MALT Lymphomas

This review addresses the biology and the treatment of lymphomas arising from mucosa-associated lymphoid tissue (MALT). This entity, first described in 1983, represents about 8% of all non-Hodgkin's lymphomas and was recently re-classified as "extranodal marginal zone lymphomas of MALT-type." The term marginal zone lymphoma (MZL) encompasses the three closely related lymphoma subtypes of nodal, primary splenic and extranodal lymphomas of MALT type: the latter represent the vast majority of MZL. These lymphomas arise at different anatomic sites, are composed of mature B-cells lacking expression of CD5 and CD10, often present with overlapping morphologic features, but typically quite distinct clinical behaviors. Only very recently cytogenetic/molecular genetic observations have underlined the distinctiveness of these three lymphoid neoplasms, which in both the R.E.A.L. and WHO-classifications are included in the general term of MZL. MALT lymphomas arise in numerous extranodal sites, but gastric MALT lymphoma is the most common and best studied and is, therefore, the paradigm for the group as a whole. Dr. Isaacson describes the principal histological features of these lymphomas, including criteria to distinguish this entity from other small B-cell lymphomas. Several lines of evidence suggest that gastric lymphoma arises from MALT acquired as the result of aH. pyloriinfection. However, at least 1/3 of cases do not respond to eradication ofH. pylori. Very recent data suggest that both t(11;18) (q21;q21) and bcl10 nuclear expression are associated with failure to respond to this treatment. Dr. Gascoyne discusses the biologic function of proteins deregulated through the different translocations, which play a role in pathogenesis of MALT lymphomas, emphasizing particularly their influence in disrupting the apoptotic pathway. Dr. Zucca reviews findings suggesting that MALT lymphoma is an antigen driven neoplasm. He also presents specific guidelines for treatment of gastric lymphomas trying to shed some light on the amazingly inconsistent and confusing data in the literature. Taking advantage on the more than 300 non-gastric MALT lymphomas collected by the International Extranodal Lymphoma Study Group (ILESG), Dr. Cavalli compares gastric lymphomas with those arising in many other sites. Overall, the data presented in this session will underline the fact, that MALT lymphomas are characterized by some unique biological properties.

TNFR-associated factor family protein expression in normal tissues and lymphoid malignancies

TNFR-associated factors (TRAFs) constitute a family of adapter proteins that associate with particular TNF family receptors. Humans and mice contain six TRAF genes, but little is known about their in vivo expression at the single cell level. The in vivo locations of TRAF1, TRAF2, TRAF5, and TRAF6 were determined in human and mouse tissues by immunohistochemistry. Striking diversity was observed in the patterns of immunostaining obtained for each TRAF family protein, suggesting their expression is independently regulated in a cell type-specific manner. Dynamic regulation of TRAFs was observed in cultured PBLs, where anti-CD3 Abs, mitogenic lectins, and ILs induced marked increases in the steady-state levels of TRAF1, TRAF2, TRAF5, and TRAF6. TRAF1 was also highly inducible by CD40 ligand in cultured germinal center B cells, whereas TRAF2, TRAF3, TRAF5, and TRAF6 were relatively unchanged. Analysis of 83 established human tumor cell lines by semiquantitative immunoblotting methods revealed tendencies of certain cancer types to express particular TRAFs. For example, expression of TRAF1 was highly restricted, with B cell lymphomas consistently expressing this TRAF family member. Consistent with results from tumor cell lines, immunohistochemical analysis of 232 non-Hodgkin lymphomas revealed TRAF1 overexpression in 112 (48%) cases. TRAF1 protein levels were also elevated in circulating B cell chronic lymphocytic leukemia specimens (n = 49) compared with normal peripheral blood B cells (p = 0.01), as determined by immunoblotting. These findings contribute to an improved understanding of the cell-specific roles of TRAFs in normal tissues and provide evidence of altered TRAF1 expression in lymphoid malignancies.

Lymphomas with follicular and monocytoid B-cell components. Evidence for a common clonal origin from follicle center cells

We investigated the clonal relationship between follicular center cell and monocytoid B-cell components of non-Hodgkin lymphoma by isolating the components and comparing the nucleotide sequences of the complementarity-determining region (CDR)3 of the rearranged immunoglobulin heavy chain (IgH) gene. Paraffin blocks from 4 cases with amplifiable DNA using the polymerase chain reaction (PCR) were identified. Multiple representative cell clusters of the 2 components were obtained by microdissection, and the IgH CDR3 was amplified using a seminested PCR. Most of the PCR products obtained from both tumor components in each case had identical lengths when analyzed with polyacrylamide gel electrophoresis (PAGE) and identical migratory patterns on denaturing gradient gel electrophoresis (DGGE). These findings indicate sequence identity of the IgH CDR3 of both tumor components. Sequence analysis showed that point mutations were responsible for bands from the same case that had nonidentical migratory patterns by DGGE. The components in each of the 4 cases studied have the same clonal origin. Intraclonal sequence variations in the IgH gene were observed in 2 cases, consistent with the presence of continued somatic hypermutation after establishment of the clone. The expression of CD10 and bcl-2, as well as the detection of bcl-2 rearrangements in 2 cases, indicate that these lymphomas are of follicular center cell origin.

Development of a biologically distinct EBV-related lymphoproliferative disorder following autologous bone marrow transplantation for an EBV-negative post-renal allograft Burkitt's lymphoma

Post-transplant lymphoproliferative disorder (PTLD) is a known complication of both solid organ transplantation and allogeneic bone marrow transplantation (BMT) but is rarely seen following autologous BMT. We report the case of a 45 year-old female who developed Burkitt's lymphoma eight years after a renal allograft. This PTLD was found to have lambda light chain restriction, contained del(8)(q24) and add(14)(q32), and was negative for EBV on immunohistochemical and DNA-based PCR analyses. Immunoglobulin heavy chain (IgH) PCR studies revealed a prominent clonal rearrangement. She responded to intravenous cyclophosphamide and proceeded to high-dose chemoradiotherapy and mafosfamide-purged autologous BMT. Thirty-nine days post-BMT she presented with cough and fever and developed hepatic dysfunction; abnormal lymphoplasmacytoid cells were noted in the peripheral blood. Investigations revealed kappa light chain restriction, an oligoclonal IgH rearrangement, a normal karyotype and PCR studies for EBV were positive, consistent with a clinically and biologically distinct PTLD. She initially improved following discontinuation of immunosuppression, but then deteriorated abruptly and died 58 days post-BMT. It is likely that the two separate episodes of PTLD in this patient, one of which was atypical, arose as a result of both the chronic use of cyclosporine and the impairment of cell-mediated immunity associated with autologous BMT. The sequence of events in this patient should contribute to a better understanding of late-onset, EBV-negative PTLD.

