T-cell Receptor Gene Rearrangement Analysis Research Articles

Detecting T-cell receptor clonality in patients with severe atopic dermatitis refractory to dupilumab.

Trials and real-life studies demonstrated clinically meaningful improvements of disease activity in the majority of patients with moderate to severe atopic dermatitis (AD) treated with the anti-IL-4RA-antibody dupilumab. However, misdiagnosis or confounding skin diseases in particular cutaneous T-cell lymphoma (CTCL) may lead to inadequate response. To investigate the clinical and pathological features of patients with AD who showed insufficient response to dupilumab. We reviewed the medical records of 371 patients treated with dupilumab for severe AD. Insufficient response was defined as failure to achieve an improvement of the eczema area severity index (EASI) of at least 50% (EASI-50) at Week 16 and of 75% (EASI-75) at Week 52. Among 46 patients with insufficient response, 35 patients consented to a re-evaluation including a full physical exam, biopsies and laboratory assessments including immunohistochemistry and T-cell receptor gene rearrangement analysis to differentiate CTCL. Of the 371 patients treated with dupilumab, 46 (12.3%) patients showed insufficient response to dupilumab. Of these, 35 underwent further evaluation, and 19 (54.2% of inadequate responders) were finally diagnosed with mycosis fungoides (MF). In these patients, transition to or addition of conventional MF treatment led to clinical improvements. Insufficient response to dupilumab treatment may help uncover early MF on an existing AD background.

Juvenile-Onset Non-Poikilodermatous CD8+CD56+ Mycosis Fungoides

The most frequent primary cutaneous lymphomas observed in childhood and adolescence are mycosis fungoides (MF) and CD30-positive lymphoproliferative diseases. We report a 22-year-old female who presented with a 6-year history of multiple well-demarcated large roundish-oval scaly and reddish-brownish patches and plaques on the trunk and extremities. Histopathology revealed the focal parakeratosis and prominent epidermotropism of atypical lymphocytes, which were positive for CD8, CD56, and TIA-1 and showed a loss of CD7 and CD5 expression. T-cell receptor (TCR) gene rearrangement analysis (multiplex-PCR, BIOMED-2) of the lesional skin demonstrated the rearrangement of the gamma chain (tube A: 162 nt). Based on clinicopathological findings and a complete work-up, she was diagnosed with juvenile non-poikilodermatous C8+/CD56+ MF in stage IA. Resolution of the skin lesions was achieved by 16-week narrowband UVB phototherapy and clobetasol propionate 0.05% ointment. Juvenile-onset non-poikilodermatous CD8+CD56+ MF represents a very rare MF subtype and is associated with an indolent course. In order to avoid too aggressive diagnostics and treatments, clinicians should be aware of this rare and indolent MF variant in childhood and adolescence.

Flow Sorting, Whole Genome Amplification and Next-Generation Sequencing as Combined Tools to Study Heterogeneous Acute Lymphoblastic Leukemia.

Next-generation sequencing (NGS) methods have been introduced for immunoglobulin (IG)/T-cell receptor (TR) gene rearrangement analysis in acute lymphoblastic leukemia (ALL) and lymphoma (LBL). These methods likely constitute faster and more sensitive approaches to analyze heterogenous cases of ALL/LBL, yet it is not known whether gene rearrangements constituting low percentages of the total sequence reads represent minor subpopulations of malignant cells or background IG/TR gene rearrangements in normal B-and T-cells. In a comparison of eight cases of B-cell precursor ALL (BCP-ALL) using both the EuroClonality NGS method and the IdentiClone multiplex-PCR/gene-scanning method, the NGS method identified between 29% and 139% more markers than the gene-scanning method, depending on whether the NGS data analysis used a threshold of 5% or 1%, respectively. As an alternative to using low thresholds, we show that IG/TR gene rearrangements in subpopulations of cancer cells can be discriminated from background IG/TR gene rearrangements in normal B-and T-cells through a combination of flow cytometry cell sorting and multiple displacement amplification (MDA)-based whole genome amplification (WGA) prior to the NGS. Using this approach to investigate the clonal evolution in a BCP-ALL patient with double relapse, clonal TR rearrangements were found in sorted leukemic cells at the time of second relapse that could be identified at the time of diagnosis, below 1% of the total sequence reads. These data emphasize that caution should be exerted when interpreting rare sequences in NGS experiments and show the advantage of employing the flow sorting of malignant cell populations in NGS clonality assessments.

