Cutaneous intravascular natural killer/T cell lymphoma with peculiar immunophenotype

An Update on EBV-related Cutaneous Lymphoproliferative Disorders: a Systematic Review

Epstein Barr virus (EBV) positive B lymphoproliferative disorders (LPD) with cutaneous involvement include a series of rare entities that go from indolent processes to aggressive lymphomas. B-cell EBV+ LPD mainly affect immunocompromised patients while T-cell EBV+ LPD are more prevalent in specific geographic regions such as Asia, Central America, and South America. Since the latest WHO-EORTC classification of cutaneous lymphomas in 2018, significant changes have been included in the new classifications of hematological malignancies. This systematic review summarizes the main clinical, histological, immunophenotypic and molecular characteristics of B- and T-cell EBV+ LPD that may compromise the skin at diagnosis. B-cell EBV+ LPD include primary cutaneous lymphomas such as EBV-Mucocutaneous Ulcer, as well as systemic lymphomas affecting the skin at diagnosis that may present such as lymphomatoid granulomatosis (LG), EBV diffuse large B cell lymphoma, NOS, plasmablastic lymphoma (PBL), Extracavitary primary effusion lymphoma (EC-PEL) EBV+, EBV-positive polymorphic B cell LPD, and post-transplant lymphoproliferative disorders (PTLD). Regarding T-cell EBV+ LPD, most of these entities are categorized within T/NK-cell lymphoproliferative processes and lymphomas of childhood, including extranodal T/NK lymphoma, and even more exceptional forms such as EBV-positive T-cell centrofollicular lymphoma and intravascular T/NK-cell lymphoma. Diagnosis is based on integrating the clinical, histological, immunohistochemical, and genetic criteria discussed throughout this article. Differential diagnosis is a challenge for dermatologists and pathologists, so having scientific evidence available in this field is of paramount importance because overtreatment must be carefully avoided.

[Translated article] An Update on EBV-related Cutaneous Lymphoproliferative Disorders: a Systematic Review

Epstein Barr virus (EBV) positive lymphoproliferative disorders (LPD) with cutaneous involvement include a series of rare entities that go from indolent processes to aggressive lymphomas. B-cell EBV+ LPD mainly affect immunocompromised patients while T-cell EBV+ LPD are more prevalent in specific geographic regions such as Asia, Central America, and South America. Since the latest WHO-EORTC classification of cutaneous lymphomas in 2018, significant changes have been included in the new classifications of hematological malignancies. This systematic review summarizes the main clinical, histological, immunophenotypic and molecular characteristics of B- and T-cell EBV+ LPD that may compromise the skin at diagnosis. B-cell EBV+ LPD include primary cutaneous lymphomas such as EBV-Mucocutaneous Ulcer, as well as systemic lymphomas affecting the skin at diagnosis that may present such as lymphomatoid granulomatosis (LG), EBV diffuse large B cell lymphoma, NOS, plasmablastic lymphoma (PBL), extracavitary primary effusion lymphoma (EC-PEL) EBV+, EBV-positive polymorphic B cell LPD, and post-transplant lymphoproliferative disorders (PTLD). Regarding T-cell EBV+ LPD, most of these entities are categorized within T/NK-cell lymphoproliferative processes and lymphomas of childhood, including extranodal T/NK lymphoma, and even more exceptional forms such as EBV-positive T-cell centrofollicular lymphoma and intravascular T/NK-cell lymphoma. Diagnosis is based on integrating the clinical, histological, immunohistochemical, and genetic criteria discussed throughout this article. Differential diagnosis is a challenge for dermatologists and pathologists, so having scientific evidence available in this field is of paramount importance because overtreatment must be carefully avoided.

Cutaneous Intravascular Hematolymphoid Entities: A Review

Intravascular lymphomas are rare disease conditions that exhibit neoplastic lymphoid cells that are confined mainly to the lumens of small capillaries and medium-sized vessels. The majority of the intravascular lymphomas are of B-cell origin, but they can include NK/T-cell and CD30+ immunophenotypes. In the histologic differential diagnosis are benign proliferations such as intralymphatic histiocytosis and intravascular atypical CD30+ T-cell proliferation. In this review, we discuss the clinical, histopathologic, and molecular findings of intravascular B-cell lymphoma, intravascular NK/T-cell lymphoma, intralymphatic histiocytosis, and benign atypical intravascular CD30+ T-cell proliferation.