Blastic mantle cell leukemia: an unusual presentation of blastic mantle cell lymphoma

Six patients had blood and bone marrow manifestations characterized by the presence of morphologically immature or blastic B-lineage lymphoid cells expressing CD5 antigen. The median patient age was 70 years, and the male-to-female ratio was 5:1. The presence or degree of lymphadenopathy and splenomegaly was variable among this group at staging evaluation, although two patients did not have these features. One patient had an antecedent diagnosis of classical nodal mantle cell lymphoma, without prior morphologic blood or bone marrow involvement. Other patients lacked a history of underlying lymphoproliferative disorders. The median white blood cell count was 120 x 10(9)/L. Most patients had thrombocytopenia, whereas only one patient had neutropenia at presentation. Leukemic peripheral blood cells in these six cases were small to medium in size with fine or granular nuclear chromatin and small or inconspicuous nucleoli. The pattern of marrow involvement was interstitial or diffuse, with cells showing immature nuclear features resembling acute leukemia or blastic lymphoma. All tumors demonstrated a consistent immunophenotype of B-cell lineage, surface immunoglobulin positivity, and CD5 antigen expression. The progenitor cell-associated markers CD34 and TdT were not expressed, and CD23 antigen was either negative (three of four cases) or only weakly present (one of four cases). The presence of a karyotypic t(11;14)(q13;q32) was documented in one tumor, whereas two other cases had BCL-1 gene rearrangements by either polymerase chain reaction or Southern blot analysis. Cyclin D1 mRNA overexpression was noted in three of four cases tested. This patient group was characterized by very poor overall survival (median, 3 months; range, 0.5 to 6 months). The aggregate clinical, pathologic, and genetic data in these unusual cases are consistent with de novo or predominant leukemic presentations of blastic mantle cell lymphoma. Accurate diagnosis in such cases is greatly facilitated by cytogenetic studies or the demonstration of BCL-1/cyclin D1 abnormalities.

Involvement of the X chromosome in non-Hodgkin lymphoma

Gain of an X chromosome is observed as a secondary, acquired karyotypic alteration in a significant proportion of malignant lymphomas. To determine the potential involvement of X-linked genes in neoplastic development, we have analyzed the inactivation status of the supernumerary X chromosome in lymphomas in both male and female patients. In males, neither methylation of FMR1 nor expression of XIST was detected, demonstrating that the duplicated chromosome was not subject to inactivation. In females, both expressed polymorphisms and polymorphisms associated with methylation differences between the active and inactive X chromosome were analyzed to determine whether the duplicated chromosome was active or inactive. To facilitate this analysis, allele-specific PCR primers were designed for detection of previously described polymorphisms in the IDSX and G6PD genes. The female lymphomas were shown to be clonal in origin, and duplication of either the active (5 cases) or inactive (4 cases) X chromosome was observed. Correlations between clinical status and the inactivation status of the X chromosome involved in the duplication were not observed in our relatively small sample, although 4/4 informative cases with a t(14;18) showed duplication of the active X chromosome. In the course of these studies, we detected hypermethylation of the androgen receptor (AR) locus in an extremely high proportion of both male (7/9) and female (9/10) samples. These results are discussed with respect to whether sex chromosome aneuploidies in tumors are involved in, or simply the result of, the neoplastic process. Genes Chromosomes Cancer 28:246-257, 2000.

Eradication of human non-Hodgkin's lymphoma in SCID mice by BCL-2 antisense oligonucleotides combined with low-dose cyclophosphamide

Cancers overexpressing Bcl-2 protein, which prevents programmed cell death (apoptosis), are less sensitive to stresses that produce cellular damage, including chemotherapy. If the level of Bcl-2 protein can be reduced sufficiently using antisense oligonucleotides (ASOs) targeting the gene message, then cytotoxic agents may be rendered more effective in eliminating disease and increasing cure rate. Preclinical studies in SCID mice bearing Bcl-2 overexpressing systemic human B-cell lymphoma (DoHH2) were undertaken to support development of a clinical trial. These data confirm that a combination of an ASO (5 mg/kg) targeting bcl-2 and a low dose of cyclophosphamide (35 mg/kg) was an effective strategy, leading to the eradication of the DoHH2 cells in vivo and cure of the animals. When mice deficient in natural killer cell activity were treated with an ASO, similar results were observed, suggesting that ASO stimulation of the host immune system was not a significant factor in elimination of lymphoma cells. These studies indicate that therapeutic strategies involving the use of an ASO targeting bcl-2 in combination with a cytotoxic agent may improve clinical outcomes.

Low grade gastric MALT Lymphoma: radiographic findings

AIMS

Gastric MALT (mucosa-associated lymphoid tissue) lymphoma is now recognized as a distinct entity within extranodal non-Hodgkin's lymphoma. The purpose of this study was to describe the radiographic findings in low grade gastric MALT lymphoma.

MATERIALS AND METHODS

We retrospectively reviewed the radiographic findings in 22 cases of low-grade gastric MALT lymphoma. The study group consisted of 15 men and seven women (median age 68 years, range 41-91 years). Lesions were designated as infiltrative or polypoid by consensus of two radiologists. Polypoid lesions were categorized by number and size. Anatomical site within the stomach and presence of transpyloric or oesophagogastric extension was determined for each case. The presence of abdominal lymphadenopathy was categorized as regional or distant. The presence of Helicobacter pylori was determined from endoscopic and surgical biopsies.