Clinicopathological features and prognosis of cytotoxic T-cell lymphoma: analysis of 134 cases

Objective: To investigate the clinicopathological features and prognosis of cytotoxic T-cell lymphoma (CTL). Methods: The clinicopathological data of 134 CTL patients in Beijing Friendship Hospital Affiliated to Capital Medical University, the 989 Hospital of PLA Joint Logistics Support force (formerly the 152 Hospital) and the Fourth Hospital of Hebei Medical University from 2008 to 2020 were retrospectively collected. Immunophenotype, Epstein-Barr virus infection status and T cell receptor (TCR) clonality of tumor cells were assessed, and clinicopathological features and prognosis of patients were analyzed. Results: Among the 134 CTL patients, the male to female ratio was 1.7∶1.0, the median age was 49.5 years (range 3-83 years), and 100 cases (74.6%) were under 60 years old. Forty-six point nine percent of the patients (53/113) had B symptoms. Most of the patients presented with systemic superficial lymphadenopathy. According to the Ann Arbor staging system, 36.8% (39/106) of the patients were in stage Ⅰ-Ⅱ, and 63.2% (67/106) in stage Ⅲ-Ⅳ. The rate of extranodal involvement was 51.6% (66/128). Spleen was involved in 24.2% (31/128) of the cases. Morphology showed diffuse growth of abnormal lymphocytes, infiltrating and destroying normal tissue structure. Immunohistochemical staining showed that tumor cells expressed T cell antigens (CD2, CD3, CD5, and CD7), and 72.0% (77/107) of them had decreased or lost expression of one or more antigens. According to the numbers of CD4 and CD8 expression in tumor cells, 70 cases (52.2%) were grouped into CD8+>CD4+group. The expression rates of TIA-1 and granzyme B were 99.2% (119/120) and 79.8% (95/119), respectively. CD20 abnormal expression rate was 27.6% (37/134) and CD56 was negative in all cases. The median Ki-67 proliferative index was 45.0% (range 5%-80%). In situ hybridization of small RNA encoded by Epstein-Barr virus was negative. Clonal TCR gene rearrangement analysis was performed on 49 cases and was positive in all cases. Ninety-one patients were followed up for a median of 36 months (range, 1 to 240 months), and 40 of the 91 patients (44.0%) died. The twenty-three patients were in complete remission (including 13 cases with localized single extranodal mass). The 3-year and 5-year overall survival rates were 53.5% and 49.4%, respectively. Univariate analysis showed that B symptom, spleen involvement, extranodal involvement, clinical stage, CD8+>CD4+phenotype, abnormal expression of CD20 and Ki-67 proliferation index (>60%) were associated with overall survival (P<0.05). The multivariate Cox regression analyses showed that spleen involvement and CD8+>CD4+ phenotype were independent prognostic factors for overall survival in CTL patients. Conclusions: CTL are more commonly found in adult males under 60 years old, often accompanied by B symptom, with a high proportion of extranodal involvement and more CD8 positive phenotypes. Spleen involvement and CD8+>CD4+phenotype are independent predictors of CTL overall survival. Some patients with localized extranodal CTL may have a good prognosis.

