Burkitt lymphoma versus diffuse large B-cell lymphoma: a practical approach

Relapse of Diffuse Large B-Cell Lymphoma as Painless Masses in the Abdominal Wall Muscles: A Rare Case Report

BACKGROUND

The most frequent type of non-Hodgkin lymphoma (NHL) is diffuse large B-cell lymphoma (DLBCL). Although lymph nodes are the most commonly affected organs compromising 70% of DLBCLs, only 5% of extranodal lymphomas represent skeletal muscle involvement. Specifically, abdominal wall muscle involvement is rare and there are only a few reported cases of DLBCL with this type of muscle involvement. Painful abdominal mass was the main presenting symptom in these reported cases.

CASE

We are reporting a relapsed DLBCL with abdominal wall muscle involvement in a 65-year-old male, presenting with a discomfort and heaviness sensation in the right iliac region with no associated pain.

CONCLUSION

A rare case of DLBCL with recurrence in the abdominal wall muscles as painless masses was reported in this case report. To our knowledge, it is considered the fourth reported in the medical literature. It shows the importance of the diagnostic process that combines imaging with histological examination and immune stains for accurate diagnosis.

Panhypopituitarism in a Patient with Burkitt Lymphoma: A Diagnostic and Therapeutic Challenge

Pituitary infiltration by systemic lymphoma is an exceedingly rare occurrence. Given its high mortality rate, it is crucial to recognize its clinical, biochemical and radiological features in order to provide timely intervention. We present the case of a 26-year-old male with a history of human immunodeficiency virus (HIV) infection who presented to the hospital with severe anemia, persistent fever, weight loss and diarrhea over the previous 4 months. Physical examination revealed a compromised general condition, fever, pallor, hepatomegaly and lymphadenopathy. Cervical lymph node biopsy confirmed Burkitt lymphoma (BL). During hospitalization, the patient developed polyuria, polydipsia, hypernatremia, fluid-resistant hypotension and hypoglycaemia. Corticosteroid therapy was initiated due to suspected adrenal insufficiency, resulting in clinical improvement but exacerbation of polyuria and hypernatremia. Plasma and urinary osmolarity confirmed arginine vasopressin deficiency, and assessment of anterior pituitary reserve revealed hypopituitarism, necessitating hormonal replacement therapy. Sellar magnetic resonance imaging with contrast revealed pituitary infiltration. The patient subsequently developed septic shock and died. BL accounts for approximately 10% of the cases of pituitary infiltration associated with lymphoma. Clinical presentation is heterogeneous, with panhypopituitarism often serving as the initial manifestation. Sellar magnetic resonance imaging plays a pivotal role in the differential diagnosis. Management typically entails chemotherapy, immunotherapy, radiation and hormonal replacement therapy. This case report describes a patient with BL and HIV infection who developed panhypopituitarism due to pituitary infiltration, an exceedingly rare presentation considered a medical emergency.

A Multicenter Study of Clinicopathology and Immunohistochemical Distinction between Adult and Pediatric Large B-Cell Lymphoma

Introduction: Pediatric DLBCL is considered a homogenous group and has superior outcomes compared to adults. This study investigated the clinical pathology and immunohistochemical distinction between adult and pediatric large B-cell lymphoma. Methods: A cross-sectional study of 314 NHLs with the morphology of diffuse pattern, large B-cell, and CD20 expression was investigated. Results: Of 314 cases, there were 6 cases of pleomorphic MCL (all in adults), 19 cases of Burkitt lymphoma (all in children), and 289 cases of DLBCL. Pediatric DLBCL had many striking differences: More frequency in extra-nodal sites; a higher proportion of centroblastic morphology; a predominance of GCB-type; a high proliferation rate; an infrequency of Bcl2 protein expression, and a lack of double-expresser lymphoma. Conclusions: Our study demonstrated the significant biological differences between adult and pediatric DLBCL.

