CHILDHOOD LYMPHOMA RESEMBLING "BURKITT TUMOR" IN THE UNITED STATES

Epstein-Barr virus and Burkitt lymphoma

In 1964, a new herpesvirus, Epstein-Barr virus (EBV), was discovered in cultured tumor cells derived from a Burkitt lymphoma (BL) biopsy taken from an African patient. This was a momentous event that reinvigorated research into viruses as a possible cause of human cancers. Subsequent studies demonstrated that EBV was a potent growth-transforming agent for primary B cells, and that all cases of BL carried characteristic chromosomal translocations resulting in constitutive activation of the c-MYC oncogene. These results hinted at simple oncogenic mechanisms that would make Burkitt lymphoma paradigmatic for cancers with viral etiology. In reality, the pathogenesis of this tumor is rather complicated with regard to both the contribution of the virus and the involvement of cellular oncogenes. Here, we review the current understanding of the roles of EBV and c-MYC in the pathogenesis of BL and the implications for new therapeutic strategies to treat this lymphoma.

Epidemiology: clues to the pathogenesis of Burkitt lymphoma

The two major epidemiological clues to the pathogenesis of Burkitt lymphoma (BL) are the geographical association with malaria--BL incidence relates to the malaria transmission rate--and early infection by Epstein-Barr virus (EBV). Both agents cause B cell hyperplasia, which is almost certainly an essential component of lymphomagenesis in BL. The critical event in lymphomagenesis is the creation of a MYC translocation, bringing the MYC gene into juxtaposition with immunoglobulin genes and causing its ectopic expression, thereby driving the proliferation of BL cells. It is highly likely that such translocations are mediated by the activation-induced cytidine deaminase (AID) gene, which is responsible for hypervariable region mutations as well as class switching. Stimulation of the Toll-like receptor 9 by malaria-associated agonists induces AID, providing a mechanism whereby malaria could directly influence BL pathogenesis. EBV-containing cells must reach the memory cell compartment in order to survive throughout the life of the individual, which probably requires traversal of the germinal centre. Normally, cells that do not produce high affinity antibodies do not survive this passage, and are induced to undergo apoptosis. EBV, however, prevents this, and in doing so may also enhance the likelihood of survival of rare translocation-containing cells.

Denis Burkitt and the African lymphoma

Burkitt lymphoma has provided a model for the understanding of the epidemiology, the molecular abnormalities that induce tumours, and the treatment of other lymphomas. It is important to remember that the early phases of this work were conducted in Africa where today, unfortunately, the disease usually results in death because of limited resources, even though most children in more developed countries are cured. This must be changed. In addition, it is time to re-explore, with modern techniques, some of the questions that were raised some 50 years ago shortly after Burkitt's first description, as well as new questions that can be asked only in the light of modern understanding of the immune system and the molecular basis of tumor development. The African lymphoma has taught us much, but there is a great deal still to be learned.

The role of Epstein-Barr virus in cancer

Epstein-Barr virus (EBV), discovered > 40 years ago from a Burkitt's lymphoma biopsy, was the first virus to be directly associated with human cancer. EBV has two distinct life cycles in the human host; a lytic form of infection that produces new infectious virions, and a latent form of infection that allows the virus to persist in a dormant state for the lifetime of the host. EBV has evolved a life cycle that mimics the natural differentiation pathway of antigen-activated B cells, giving the virus access to its site of latent infection, the resting memory B cell. By steering infected cells through the various stages of lymphocyte differentiation, EBV is able to enter a cell type suitable for long-term latent persistence and periodic reactivation. However, its presence in various stages of B-cell development, and its ability to infect certain epithelial cells, can have pathogenic consequences, and can contribute to the development of a diverse group of lymphomas and carcinomas. The presence of EBV in the tumour cells of EBV-associated cancers might provide a basis for specific therapy. This article focuses on the contributions that the virus may play in different types of human cancer, particularly Burkitt's lymphoma, Hodgkin's lymphoma, lymphomas and lymphoproliferative diseases in the immunocompromised, and nasopharyngeal and gastric carcinoma.

