Clinicopathological and molecular genetic alterations in monomorphic-epitheliotropic intestinal T-cell lymphoma of the small intestine

BACKGROUND

Small intestinal monomorphic-epitheliotropic intestinal T-cell lymphoma (MEITL) is a rare aggressive T-cell lymphoma originating in the gastrointestinal tract. This study aimed to investigate the clinicopathological features, immunophenotypes, and molecular genetic changes of MEITL.

METHODS

The clinicopathological data for three patients with surgically resected MEITL of the small intestine were collected. Next, immunohistochemical labeling, Epstein-Barr virus (EBV) in situ hybridization, assessment of clonal rearrangement of T-cell receptor (TCR) genes, and next-generation sequencing (NGS) were performed.

RESULTS

Of the three patients, two were male and one was female, with ages of 61, 67, and 73 years, respectively. Clinical manifestations were predominantly abdominal pain and distension. Histopathology revealed infiltrative growth of small-to-medium-sized lymphocytes with a consistent morphology between the intestinal walls, accompanied by an obvious pro-epithelial phenomenon. The expression of CD3, CD8, CD43, CD56, TIA-1, CD103, H3K36me3, and Bcl-2 was detected, and the Ki-67 proliferation index ranged from 50% to 80%. All three patients tested negative for EBER. However, monoclonal rearrangement of the TCR gene was detected in them. NGS testing showed a JAK3 mutation in all three cases. Further, STAT5B, SETD2, and TP53 mutations were each observed in two cases, and a BCOR mutation was found in one case. All patients were treated with chemotherapy after surgery. Two patients died 7 and 15 month post-operation, and one patient survived for 5 months of follow-up.

CONCLUSIONS

Our findings demonstrate that mutations in JAK3 and STAT5B of the JAK/STAT pathway and inactivation of the oncogene SETD2 markedly contribute to the lymphomagenesis of MEITL.

Clinical and Histopathological Features of an Italian Monocentric Series of Primary Small Bowel T-Cell Lymphomas

The gastrointestinal (GI) tract is the most common extranodal site of occurrence of non-Hodgkin lymphomas. Most GI lymphomas are of B-cell lineage, while T-cell lymphomas are less frequent. The aim of our retrospective study was to depict the clinical-pathological profile of a series of patients affected by intestinal T-cell lymphomas (ITCL) and possibly define hallmarks of these neoplasms. A total of 28 patients were included: 17 enteropathy-associated T-cell lymphomas (EATL), 5 monomorphic epitheliotropic T-cell lymphomas (MEITL), 3 indolent T-cell lymphoproliferative disorders of the gastrointestinal tract (ITCLDGT), and 3 intestinal T-cell lymphomas not otherwise specified (ITCL-NOS). Celiac disease (CD) was diagnosed in around 70% of cases. Diagnosis of EATL showed a significant correlation with CD30 expression, whereas MEITL with angiotropism and CD56 positivity. ITCLDGT cases showed plasma cells infiltration. Peripheral lymphocytosis, the absence of a previous diagnosis of CD, an advanced Lugano clinical stage, and the histological subtype ITCL-NOS were significantly associated with worse survival at multivariate analysis. Our findings about the epidemiological, clinical, and histopathological features of ITCL were in line with the current knowledge. Reliable prognostic tools for these neoplasms are still lacking but according to our results lymphocytosis, diagnosis of CD, Lugano clinical stage, and histological subtype should be considered for patient stratification.

Clinical, endoscopic and pathological characteristics of primary gastrointestinal T-cell and NK/T-cell lymphomas

BACKGROUND AND AIMS

Gastrointestinal T-cell and NK/T-cell lymphomas are relatively rare and may be difficult to diagnose. Therefore, we performed a retrospective study of the clinical, endoscopic and pathological characteristics of these lymphomas, to provide additional data on this issue.

METHODS

From April 2013 to April 2021, consecutive patients diagnosed with primary gastrointestinal T-cell and NK/T-cell lymphomas were retrospectively reviewed. Their medical histories, laboratory, imaging, endoscopic, and pathology results were analyzed.