Phosphorylation of PBK/TOPK Tyr74 by JAK2 promotes Burkitt lymphoma tumor growth

Burkitt lymphoma (BL), which is characterized by high invasiveness, is a subgroup of non-Hodgkin lymphoma. Although BL is regarded as a highly curable disease, especially for children, some patients unfortunately still do not respond adequately. The understanding of the etiology and molecular mechanisms of BL is still limited, and targeted therapies are still lacking. Here, we found that T-LAK cell-derived protein kinase (TOPK) and phosphorylated Janus kinase 2 (p-JAK2) are highly expressed in the tissues of BL patients. We report that TOPK directly binds to and is phosphorylated at Tyr74 by JAK2. Histone H3, one of the downstream targets of TOPK, is also phosphorylated in vivo and in vitro. Furthermore, we report that the phosphorylation of TOPK at Tyr74 by JAK2 plays a vital role in the proliferation of BL cells and promotes BL tumorigenesis in vivo. Phosphorylation of TOPK at Tyr74 by JAK2 enhances the stability of TOPK. Collectively, our results suggest that the JAK2/TOPK/histone H3 axis plays a key role in the proliferation of BL cells and BL tumorigenesis in vivo.

Gut and liver involvement in pediatric hematolymphoid malignancies

Hematolymphoid malignancies are common neoplasms in childhood. The involvement of the gastrointestinal (GI) tract, liver, biliary system, pancreas, and peritoneum are closely interlinked and commonly encountered. In leukemias, lymphomas, and Langerhans cell histiocytosis (LCH), the manifestations result from infiltration, compression, overwhelmed immune system, and chemotherapy-induced drug toxicities. In acute leukemias, major manifestations are infiltrative hepatitis, drug induced gastritis, neutropenic typhlitis and chemotherapy related pancreatitis. Chronic leukemias are rare. Additional presentation in lymphomas is cholestasis due to infiltration or biliary obstruction by lymph nodal masses. Presence of ascites needs a thorough workup for the underlying pathophysiology that may modify the therapy and affect the outcome. Uncommon hematolymphoid malignancies are primary hepatic, hepatosplenic, and GI lymphomas which have strict definitions. In advanced diseases with extensive spread, it may be impossible to distinguish these diseases from the primary site of origin. LCH produces biliary strictures that mimic as sclerosing cholangitis. Liver infiltration is associated with poor liver recovery even after chemotherapy. The heterogeneity of gut and liver manifestations in hematolymphoid malignancies has a clinical impact on their management. Though chemotherapy is the mainstay of therapy in all hematolymphoid malignancies, debulking surgery and radiotherapy have an adjuvant role in specific clinical scenarios. Rare situations presenting as liver failure or end-stage liver disease require liver transplantation. At their initial presentation to a primary care physician, given the ambiguity in clinical manifestations and the prognostic difference with time-bound management, it is vital to recognize them early for optimal outcomes. Pooled data from robust registries across the world is required for better understanding of these complications.

Primary ovarian Burkitt's lymphoma presentation in a young woman: A case report

INTRODUCTION AND IMPORTANCE

Burkitt's lymphoma is one of the fastest growing human cancers and it needs a rapid diagnosis.

CASE PRESENTATION

A young woman presented to our institution with acute abdominal pain, tenderness and constipation. Ultrasound reported a right ovarian mass; at laparoscopy, we discovered ascites, peritoneal carcinomatosis and a voluminous pelvic mass.

CLINICAL DISCUSSION

Diagnosis was confirmed as non-Hodgkin sporadic Burkitt's lymphoma: the careful workup was the key to initiate multiagent chemotherapy.

CONCLUSION

Primary ovarian Burkitt's lymphoma, in a young woman in a non-endemic zone, is a rarity that represents a strong diagnostic challenge, but rapid identification can lead the patient to appropriate therapies and improvement of prognosis.

Transcriptome integration analysis and specific diagnosis model construction for Hodgkin's lymphoma, diffuse large B-cell lymphoma, and mantle cell lymphoma