Burkitt's lymphoma presenting as a rapidly growing thyroid mass

A 53-year-old man was admitted to the hospital because of tracheal compressive symptoms from a rapidly expanding thyroid mass. The patient first noticed the nodule less than a week prior to admission. Thyroid tests were normal. A fine-needle aspiration (FNA) biopsy showed a monotonous population of intermediate-sized lymphoid cells with scant cytoplasm suspicious for lymphoma. Twelve hours later an emergent computed tomography (CT) scan confirmed left tracheal deviation with compression, however, there were no signs of tumor invasion. The patient received emergent CHOP (clophosphamide, adriamycin, vincristine, prednisone) and rituxan therapy. His mass completely resolved within 36 hours. Bone marrow biopsy provided the final diagnosis of stage IV Burkitt's lymphoma and his therapy was changed to hyper CVAD-R chemotherapy (cytoxan, vincristine, adriamycin, dexamethasone, rituxan). The patient's hospital course was complicated by tumor lysis syndrome that was managed by hydration and allopurinol. To our knowledge, this is only the second reported case of Burkitt's lymphoma presenting as a thyroid mass. His presentation highlights the urgency in diagnosis and provides an opportunity to review a rare type of primary thyroid lymphoma.

Pediatric Burkitt's lymphoma: CT findings

PURPOSE

To review and analyze all CT scans of the cases of Burkitt's lymphoma (BL) in children diagnosed in our institution.

MATERIALS AND METHODS

A retrospective analysis of 33 children with BL between the years 2003 and 2005 seen in our institution was undertaken. Twenty-nine male and four female patients from age 3 to 16 years (with a mean age 5.9 years) were reviewed.

RESULTS

The gastrointestinal tract was involved in 19 patients (57.5%), kidneys in 9 (27.2%), peritoneum in 8 (24.2%), liver in 4 (12.1%), spleen in 3 (9%), adrenals in 3 (9%), and pancreas in 1 patient (3%). Extra-nodal head and neck involvement was seen in eight patients (24.2%). Bone involvement in four (12.1%), lung in three (9%), heart in two (6%), skin in two (6%), and testis in one (3%) of these patients. Abdominal lymph nodes were enlarged in 21 children (63.6%), while cervical lymph nodes were enlarged in 8 (24.2%).

CONCLUSION

CT proved to be an invaluable tool in the characterization of the disease processes in these children. In addition, it provided us with useful information about the anatomical distribution, patterns of involvement, as well as complications of BL.

Burkitt's lymphoma: new insights into molecular pathogenesis

The World Health Organisation classification reports three subcategories of Burkitt's lymphoma (BL)--endemic, non-endemic, and immunodeficiency associated--proposed to reflect the major clinical and genetic subtypes of this disease. These different types of BL have been reviewed and studied by immunohistochemistry and molecular methods. The results point out the heterogeneity of BL and suggest that AIDS related BL may have a different pathogenesis from that of classic BL.

Burkitt's lymphoma: historical background and recent insights into classification and pathogenesis

In this paper, the authors evaluate the historical evolution of the definition of Burkitt's lymphoma (BL) and of its clinicoepidemiological (endemic, sporadic, and acquired immunodeficiency syndrome-associated BL) and morphological variants. On the basis of the morphological, immunologic, genetic, and clinical characteristics of these tumors, the authors also emphasize the importance of precise disease definitions for biological and epidemiological studies. These principles were used in accordance with the Revised European-American classification of lymphoid neoplasms (REAL), which proposed that disease entities should be defined by a constellation of pathobiological and clinical features.

A case of Burkitt's lymphoma that presented initially with resorption of alveolar bone

A 16-year-old male was evaluated for a 1-month history of alveolar bone resorption, which had been treated with endodontics by a neighborhood dentist. Intraoral examination showed slight gingival swelling and teeth mobility. However, no tumor mass was seen. The panoramic image showed resorption of alveolar bone and loss of teeth lamina dura. Because he complained of general fatigue, he was introduced to the internist. Biopsies of gingiva and bone marrow aspiration revealed a massive proliferation of lymphoblasts expressing CD10, 19, 20 and HLA-DR antigens on the surface. Their karyotypes were abnormal; 46, XY, t (8;14) (q24;q32). Accordingly, he was diagnosed as Burkitt's lymphoma, and received intensive chemotherapy which relieved his symptoms and decreased his tumor. However, his disease soon became refractory to chemotherapy, and he died 11 weeks after the onset.