Intravascular NK/T-cell lymphoma: a case report and literature review

Intravascular lymphoma is characterized by an exclusively intravascular distribution of tumor cells. Intravascular natural killer/T-cell lymphoma (IVNKTL) is extremely rare, highly aggressive, commonly Epstein-Barr virus (EBV)-positive, and predominantly affects the skin and central nervous system. Here we report a case of IVNKTL diagnosed in a 67-year-old female, presenting with persistent intermittent fever and skin rashes throughout the body. Incisional biopsy of an erythematous lesion on the chest exhibited aggregation of medium to large-sized atypical lymphoid cells confined to the lumen of small vessels that were positive for CD3, granzyme B, and CD56 on immunohistochemistry and EBV-encoded RNA in situ hybridization. EBV DNA was also detected in serum after diagnosis. With a review of 26 cases of IVNKTL to date, we suggest that active biopsy based on EBV DNA detection may facilitate early diagnosis of IVNKTL.

Intravascular NK/T-Cell Lymphoma: What We Know about This Diagnostically Challenging, Aggressive Disease

Intravascular lymphoma is a form of lymphoid malignancy characterized by neoplastic cells growing almost exclusively within the lumina of small- to medium-sized blood vessels. Most cases are of B-cell origin with rare cases of natural killer or T-cell lineage. Extranodal sites are affected, mainly the skin and central nervous system, although any organ may be involved. Intravascular NK/T-cell lymphoma deserves special attention because of its clinicopathologic features and the need for adequate immunophenotyping combined with clonality test for a proper diagnosis. Moreover, intravascular NK/T-cell lymphoma is strongly linked to Epstein-Barr virus (EBV), which is considered to play a role in tumorigenesis and to be responsible for the aggressive behavior of the disease. In this paper, we review the current knowledge on this rare lymphoma and, in particular, the most recent advances about its molecular landscape. The main distinguishing features with other EBV-related entities, such as extranodal NK/T-cell lymphoma, EBV-positive primary nodal T/NK-cell lymphoma, and aggressive NK-cell leukemia, are discussed to help pathologists obtain the correct diagnosis and consequently develop an adequate and prompt therapy response.

The 5th edition of the World Health Organization Classification of Haematolymphoid Tumours: Lymphoid Neoplasms

We herein present an overview of the upcoming 5^th edition of the World Health Organization Classification of Haematolymphoid Tumours focussing on lymphoid neoplasms. Myeloid and histiocytic neoplasms will be presented in a separate accompanying article. Besides listing the entities of the classification, we highlight and explain changes from the revised 4^th edition. These include reorganization of entities by a hierarchical system as is adopted throughout the 5^th edition of the WHO classification of tumours of all organ systems, modification of nomenclature for some entities, revision of diagnostic criteria or subtypes, deletion of certain entities, and introduction of new entities, as well as inclusion of tumour-like lesions, mesenchymal lesions specific to lymph node and spleen, and germline predisposition syndromes associated with the lymphoid neoplasms.

The Pathologic and Genetic Characteristics of Extranodal NK/T-Cell Lymphoma

Extranodal NK/T-cell lymphoma is a neoplasm of NK cells or cytotoxic T cells presenting in extranodal sites, most often in the nasal cavity. The typical immunophenotypes are cCD3+, sCD3-, CD4-, CD5-, CD8-, CD16-, and CD56+ with the expression of cytotoxic molecules. Tumor subsets express NK cell receptors, CD95/CD95L, CD30, MYC, and PDL1. Virtually all the tumor cells harbor the EBV genome, which plays a key role in lymphomagenesis as an epigenetic driver. EBV-encoded oncoproteins modulate the host-cell epigenetic machinery, reprogramming the viral and host epigenomes using host epigenetic modifiers. NGS analysis revealed the mutational landscape of ENKTL, predominantly involving the JAK-STAT pathway, epigenetic modifications, the RNA helicase family, the RAS/MAP kinase pathway, and tumor suppressors, which indicate an important role of these pathways and this group of genes in the lymphomagenesis of ENKTL. Recently, three molecular subtypes were proposed, the tumor-suppressor/immune-modulator (TSIM), MGA-BRDT (MB), and HDAC9-EP300-ARID1A (HEA) subtypes, and they are well-correlated with the cell of origin, EBV pattern, genomic alterations, and clinical outcomes. A future investigation into the function and interaction of discovered genes would be very helpful for better understanding the molecular pathogenesis of ENKTL and establishing better treatment strategies.