Extranodal nasal type natural killer/T-cell lymphoma of the digestive system: a clinicopathological study of thirteen cases

Objective: To investigate the clinicopathological features, and diagnostic and differential diagnostic characteristics of extranodal nasal type natural killer/T-cell lymphoma (ENKTCL) of the digestive system. Methods: Thirteen cases of ENKTCL in the digestive system were collected at the Henan Provincial People's Hospital, Zhengzhou, China, from August 2000 to August 2020. The histopathological, immunohistochemical and in situ hybridization features were analyzed, as well as those of T-cell receptor (TCR) gene rearrangement in some cases. The patients were followed up. Results: There were 11 males and 2 females. The age ranged from 28 to 80 years (median=53 years). Seven cases were present in the colorectum, and 3 cases were present in the small intestine. The other three cases were in stomach, gallbladder and liver (one case each). The main clinical symptoms were fever, and abdominal pain, often accompanied by fatigue, diarrhea, hematochezia, elevated serum albumin, elevated lactate dehydrogenase, and increased peripheral blood EB virus DNA copy. Histologically, the tumor accompanied by a heavy admixture of inflammatory cells (small lymphocytes, plasma cells and histiocytes). There was diffuse dense tumor cell infiltrate, with prominent coagulative necrosis. The lymphomatous infiltrate had angiocentric and angio-necrotic changes. Immunohistochemically, lymphoid cells expressed CD3 in all cases. Some of them showed weakened/absent other T cell markers, while all of them expressed CD56 except 1 case. A few of the cases showed CD4-/CD8+ killer T cell phenotypes. In situ hybridization showed EB virus encoded RNA (EBER) was positive in all cases. Clonal TCR gene rearrangement was not detected in all 7 cases tested. The median survival time was 9 months. Conclusions: ENKTCL of the digestive system is extremely rare. It often predisposes the patients to acute abdomen such as perforation of the gastrointestinal tract. The treatment outcomes are dismal, and the prognosis is poor. Clinical and imaging studies are often non-specific. It is also easy to be misdiagnosed as non-specific ulcers. Combined with immunohistochemistry, in situ hybridization and TCR gene rearrangement analysis and better understanding of this tumor's clinicopathological characteristics can help improve its diagnosis and early treatment.

Acute Epstein‐Barr virus associated haemophagocytosis in an Asian female: What is the diagnosis?

Acute <scp>Epstein‐Barr</scp> virus associated haemophagocytosis in an Asian female: What is the diagnosis?

Erythroderma: psoriasis or lymphoma? A diagnostic challenge and therapeutic pitfall.

Psoriasis and lymphoma risk is widely debated, but few is known about misdiagnosis risk between erythrodermic psoriasis and lymphoma. In fact, erythroderma might represent a clinical presentation of psoriasis, cutaneous T-cell lymphomas and skin dissemination of systemic lymphomas. All patients referred to psoriasis outpatient service with a diagnosis of erythrodermic psoriasis were re-examined. Among them, all the patients with a subsequent lymphoma diagnosis were included. For each patient data concerning age, gender, age at erythroderma onset, age at lymphoma diagnosis, immune-suppressive therapy, type of lymphoma and relative stage, lymphoma treatment and outcome were obtained. Twenty-five patients (15 females and 10 males) with a diagnosis of erythrodermic psoriasis were retrieved. Among them, 9 patients (5 males and 4 females) were affected by erythrodermic lymphoma, including 4 patients with Sèzary Syndrome, 3 with mycosis fungoides, and 2 with peripheral T-cell lymphoma not otherwise specified. Prior to lymphoma diagnosis all the patients (9/9) received cyclosporine, two (2/9) of them methotrexate, one (1/9) azatioprine, and two (2/9) systemic corticosteroids. The prognosis of our patients was poor, due to immune-suppressive drugs administration in patients with undiagnosed lymphoma. The only exception was one (1/9) patient with Sèzary Syndrome still alive with disease after 120 months of follow-up. In case of patients with erythroderma, multiple skin biopsies and specific peripheral blood studies like flow cytometry and T-cell receptor gene rearrangement analysis are required in order to avoid misdiagnosis risk between psoriasis and lymphoma.

Consensus Recommendations for MRD Testing in Adult B-Cell Acute Lymphoblastic Leukemia in Ontario.