RESULTS

Computed tomography (CT) revealed abnormalities of the stomach in 19 cases of the 21 in which it was performed. There were 14 infiltrative lesions and five polypoid lesions. Of the 14 infiltrative lesions, the mean gastric wall thickness was 2.2 cm (range 0.8-6.0 cm). There were three single and two multiple polypoid lesions (mean size 2.2 cm, range 1. 5-2.7 cm). Transpyloric extension was observed in two cases and oesophagogastric extension in one. Abdominal lymphadenopathy was observed in 10 of 21 patients. Helicobacter pylori was found in 19 of 22 cases (86%).

CONCLUSION

Low grade B cell gastric MALT lymphomas present with an infiltrative form on CT in about three-quarters of cases and a polypoid pattern in the remainder. Abdominal lymphadenopathy is seen in approximately one-half of cases. There is a high association with Helicobacter pylori.

Allografting for indolent lymphoid neoplasms

BACKGROUND

Allogeneic bone marrow transplantation (BMT) has been used in patients with low-grade lymphoma (LGL) and chronic lymphocytic leukemia (CLL) with the goal of achieving long-term disease-free survival.

PATIENTS AND METHODS

Twenty-nine patients with these diagnoses (LGL = 19, CLL = 10) received allogeneic BMT between September 1995 and January 1999. Median age was 42 (range 20-52) years. Twenty-three of twenty-nine patients (79%) were Ann Arbor or Rai stage IV at the time of transplant; twenty-four (83%) had never achieved complete remission (CR). Donor source was HLA-matched sibling (20), unrelated (8) and syngeneic (1).

RESULTS

Seventeen patients are currently alive, a median of 29 months (range 1-85) post-BMT with a median KPS of 90%. Twenty-three of twenty-seven evaluable patients (85%) achieved CR post-BMT. Six patients had refractory/recurrent disease. Death occurred related to transplant complications in eight patients and underlying disease in four. Overall and event-free survival for the whole group is 51% and 44%, respectively.

CONCLUSIONS

Allogeneic BMT for young patients with advanced stage LGL or CLL is a feasible strategy that can result in achievement of long-term disease-free survival.

Allogeneic bone marrow transplantation for low-grade lymphoma and chronic lymphocytic leukemia

Twenty-six patients with low-grade lymphoma (LGL) (n = 18) or chronic lymphocytic leukemia (CLL) (n = 8) received allogeneic BMTs between 1985 and 1998. Median age was 42 years, median interval from diagnosis to transplant 22 months and median number of prior treatments three. Twenty (77%) had stage IV disease; 22 (85%) had never achieved CR. Donor source was HLA matched sibling (n = 19, 73%), matched unrelated (n = 6, 23%) or syngeneic (n = 1). Conditioning therapy included total body irradiation in 23 patients and busulphan in three. Twenty-five received GVHD prophylaxis with cyclosporine A; + methotrexate (n = 19), + methylprednisolone (n = 2) or + T cell depletion of allograft +/- methotrexate (n = 4). Sixteen patients are alive, a median of 2.4 years post BMT. Death occurred due to transplant complications (n = 7) or underlying disease (n = 3). Eighteen (12 LGL, six CLL) of 22 evaluable patients (82%) achieved CR post BMT. Cumulative incidence of refractory/recurrent disease was 18% (95% confidence interval (CI) 7-42%). Overall and event-free survivals were 58% (95% CI 35-75%) and 54% (95% CI 32-72%), respectively. Allogeneic BMT for young patients with advanced LGL or CLL is feasible and can result in long-term disease-free survival.

Clinical significance of the t(14;18) and BCL2 overexpression in follicular large cell lymphoma

Follicular large cell lymphoma (FLCL) is an aggressive disease that responds to anthracycline-containing chemotherapy much like diffuse large B-cell lymphoma (DLBCL). Since the t(14;18) and/or bcl2 protein expression are less common in FLCL than in its low-grade counterparts, we sought to determine whether these features were predictive of survival as in DLBCL. We studied 50 patients with FLCL who were treated with curative intent. The t(14;18) was found by cytogenetic analysis in 56% of the patients and bcl2 protein was expressed by the tumor cells in 73%, but neither was predictive of survival. However, abnormalities of chromosome 17p and the presence of trisomy 21 were adverse predictors of survival, as were a number of clinical features. We conclude that neither the absence of the t(14;18) nor the lack of bcl2 expression explain the good response of a subset of patients with FLCL to curative therapy.

Anaplastic large cell lymphoma: a clinicopathologic analysis

The clinicopathologic features of anaplastic large cell lymphoma (ALCL) are reviewed. ALCL is a heterogeneous group of tumours, and histologic examination alone is not adequate in providing useful prognostic information. However, using a combination of clinical, phenotypic, and genotypic features, several distinct clinicopathologic entities have been identified. A subset of ALCL as presently defined is characterized by a balanced translocation, t(2;5)(p23;q35), resulting in a novel fusion protein (NPM-ALK) that can be readily detected by immunohistochemical methods using antibodies against the ALK protein. Detection of ALK protein, along with other methods for demonstrating the t(2;5), has assisted in identifying a distinct biologic entity within the heterogeneous group of ALCL with significant prognostic implications. It is important to separate these from cases of ALK-negative ALCL, which have a poorer prognosis, and cases of primary cutaneous ALCL, which have an excellent prognosis.

Treatment of post-transplant lymphoproliferative disease with rituximab monoclonal antibody after lung transplantation

Three patients with diffuse large B-cell type of post-transplant lymphoproliferative disease after lung transplantation were treated with rituximab, an anti-CD20 monoclonal antibody. Treatment resulted in two complete remissions and one non-response.

Hepatitis C infection and B-cell non-Hodgkin's lymphoma in British Columbia: a cross-sectional analysis

OBJECTIVES

To determine the prevalence of hepatitis C virus (HCV) infection in patients with B-cell non-Hodgkin's lymphoma (NHL) in British Columbia.

DESIGN

A cross-sectional analysis.

SETTING

The British Columbia Cancer Agency (BCCA), a Canadian provincial tertiary oncology referral center.

SUBJECTS

Consecutive patients with B-cell NHL registered onto the BCCA lymphoma database in 1996 and part of 1997 and a control group of patients with T-cell NHL registered on the database from 1995 through 1997. Patients with HIV infection were excluded from the analysis. A second control group (n = 1085) consisted of health-care workers tested for HCV infection following a needle-stick injury.