Transcriptome differences between Hodgkin's lymphoma (HL), diffuse large B-cell lymphoma (DLBCL), and mantle cell lymphoma (MCL), which are all derived from B cell, remained unclear. This study aimed to construct lymphoma-specific diagnostic models by screening lymphoma marker genes. Transcriptome data of HL, DLBCL, and MCL were obtained from public databases. Lymphoma marker genes were screened by comparing cases and controls as well as the intergroup differences among lymphomas. A total of 9 HL marker genes, 7 DLBCL marker genes, and 4 MCL marker genes were screened in this study. Most HL marker genes were upregulated, whereas DLBCL and MCL marker genes were downregulated compared to controls. The optimal HL-specific diagnostic model contains one marker gene (MYH2) with an AUC of 0.901. The optimal DLBCL-specific diagnostic model contains 7 marker genes (LIPF, CCDC144B, PRO2964, PHF1, SFTPA2, NTS, and HP) with an AUC of 0.951. The optimal MCL-specific diagnostic model contains 3 marker genes (IGLV3-19, IGKV4-1, and PRB3) with an AUC of 0.843. The present study reveals the transcriptome data-based differences between HL, DLBCL, and MCL, when combined with other clinical markers, may help the clinical diagnosis and prognosis.

Principal component analysis of blood microRNA datasets facilitates diagnosis of diverse diseases

Early, ideally pre-symptomatic, recognition of common diseases (e.g., heart disease, cancer, diabetes, Alzheimer’s disease) facilitates early treatment or lifestyle modifications, such as diet and exercise. Sensitive, specific identification of diseases using blood samples would facilitate early recognition. We explored the potential of disease identification in high dimensional blood microRNA (miRNA) datasets using a powerful data reduction method: principal component analysis (PCA). Using Qlucore Omics Explorer (QOE), a dynamic, interactive visualization-guided bioinformatics program with a built-in statistical platform, we analyzed publicly available blood miRNA datasets from the Gene Expression Omnibus (GEO) maintained at the National Center for Biotechnology Information at the National Institutes of Health (NIH). The miRNA expression profiles were generated from real time PCR arrays, microarrays or next generation sequencing of biologic materials (e.g., blood, serum or blood components such as platelets). PCA identified the top three principal components that distinguished cohorts of patients with specific diseases (e.g., heart disease, stroke, hypertension, sepsis, diabetes, specific types of cancer, HIV, hemophilia, subtypes of meningitis, multiple sclerosis, amyotrophic lateral sclerosis, Alzheimer’s disease, mild cognitive impairment, aging, and autism), from healthy subjects. Literature searches verified the functional relevance of the discriminating miRNAs. Our goal is to assemble PCA and heatmap analyses of existing and future blood miRNA datasets into a clinical reference database to facilitate the diagnosis of diseases using routine blood draws.

Improving Augmented Human Intelligence to Distinguish Burkitt Lymphoma From Diffuse Large B-Cell Lymphoma Cases

OBJECTIVES

To assess and improve the assistive role of a deep, densely connected convolutional neural network (CNN) to hematopathologists in differentiating histologic images of Burkitt lymphoma (BL) from diffuse large B-cell lymphoma (DLBCL).

METHODS

A total of 10,818 images from BL (n = 34) and DLBCL (n = 36) cases were used to either train or apply different CNNs. Networks differed by number of training images and pixels of images, absence of color, pixel and staining augmentation, and depth of the network, among other parameters.

RESULTS

Cases classified correctly were 17 of 18 (94%), nine with 100% of images correct by the best performing network showing a receiver operating characteristic curve analysis area under the curve 0.92 for both DLBCL and BL. The best performing CNN used all available training images, two random subcrops per image of 448 × 448 pixels, random H&E staining image augmentation, random horizontal flipping of images, random alteration of contrast, reduction on validation error plateau of 15 epochs, block size of six, batch size of 32, and depth of 22. Other networks and decreasing training images had poorer performance.

CONCLUSIONS

CNNs are promising augmented human intelligence tools for differentiating a subset of BL and DLBCL cases.

Educational Case: Extranodal NK/T-Cell Lymphoma, Nasal Type

The following fictional case is intended as a learning tool within the Pathology Competencies for Medical Education (PCME), a set of national standards for teaching pathology. These are divided into three basic competencies: Disease Mechanisms and Processes, Organ System Pathology, and Diagnostic Medicine and Therapeutic Pathology. For additional information, and a full list of learning objectives for all three competencies, seehttp://journals.sagepub.com/doi/10.1177/2374289517715040.¹

Intraoral EBV-positive sporadic Burkitt lymphoma in an elderly patient with bilateral presentation