Measurable (minimal) residual disease (MRD) is an established, key prognostic factor in adult B-cell acute lymphoblastic leukemia (B-ALL), and testing for MRD is known to be an important tool to help guide treatment decisions. The clinical value of MRD testing depends on the accuracy and reliability of results. Currently, there are no Canadian provincial or national guidelines for MRD testing in adult B-ALL, and consistent with the absence of such guidelines, there is no uniform Ontario MRD testing consensus. Moreover, there is great variability in Ontario in MRD testing with respect to where, when, and by which technique, MRD testing is performed, as well as in how the results are interpreted. To address these deficiencies, an expert multidisciplinary working group was convened to define consensus recommendations for improving the provision of such testing. The expert panel recommends that MRD testing should be implemented in a centralized manner to ensure expertise and accuracy in testing for this low volume indication, thereby to provide accurate, reliable results to clinicians and patients. All adult patients with B-ALL should receive MRD testing after induction chemotherapy. Philadelphia chromosome (Ph)-positive patients should have ongoing monitoring of MRD during treatment and thereafter, while samples from Ph-negative B-ALL patients should be tested at least once later during treatment, ideally at 12 to 16 weeks after treatment initiation. In Ph-negative adult B-ALL patients, standardized, ideally centralized, protocols must be used for MRD testing, including both flow cytometry and immunoglobulin (Ig) heavy chain and T-cell receptor (TCR) gene rearrangement analysis. For Ph-positive B-ALL patients, MRD testing using a standardized protocol for reverse transcription real-time quantitative PCR (RT-qPCR) for the BCR-ABL1 gene fusion transcript is recommended, with Ig/TCR gene rearrangement analysis done in parallel likely providing additional clinical information.

Utility of clonal T-cell rearrangement study in the diagnosis of early mycosis fungoides

To the Editor: The diagnosis of early mycosis fungoides (MF) is challenging, as clinical and histopathologic presentation can mimic inflammatory dermatoses. In 2005, the International Society for Cutaneous Lymphoma (ISCL) established a clinicopathologic algorithm for the diagnosis of early MF based on clinical, histopathologic, molecular, and immunopathologic criteria, requiring a total of 4 points (Table I).1 One criterion, the clonal T-cell receptor (TCR) gene rearrangement analysis, represents a significant cost in the workup of early MF and is often unavailable in-house.

Inhibition of Immune Cell Subsets Is Differentially Affected By Dasatinib Dosage in Patients with Chronic Phase CML

Inhibition of Immune Cell Subsets Is Differentially Affected By Dasatinib Dosage in Patients with Chronic Phase CML

Minimal residual disease in acute lymphoblastic leukemia: technical aspects and implications for clinical interpretation.

Minimal residual disease (MRD) monitoring has proven to be one of the fundamental independent prognostic factors for patients with acute lymphoblastic leukemia (ALL). Sequential monitoring of MRD using sensitive and specific methods, such as real-time quantitative polymerase chain reaction (qPCR) or flow cytometry (FCM), has improved the assessment of treatment response and is currently used for therapeutic stratification and early detection. Although both FCM and qPCR yield highly consistent results with sensitivities of 10‒4, each method has several limitations. For example, qPCR is time-consuming and laborious: designing primers that correspond to the immunoglobulin (IG) and T-cell receptor (TCR) gene rearrangements at diagnosis can take 3‒4 weeks. In addition, the evolution of additional clones beyond the first or index clone during therapy cannot be detected, which might lead to false-negative results. FCM requires experienced technicians and sometimes does not achieve a sensitivity of 10‒4. Accordingly, a next generation sequencing (NGS)-based method has been developed in an attempt to overcome these limitations. With the advent of high-throughput NGS technologies, a more in-depth analysis of IG and/or TCR gene rearrangements is now within reach, which impacts all applications of IG/TR analysis. However, standardization, quality control, and validation of this new technology are warranted prior to its incorporation into routine practice.

Folliculotropic mycosis fungoides: clinicopathological analysis of 17 patients.