RESULTS

Forty-two patients were finally chosen, among whom, 24 patients had ENKTCL, 9 patients had MEITL, 2 patients had ALCL, ALK-, 1 patient had ALCL, ALK+, and 6 patients had PTCL, NOS. The median age of all the patients was 48 years old, and 73.81% (31 patients) were male. The patients' symptoms were abdominal pain, diarrhea, gastrointestinal bleeding, weight loss, fever, and others. The endoscopic results of 26 patients could be traced, and 69.23% of the patients showed multiple lesions. Ulcerative and ulceroinfiltrative lesions were common. Among the pathologic findings, necrosis, ulceration, and crypt atrophy were commonly found while epitheliotropism was relatively less common. Twelve patients (28.57%) had a history of misdiagnosis. After a median follow-up time of 26.9 months, 26 patients (66.70%) died of the disease. The median overall survival time was 8 months.

CONCLUSIONS

These lymphomas had nonspecific clinical manifestations, various endoscopic features, and were likely to be misdiagnosed as other diseases. The prognosis is still poor, and more in-depth research is needed to develop more precise treatments.

Cellular Origins and Pathogenesis of Gastrointestinal NK- and T-Cell Lymphoproliferative Disorders

The intestinal immune system, which must ensure appropriate immune responses to both pathogens and commensal microflora, comprises innate lymphoid cells and various T-cell subsets, including intra-epithelial lymphocytes (IELs). An example of innate lymphoid cells is natural killer cells, which may be classified into tissue-resident, CD56bright NK-cells that serve a regulatory function and more mature, circulating CD56dim NK-cells with effector cytolytic properties. CD56bright NK-cells in the gastrointestinal tract give rise to indolent NK-cell enteropathy and lymphomatoid gastropathy, as well as the aggressive extranodal NK/T cell lymphoma, the latter following activation by EBV infection and neoplastic transformation. Conventional CD4+ TCRαβ+ and CD8αβ+ TCRαβ+ T-cells are located in the lamina propria and the intraepithelial compartment of intestinal mucosa as type 'a' IELs. They are the putative cells of origin for CD4+ and CD8+ indolent T-cell lymphoproliferative disorders of the gastrointestinal tract and intestinal T-cell lymphoma, NOS. In addition to such conventional T-cells, there are non-conventional T-cells in the intra-epithelial compartment that express CD8αα and innate lymphoid cells that lack TCRs. The central feature of type 'b' IELs is the expression of CD8αα homodimers, seen in monomorphic epitheliotropic intestinal T-cell lymphoma (MEITL), which primarily arises from both CD8αα+ TCRαβ+ and CD8αα+ TCRγδ+ IELs. EATL is the other epitheliotropic T-cell lymphoma in the GI tract, a subset of which arises from the expansion and reprograming of intracytoplasmic CD3+ innate lymphoid cells, driven by IL15 and mutations of the JAK-STAT pathway.

Palliative Radiation Therapy without Chemotherapy for a Patient with Monomorphic Epitheliotropic Intestinal T Cell Lymphoma: A Case Report

Monomorphic epitheliotropic intestinal T cell lymphoma (MEITL), which used to be known as type 2 enteropathy-associated T cell lymphoma, is a rare lymphoma and is generally treated with chemotherapy. However, the MEITL prognosis is poor, and intestinal lymphoma including MEITL has the risk of bowel perforation not only at presentation but also during chemotherapy. A 67-year-old man was diagnosed with MEITL after presenting in our emergency room with bowel perforation. He and his family did not opt for the administration of anticancer drugs because of the risk of bowel perforation. However, they wanted the patient to receive palliative radiation therapy without chemotherapy. This treatment shrunk the tumor size without causing severe complications or decline in the quality of life, until he accidentally died due to traumatic intracranial hematoma. Considering the potential efficacy and safety of this treatment, it should be studied in more patients with MEITL.