INTERVENTIONS

Stored sera from patients with B-cell NHL (n = 88) and T-cell NHL (n = 37), identified from the database, were tested for the presence of HCV infection with commercially available serologic tests.

MAIN OUTCOME MEASURES

HCV seropositivity in the B-cell lymphoma group compared to the control groups (T-cell NHL and health-care workers).

RESULTS

2.3% of the B-cell NHL group, none of the T-cell NHL group and 1% of the health-care worker control group were positive for HCV infection. These results were not statistically significantly different.

CONCLUSION

Patients in British Columbia with B-cell NHL do not have an increased prevalence of HCV infection. These data suggest that the lymphotrophism of HCV may differ by regional, racial and genotypic variations around the world.

Primary non-Hodgkin's lymphoma and malakoplakia of the vagina: a case report

The vagina is a rare site for both primary non-Hodgkin's lymphoma and malakoplakia. We report a case of concurrent diffuse large B-cell lymphoma and malakoplakia of the vagina in a 67-year-old woman presenting with a vaginal discharge and a vaginal mass. The patient had two biopsy specimens reported as showing malakoplakia only, followed by a third biopsy specimen 10 months later which was diagnosed as diffuse large B-cell lymphoma. Review of the first two biopsy specimens showed areas of histiocytes with Michaelis-Gutman bodies merging with areas of cells with slightly larger nuclei and more amphophilic cytoplasm. Immunohistochemistry for the B-cell marker L-26 (CD20) and polymerase chain reaction analysis of the immunoglobulin heavy chain gene were helpful in retrospectively distinguishing the population of diffuse large B-cell lymphoma from the areas of malakoplakia. The third biopsy specimen showed sheets of large atypical lymphoid cells characteristic of a large cell lymphoma. Malakoplakia has been described in association with a variety of cancers, and this is only the second report of malakoplakia associated with non-Hodgkin's lymphoma. Considering the rarity of these two entities in the vagina, it is unlikely that the association in this case is coincidental, raising the possibilities of an unusual reaction to the presence of lymphoma or a common pathogenesis such as underlying chronic inflammation. Epstein-Barr virus DNA was detected in the second biopsy specimen, suggesting a possible role in the pathogenesis of this lymphoma.

Bcl-6 and Bcl-2 protein expression in diffuse large B-cell lymphoma and follicular lymphoma: correlation with 3q27 and 18q21 chromosomal abnormalities

The bcl-2 gene on chromosome 18 at q21 and the bcl-6 gene on chromosome 3 at q27 are both highly regulated during B-cell differentiation and show an inverse relationship of expression in the normal secondary lymphoid follicle. The objective of this study was to investigate the relationship between bcl-2 and bcl-6 protein expression and the relationship between protein expression and the corresponding chromosomal alterations in malignant lymphomas, including those associated with the germinal center. Expression of bcl-2 and bcl-6 proteins was studied in 55 cases of diffuse large B-cell lymphoma (DLBCL) and 21 cases of follicular lymphoma (FL), and the results correlated with the presence of t(14;18) and 3q27 abnormalities in a subset of 52 cases with cytogenetic analysis. These cases were selected to represent a spectrum of nodal and extranodal lymphomas, including those with and without a t(14;18). It was shown that the neoplastic cells in 71% of DLBCLs and 100% of FLs expressed bcl-6 protein. Expression of bcl-6 was seen more frequently in diffuse large B-cell lymphomas with large noncleaved morphology compared with immunoblastic morphology (82% v 27%, P = .0015), but failed to correlate with 3q27 abnormalities. Thirty-eight percent of cases with 3q27 abnormalities were bcl-6 protein negative, whereas 85% of cases without a 3q27 abnormalities were bcl-6 protein positive. Expression of bcl-2 protein was shown in 51% DLBCLs (nodal v extranodal, 71% v 30%, P = .012). bcl-2 protein was expressed in 89% of FLs with t(14;18), in contrast to 25% of FLs without t(14;18) (P = .016). In DLBCL and FL with t(14;18), the most common pattern of expression was bcl-2+/bcl-6+. In lymphomas without t(14;18), there was not an inverse relationship between bcl-2 and bcl-6 protein expression. In conclusion, these data suggest that mechanisms other than gene rearrangements can deregulate bcl-2 and bcl-6 expression in lymphomas, and there does not appear to be an inverse relationship between these two proteins as seen in the normal germinal center.

Use of the polymerase chain reaction to detect B- and T-cell gene rearrangements in vitreous specimens from patients with intraocular lymphoma

OBJECTIVE

To determine whether the polymerase chain reaction for B- and T-cell gene rearrangements could be applied to vitreous specimens to aid in the diagnosis of intraocular lymphoma.

METHODS

Vitreous washing specimens from 4 patients were received in balanced saline solution and centrifuged, and a portion of the pellet was used to make routine cytospins. The remainder was used to make a crude extract of DNA that was amplified for immunoglobulin heavy chain and T-cell receptor gamma gene rearrangements and the 14;18 translocation by polymerase chain reaction.

RESULTS

One patient had 2 specimens 2 years apart. In each, there was an identical band corresponding to the minor cluster region breakpoint of the bcl-2 oncogene, indicating the presence of a 14;18 translocation. One patient showed an immunoglobulin heavy chain gene rearrangement indicating a B-cell lymphoma. Two patients showed rearrangements of the T-cell receptor gamma gene, indicating the presence of a T-cell lymphoma.

CONCLUSIONS AND CLINICAL RELEVANCE

Vitreous washing specimens can be used successfully to detect B- and T-cell gene rearrangements by polymerase chain reaction. This may be useful to confirm the diagnosis of intraocular large cell lymphoma in cases suggestive of the diagnosis. Prompt handling of the specimens is necessary to prevent degradation of the DNA.