What Effect Does Epstein-Barr Virus Have on Extranodal Natural Killer/T-Cell Lymphoma Prognosis? A Review of 153 Reported Cases

The primary aim of this review is to identify the relationship between Epstein-Barr virus (EBV) and prognosis in extranodal natural killer/T-cell lymphoma (ENKTL). Additionally, a literature review of ENKTL was carried out. The investigators designed and implemented a 21-year literature review using the online databases PubMed and Google Scholar. The total number of cases analyzed was 153 (64 case reports; one comparative study; one systematic review). Information related to ENKTL from July 1999 to February 2021 was included in the study. Study variables included: patient demographics, tumor classification, screening modalities, tumor characteristics, symptomatology, treatment, and prognosis. The average age at diagnosis was 50.9 years (range: 4-90 years). Patients of Asian ethnicity were most commonly affected, and there was a 1.6:1 male to female ratio. ENKTL was most frequently detected in the head and neck region, and 53.1% of cases metastasized. Of all head and neck cases, the nose was the most affected location. Immunohistochemistry positivity included: EBV (32.0%), CD2 (96.6%), CD3ϵ (81.7%), CD43 (91.7%), CD56 (86.4%), Granzyme (97.1%), Perforin (90.9%), TIA-1 (97.8%), p53 (33.3%). The most frequently employed single treatment modality was chemotherapy alone, and 34.2% of patients expired within five years of diagnosis. The average follow-up period was 16.51 months (range: 0.25-66 months). EBV was significantly associated with metastatic ENKTL (χ² = 4.36; CV = 3.84; p = 0.037). We found no association between EBV and ENKTL prognosis (χ² = 17.2; CV = 21.0; p = 0.14).

[Clinicopathological features of intravascular peripheral T-cell lymphoma]

Objective: To summarize the clinical and pathological features of intravascular NK and T cell lymphoma for better understanding of such disease to reduce misdiagnosis and miss-diagnosis. Methods: Clinical and pathological features were analyzed retrospectively in one case of intravascular peripheral T-cell lymphoma, not otherwise specified (IVPTCL, NOS) , with literatures review. Results: The case presented in this study was a 66-year-old man. PET/CT scan showed multiple lymph nodes enlargement throughout the body. Normal lymph node structure could not be observed by tissue biopsy, while lymph follicles were partially disrupted. High-power light microscope revealed a large number of blood vessels with diffuse proliferation and dilation, where atypical lymphoid cell mass was restricted in the lumen and partially infiltrated the large blood vessel wall. These tumor cells were medium to large with moderate cytoplasm. The nucleus was irregular, single or multiple nucleoli could be seen, chromatin was condensed, some were empty and bright, and mitotic figures could be seen. Immunohistochemical staining showed that the neoplastic cells were positive for expression of CD3, CD43, CD8, GrB, TIA-1 and perforin. EBER in situ hybridization result was negative. Polymerase chain reaction test identified a clonal gene rearrangement of T-cell receptor γ. The patient was treated with CHOP in combination with chidamide, but died of infection and cardiopulmonary failure within 2 months. 56 cases of intravascular NK/T cell lymphoma with definite classification were collected from relevant literatures, including 47 cases with nasal type of extranodal NK/T cell lymphoma (27 were male and 20 were female) , 8 cases with anaplastic large cell lymphoma (3 males and 5 females) , and only one case with de nova IVPTCL, NOS in brain. We report the second case of IVPTCL,NOS, and notably originated from lymph node for the first time. Conclusions: Intravascular NK/T cell lymphoma is a highly aggressive disease with no effective treatment at present. Involvement of Lymph node has rarely been reported, and further studies on more cases are necessary.