Genetic alterations of the retinoblastoma-related gene RB2/p130 identify different pathogenetic mechanisms in and among Burkitt's lymphoma subtypes

Alterations of cell cycle-associated genes probably contribute to the pathogenesis of Burkitt's Lymphoma (BL), in addition to c-myc translocation. Mutations disrupting the nuclear localization signal of the retinoblastoma-related gene RB2/p130 have been documented recently in BL cell lines and primary tumors. Given the importance of the RB2/p130 gene in controlling cell growth, mutations of this gene may result in uncontrolled cell proliferation. We tested the expression and genomic organization of the RB2/p130 gene in relation to the proliferative features of a series of BL samples collected from the endemic and sporadic regions, regardless of whether the samples were acquired immune deficiency syndrome (AIDS)-related. The expression of the Rb2/p130, p107, and cell proliferation-related proteins (cyclin A and B) was determined by immunohistochemistry. The structures of exons 19 through 22 of the RB2/p130 gene, encoding for the B domain and C terminus, were analyzed by polymerase chain reaction (PCR) analysis and single-strand conformation polymorphism (SSCP) technique. The direct PCR products were sequenced to identify the actual mutations. Our results suggest that BL is composed of a mixture of molecular types with distinct genetic and phenotypic patterns, probably resulting from different pathogenetic mechanisms. In endemic BL, the RB2/p130 gene is mutated in most of the cases, and the protein is restricted to the cytoplasm. In AIDS-related BL, high levels of nuclear expression of the wild-type pRb2/p130, p107, and cell proliferation-related proteins were detected. This finding is in line with the molecular mechanisms observed in virus-linked oncogenesis. Sporadic BLs were mainly characterized by the low nuclear values of the wild-type pRb2/p130 and, conversely, the high values of p107. The increased cell proliferation due to different alterations of cell growth control by Rb-related proteins may be the first step in lymphomagenesis, during which additional genetic changes, including missense mutations of c-myc, may subsequently occur.

In vivo models for Epstein-Barr virus (EBV)-associated B cell lymphoproliferative disease (BLPD)

EBV infects B lymphocytes in vivo and establishes a life-long persistent infection in the host. The latent infection is controlled by EBV-specific MHC class 1-restricted CTL. Immunosuppression reduces CTL activity, and this facilitates outgrowth of EBV+ve B cell lymphoproliferative disease (BLPD). BLPD are aggressive lesions with high mortality. This review presents some key facets in the development of EBV-associated BLPD and in vivo studies on its pathogenesis. The animal models used to date include the common marmoset (Callithrix jacchus), the cottontop tamarin (Saguinus oedipus oedipus), rhesus monkey, murine herpesvirus 68 (MHV68), and the severe combined immunodeficient (scid) mouse, each of which has been used to address particular aspects of EBV biology and BLPD development. Scid mice inoculated i.p. with PBMC from EBV-seropositive individuals develop EBV+ve BLPD-like tumours. Thus this small animal model (hu-PBMC-scid) is currently used by many laboratories to investigate EBV-associated diseases. We and others have studied BLPD pathogenesis in the hu-PBMC-scid model and shown that EBV+ve B cells on their own do not give rise to tumours in this model without inclusion of autologous T cell subsets in the inoculum. Based on the findings that (1) established tumours do not contain T cells and (2) tumour cells express a variety of B cell growth factors, a stepwise model of lymphomagenesis in the scid mouse model can be defined. Additionally, the hu-PBMC-scid model can be used to assess novel therapeutic regimes against BLPD before introduction into a clinical setting.

Burkitt's lymphoma of the oral cavity in Israel

The clinical presentation of Burkitt's lymphoma in the maxillofacial area is variable. The objective of this study is to review and analyse all cases of Burkitt's lymphoma with oral or maxillofacial involvement diagnosed in our department. A retrospective review of patients with Burkitt's lymphoma in the facial area between the years 1978 and 1997 was undertaken. The patients, 8 male and 5 female, were from 7 to 50 years old (mean 15.3 years). Six patients were Stage I and 7 were Stage II. Five had abdominal involvement and 2 lymph node involvement besides the maxillofacial presentation. Three tumours were in the mandible, 3 in both mandible and maxilla, 2 in the palate, and 5 in the maxilla alone. In 5 patients the tumour presented as a facial swelling, in 3 as an exophytic mass, in 2 as an ulcer, 1 case presented as a hyperplastic lesion, and 2 were periapical lesions. Complaints included pain (7), swelling (5), and sensory disturbance (2). EBV titres were positive in 4 patients. Abdominal involvement was only seen in patients under 12 years old. All patients were treated with chemotherapy, while adjuvant radiotherapy was indicated in 3 cases. Follow-up of 1-20 years revealed a 2-year survival rate of 61.5%. It seems that the Israeli disease is between that of the African and American types, when considering age distribution.