Folliculotropic mycosis fungoides (FMF) represents a variant of MF characterized by hair follicle invasion of mature, CD4-positive small lymphoid cells with cerebriform nuclei. The disease displays resistance to standard treatment modalities and has an unfavourable course. Clinical analysis of 17 patients with FMF collected between 2005 and 2012, investigation of tumour cells and involved hair follicle. Re-evaluation of clinical data, wide panel immunohistochemistry investigation on paraffin-embedded biopsy material, T-cell receptor gene rearrangement analysis of the samples. Male and older age group predominance, frequent head-neck involvement, acneiform lesions, keratotic plugs, cysts, nodules, follicular papules, alopecia and classic mycosis fungoides-like plaques represented the main clinical characteristics. Treatment response showed a wide range from transient complete response to therapy resistance and death due to the disease. The pathological alterations: folliculotropism, mild epidermotropism, follicular plugging, mucinous degeneration of hair follicle, basaloid hyperplasia, syringotropism were similar to those observed previously. The first case of a CD8-positive folliculotropic mycosis fungoides - with unusual clinical presentation - is reported here. Nestin overexpression of mesenchymal cells of the isthmic and suprabulbar regions of hair follicle and the reappearance of dermal nestin-expressing cells were observed in association with immature dendritic cell hyperplasia. Altered CK19 expression was detected suggesting a potential role of follicular keratinocytes in the disease process. It was found that a proportion of neoplastic T cells constantly express programmed death-1 receptor in our patients contrary to classic mycosis fungoides. The spectrum of the clinical manifestation and the course of folliculotropic mycosis fungoides are broad and differ from classic mycosis fungoides. Folliculotropic neoplastic T-cell proliferation is associated with activation of inflammatory reactive T- and B-lymphoid cells, mesenchymal cells and changes in the hair follicle.

T‐cell receptor gene rearrangement analysis of sequential biopsies in cutaneous T‐cell lymphomas with the Biomed‐2 PCR reveals transient T‐cell clones in addition to the tumor clone

Detection of a dominant T-cell clone by T-cell receptor (TCR) gene rearrangement analysis is often essential for the diagnosis of cutaneous T-cell lymphomas (CTCL). The occurrence of T-cell clones in addition to the diagnostic T-cell clone during the course of CTCL has been reported, but the data of these studies have been contradictory. We retrospectively evaluated the data of 114 lesional skin biopsies from 26 patients with Mycosis fungoides and two patients with primary cutaneous anaplastic large cell lymphoma, which were analysed with the standardized Biomed-2 PCR for the TCRγ and TCRβ locus. A dominant T-cell clone was repetitively detected in 93% (26/28) of patients. Additional T-cell clones appeared temporarily in 39% (11/28) of patients. Correlation with the clinical data did not show an association of the presence of additional T-cell clones with age, number of treatments, progression of disease or survival. Our findings demonstrate that a persistent T-cell clone, most likely the disease causing tumor clone, is detectable in almost all CTCL patients. In addition, transiently appearing T-cell clones frequently occur during the course of disease. The biological relevance of these additional clones has still to be determined. However, it is important to take the possibility of additional T-cell clones into account for diagnostic analyses.

The spectrum of primary mucosal CD30-positive T-cell lymphoproliferative disorders of the head and neck

To retrospectively investigate the clinicopathologic spectrum of primary mucosal CD30-positive T-cell lymphoproliferative disorders (PTCLDs) of the head and neck. Archives of PTCLDs primarily arising in head and neck mucosa were reviewed. Immunostaining of CD20, CD3, CD4, CD8, CD30, CD56, anaplastic lymphoma kinase (ALK), epithelial membrane antigen (EMA), cytotoxic molecules (TIA-1, granzyme B, or perforin), and Ki67; in situ hybridization for Epstein-Barr virus; and T-cell receptor gene rearrangement analysis were performed. Fourteen cases of primary mucosal anaplastic large cell lymphoma (M-ALCL) were identified, and no lymphomatoid papulosis (LyP) cases were found. All cases demonstrated atypical mononuclear neoplastic cells with diverse histology and cytomorphology. The typical immunophenotype of neoplastic cells was CD3-positive, CD4-positive, CD8-negative, CD30-positive, ALK-negative, and cytotoxic molecules-positive. Infiltration of inflammatory cells was common. All cases presented an indolent course, regardless of therapy. PTCLDs of the head and neck provisionally included M-ALCL alone.