Prognostic significance of anaplastic lymphoma kinase (ALK) protein expression in adults with anaplastic large cell lymphoma

Anaplastic large cell lymphoma (ALCL) is an aggressive lymphoma that is frequently associated with the t(2;5)(p23;q35), resulting in expression of a fusion protein, nucleophosmin-anaplastic lymphoma kinase (NPM-ALK), which can be detected by either monoclonal or polyclonal antibodies to the ALK protein. The clinical features of adults with ALCL are incompletely described, and the prognostic factors that are useful for predicting survival remain unclear. This report describes the clinical and laboratory findings in 70 adults with systemic ALCL who were treated with curative intent. We attempted to identify the clinical and pathological factors of prognostic importance, including the International Prognostic Index (IPI), immunophenotype, and expression of the ALK protein. The median age of the patients was 49 years (range, 15 to 75). There were 26 women and 44 men with a median follow-up of 50 months for living patients. Advanced stage was present in 56% and B symptoms were noted in 70% of the patients. Immunostains showed that 46% of the cases had a T-cell phenotype, 36% a null phenotype, and 18% a B-cell phenotype. The expression of ALK protein was found in 51% of the cases. The IPI factors were evenly distributed between the ALK+ and ALK- groups, except that the ALK+ patients were younger (median age, 30 v 61 years; P <.002). The ALK+ cohort included cases with null (44%), T-cell (42%), and B-cell (14%) phenotypes. All 10 cases with cytogenetic or molecular evidence of a t(2;5) were ALK+. The 5-year overall survival (OS) of the entire cohort was 65%. The 5-year OS of the ALK+ and ALK- cases was 79% and 46%, respectively (P <.0003). Analysis of only the T-cell/null cases (n = 57) showed a 5-year OS of 93% for the ALK+ cases and only 37% for the ALK- cases (P <.00001). Univariate analysis of the clinical features showed that age </=60 years (P <.007), a normal serum lactate dehydrogenase (LDH) (P <.00001), a good performance status (Eastern Cooperative Oncology Group [ECOG] <2) (P <.03), </=1 extranodal site of disease (P <.012), and an IPI score </=3 (P <.00001) were associated with improved OS. Although a younger age correlated with ALK positivity, multivariate analysis showed that only a normal serum LDH (P <. 00001), an IPI score of </=3 (P <.0005), and ALK protein expression (P <.005) predicted independently for an improved OS. We conclude that ALCL is a heterogeneous disorder. However, ALK protein expression is an independent predictor of survival and serves as a useful biologic marker of a specific disease entity within the spectrum of ALCL.

Concurrent chromosomal alterations at 3q27, 8q24 and 18q21 in B-cell lymphomas

Recurrent chromosomal translocations in malignant lymphomas most commonly involve 18q21(bcl-2), 8q24 (c-myc) and 3q27 (bcl-6), with an incidence of 27%, 11% and 6%, respectively. Individual cases concurrently harbouring two of these three rearrangements have been previously reported. This report describes four patients with cytogenetic alterations affecting all three loci, which was confirmed by molecular analysis in one case. Clinically, each patient had aggressive B-cell lymphoma with disseminated disease often involving the central nervous system, poor response to chemotherapy and short survival. Activation of c-myc in association with deregulation of bcl-2, bcl-6 or both confers high-grade disease with a poor prognosis.

Small noncleaved, non-Burkitt's (Burkit-Like) lymphoma: cytogenetics predict outcome and reflect clinical presentation

PURPOSE

To correlate cytogenetic abnormalities with clinical presentation and outcome in Burkitt-like, small noncleaved non-Burkitt's lymphoma (SNC-NB).

PATIENTS AND METHODS

Thirty-nine patients with SNC-NB lymphoma and a clonal karyotype were evaluated between January 1989 and January 1996. All were from British Columbia, Canada, underwent uniform clinical staging, and were treated on investigational protocols by a small group of clinicians.

RESULTS

Three groups of patients were identified by clonal karyotype on cytogenetic analysis: (1) those with a c-myc translocation (n = 11); (2) those with dual translocation of c-myc and bcl-2 (n = 13); and (3) those with other cytogenetic abnormalities (n = 15). The c-myc group was younger, presented with earlier stage de nova disease, and had a better clinical prognostic factor profile. The dual-translocation and other groups were older and presented in advanced stage with poorer prognostic features, and a larger proportion of the dual-translocation group patients had transformed from previously diagnosed follicular lymphoma. The median overall survival (OS) time for all patients was 5 months. The median OS time for the dual-translocation group was only 2.5 months, as compared with 7 months and 8 months for the c-myc and other group, respectively (P < .001). There were no survivors beyond 7 months among the dual-translocation group, as opposed to 32% and 25% 2-year OS rates in the c-myc and other group.

CONCLUSION

SNC-NB lymphoma is a clinically and cytogenetically heterogenous disease. Dual translocation of c-myc and bcl-2 is characterized by a rapid clinical course and extremely poor outcome. This latter entity may represent the most clinically aggressive lymphoma thus far characterized and warrants intensive investigational treatment where feasible.

Incidence of second neoplasms in patients with MALT lymphoma: no increase in risk above the background population

BACKGROUND

Lymphomas of mucosa associated lymphoid tissue (MALT) are a special type of extranodal lymphoma, possibly related to chronic antigenic stimulation. Increased cancer susceptibility may also contribute to the development of MALT lymphoma (MALToma). It has been suggested that patients with MALToma have an increased incidence of other malignancies.

PATIENTS AND METHODS

We retrospectively reviewed the histology and clinical records of 147 patients with MALToma, including 51 cases of gastric MALToma. The incidence of any second malignancy was confirmed with a provincial registry. The relative rates of cancer, excluding MALToma, were calculated relative to the background population of the same age group and secular year.

RESULTS

A total of 41 tumors occurred in 32 patients (21%), including 22 solid tumors. The incidence of solid tumors in the gastric MALToma group was 15%. Seven patients had two or more second malignancies. Cancer occurred before diagnosis of MALToma in 29 cases, concurrent with MALToma in three, and after MALToma in nine. Follow-up of the surviving patients is short (median 17.6 months). The relative rate from birth of a second malignancy was 0.86 in the whole group (90% confidence interval (CI): 0.62-1.16) and 0.95 (90% CI: 0.55-1.54) in the gastric MALToma group. The rates were roughly the same if skin cancers were excluded.

CONCLUSIONS

The incidence of second cancers in this series is similar to previous reports. However, when compared to an age-matched population followed for the same period of time, MALToma patients do not appear to have a statistically significant increased rate of cancers.