Spinal cord compression resulting from Burkitt's lymphoma in children

We report seven cases of spinal cord compression resulting from Burkitt lymphoma in boys aged 15 years and below. This became manifest clinically as acute or rapidly progressive spinal cord compression. All the patients showed total paraplegia with a sensory loss at thoracic level and sphincter disturbances. Four patients were operated on, the operation permitting exeresis of an epidural tumor. In three cases surgery was followed by chemotherapy. One patient was treated exclusively with chemotherapy. Owing to the effectiveness of chemotherapy, surgery should be considered only in cases of rapid deterioration or for diagnostic purposes.

Epstein-Barr virus as an agent of haematological disease

Epstein-Barr virus (EBV) encodes genes that permit its persistence in human B lymphocytes and genes that ensure its replication in epithelial cells. Immune restraints on the virus are usually so effective that most EBV infections are limited to a minute fraction of B lymphocytes and of epithelial cells. As a result, most EBV infections are never symptomatic. Occasionally, the virus causes disease, often with the cooperation of the immune system or other less characterized cofactors. Infectious mononucleosis, a generally self-limited lymphoproliferative illness common in adolescents and young adults, is due to primary EBV infection and to the brisk cellular immune response it elicits. Lymphoproliferative disorders of EBV-infected B cells arise almost exclusively when cellular immunity is grossly compromised. EBV-positive Burkitt's lymphoma contain a translocated and deregulated c-myc oncogene and EBV-positive non-Hodgkin's lymphomas are characterized by the presence of Reed-Sternberg's and Hodgkin's cells, features that have not been directly linked to EBV. Many recent observations, however, including evidence that virus infection precedes malignant transformation and is often associated with a characteristic pattern of viral gene expression, provide continued interest in the relationship between the virus and these haematological malignancies.

Childhood cancer

BACKGROUND

Cancers of individual organs generally are composed of various histologic types, each with its own frequency and demographic patterns. For childhood cancers in particular, a classification of cancers by histologic type is important for understanding the etiology and progression of the disease.

METHODS

Data from the Surveillance, Epidemiology, and End Results (SEER) Program on 9308 microscopically confirmed malignant neoplasms in children younger than age 15, newly diagnosed during 1973-1987, were made available for analysis. Tumors were grouped histologically according to a classification previously utilized in an international volume of childhood cancer incidence.

RESULTS

The most frequent histologic types were acute lymphocytic leukemia (23.6%), astrocytoma (9.6%), neuroblastoma (6.6%), and Wilms' tumor (6.4%). Acute lymphocytic leukemia accounted for 75% of childhood leukemia. The most common form of Hodgkin's disease was the nodular sclerosing subtype, which was diagnosed in 56% of all cases. Burkitt's and Burkitt-like disease accounted for approximately one third of non-Hodgkin's lymphoma, the sex ratio (male to female) being unusually high (5.7). Among the brain tumors, glioma was of interest because 198 cases (excluded from this analysis) were diagnosed without histologic confirmation--due, no doubt, to their inaccessibility for biopsy because they were located in the brain stem. The most common histologic type of soft tissue sarcoma was rhabdomyosarcoma, which accounted for 51% of the total, more than half of which were of the embryonal type. To the authors' knowledge, this report offers for the first time the relative frequencies of rare types of leukemias, such as megakaryoblastic leukemia, in childhood. This report also includes the frequencies of 21 rarer forms of soft tissue sarcoma. Five forms of childhood cancer had a 5-year relative survival rate of 85% or better. Of the cancers with the poorest outcome, three had relative survival rates of 46.5-49%; the relative survival rate of acute myelogenous leukemia was only 26.4%. The trends in survival over time for 21 types of childhood cancer also are included in this report.

CONCLUSIONS

Further refinements in classification now are available through laboratory techniques utilizing molecular biology, immunology, and cytogenetics, which are of importance in etiologic studies, diagnosis, treatment, and prognosis. It would be important in the future for cancer registries to record the results of relevant laboratory tests for further analysis by subtype.

Immunophenotypic analysis of childhood Burkitt's lymphoma in the West Midlands 1957-1986

AIMS

To analyse the immunophenotype of a large number of non-endemic Burkitt's lymphomas to determine whether a B cell phenotype is consistently recognisable using formalin fixed, paraffin wax embedded archival material and a standard panel of commercially available antibodies.

METHODS

Archival material was obtained from 30 cases of childhood Burkitt's lymphoma registered with the West Midlands Regional Children's Tumour Research Group. These were analysed by a standard avidin biotin complex immunoperoxidase method using antibodies to CD45, CD43, CD30, CD20, CD15, and immunoglobulin heavy and light chains.