Sporadic Burkitt lymphoma (SBL) is a variant of Burkitt lymphoma that occurs worldwide, affecting mainly children and young adults. Association with Epstein-Barr virus (EBV) can be identified in approximately 20-30% of cases. Herein we described a case of a 63-year-old male presenting intraoral bilateral mandibular swelling, subjacent to fixed dental prosthesis, with one month of duration. Incisional biopsies were performed, and after two days, the patient was hospitalized due to malaise and breathing difficulty, and died after a week when an abdominal tumor was detected. The mandibular biopsies revealed a diffuse proliferation of medium-sized monomorphic atypical lymphoid cells exhibiting numerous mitoses and areas of "starry-sky" pattern. The tumor showed immunohistochemical positivity for CD20, CD10, Bcl-6, and Ki-67 (≈ 100%); it was negative for CD3, Bcl-2, Vs38c, and MUM-1. Positivity for EBV was found by in situ hybridization. The final diagnosis was intraoral SBL positive for EBV. Clinical, morphological and molecular criteria are necessary for the correct diagnosis of aggressive B-cell neoplasms positive for EBV in elderly patients.

Age-Related Gliosis Promotes Central Nervous System Lymphoma through CCL19-Mediated Tumor Cell Retention

How lymphoma cells (LCs) invade the brain during the development of central nervous system lymphoma (CNSL) is unclear. We found that NF-κB-induced gliosis promotes CNSL in immunocompetent mice. Gliosis elevated cell-adhesion molecules, which increased LCs in the brain but was insufficient to induce CNSL. Astrocyte-derived CCL19 was required for gliosis-induced CNSL. Deleting CCL19 in mice or CCR7 from LCs abrogated CNSL development. Two-photon microscopy revealed LCs transiently entering normal brain parenchyma. Astrocytic CCL19 enhanced parenchymal CNS retention of LCs, thereby promoting CNSL formation. Aged, gliotic wild-type mice were more susceptible to forming CNSL than young wild-type mice, and astrocytic CCL19 was observed in both human gliosis and CNSL. Therefore, CCL19-CCR7 interactions may underlie an increased age-related risk for CNSL.

BURKITT LYMPHOMA IN GASTROINTESTINAL TRACT: A REPORT OF TWO CASES

Burkitt lymphoma, a type of non-Hodgkin B-cell lymphoma, is the fastest growing human cancer, presenting pathologically with a ‘starry sky’ pattern. It is most often found in the abdomen and the jaw, however, localization in the abdomen other than the ileocecal area is very rare and described only in a handful of cases. Standard treatment consists of initial tumor cytoreduction followed by intense chemotherapy. Most of the relapses occur within one year of the diagnosis, while the 5-year survival is around 80%. We present two cases which are specific for unusual location of Burkitt lymphoma in the colon and stomach, in immunocompetent patients with negative Epstein-Barr virus tests. Also, one of the patients presented is one of the oldest ever reported with abdominal Burkitt lymphoma, while the other patient is an example of diagnostic difficulties in distinguishing Burkitt lymphoma from similar lymphomas. Due to the rapidly growing tumors and urgent need for cytoreductive surgery, it is crucial to consider the diagnosis of Burkitt lymphoma even in atypical localizations or absence of the common risk factors associated with Burkitt lymphoma.

Clinicopathological Analysis of B Cell Lymphomas, Unclassifiable; with Features Intermediate Between Diffuse Large B-Cell Lymphoma and Burkitt Lymphoma in a Tertiary Care Hospital in Southern India

B-cell lymphomas, unclassifiable; with features intermediate between large B-cell lymphoma and Burkitt lymphoma (BCLu-DLBCL/BL) is a new entity included in the recent World Health Organization (WHO) classification of Tumours of the Hematopoietic and Lymphoid Tissues (2008) to overcome the problems of difficulty in classifying certain lymphomas having overlapping morphological, immunophenotypical and genetic features. To study the clinicopathological profile of BCLu-DLBCL/BL. Cross-sectional study over 3 year period in the Haematology section of Department of Pathology in a large teaching hospital in Southern India from January 2011 to December 2013. All the cases reported as BCLu-DLBCL/BL were collected and the clinical, morphological and immunohistochemical parameters were analyzed. Descriptive statistics. There were seven cases, four males and three females, of age ranging from 20 to 70 years. Five cases had extranodal involvement. Four cases had Burkitt morphology with strong Bcl2 positivity and absent CD10 expression. One case had the morphology and immunophenotype that of typical BL, along with strong positivity to Bcl2 suggesting a double hit hypothesis. Two cases had morphology and immunophenotype of BL with low Ki 67. Three patients on follow up had adverse outcome. BCLu-DLBCL/BL, a provisional category in WHO 2008 is useful in classifying the cases not meeting the criteria for classical BL or DLBCL. Each of these cases was interesting with different sites of involvement, different morphological features and immunophenotype with most of the patients on follow up ending with a grave prognosis.