Identification of genuine primary pulmonary NK cell lymphoma via clinicopathologic observation and clonality assay

Extranodal natural killer (NK)/T-cell lymphoma, nasal type, is an uncommon lymphoma associated with the Epstein-Barr virus (EBV). It most commonly involves the nasal cavity and upper respiratory tract. Primary pulmonary NK/T cell lymphoma is extremely rare. If a patient with a NK or T-cell tumor has an unusual reaction to treatment or an unusual prognosis, it is wise to differentiate NK from T-cell tumors. The clinicopathologic characteristics, immunophenotype, EBV in situ hybridization, and T cell receptor (TCR) gene rearrangement of primary pulmonary NK cell lymphoma from a 73-year-old Chinese woman were investigated and the clonal status was determined using female X-chromosomal inactivation mosaicism and polymorphisms at the phosphoglycerate kinase (PGK) gene. The lesion showed the typical histopathologic characteristics and immunohistochemical features of NK/T cell lymphoma. However, the sample was negative for TCR gene rearrangement. A clonality assay demonstrated that the lesion was monoclonal. It is concluded that this is the first recorded case of genuine primary pulmonary NK cell lymphoma. The purpose of the present work is to recommend that pathologists carefully investigate the whole lesion to reduce the likelihood that primary pulmonary NK cell lymphoma will be misdiagnosed as an infectious lesion. In addition, TCR gene rearrangement and clonal analysis, which is based on female X-chromosomal inactivation mosaicism and polymorphisms at PGK and androgen receptor (AR) loci, were found to play important roles in differentiating NK cell lymphoma from T cell lymphoma.Virtual slidesThe virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/5205300349457729

Nævus géant congénital

A hallmark of lymphoid malignancies is the presence of a monoclonal lymphocyte population. Monoclonality of B- and T-cell populations can be established through immunoglobulin (IG) or T-cell receptor (TCR) gene rearrangement analysis, respectively. The biological rationale of IG and TCR gene rearrangement analysis is that due to the extensive combinatorial repertoire made possible by V(D)J recombination in lymphocytes, it is unlikely that any substantive lymphocyte population would share the same IG or TCR gene rearrangement pattern unless there is an underlying neoplastic or reactive origin. Modern IG and TCR gene rearrangement analysis is typically performed by polymerase chain reaction (PCR) using commercially available primer sets followed by gel capillary electrophoresis. This process is highly sensitive in the detection of nearly all lymphoid malignancies. Several pitfalls and limitations, both biological and technical, apply to IG/TCR gene rearrangement analysis, but these can be minimised with high quality controls, performance of assays in duplicate, and adherence to strict criteria for interpreting and reporting results. Next generation sequencing (NGS) will likely replace PCR based methods of IG/TCR gene rearrangement analysis but is not yet widespread due to the absence of standardised protocols and multicentre validation.

Clinicopathologic features of gastrointestinal tract involvement of anaplastic large cell lymphoma.

To investigate the clinicopathological characteristics of gastrointestinal tract involvement of anaplastic large cell lymphoma (ALCL). The clinicopathological features of four patients with ALCL that involved gastrointestinal tract were retrospectively analyzed using immunohistochemical study, T-cell receptor gene rearrangement analysis, and evaluation for Epstein Barr virus infection status. Most tumor cells in all these four cases are large and highly pleomorphic, and all four cases were classified as the common pattern ALCL. Tumor cells in all four tumors expressed CD30, and expressed at least one cytotoxic maker. Two patients were confirmed to be with anaplastic lymphoma kinase (ALK)-positive ALCL, and four patients were negative during in situ hybridization for Epstein-Barr virus-encoded RNA but showed clonal T-cell receptor gene rearrangement. Gastrointestinal tract involvement of ALCL has the unique clinicopathological features.