Primary Gastrointestinal T-Cell Lymphoma and Indolent Lymphoproliferative Disorders: Practical Diagnostic and Treatment Approaches

Simple Summary

It is challenging for pathologists to diagnose primary gastrointestinal T-cell neoplasms. Besides the rarity of the diseases, the small biopsy material makes it more difficult to differentiate between non-neoplastic inflammation and secondary involvement of extra gastrointestinal lymphoma. Since this group of diseases ranges from aggressive ones with a very poor prognosis to indolent ones that require caution to avoid overtreatment, the impact of the diagnosis on the patient is enormous. Although early treatment of aggressive lymphoma is essential, the treatment strategy is not well established, which is a problem for clinicians. This review provides a cross-sectional comparison of histological findings. Unlike previous reviews, we summarized up-to-date clinically relevant information including the treatment strategies as well as practical differential diagnosis based on thorough literature review.

Abstract

Primary gastrointestinal (GI) T-cell neoplasms are extremely rare heterogeneous disease entities with distinct clinicopathologic features. Given the different prognoses of various disease subtypes, clinicians and pathologists must be aware of the key characteristics of these neoplasms, despite their rarity. The two most common aggressive primary GI T-cell lymphomas are enteropathy-associated T-cell lymphoma and monomorphic epitheliotropic intestinal T-cell lymphoma. In addition, extranodal natural killer (NK)/T-cell lymphoma of the nasal type and anaplastic large cell lymphoma may also occur in the GI tract or involve it secondarily. In the revised 4th World Health Organization classification, indolent T-cell lymphoproliferative disorder of the GI tract has been incorporated as a provisional entity. In this review, we summarize up-to-date clinicopathological features of these disease entities, including the molecular characteristics of primary GI T-cell lymphomas and indolent lymphoproliferative disorders. We focus on the latest treatment approaches, which have not been summarized in existing reviews. Further, we provide a comprehensive review of available literature to address the following questions: How can pathologists discriminate subtypes with different clinical prognoses? How can primary GI neoplasms be distinguished from secondary involvement? How can these neoplasms be distinguished from non-specific inflammatory changes at an early stage?

Small bowel T-cell lymphoma: a MEITL-ing diagnosis

Monomorphic epitheliotropic intestinal T-cell lymphoma (MEITL), previously known as Type-II enteropathy-associated T-cell lymphoma (EATL), is a rare subset of relatively aggressive lymphoma with a poor prognosis. We present a case of a previously healthy 59-year-old male with a 2-week history of abdominal distention who was found to have a non-bleeding ulcerated segment in the proximal jejunum secondary to MEITL. This exceedingly rare type of lymphoma usually presents with non-specific symptoms and can be challenging to diagnose. Our case demonstrates the importance of understanding the endoscopic and histological findings to allow the prompt diagnosis and treatment of this aggressive disease.

Diagnostic approach to T- and NK-cell lymphoproliferative disorders in the gastrointestinal tract

Most gastrointestinal NK and T cell lymphomas are aggressive in behavior, although in recent years a subset of indolent lymphoproliferative disorders have been described, which must be distinguished from their more malignant mimics. Intestinal T-cell lymphomas may arise from intra-epithelial lymphocytes and display epitheliotropism, such as enteropathy-associated T-cell lymphoma and monomorphic epitheliotropic intestinal T-cell lymphoma. They are both aggressive in behavior but differ in their clinic-pathological features. On the other hand, intra-epithelial lymphocytes are not prominent in intestinal T-cell lymphoma, NOS, which is a diagnosis of exclusion and probably represents a heterogeneous group of entities. Indolent lymphoproliferative disorders of NK- and T-cells of both CD8 and CD4 subsets share a chronic, recurring clinical course but display differences from each other. CD8+ T-cell lymphoproliferative disorder of GI tract has a low proliferative fraction and does not progress nor undergo large cell transformation. Whilst NK-cell enteropathy runs an indolent clinical course, it may display a high proliferation fraction. On the other hand, CD4+ indolent T-cell lymphoproliferative disorder displays variable proliferation rates and may progress or transform after a number of years. In Asia and South America, it is not uncommon to see involvement of the gastrointestinal tract by EBV-associated extranodal NK/T cell lymphoma, nasal type, which must be distinguished from NK cell enteropathy and EBV-associated mucocutaneous ulcers.