Workshop report on Hodgkin's disease and related diseases ('grey zone' lymphoma)

Despite advances in immunohistochemistry and molecular biology, the distinction between classical Hodgkin's lymphoma and related diseases such as nodular lymphocyte-predominant Hodgkin's disease, T-cell rich large B-cell lymphoma or anaplastic large cell lymphoma has remained difficult in rare cases. Lack of clear-cut diagnostic criteria represents a problem for both the pathologist and the clinician. To delineate this 'grey zone' between classical Hodgkin's lymphoma and non-Hodgkin's lymphoma (NHL) and to develop criteria for classification of such cases, 12 expert hematopathologists each submitted one to five borderline cases to a workshop. Cases were reviewed and classified at a multiheaded microscope and criteria were established for the diagnosis of questionable cases. Well established entities such as classical Hodgkin's lymphoma, anaplastic large-cell lymphoma and TCRBCL were defined more strictly and cases with unusual morphology or antigen expression could be identified. A distinctive subset of cases representing mediastinal large B-cell lymphomas with features of Hodgkin's lymphoma was identified.

Lymphoproliferative disorders following allogeneic bone marrow transplantation: the Vancouver experience

Between June 1988 and May 1996, 428 patients underwent allogeneic BMT (288 related donor (RD) and 140 unrelated donor (UD)) at the Vancouver General Hospital. Eight patients (UD six and RD two) developed a post-transplant lymphoproliferative disorder (PTLD). Median age at BMT was 38 years (range 22-51). Five of the six UD allografts were T cell depleted. Cyclosporine+/-methotrexate was used for GVHD prophylaxis. All eight patients developed GVHD; in six this was refractory to treatment with corticosteroids. Rabbit antithymocyte globulin (ATG) or an anti-CD5-ricin A chain immunotoxin (Xomazyme) was used as second-line therapy for GVHD. Presentation with PTLD occurred at median day 90.5 (range 34-282) post BMT. Five of the eight patients had a rapidly progressive course characterized by fever, lymphadenopathy, lung and liver involvement and died within 3-8 days. PTLD was an incidental finding at post mortem examination in two patients. The remaining patient had localized disease and recovered. Pathological analysis revealed two morphological patterns; diffuse large B cell lymphoma (DLBC lymphoma, five patients) and polymorphous B cell hyperplasia (PBCH, three patients). EBV expression was positive in all eight cases and monoclonality was demonstrated in seven cases. In multivariate analysis, T cell depletion of the allograft (P=0.0001, relative risk (RR)=30.5), anti-T cell therapy for GVHD (P=0.006, RR=12.7) and acute GVHD grades 3-4 (P=0.04, RR=7.7) were the significant factors for development of PTLD. In conclusion, we have identified two forms of PTLD after BMT: one is characterized by disseminated disease with a rapidly progressive and often fulminant course and the other by localized, relatively indolent disease. Morphology, EBV positivity and clonality do not appear to correlate with the clinical course. The major risk factors for development of PTLD after BMT are ex vivo T cell depletion of the allograft and in vivo anti-T cell therapy for GVHD.

Establishing the diagnosis of lymphoma: from initial biopsy to clinical staging

Successful therapy for most of the non-Hodgkin's lymphomas requires an accurate pathologic diagnosis. Routine morphologic examination of excisional biopsies from nodal or extranodal sites provides the cornerstone for establishing a definitive diagnosis. The list of ancillary studies, however, used to complement these routine approaches is increasing both in number and complexity. Proper use of these diagnostic tools can be of great help in arriving at the correct diagnosis in difficult cases. Fine-needle aspiration and needle-core biopsies have a role in lymphoma staging and in the assessment of recurrent disease, but are limited as primary diagnostic tests. This review will focus on the standard approaches used to establish a diagnosis of malignant lymphoma, and the clinical utility of immunophenotypic, molecular genetic, and cytogenetic studies in providing useful data for diagnosis. The standard practice of synthesizing all of the data from multiparameter analysis to arrive at a diagnosis in difficult cases will be emphasized.

Second malignancies in patients with hairy cell leukemia in british columbia: a 20-year experience

The purpose of this study was to compare the relative risk of second malignancies in a cohort of patients with hairy cell leukemia (HCL) against the normal population. Potential effects of type of treatment and duration of follow-up and the site distribution of cancer were also examined. Between 1976 and 1996, 117 patients were diagnosed with HCL in British Columbia who were referred to the British Columbia Cancer Agency (BCCA) for treatment. All additional malignancies were traced using a provincial population-based cancer registry and follow-up records from the BCCA. There were 90 men and 27 women. Median age at diagnosis was 53 years. The median follow-up time was 68 months. Twenty-three patients underwent primary splenectomy, 65 received interferon alpha, 24 deoxycoformycin, and 67 cladribine (2-chlorodeoxyadenosine). Thirty-six patients had an additional malignancy (30.7%) with a total of 44 tumors. Six patients (5.1%) had two or more malignancies. Twenty-five patients had malignancies diagnosed after HCL (21.3%), three concurrent with HCL (2.6%), and 12 preceding HCL (10.2%). Second tumors (n = 28 tumors) occurred at a median of 40 months after HCL (range, 3 to 167). The relative rate (RR) of second malignancy among men and women was 2.91 (P < .001) and 1.65 (P = .23), respectively, compared with age and secular trend-matched controls. There were eight prostate cancers, nine nonmelanoma skin cancers, two lung cancers, and four gastrointestinal adenocarcinomas. The RR (90% confidence interval [CI]) in the various treatment groups were: splenectomy (RR = 0.21 to 3.81), purine analogues (RR = 0.60 to 5.69), interferon then purine analogues (RR = 1.60 to 4.31), interferon alone (RR = 1. 57 to 8.40). Cancer risk peaked at 2 years after HCL (RR = 4.13) and fell steadily afterwards, reaching a RR of 1.82 at 6 years. Twenty patients died, six due to HCL, 10 due to second malignancies, and four of unrelated causes. HCL patients appear to be inherently prone to malignancies. This appears to be more related to HCL tumor burden than to genetic predisposition or treatment effect. RR tends to fall with time after effective treatment. However, close monitoring for and vigorous prevention of cancer in HCL patients is advisable.