RESULTS

There was a high incidence of the CD45RB and CD20 immunophenotypes, with a clearly recognisable B cell lineage even in archival material. IgM was identifiable in 13 of the 23 (56.5%) cases tested. Only three of 17 (18%) cases expressed CD30. Positive membrane staining with CD45RO was observed in two (6.7%) cases.

CONCLUSIONS

A B cell lineage can be identified in Burkitt's lymphoma in formalin fixed, paraffin wax embedded material, even in archival tissue. There was a low incidence of membrane staining with CD45RO which is a potential source of diagnostic confusion.

Non-Hodgkin's lymphomas in children. I. Patterns of disease and classification

Non-Hodgkin's lymphomas (NHL) are part of an overlapping spectrum of lympho-proliferative diseases in childhood. In the first of this 2 part series, the clinicopathological aspects of NHL in childhood are discussed. The rapid progression of disease, the high incidence of micrometastases (over 80%) at diagnosis, and the propensity of hematogenous spread to the bone marrow and the central nervous system (CNS) as well as the clinico-pathologic 'clusters' associated with particular presenting sites distinguish the pediatric forms of disease. Abdominal primary sites most frequently manifest diffuse undifferentiated (Burkitt's or non-Burkitt's) histopathology, B-cell immunophenotype, FAB-L3 cytomorphology and specific karyotypic and/or genotypic alterations of the immuno-globulin genes and the c-myc oncogene. Mediastinal presentation is associated with lymphoblastic histopathology, T-cell immunophenotype and a variety of less consistent karyotypic and genotypic aberrations. Ki-1 lymphoma, a rare subtype of large cell NHL with specific features is often of T cell origin. The requirements for diagnosis, staging and monitoring are presented in the context of the associations between clinico-pathological presentation and subsequent behavior. The most frequent sites of disease progression and relapse are involvement of the bone marrow and the CNS. For Burkitt's lymphoma there is a historic perspective and a description of particular epidemiologic, clinical, virologic, immunophenotypic and genotypic features. Cytogenetic and molecular biologic studies of genomic rearrangements are advancing the understanding of oncogenesis, clonality, lineage, and clinical behavior. The capacity to detect and amplify DNA from submicroscopic disease may contribute to prognostic stratification both at diagnosis and during subsequent monitoring.

Burkitt's lymphoma: a model for clinical oncology

Burkitt's lymphoma, a pathological entity initially described in Africa, is the most common childhood lymphoma in western countries and represents approximately 5% of all adults lymphomas. This high grade small non-cleaved diffuse lymphoma is a model with which to study the relations between cancer and viruses, the chromosomes and the genes. Burkitt's lymphoma is also a model for clinical research which allows evaluation of the dose effect concept with chemotherapy and the role of megatherapy with autologous bone marrow rescue.

Imprint cytology of non-Hodgkin's lymphomas based on a study of 212 immunologically characterized cases: correlation of touch imprints with tissue sections

The classification of non-Hodgkin's lymphomas (NHLs) has been traditionally based on analysis of histologic sections and has been supplemented more recently by immunologic marker studies. It was the purpose of the present study to illustrate, side-by-side, sections and Romanowsky-stained imprints from the same surgical specimen from practically all categories of immunophenotyped NHLs, including rare and atypical variants that were difficult to classify from the histologic sections alone. Our results indicate that imprint cytology may reveal nuclear and cytoplasmic details not discernible in even the best tissue sections and that it may be selectively helpful in contributing to the classification of NHLs. Our results also show that the relative value of imprint cytology in the classification of malignant lymphomas varies greatly among categories. Specifically, we have found that imprints assist in three ways: the recognition of plasmacytoid features in small cell lymphocytic lymphomas, the recognition of plasmacytoid immunoblastic lymphoma, and the differentiation between NHLs which may be difficult to distinguish histologically. These include (1) small lymphocytic lymphoma versus lymphocytic lymphoma of intermediate differentiation, (2) true histiocytic malignancies versus large cell malignant lymphomas with abundant cytoplasm and/or phagocytosis, (3) anaplastic myeloma versus plasmacytoid immunoblastic lymphoma, (4) large noncleaved versus plasmacytoid immunoblastic lymphoma, (5) lymphoblastic lymphoma versus diffuse small cleaved cell lymphoma, and (6) lymphoblastic lymphoma versus small noncleaved cell lymphoma. Lymph node imprints are easy to prepare and readily interpretable by those experienced in the study of abnormal blood and bone marrow films. Their value as an ancillary methodology aimed at optimal accuracy in the classification of NHLs should be recognized.