Monomorphic Epitheliotropic Intestinal T-Cell Lymphoma in Asia Frequently Shows SETD2 Alterations

Simple Summary

Monomorphic epitheliotropic intestinal T-cell lymphoma (MEITL) is a rare primary T-cell lymphoma of the digestive tract that is characterized by an aggressive clinical course. The aim of this study was to analyze the clinicopathological characteristics and genomic profile of Asian MEITL. In this study, nine cases of Japanese MEITL were analyzed by targeted Next Generation Sequencing and immunohistochemistry and were integrated with previously reported whole-genome copy number microarray-based assay data. All cases showed alterations of the tumor suppressor gene SETD2 and mutations in one or more genes of the JAK/STAT pathway. Therefore, we concluded that the combination of epigenetic deregulation and cell signaling activation may represent a major oncogenic event in the pathogenesis of Asian MEITL, similar to Western MEITL.

Abstract

Monomorphic epitheliotropic intestinal T-cell lymphoma (MEITL) is a rare primary T-cell lymphoma of the digestive tract derived from intraepithelial lymphocytes and characterized by an aggressive clinical course. In this study, nine cases of Japanese MEITL were analyzed by targeted Next Generation Sequencing (NGS) and immunohistochemistry and were integrated with previously reported whole-genome copy number microarray-based assay data. The highlight of our findings is that all cases showed alterations of the tumor suppressor gene SETD2 by mutations and/or loss of the corresponding 3p21 locus. We also demonstrated that all cases showed mutations in one or more genes of JAK/STAT pathway. Therefore, the combination of epigenetic deregulation and cell signaling activation represent major oncogenic events in the pathogenesis of MEITL in Asian MEITL, similar to Western MEITL.

Endoscopic and clinicopathological characteristics of colorectal T/NK cell lymphoma

BACKGROUND

Colorectal T/natural killer (NK)-cell lymphomas (TNKCL) are very rare. Endoscopic and clinicopathological characteristics of colorectal TNKCL have not been clearly demonstrated. In this study, we demonstrated the clinical characteristics of colorectal TNKCL.

METHODS

Endoscopic and clinicopathological characteristics were investigated in 27 patients with colorectal monomorphic epitheliotropic intestinal T-cell lymphoma (MEITL), adult T-cell leukemia/lymphoma (ATLL), and other types of TNKCL.

RESULTS

Nine TNKCL patients (33%) were classified as MEITL, 11 (41%) as ATLL, and seven (26%) as other. Four patients with Epstein-Barr Virus-positive (EBV+) TNKCL, two indolent T-cell lymphoproliferative disorder and one anaplastic large cell lymphoma were included in the other group. Endoscopically, six MEITL (67%) and five ATLL (46%) showed diffuse-infiltrating type, in which the main endoscopic lesion was edematous mucosa in MEITL, while aphthoid erosion and edematous mucosa were typical in ATLL. Ulcerative type was identified in four other group patients (57%), including two EBV+ TNKCL. An increase in atypical T-intraepithelial lymphocytes (T-IELs) was noted in seven MEITL (88%) and six ATLL (60%) patients, but not in the other group (0%) patients. Five MEITL patients (56%) showed features of lymphocytic proctocolitis with increased CD8+ T-IELs.

CONCLUSIONS

MEITL and ATLL occasionally invaded the colorectum, and primary involving MEITL was observed. Diffuse infiltrating type was the characteristic endoscopic finding in colorectal MEITL and ATLL, while ulcerative type was observed in the other group. Features of lymphocytic proctocolitis may be prodromal findings of MEITL.

Monomorphic Epitheliotropic Intestinal T-cell Lymphoma of the Stomach: Two Case Reports and a Literature Review

We describe the clinicopathologic and molecular features of 2 cases of gastric monomorphic epitheliotropic intestinal T-cell lymphoma (MEITL), which were first diagnosed from gastric biopsies, one was primary whereas the other was gastric involvement by MEITL. Both cases were older men with stomach ulcers. Case 1 was admitted for a hemorrhage in the upper digestive tract and case 2 for edema. Histology of both cases showed infiltrated monomorphic and medium-sized lymphocytes with lymphoid epithelial phenomenon. An inflammatory background and vascular hyperplasia were also observed likely due to the ulceration. Neoplastic cells expressed CD2, CD3, CD7, CD8, CD56, TIA-1, and MYC, not CD5, CD4, Granzyme B, CD20, CD30, TdT, or EBER. Both lymphomas showed TCRG gene rearrangement and c-MYC gains. Moreover, we first affirmed polysomy of chromosome 8 in case 2. For correct diagnosis of this rare tumor at the rare location, it is important that pathologists raise the possibility and exclude other differential diagnoses.