Composite Lymphocyte-Rich Thymoma and Peripheral T-Cell Lymphoma Not Otherwise Specified: Case Report and Literature Review

The simultaneous occurrence of thymoma and peripheral T-cell lymphoma not otherwise specified (PTCL-NOS) has not been previously reported, to our knowledge. We describe a 59-year-old ethnic Filipina woman with myasthenia gravis who was found to harbor an invasive lymphocyte-rich thymoma (World Health Organization [WHO] type B1). Subsequent pathologic examination of her mediastinal and abdominal lymph nodes revealed concurrent PTCL-NOS. A bone marrow examination revealed T-cell lymphoma, which was confirmed by flow cytometric and T-cell receptor gene rearrangement analysis. * NHL : non-Hodgkin lymphoma WBC : white blood cell PTCL-NOS : peripheral T-cell lymphoma not otherwise specified MRI : magnetic resonance imaging CT : computed tomographic WHO : World Health Organization HTLV-1 : human T-cell leukemia virus type 1 HTLV-2 : human T-cell leukemia virus type 2 PCR : polymerase chain reaction TCR : T-cell receptor CML : chronic myelogenous leukemia

Aberrant antigenic expression in extranodal NK/T-cell lymphoma: a multi-parameter study from Thailand

BackgroundExtranodal NK/T-cell lymphoma, nasal type (ENKTL) is not common worldwide, but it is the most common T- and NK-cell lymphomas in many Asian countries. Immunophenotypic profiles were studied based on limited series. The authors, therefore, studied on ENKTL according to characterize immunophenotypic profiles as well as the distribution of EBV subtype and LMP-1 gene deletion.MethodsBy using tissue microarray (TMA), immunohistochemical study and EBV encoded RNA (EBER) in situ hybridization were performed. T-cell receptor (TCR) gene rearrangement, EBV subtyping, and LMP-1 gene deletion were studied on the available cases.ResultsThere were 22 cases eligible for TMA. ENKTL were positive for CD3 (91%), CD5 (9%), CD7 (32%), CD4 (14%), CD56 (82%), TIA-1 (100%), granzyme B (95%), perforin (86%), CD45 (83%), CD30 (75%), Oct2 (25%), and IRF4/MUM1 (33%). None of them was positive for βF1, CD8, or CD57. TCR gene rearrangement was negative in all 18 tested cases. EBV was subtype A in all 15 tested cases, with 87% deleted LMP-1 gene. Cases lacking perforin expression demonstrated a significantly poorer survival outcome (p = 0.008).ConclusionsThe present study demonstrated TIA-1 and EBER as the two most sensitive markers. There were a few CD3 and/or CD56 negative cases noted. Interestingly, losses of CD45 and/or CD7 were not uncommon while Oct2 and IRF4/MUM1 could be positive in a subset of cases. Based on the present study in conjunction with the literature review, determination of PCR-based TCR gene rearrangement analysis might not be a useful technique for making diagnosis of ENKTL.

Clinicopathologic study of 7 cases of gastric T-cell lymphoma

To study the clinicopathologic characteristics of gastric T-cell lymphoma. The clinicopathologic features of 7 cases of gastric T-cell lymphoma were retrospectively reviewed. Immunohistochemical study, T-cell receptor gene rearrangement analysis and evaluation of Epstein Barr virus (EBV) status were also performed. The median age at onset of gastric T-cell lymphoma was 45 years. The male-to-female ratio was 6 to 1. The clinical information was available in 6 cases; and one of them had history of persistent diarrhea and 5 had hypoproteinemia. Histologically, 5 cases consisted of large lymphoma cells and the remaining 2 cases showed mainly medium-sized cells. Intraepithelial lymphoma cell infiltration was found in one case. The lymphoma cells of all cases were negative for CD20 and CD79a. CD3 and TIA-1 expression was noted in 6 of the 7 cases. CD5, βF-1 and CD30 were positive in 4 cases and CD4 was positive in 3 cases. In-situ hybridization for Epstein-Barr virus-encoded RNA was negative. Clonal T-cell receptor gene rearrangement was demonstrated in all cases. Gastric T-cell lymphoma is a rare type of malignant lymphoma, with distinctive clinicopathologic characteristics.