in 12% (3/25), and lymphocyte depleted in 4% (1/25).

CONCLUSIONS

We provide documentation of a large series of CHL with secondary skin involvement in association with CHL with additional clinical, morphologic, and immunophenotypic features.

Virus-Driven Carcinogenesis

Cancer arises from the accumulation of genetic and epigenetic alterations. Even in the era of precision oncology, carcinogens contributing to neoplastic process are still an important focus of research. Comprehensive genomic analyses have revealed various combinations of base substitutions, referred to as the mutational signatures, in cancer. Each mutational signature is believed to arise from specific DNA damage and repair processes, including carcinogens. However, as a type of carcinogen, tumor viruses increase the cancer risk by alternative mechanisms, including insertional mutagenesis, viral oncogenes, and immunosuppression. In this review, we summarize virus-driven carcinogenesis to provide a framework for the control of malignant cell proliferation. We first provide a brief overview of oncogenic viruses and describe their implication in virus-related tumors. Next, we describe tumor viruses (HPV, Human papilloma virus; HBV, Hepatitis B virus; HCV, Hepatitis C virus; EBV, Epstein-Barr virus; Kaposi sarcoma herpesvirus; MCV, Merkel cell polyoma virus; HTLV-1, Human T-cell lymphotropic virus, type-1) and tumor virus-related cancers. Lastly, we introduce emerging tumor virus candidates, human cytomegalovirus (CMV), human herpesvirus-6 (HHV-6) and adeno-associated virus-2 (AAV-2). We expect this review to be a hub in a complex network of data for virus-associated carcinogenesis.

EBV-positive Mucocutaneous Ulcer With Small Lymphocytic Infiltration Mimicking Nonspecific Ulceration

Epstein-Barr virus (EBV)-associated lymphoproliferative disorder may resemble nonspecific inflammation. We report 3 cases of immunosuppressed adult patients with small lymphocytic EBV ulcers in the skin and oral mucosa, characterized by a lack of atypical lymphocytic infiltration. All 3 cases were diagnosed in routine practice. For comparisons, cases of conventional Epstein-Barr virus-positive mucocutaneous ulcer (EBVMCU) were reviewed which were extracted from our pathology archives (n=11). The present patients were 2 females and 1 male, aged above 70 years. The primary disease was rheumatoid arthritis (n=2) and dermatitis herpetiformis (n=1). The main source of immunosuppression was prednisolone (n=2) and methotrexate (n=1). The ulcers were located in the oral cavity, buttock, and/or external genitalia. Histology evaluation revealed nonspecific lymphocytic infiltration. Epstein-Barr virus-encoded small RNA (EBER)-positive cells were small and coexpressed CD20. The number of EBER-positive cells ranged from 52 to 132/HPF, which was within the range of that observed in the reviewed conventional EBVMCUs (range, 48 to 1328; median, 121). All 3 cases regressed spontaneously or by the reduction of immunosuppressants. Although the present cases lacked cytologic atypia, those clinical course and loads of EBER-positive cells (>50/HPF) suggested EBV involvement. Current cases of EBVMCU with small lymphocytic infiltration underscore the need for EBER in situ hybridization when an etiology of ulcer with predominant lymphocytes in an immunosuppressed patient is unclear.

Rare EBV-associated B cell neoplasms of the gastrointestinal tract

EBV-driven B cell neoplasms can rarely present as an extranodal mass in the gastrointestinal tract and can be missed, even by experienced pathologists, because of this uncommon presentation. A selection of these neoplasms, namely EBV-positive diffuse large B cell lymphoma, not otherwise specified (DLBCL NOS), EBV-positive mucocutaneous ulcer (EBV MCU), extracavitary primary effusion lymphoma (EPEL), and EBV-positive Burkitt lymphoma, will be discussed in the present review. Besides the common thread of EBV positivity, these lymphoproliferative disorders arise in unique clinical settings that are often associated with immunodeficiency, immunosuppression or immunosenescence and can present as solitary masses albeit rarely, within the gastrointestinal tract.

Epstein-Barr Virus-Positive Mucocutaneous Ulcer: A Unique and Curious Disease Entity

Epstein–Barr virus (EBV)-positive mucocutaneous ulcer (EBVMCU) was first described as a lymphoproliferative disorder in 2010. EBVMCU is a unifocal mucosal or cutaneous ulcer that often occurs after local trauma in patients with immunosuppression; the patients generally have a good prognosis. It is histologically characterized by proliferating EBV-positive atypical B cells accompanied by ulcers. On the basis of conventional pathologic criteria, EBVMCU may be misdiagnosed as EBV-positive diffuse large B-cell lymphoma or other lymphomas. However, its prognosis differs from that of EBV-associated lymphomas, in that patients with EBVMCU frequently show spontaneous regression or complete remission without chemotherapy. Therefore, EBVMCU is now recognized as a low-grade malignancy or a pseudo-malignant lesion. Avoiding unnecessary chemotherapy by distinguishing EBVMCU from other EBV-associated lymphomas will reduce the burden and unnecessary harm on patients. On the basis of these facts, EBVMCU was first described as a new clinicopathological entity by the World Health Organization in 2017. In this review, we discuss the clinicopathological characteristics of previously reported EBVMCU cases, while focusing on up-to-date clinical, pathological, and genetic aspects.

Clinicopathological evaluation of methotrexate-associated lymphoproliferative disorders with special focus on Epstein-Barr virus-positive mucocutaneous lesions

Some patients diagnosed with methotrexate-associated lymphoproliferative disorder (MTX-LPD) develop spontaneous regression upon the discontinuation of MTX, whereas others require chemotherapy. The mechanisms underlying this differential response and the capacity to spontaneously regress are not clearly understood. We evaluated numerous clinicopathological features in 63 patients diagnosed with MTX-LPD, with a special focus on those with Epstein-Barr virus (EBV)-positive mucocutaneous lesions (EBVMCL). The diagnosis of EBVMCL included cases of both EBV-positive mucocutaneous ulcers (EBVMCU) and diffuse gingival swelling associated with proliferation of EBV-positive large B-cells. Of the four subgroups of MTX-LPD, one-year treatment-free survival (TFS) after the discontinuation of MTX was achieved among those with EBVMCL (100%), diffuse large B-cell lymphoma (57%), Hodgkin-like lesions (60%), or classical Hodgkin lymphoma (29%); a significant difference in TFS was observed when comparing the responses of patients with EBVMCL to the those diagnosed with other subtypes. Multivariate analysis revealed predictive factors for prolonged TFS that included EBV-positive lesions and comparatively low levels of serum LDH. Taken together, our study suggests that a diagnosis of EBVMCL is related to the overall clinical outcome after the discontinuation of MTX.