Burkitt's lymphoma protruding through the anus. Report of an unusual case

A four-year-old boy had a cecoanal intussusception prolapsing through the anus. A 4 x 4 cm cecal tumor served as the leading point of the intussusception. Laparotomy and histology revealed that the tumor was a solitary Burkitt's lymphoma of the cecum. Isolated Burkitt's lymphoma, as presented here, is rare, and such a combination has never been reported. Intussusception prolapsing through the anus and Burkitt's lymphoma are discussed, as well as a possible reason for the rarity of the condition.

Burkitt's lymphoma in the mandible--a case report

Burkitt's lymphoma is a tumour that most often affects the jaws, especially in endemic areas of Africa. In non-endemic areas, the jaws are affected in about 15-18% of cases. A case is presented which demonstrates the significance of jaw lesions in the disease. The history and pathogenesis of the disease also are discussed.

Expression of CR1 and CR2 complement receptors following Epstein-Barr virus infection of Burkitt's lymphoma cell lines

Epstein-Barr virus (EBV) infection of human B lymphocytes involves a specific receptor closely associated with, or identical to, the C3d complement receptor, CR2. Thus, 25 out of 29 EBV-positive Burkitt's lymphoma (BL) cell lines but none of 15 EBV-negative BL lines were found to express C3 receptors. Furthermore, in vitro infection with EBV of six EBV-negative cell lines resulted in the expression of C3 receptors in association with that of EBV-determined nuclear antigen (EBNA). Rosette assays using erythrocytes coated with human C3b, C3bi, and C3d, inhibition of rosette formation with anti-receptor antibodies, and flow cytometry analysis of stained cells demonstrated that EBV-converted lines expressed C3b and C3d receptors, CR1 and CR2. Anti-receptor antibodies recognized an average of 40,700 anti-CR1 and 140,000 anti-CR2 binding sites on an EBV-converted line (BL41/B95), whereas no specific binding occurred on the corresponding EBV-negative (BL41) cells. Because CR1 and CR2 are involved in B-cell proliferation and/or differentiation, enhanced expression of C3 receptors following the interaction between EBV and B cells and/or subsequent infection of the cells by EBV may provide a basis for positive control of B lymphocyte proliferation by EBV.

Small non-cleaved follicular center cell lymphoma in Turkey. Burkitt's and non-Burkitt's types. A retrospective clinicopathologic analysis of 53 cases in the pediatric age group

Fifty-three patients in the pediatric age group diagnosed as having small non-cleaved follicular center cell (FCC) lymphoma (40 Burkitt's and 13 non-Burkitt's type) have been re-evaluated. Although the histopathologic distinction between the two subgroups is fairly easy to determine there is a considerable degree of clinical overlap in regard to age, sex, anatomic presentation of the disease, the incidence of bone marrow and central nervous system involvement, and the survival. The most important determinant of survival in both subgroups is the stage of the disease.

Burkitt's lymphoma

Cancer is the second leading cause of death in children and, among cancers, lymphoma is the third most frequently diagnosed type. The majority of these are non-Hodgkin's lymphomas (NHL). Although NHL have been grouped in a variety of confusing ways, recent research in cytogenetics and immunology, coupled with a better understanding of the normal pathways of lymphoid differentiation, has greatly lessened this confusion. Burkitt's lymphoma (BL) is a type of B-cell NHL which is sub-classified as either endemic (African) or non-endemic (American). Kinetic studies have demonstrated a doubling time of only 24 h. As a result of this extremely rapid growth, symptomatic complaints occur early in the disease course. Structures contiguous to the primary become compressed and metabolic derangements occur. Signs of chronic debilitation such as cachexia, diarrhea, generalized lymphadenopathy, and weight loss usually are not found. Thirteen cases of American BL have been treated since 1980 at the Texas Children's Hospital and form the basis of this review. Ten patients had obstructive abdominal symptoms including constipation and pain, and 3 had masses in the neck, maxilla, or tonsil. Systemic manifestations included ascites, jaundice, fever, and hepatosplenomegaly. Two patients ultimately developed central facial nerve paralysis.