Disruption of HLA class II antigen presentation in Burkitt lymphoma: implication of a 47,000 MW acid labile protein in CD4+ T-cell recognition

While Burkitt lymphoma (BL) has a well-known defect in HLA class I-mediated antigen presentation, the exact role of BL-associated HLA class II in generating a poor CD4(+) T-cell response remains unresolved. Here, we found that BL cells are deficient in their ability to optimally stimulate CD4(+) T cells via the HLA class II pathway. This defect in CD4(+) T-cell recognition was not associated with low levels of co-stimulatory molecules on BL cells, as addition of external co-stimulation failed to elicit CD4(+) T-cell activation by BL. Further, the defect was not caused by faulty antigen/class II interaction, because antigenic peptides bound with measurable affinity to BL-associated class II molecules. Interestingly, functional class II-peptide complexes were formed at acidic pH 5·5, which restored immune recognition. Acidic buffer (pH 5·5) eluate from BL cells contained molecules that impaired class II-mediated antigen presentation and CD4(+) T-cell recognition. Biochemical analysis showed that these molecules were greater than 30,000 molecular weight in size, and proteinaceous in nature. In addition, BL was found to have decreased expression of a 47,000 molecular weight enolase-like molecule that enhances class II-mediated antigen presentation in B cells, macrophages and dendritic cells, but not in BL cells. These findings demonstrate that BL likely has multiple defects in HLA class II-mediated antigen presentation and immune recognition, which may be exploited for future immunotherapies.

Burkittts lymphoma revisited: series of three cases with varied clinical presentation

Burkitt's lymphoma is a form of non-Hodgkin's B-cell lymphoma with more than one identifiable variant. This tumour was first noted in Africans. The sporadic form most commonly presents with abdominal lymph node involvement. This tumour predominently affects children and is probably the fastest growing tumours in humans, with exuberant proliferation. We here in report on three patients from our experience both adult and children who presented with varied clinical features.

Challenges in lymphoma diagnosis in HIV positive patients in the South African setting

An increase in high grade B-cell lymphomas has been noted in HIV infection. Sub-Saharan Africa is the epicentre of the epidemic and in Gauteng, South Africa >90% of patients with high grade lymphoma tested positive for HIV infection. The diagnosis of lymphoma may be challenging in HIV because of reactive conditions which mimic lymphomas, the atypical clinical presentation and the atypical histological findings. The WHO classification divides lymphomas into discrete categories. Despite this, tumours in HIV positive patients commonly show atypical morphological, immunophenotypic, molecular and cytogenetic features, making exact classification difficult. This has lead to an increase in the diagnosis of the highly aggressive B-cell lymphoma, unclassifiable with features intermediate between DLBCL and BL. It appears likely that HIV-associated lymphomas represent a continuum of disease.

Burkitt's Lymphoma in a Pregnant Woman: Case Report and Review of the Literature

Burkitt's lymphoma (BL) is an aggressive B-cell malignancy with very high proliferation rate, more common in males than females. Here, we describe a case of Burkitt's lymphoma in a 24-week pregnant woman with cervical and abdominal involvement. The common genetic event of virtually all BL is a reciprocal chromosomal translocation involving the proto-oncogene MYC and one of the Ig gene heavy or light chain loci. Supportive treatment was administered until early delivery, after which the patient was treated according to protocol LMB96. Pregnancy and tumorogenesis share some important events such as immunologic tolerance, angiogenesis, and editing the host immune response. Little is known about the relationship between these events in pregnancy and in tumorogenesis.