Molecular methods for detecting t(11;14) translocations in mantle-cell lymphomas

The t(11;14)(q13;q32) and its molecular counterpart, bcl1/JH, are characteristic of mantle-cell lymphomas (MCL). Molecular detection of the translocation is useful in diagnosis and classification, and also shows promise in detecting minimal residual disease. The purpose of this study was to determine the frequency of detecting bcl1/JH by polymerase chain reaction (PCR) compared with Southern blot analysis in cases proven by cytogenetic analysis to harbor t(11;14). Southern blot analysis using two probes targeting the major translocation cluster (MTC) and a third probe targeting the p94 region was performed, along with PCR using two different bcl1 MTC primers, on 18 cases of MCL known to have t(11;14). Southern blot analysis revealed bcl1 rearrangement in 13 of 18 cases (72%), 12 with MTC breakpoints and 1 with a p94 breakpoint. The 2.1-kb MTC probe "b" was superior to the smaller 700-bp probe "a" in detecting these rearrangements. The MTC translocation was identified by PCR in 10 of 12 cases, and both primer sets that were tested performed equally well. This study illustrates the frequency with which molecular methods detect known t(11;14) translocations in MCLs. These results may help clinical laboratory scientists optimize their procedure for detecting bcl1 translocations by molecular methods at initial diagnosis and for purposes of detecting minimal residual disease.

Immunohistochemical analysis of bcl-2, bax, mcl-1, and bcl-X expression in ovarian surface epithelial tumors

Cell survival may be enhanced in tumors by the inhibition of apoptosis, which allows tumor promotors to exert their effects. The bcl-2 related genes have been shown to contribute to either the inhibition or induction of apoptosis in a variety of neoplasms; therefore, it was hypothesized that the expression of these genes might contribute to malignant transformation in ovarian surface epithelial tumors. The expression of bcl-2 family proteins was investigated in 28 ovarian surface epithelial tumors, including serous and mucinous benign, borderline, and malignant tumors by immunohistochemical staining with antibodies to bcl-2, bax, bcl-X, and mcl-1 proteins. Staining intensity was scored on a 1+ to 3+ scale and the benign, borderline, and malignant tumors were compared. Significantly less immunoreactive bcl-2 and bcl-X proteins were present in malignant serous tumors compared to their benign counterparts. No difference was seen in immunostaining for bax or mcl-1 when benign, borderline, or malignant serous tumors were compared. In the mucinous tumors, no differences were seen in immunostaining for any of the bcl-2 family proteins between tumor types. The loss of expression of the antiapoptotic proto-oncogenes bcl-2 or bcl-X in serous carcinomas compared to benign serous tumors, together with previous demonstrations that the presence of bcl-2 in ovarian surface epithelial cancers is a favorable prognostic indicator, suggests that bcl-2 and bcl-X have biological functions in the ovary other than inducing apoptosis, acting instead as tumor suppressor proteins.

Homozygous deletions at chromosome 9p21 involving p16 and p15 are associated with histologic progression in follicle center lymphoma

Low-grade follicle center lymphoma (LGFCL) is characterized genetically by the t(14;18) translocation and an indolent clinical course. Histologic progression from LGFCL to an aggressive diffuse large B-cell lymphoma (DLCL) occurs in 60% to 80% of cases, and this transformation is associated with the accumulation of secondary genetic alterations. Using 10 polymorphic microsatellite markers spanning the chromosome 9p21 region harboring the p15 (p15(INK4B)/MTS-2/CDKN2B) and p16 (p16(INK4A)/MTS-1/CDKN2) tumor-suppressor gene loci, we analyzed 11 matched pairs of LGFCL and their corresponding progressed DLCL biopsies for loss of heterozygosity and homozygous deletions at 9p21. A comparative multiplex polymerase chain reaction assay was also used for the detection of homozygous deletions. Deletions were identified in 8 of the 11 cases studied (73%): 6 homozygous (54%) and 2 hemizygous (18%). The deletions were identified exclusively in the progressed DLCL biopsies. Immunohistochemical studies showed an excellent correlation with the results from the genetic analyses. Of the 9 matched pairs of LGFCL and progressed DLCL with interpretable immunohistochemical staining, 9 of 9 (100%) of the LGFCL showed diffuse reactivity for p16. Four of the 9 (44%) immunohistochemically evaluable cases of progressed DLCL showed loss of or, in 1 case, markedly diminished p16 expression. All 4 of these cases correspondingly showed homozygous deletions at 9p21. Five of the 9 progressed DLCL cases showed p16 expression and demonstrated retention of one or both 9p21 alleles by genetic analysis. This is the first longitudinal series examining sequential biopsy specimens of low-grade and progressed FCL for genetic loss at 9p21 encompassing the p16 and p15 loci. The high frequency and exclusive occurrence of deletions involving p16 in the progressed DLCLs suggests that genetic loss at 9p21 targeting p16 and/or p15 is an important secondary genetic event in the histologic progression of FCL.

TRAF-4 expression in epithelial progenitor cells. Analysis in normal adult, fetal, and tumor tissues

TRAF-4 was discovered because of its expression in breast cancers and is a member of the tumor necrosis factor (TNF) receptor-associated factor (TRAF) family of putative signal-transducing proteins. In vitro binding assays demonstrated that TRAF-4 interacts with the cytosolic domain of the lymphotoxin-beta receptor (LT beta R) and weakly with the p75 nerve growth factor receptor (NGFR) but not with TNFR1, TNFR2, Fas, or CD40. Immunofluorescence analysis of TRAF-4 in transfected cells demonstrated localization to cytosol but not nucleus. Immunohistochemical assays of normal human adult tissues revealed prominent cytosolic immunostaining in thymic epithelial cells and lymph node dendritic cells but not in lymphocytes or thymocytes, paralleling the reported patterns of LT beta R expression. The basal cell layer of most epithelia in the body was very strongly TRAF-4 immunopositive, including epidermis, nasopharynx, respiratory tract, salivary gland, and esophagus. Similar findings were obtained in 12- to 18-week human fetal tissue, indicating a highly restricted pattern of expression even during development in the mammary gland, epithelial cells of the terminal ducts were strongly TRAF-4 immunopositive whereas myoepithelial cells and most of the mammary epithelial cells lining the extralobular ducts were TRAF-4 immunonegative. Of 84 primary breast cancers evaluated, only 7 expressed TRAF-4. Ductal carcinoma in situ (DCIS) lesions were uniformly TRAF-4 immunonegative (n = 21). In the prostate, the basal cells were strongly immunostained for TRAF-4, whereas the secretory epithelial cells were TRAF-4 negative. Basal cells in prostate hypertrophy (n = 6) and prostatic intraepithelial neoplasia (PIN; n = 6) were strongly TRAF-4 positive, but none of the 32 primary and 16 metastatic prostate cancer specimens examined contained TRAF-4-positive malignant cells. Although also expressed in some types of mesenchymal cells, these findings suggest that TRAF-4 is a marker of normal epithelial stem cells, the expression of which often ceases on differentiation and malignant transformation.