Case of Extranodal Natural Killer/T-Cell Lymphoma, Nasal Type, Presenting With Intravascular Localization of Tumor Cells in Skin Biopsies From Both Plaque and Normal-Appearing Skin: A Case Report and Literature Review

Extranodal natural killer/T-cell lymphoma, nasal type (ENKTL-NT), is a rare subtype of non-Hodgkin lymphoma associated with Epstein-Barr virus. This type of lymphoma is rare in Western countries but is more frequent in East Asia and Latin America. ENKTL-NT mostly occurs in the nose and paranasal area, including the upper aerodigestive tract. The skin is the second-most commonly involved organ. ENKTL-ET is characterized by an angiocentric, angiodestructive pattern of growth with ulceration and necrosis evident on histopathological examination. We provide the first description of ENKTL-NT presenting with intravascular localization of tumor cells in skin biopsies from both plaque and normal-appearing skin. Random skin biopsy might thus be useful for early diagnosis, staging, and estimation of prognosis in ENKTL-NT. Moreover, the current case indicates that ENKTL-NT and intravascular natural killer/T-cell lymphoma may represent related diseases.

Cytogenetic complexity and heterogeneity in intravascular lymphoma

AIMS

To characterise the karyotypic abnormalities and heterogeneities in intravascular lymphoma (IVL).

METHODS

G-banded karyotyping was performed on biopsy specimens from a single-centre IVL cohort comprising intravascular large B-cell lymphoma (IVLBCL, n=12) and NK/T-cell lymphoma (IVNKTCL, n=1).

RESULTS

Five IVLBCL cases and one IVNKTCL case (total 46%) were found to have normal karyotypes, and the cytogenetic abnormalities observed in the other seven IVLBCL cases (54%) were investigated further. These seven karyotypes were uniformly complex with an average of 13 aberrations. The seven cases all had abnormalities involving chromosome 6, with 57% involving structural abnormalities at 6q13, and chromosome 8, with 43% involving abnormalities at 8p11.2. In addition, 71% had aberrations at 19q13. On average, 4.4 chromosomal gains and losses were detected per case. Cytogenetic heterogeneities were observed in six cases (86%) and tetraploidy in three cases (43%). There was no significant difference in progression-free survival (p=0.92) and overall survival (p=0.61) between the IVLBCL cases with complex and normal karyotypes.

CONCLUSION

Approximately half of IVLBCL cases had a highly heterogeneous pattern of karyotypes with different clonal numerical and structural chromosome aberrations.

Transcriptome complexity in intravascular NK/T-cell lymphoma

AIMS

Intravascular NK/T-cell lymphoma (IVNKTCL) is a rare disease, which is characterised by exclusive growth of large cells within the lumen of small vessels, Epstein-Barr virus infection and somatic mutations in epigenetic regulator genes. Here, we elucidate the transcriptomic complexity of IVNKTCL.

METHODS

IVNKTCL cases were retrieved from a single-centre cohort of 25 intravascular lymphomas. RNA-seq and whole exome sequencing (WES) were performed to analyse transcriptomic abnormalities and mutations in splicing factors.

RESULTS

Approximately 88% of the total reads from the RNA-seq were considered exonic, while the remaining reads (12%) were mapped to intronic or intergenic regions. We detected 28,941 alternative splicing events, some of which would produce abnormal proteins rarely found in normal cells. The detected events also included tumour-specific splicing alterations in oncogenes and tumour suppressors (e.g., HRAS, MDM2 and VEGFA). WES identified premature termination mutations or copy number losses in a total of 15 splicing regulator genes, including SF3B5, SRSF12 and TNPO3.

CONCLUSIONS

This study raises the possibility that IVNKTCL may be driven by multiple complex regulatory loops, including non-exonic expression and aberrant splicing, in addition to defects in epigenetic regulation.