Gastrointestinal B-cell lymphomas: From understanding B-cell physiology to classification and molecular pathology

The gut is the most common extranodal site where lymphomas arise. Although all histological lymphoma types may develop in the gut, small and large B-cell lymphomas predominate. The sometimes unexpected finding of a lymphoid lesion in an endoscopic biopsy of the gut may challenge both the clinician (who is not always familiar with lymphoma pathogenesis) and the pathologist (who will often be hampered in his/her diagnostic skill by the limited amount of available tissue). Moreover, the past 2 decades have spawned an avalanche of new data that encompasses both the function of the reactive B-cell as well as the pathogenic pathways that lead to its neoplastic counterpart, the B-cell lymphoma. Therefore, this review aims to offer clinicians an overview of B-cell lymphomas in the gut, and their pertinent molecular features that have led to new insights regarding lymphomagenesis. It addresses the question as how to incorporate all presently available information on normal and neoplastic B-cell differentiation, and how this knowledge can be applied in daily clinical practice (e.g., diagnostic tools, prognostic biomarkers or therapeutic targets) to optimalise the managment of this heterogeneous group of neoplasms.

Gastric Burkitt's lymphoma in a child: A rare case

Burkitt's lymphoma (BL) is a high-grade lymphoma which represents 8-10% of all tumors in individuals younger than 15 years old. It may occur as an abdominal tumor, which in rare cases may include gastric mucosa, although in most cases, the tumor is located in the ileum or cecum. Primary gastric lymphoma constitutes as low as 1.48% of all gastric cancers in children. In this study, we described a case of gastric BL in a 4-year-old child, presenting discontinuous abdominal pain, weight loss, constipation and irritability. Despite its rarity in children, this tumor should be treated aggressively and long-term survival has been reported.

A case of B-cell lymphoma, unclassifiable, with features intermediate between diffuse large B-cell lymphoma and Burkitt lymphoma in a Korean child

B-cell lymphoma, unclassifiable, with features intermediate between diffuse large B-cell lymphoma (DLBCL) and Burkitt lymphoma (BL) (intermediate DLBCL/BL), is a heterogeneous group with some features resembling DLBCL and others resembling BL. Here, we report a case of intermediate DLBCL/BL in a Korean child. A 2-yr-old male was admitted for evaluation and management of left hip pain. Immunohistochemistry of a biopsy of the femur neck revealed tumor cells positive for CD20, CD10, BCL2, BCL6, and Ki67. A bone marrow (BM) aspirate smear revealed that 49.3% of all nucleated cells were abnormal lymphoid cells, composed of large- and medium-sized cells. Immunophenotyping of the neoplastic cells revealed positivity for CD19, CD10, CD20, and sIg lambda and negativity for CD34, Tdt, and myeloperoxidase (MPO). Cytogenetic and FISH analyses showed a complex karyotype, including t(8;14)(q24.1;q32) and IGH-MYC fusion. Intensive chemotherapy was initiated, including prednisone, vincristine, L-asparaginase, daunorubicin, and central nervous system prophylaxis with intrathecal methotrexate (MTX) and cytarabine. One month after the initial diagnosis, BM examination revealed the persistent of abnormal lymphoid cells; cerebrospinal fluid cytology, including cytospin, showed atypical lymphoid cells. The patient was treated again with cyclophosphamide, vincristine, prednisone, adriamycin, MTX, and intrathecal MTX and cytarabine. The patient died of sepsis 5 months after the second round of chemotherapy.

Aggressive B cell lymphomas of the gastrointestinal tract: clinicopathologic and genetic analysis

Aggressive B cell lymphomas of the gastrointestinal tract include Burkitt lymphoma (BL), diffuse large B cell lymphoma, and B cell lymphoma, unclassifiable, with features intermediate between DLBCL and BL. To investigate the clinical characters of DLBCL/BL of the gastrointestinal (GI) tract, 101 cases of aggressive B cell lymphoma of the GI tract were analyzed by immunohistochemistry and fluorescence in situ hybridization (FISH) using break apart probe for c-MYC gene. For cases with c-MYC rearrangement, additional FISH studies with MYC/IgH fusion probe, BCL2 break apart probe, and BCL6 break apart probe were performed. MYC rearrangement was detected in 23 of 101 cases of aggressive B cell lymphomas (22.5%). The cases with MYC rearrangement were divided into 14 BL, three DLBCL/BL, and six DLBCL. One of the three DLBCL/BL had double translocation for MYC and BCL6 gene. Clinically, DLBCL/BL of the GI tract was more akin to Burkitt lymphoma than it is to GI tract DLBCL with c-MYC rearrangement. The overall prognosis of patients with DLBCL/BL was the worst among aggressive B cell lymphomas. DLBCL/BL is uncommon category of B cell lymphoma in the GI tract with aggressive clinical course despite of intensive chemotherapy.