A Japanese Burkitt's lymphoma with t(2;8) and EBNA

A 56-year-old Japanese man was admitted to the hospital with a large mass in his right axilla. Histological investigation revealed that it was a Burkitt's lymphoma. Ultrastructures of the tumor cells showed immature lymphoid features with frequent lipid droplets within the cytoplasms. Virological studies before the treatment revealed that the lymphoma was closely related to EB virus infection, being positive for EBNA (more than 95% of all tumor cells) and IgG antibodies to VCA (X 5,120), EA (X 640), and EBNA (X 160). The tumor cells exhibited low levels of cytoplasmic IgM and other properties of B cells. They were positively stained with L26, L27, Leu 14, and HLA-DR MAb. In cultured tumor cells, L25 and CALLA antigens were demonstrated, but no surface Ig was shown. In contrast, the tumor cells were negative for T cell markers including AcP, E-receptor, and Leu 1, 2, and 3. Cytogenetic studies demonstrated that the karyotype of the tumor cells was 46, XY, dup (1q), t(2;8)/46, X, -Y, t(2;8), +mar. VEMP therapy was immediately conducted. However, following a two-month partial remission, a relapse with bone marrow infiltration occurred. Thus, a case of Japanese Burkitt's lymphoma with EBNA (+) and t(2;8) properties is described, and the relationships among primary sites, phenotypes, and genotypes are discussed.

Jaw involvement in American Burkitt's Lymphoma

A total of 100 patients with American Burkitt's lymphoma (AMBL) (mean age, 15 years; M:F ratio 3:1; 3% black) have been treated at the National Cancer Institute since 1964. Eighteen of these had jaw involvement, 16 at presentation and 2 at relapse (mean age, 16 years; M:F ratio 1.6:1). None of these 18 patients was black. Of the 16 patients presenting initially with jaw tumors, 14 were first evaluated by their dentist; 8 were 16 years of age or older (adults) and 6 were younger than 16 years of age (children). Toothache and perioral numbness were the most frequent findings in adults, whereas toothache, loose teeth, intra-oral and extra-oral swelling were the most common complaints in children. Ten patients were treated with antibiotic therapy and/or dental extractions for presumed tooth infection. The distribution of jaw lesions was: unilateral mandibular (7), unilateral maxillary (4), bilateral mandibular (5), and four quadrants (2). Radiologic evaluation was abnormal in all 17 cases evaluated. Only three patients (all children) had disease limited to the jaw. Four of eight children and 3 of 10 adults are long-term survivors with a median follow-up of seven years (range, 2-15 years). American Burkitt's lymphoma with jaw involvement differs from African Burkitt's lymphoma (AFBL) with jaw involvement in a number of ways: (1) the incidence of jaw tumors in adults is similar to that in children; (2) the incidence of jaw tumors is not greater in males; (3) tumor is considerably more limited in extent with a single quadrant mandibular lesion being the most common presentation; and (4) clinical presentation also differs, with toothache and perioral numbness, uncommon in AFBL, being the most frequent complaints. These marked differences in the frequency and clinical characteristics of jaw tumor of AMBL and AFBL are consistent with other findings indicating that these diseases may differ phenotypically.

A Danish adult case of EBV-positive Burkitt's lymphoma

A 50-year-old Danish male presenting with swelling in fossa supraclavicularis and slight swelling of axillary and inguinal lymphnodes was diagnosed histologically as having malignant, non-Hodgkin, blast lymphoma. The EBV association was established by demonstration of EBV-DNA-positive tumor cells and the presence of high titers of antibodies of the IgG class to VCA, EA (D) and EBNA. The unique finding in this case was the high titers of IgA antibodies to VCA and to EA (D). This latter serological picture is characteristic of nasopharyngeal carcinoma (NPC) but has not previously been observed in Burkitt's lymphoma.

Undifferentiated non-Hodgkin's lymphomas (Burkitt's and non-Burkitt's types). The relevance of making this histologic distinction

A retrospective study of 66 cases of undifferentiated non-Hodgkin's lymphomas at the National Cancer Institute over a 22-year period suggests that the histologic distinction between Burkitt's and non-Burkitt's types is clinicopathologically meaningful. Thirty-nine patients with Burkitt's lymphoma had a median age at presentation of ten years. The primary site of disease in these patients was more commonly extranodal; at the time of diagnosis 26 (66%) of these cases revealed intra-abdominal involvement; 25 (64%) of the cases were Stage IV. The 27 patients with non-Burkitt's lymphomas had a median age at presentation of 34 years; the primary site of disease was more commonly nodal (peripheral adenopathy was often present at the time of diagnosis); only nine (33%) of the cases were Stage IV. Median survival was essentially equivalent in the two groups, 9.5 months for Burkitt's lymphoma and 10.0 months for the non-Burkitt's lymphoma. Overall, survival was not significantly different among the two patient populations; however, patients with Burkitt's lymphoma had a longer survival than those with non-Burkitt's lymphoma. Estimates of five-year survival (with 95% confidence) are 42% for Burkitt's lymphoma and 11% for non-Burkitt's lymphoma, respectively, which are significantly different (P = 0.01).