Nasal-type extranodal natural killer/T-cell lymphoma presenting with a mass on the buttock: A case report

RATIONALE

Nasal-type extranodal natural killer (NK)/T-cell lymphoma is a highly unusual disease with no standard curative managements yet. Our focus is to emphasize a very rare case of nasal-type extranodal NK/T-cell lymphoma with onset of the mass on the buttock successfully operated by combination of surgical excision together with chemotherapy. The management of these unique cases is of great clinical guiding significance.

PATIENT CONCERNS

A 20-year-old woman presented with a 2-month history of continuous and progressive severe pain on her left buttock. Since December 2017, the patient developed nasal congestion, accompanied with mild pain in the left eye, and new subcutaneous nodules on both cheeks.

DIAGNOSIS

Postoperative pathology confirmed the diagnosis of extranodal NK/T cell lymphoma. This is an extremely rare presentation of nasal-type NK/T-cell lymphoma.

INTERVENTIONS

The patient underwent enlarged resection of the tumor on the buttock. After the diagnosis of extranodal NK/T-cell lymphoma was established, the patient received chemotherapy and autologous hematopoietic stem cell transplantation.

OUTCOMES

The patient's symptoms improved significantly after the surgery, and the postoperative period was uneventful at the 1-year follow-up visit. There were no complications associated with the operation and adjuvant therapies during the follow-up period.

LESSONS

Taken together, the lesion's clinical features, imaging results, and pathological characteristics are unique. Extranodal NK/T-cell lymphoma, although rare, should be part of the differential diagnosis when the patient presents with the mass on the buttock. We recommend enlarged excision of the extranodal lymphoma. Combined of surgical excision of the extranodal lymphoma, chemotherapy and autologous hematopoietic stem cell transplantation are good choice for proper treatment.

Intravascular NK/T-cell lymphoma: clinicopathological and integrated molecular analysis of two cases provides a clue to disease pathogenesis

Aims

To elucidate the clinicopathological and molecular features of intravascular NK/T-cell lymphoma (IVNKTCL).

Methods

Two cases of IVNKTCL were retrieved from a single-centre cohort composed of 25 intravascular lymphomas. Whole-exome and RNA sequencing and immunohistochemistry were performed.

Results

We identified somatic mutations in the following epigenetic regulators: four histone genes (HIST1H2AN, HIST1H2BE, HIST1H2BN and H3F3A), histone deacetylase (HDAC5), two helicases (WRN and DDX3X), two methylation-related enzymes (TET2 and DNMT1) and the SNI/SWF pathway (ARID1A). Copy number analysis identified driver gene alterations comprising the loss of ARID1B, HACE1 and SMAD4, and the gain of SOX2 and histone clusters. RNA sequencing analysis did not indicate the presence of any fusion gene. Both cases were positive for Epstein-Barr virus (EBV) and showed strong expression of programmed death-ligand 1 (PD-L1).

Conclusions

This study raises the possibility that, at least for some patients, IVNKTCL may be considered an epigenetic disease with EBV infection-associated aetiopathogenesis.

Intravascular NK/T-cell lymphoma, Epstein-Barr virus positive with multiorgan involvement: a clinical dilemma

Background

Intravascular lymphoma is a rare type of non-Hodgkin lymphoma mostly of B-cell lineage. A few cases of intravascular lymphoma have been found to be of NK/T-cell origin, mainly affecting the skin and central nervous system.

Case presentation

A 54-year-old Caucasian man sought care because of a 2 weeks history of jaundice and intermittent fever, not responsive to antibiotics and antipyretics. Laboratory tests showed low blood oxygen concentration and pancytopenia. Serum microbiological tests were negative. Computerized tomography (CT) scan revealed hepatosplenomegaly and diffuse ground-glass opacities in both lungs without interlobular septal thickening. Despite oxygen therapy, the clinical conditions rapidly deteriorated leading to death 3 days after admission. Autopsy revealed a multiorgan involvement by an Epstein-Barr virus positive NK/T-cell lymphoma, strikingly growing within the blood vessel lumina, in absence of skin lesions.

Conclusions

The current case highlights the pathological features of this rare entity, the protean clinical presentation of which is often misleading, resulting in delayed diagnosis and treatment.