Expression of JL1 in Burkitt lymphoma is associated with improved overall survival

JL1 is a novel molecule expressed in the surface of hematopoietic precursor cells, but not on any other mature human tissue. Accordingly, JL1 is expressed in acute lymphoblastic leukemia (ALL) cells and can be used both for specific diagnosis and as a target for treatment. However, expression of JL1 by lymphomas has not been thoroughly assessed. Burkitt lymphoma is a potentially curable aggressive lymphoma, but prognostic markers that stratify risk have not been established. We therefore assayed JL1 expression in Burkitt lymphoma patients to assess its value as a prognostic marker for this disease. Tissue microarray blocks of formalin-fixed paraffin-embedded tissue samples from patients with Burkitt lymphoma and other B-cell lymphomas, at the Asan Medical Center and Seoul National University Hospital from January 1998 to December 2008 were immunohistochemically assayed using a mouse monoclonal antibody against JL1. We found that 30.2% of Burkitt lymphoma samples, but no other lymphoma samples, were positive for JL1. JL-1 expression was significantly correlated with patient survival (P = 0.022), but not with other clinical manifestations of the disease, with 91.6% of JL1-positive patients achieving complete remission in response to chemotherapy and 6.25% experiencing disease recurrence. JL1 positivity was significantly correlated with prolonged overall survival by both Kaplan-Meier survival (P = 0.035) and Cox proportional hazard model (P = 0.043) analysis. JL1 expression in Burkitt lymphoma was positively correlated with overall survival and better response to chemotherapy, suggesting that JL1 may be a prognostic marker for risk stratification in these patients.

Burkitt lymphoma and atypical Burkitt or Burkitt-like lymphoma: should these be treated as different diseases?

Burkitt lymphoma (BL) is a mature B-cell non-Hodgkin lymphoma with an aggressive clinical course. Since the advent of short, intensive, multiagent chemoimmunotherapy regimens, it has carried a favorable prognosis. BL has been rather well characterized, whereas the other lymphomas morphologically resembling it are more heterogeneous. The cases classified as atypical BL/Burkitt-like lymphoma by the 2001 World Health Organization (WHO) Classification of Tumors of Hematopoietic and Lymphoid Tissue were thought to represent a continuum between BL and diffuse large B-cell lymphoma (DLBCL). The optimal therapeutic strategy for this provisional entity was not definitively established. However, recent incorporation of molecular genetic data into the 2008 WHO Classification has allowed further refinements with significant therapeutic implications, including the designation of a new provisional entity, "B-cell lymphoma, unclassifiable, with features intermediate between BL and DLBCL." This review presents a comprehensive overview of the previously designated provisional entity of atypical BL/BLL in conjunction with a detailed comparison with BL and DLBCL.

Burkitt lymphoma: pathogenesis and immune evasion

B-cell lymphomas arise at distinct stages of cellular development and maturation, potentially influencing antigen (Ag) presentation and T-cell recognition. Burkitt lymphoma (BL) is a highly malignant B-cell tumor associated with Epstein-Barr Virus (EBV) infection. Although BL can be effectively treated in adults and children, leading to high survival rates, its ability to mask itself from the immune system makes BL an intriguing disease to study. In this paper, we will provide an overview of BL and its association with EBV and the c-myc oncogene. The contributions of EBV and c-myc to B-cell transformation, proliferation, or attenuation of cellular network and immune recognition or evasion will be summarized. We will also discuss the various pathways by which BL escapes immune detection by inhibiting both HLA class I- and II-mediated Ag presentation to T cells. Finally, we will provide an overview of recent developments suggesting the existence of BL-associated inhibitory molecules that may block HLA class II-mediated Ag presentation to CD4+ T cells, facilitating immune escape of BL.