A review of Burkitt's lymphoma. Importance of radiographic diagnosis

Burkitt's lymphoma is a malignant proliferation of undifferentiated B lymphocytes that most often affects children. In endemic areas of Africa, the jaws are the sites most frequently involved. In non-endemic areas of North America, the jaws are involved in only 15-18 per cent of the cases. The oral and maxillofacial surgeon can play an important role in the early diagnosis of Burkitt's lymphoma by recognizing the clinical signs of multiple loose teeth and jaw tenderness coupled with the radiographic signs of generalized destruction of tooth crypts and diffuse disruption of jaw trabeculation. Successful treatment results from a combination of early diagnosis and controlled chemotherapy.

The presence of Burkitt-like cells in non-Burkitt's neoplasms

In four cases, the morphology of neoplastic cells from the peripheral blood and bone marrow suggested the diagnosis of American Burkitt's lymphoma or acute lymphocytic leukemia (French--American--British--Classification; FAB-L3). Cytochemical and immunologic studies, however, indicated that the neoplastic cells in one case were characteristic of acute lymphocytic leukemia (non-B, non-T-cell type); in another case, metastatic carcinoma; and in two two cases acute myelomonocytic leukemia. We conclude that cytochemical and immunologic cell markers are necessary for the diagnosis of American Burkitt's lymphoma. In addition, neoplastic cells simulating lymphoblasts of acute lymphocytic leukemia, FAB-L3 may derive from non-B lymphocytic lineage.

Infantile non-African Burkitt's lymphoma presenting as bilateral fulminant exophthalmos

A case of non-african Burkitt's lymphoma presenting an acute bilateral fulminant exophthalmos in an infantile male is reviewed. The rapid progression of proptosis, and the dramatic response to chemotherapy is documented photographically. A brief description on non-African Burkitt's lymphoma and a differential diagnosis of bilateral infantile fulminant exophthalmos is included.

A comparative study of Burkitt's and non-Burkitt's "undifferentiated" malignant lymphoma: immunologic, cytochemical, ultrastructural, cytologic, histopathologic, clinical and cell culture features

Nine patients with "undifferentiated" lymphoma (DUL) of Burkitt's (AMB, four cases) and non-Burkitt's (NB, five cases) types were studied. All specimens stained for a single immunoglobulin light chain indicating a monoclonal B-cell lymphoid proliferation. Striking methyl green pyronine and punctate Oil-Red O staining were demonstrated in both groups. Histologic and cytologic examination demonstrated a lymphoid proliferation with a high mitotic count, a "starry-sky" pattern, prominent cytoplasmic basophilia and vacuolation in both subtypes. The AMB cases showed a predominance of regular nuclei with 3-5 basophilic nucleoli, while the NB cases showed slightly greater nuclear variability with a greater proportion of nuclei containing 1-2 eosinophilic nucleoli. The AMB patients were all children (median, 12 age years) and those with NB were adults (median, age 54 years). The site of presentation in both groups was predominantly extranodal and abdominal. This report emphasizes the considerable immunologic, morphologic, cytochemical and clinical overlap present among the subtypes of "undifferentiated" lymphoma.

Burkitt's leukemia: a re-evaluation

Two patients who presented with acute leukemia of Burkitt's cell type are discussed. Although one patient died within four months of diagnosis, the other has maintained a one year clinical complete remission. The clinical and morphologic picture of Burkitt's leukemia is nonspecific and therefore requires complementary studies including cytochemistry, transmission electron microscopy, cell surface markers and cytogenetics studies to establish diagnosis. Serial bone marrow aspirations with marker analyses may detect relapse at an earlier stage than conventional cytology, allowing therapy to be modified prior to overt clinical relapse.

Burkitt's lymphoma of the vulva. Case report

A 13-year-old Nigerian girl with Burkitt-type metastatic malignant lymphoma of the vulva is presented. Diagnosis and treatment are discussed and the literature is reviewed.

Burkitt's lymphoma of the appendix: report of two cases

Two cases of primary Burkitt's lymphoma of the appendix are reported. Both children presented with abdominal pain, and the tumors were discovered during routine appendectomy for suspected "appendicitis." The rarity of the lesion and the prognosis are briefly discussed.

Burkitt lymphoma in an American infant under one year of age, with electron microscopic examination of the tumor

Burkitt lymphoma in the United States has not been reported in a child under the age of one year. We report here a nine-month-old child who had facial involvement and a rapidly downhill course. This occurred despite an early response to combination chemotherapy and vigorous supportive measures. Electron microscopic examination of the tumor is also presented.