New/Revised Entities in Gastrointestinal Lymphoproliferative Disorders

The gastrointestinal tract is a common extranodal site of involvement by lymphomas. These may be diagnostically challenging because they can mimic a variety of benign conditions and may be difficult to subclassify when malignant. The classification of gastrointestinal lymphomas is an evolving area with some recent changes. Although some of these entities are rare, they are important to recognize because of the variable clinical presentations, comorbidities, and treatment implications. This article explores new and revised entities in gastrointestinal lymphoproliferative disorders.

Use of PEG-asparaginase in monomorphic epitheliotropic intestinal T-cell lymphoma, a disease with diagnostic and therapeutic challenges

Monomorphic epitheliotropic intestinal T-cell lymphoma (MEITL), previously known as enteropathy associated T-cell lymphoma (EATL) type II, is a rare haematological malignancy with a difficult and delayed diagnosis. Symptoms can include abdominal pain, weight loss, and chronic diarrhoea. However, most patients are only diagnosed after complications, such as perforation or obstruction, have developed. There is no standard treatment for MEITL; most accepted regimens consist of surgical resection and anthracycline-based chemotherapy. Prognosis is poor with an approximate survival of less than a year. Even though other therapies, such as autologous stem cell transplant, has shown promising results, not all patients can tolerate this course of treatment especially if they are elderly, have several comorbidities or are malnourished. Innovative therapies that improve survival and can be used as an alternative for more intensive treatment are needed. We report the use of PEG-asparaginase along with conventional anthracycline therapy in a 70-year-old woman diagnosed with MEITL, who went into remission and survived for more than one year before succumbing to relapsed disease.

Monomorphic epitheliotropic intestinal T-cell lymphoma in pleural effusion: A case report

Dissemination of lymphomas in serous effusions is quite common. Cytology aims to contribute in the clinical management of haematologic patients, providing an accurate and rapid diagnosis. Ancillary techniques such as immunocytochemistry and flow cytometry are essential to classify the lymphoma entity. Comprehensive awareness of the clinical picture and previous histologic documentation are essential for a lymphomatous effusion diagnosis. We report an unusual case of monomorphic epitheliotropic intestinal T-cell lymphoma, formerly known as enteropathy associated T-cell lymphoma (EATL) type II, spreading in the pleural cavity. Cell morphology and immunohistochemistry of the pleural fluid were consistent with the histology of a jejunal tumor previously excised. Flow cytometry data were consistent, though not pathognomonic for the disease. Serous effusions with evidence of lymphoma involvement should be thoroughly examined with cytology and adjuvant techniques to provide diagnosis for proper therapeutic strategies.

Occult recurrence of monomorphic epitheliotropic intestinal T-cell lymphoma and the role of MATK gene expression in diagnosis

Monomorphic epitheliotropic intestinal T-cell lymphomas (MEITL), formerly Type II enteropathy-associated T-cell lymphomas (EATL), are rare peripheral T-cell lymphomas. They are associated with poor survival outcomes, in part because of their late diagnosis. Although MEITLs may be reliably diagnosed based on histological and immunophenotypic findings, overlaps with other NK/T and T-cell lymphomas may confound the diagnosis. The distinctive high-level nuclear staining of the novel marker Megakaryocyte-associated tyrosine kinase (MATK) in MEITLs is an invaluable tool in distinguishing MEITL from classical EATL and other NK/T or T-cell lymphomas. 18-Fluorine-2-fluorodeoxyglucose positron emission tomography (¹⁸ F-FDG PET) has been shown to be a useful tool in the staging and follow-up of aggressive lymphomas. Herein, we describe an unusual case of occult hepatic recurrence of MEITL that was non-avid on ¹⁸ F-FDG PET, in which diagnosis was confirmed based on the expression of MATK in tumour cells. Copyright © 2016 John Wiley & Sons, Ltd.