Origin of the Hodgkin/Reed-Sternberg cells in chronic lymphocytic leukemia with "Hodgkin's transformation"

A lymphoma with the characteristic features of Hodgkin's disease (HD) occasionally develops in patients with B-cell chronic lymphocytic leukemia (CLL), and has been called Richter's syndrome with HD features. In such cases, large tumor cells have the morphological and immunophenotypic features of classical Hodgkin and Reed-Sternberg (H-RS) cells. However, it is not known whether the H-RS cells arise from transformation of the underlying CLL cells or from a different pathological process. We report herein a study of the clonal relationship between the CLL cells and the H-RS cells in three cases of Richter's syndrome with HD features by using a single cell assay. We isolated single CLL cells and H-RS cells from immunostained tissue sections by micromanipulation. The immunoglobulin heavy chain gene (IgH) complementarity determining region (CDR) III of each cell was amplified by the polymerase chain reaction (PCR). The products were then compared by gel electrophoresis and nucleotide sequencing. The IgH CDRIII sequences from the H-RS cells were identical to those from the CLL cells in two cases. In one case, the clonal relationship between the two types of cells could not be determined because PCR products could not be obtained from any of the H-RS cells. This study shows that the H-RS cells and the CLL cells belong to the same clonal population in some cases of Richter's syndrome with HD features. Furthermore, our findings indicate that mature B cells can undergo transformation to cells with the features of H-RS cells, in association with a cellular background typical of HD. This study also supports recent findings suggesting that the H-RS cells in classical HD are derived from transformed B cells.

Translocations of 11q13 in mantle cell lymphoma fail to disrupt the S mu bp-2 gene

We recently cloned a gene whose protein product binds to the Epstein-Barr virus BZLF1 gene promoter. The same gene has been previously cloned by another group who named it S mu bp-2 because its protein product binds to the S mu motif of the immunoglobulin heavy chain gene where it is postulated to function in immunoglobulin class switching. In the current study, we confirm that the S mu bp-2 gene is located on chromosome 11q13, a locus known to be altered by translocation in 50-70% of mantle cell lymphomas. We used Southern blot analysis to determine whether the S mu bp-2 gene was structurally rearranged in any of 25 mantle cell lymphomas. We found no evidence of rearrangement in any of these lymphomas including 18 that were proven to contain t(11;14) by cytogenetic analysis. These data suggest that structural alteration of the S mu bp-2 gene is not an underlying mechanism of tumorigenesis in mantle cell lymphomas.

Clinicopathological analysis of follicular lymphoma with a polyploid karyotype

The prognostic significance of specific cytogenetic abnormalities in follicular lymphoma (FL) is an area of ongoing research. A small percentage of FL are characterized by a polyploid karyotype. Several studies have analyzed ploidy level to determine its role as an independent prognostic factor in non-Hodgkins lymphoma, with equivocal results, mostly using DNA flow cytometry to ascertain ploidy status. We have performed cytogenetic analyses on 180 cases of FL with a t(14;18) diagnosed between 1980 and 1995. Cases were divided into a polyploid group (20 cases) and a non-polyploid group (160 cases), polyploidy defined as a modal chromosome number of 58 or greater. Each group included examples of the 3 subtypes of FL, [Working Formulation]: 1) follicular small cleaved cell (FSC), 2) follicular mixed, small and large cell (FM), and 3) follicular large cell (FLC). The median follow-up time was 38.5 months. The histological subclassification of the polyploid group revealed much less FSC (30% vs 66%, p < 0.004) and much more FLC (25% vs 4%, p < 0.003) than the non-polyploid group, implying histological progression may occur in parallel with the development of polyploidy. Recognized clinical prognostic factors were evenly distributed between the two groups and no survival difference was detected. We show that polyploidy as determined by classical cytogenetics is present in different frequencies across the subtypes of FL with a t(14;18), but is not an independent prognostic factor for survival in FL.

t(2;5) positive lymphoma with peripheral blood involvement

We report two cases of CD30 and t(2;5) positive lymphomas with peripheral blood (PB) involvement. Case one demonstrated the histological appearance of a diffuse large cell lymphoma with disease in the bone marrow (BM) and PB. Immunoperoxidase stains of the BM for CD30 proved to be of value in detecting disease. RT-PCR for the t(2;5) translocation product was positive in the PB, BM and lymph node. Case two had a typical anaplastic large cell lymphoma (ALCL) morphology, with a suboptimal BM biopsy, but abnormal circulating cells in the PB showing the presence of the NPM/ALK fusion product demonstrated by RT-PCR. The first case demonstrates that not all CD30 positive and t(2;5)-associated lymphomas have an anaplastic appearance. Routine staining for CD30 and EMA in BM biopsies is useful for pathological staging. The significance of the t(2;5) in defining a specific histological subtype is unclear. RT-PCR for the t(2;5) is a more sensitive test to detect disease in PB and BM as compared with light microscopy. The clinical significance of molecular staging for patients with ALCL using RT-PCR needs to be evaluated.

Immunohistochemical analysis of in vivo patterns of TRAF-3 expression, a member of the TNF receptor-associated factor family

An immunohistochemical approach was used to explore the in vivo expression of TNF receptor-associated factor 3 (TRAF-3), a putative signaling protein that binds to the cytosolic domains of CD30, CD40, and lymphotoxin-beta receptors. TRAF-3 immunostaining was detected in many types of cells throughout the human body. TRAF-3 immunostaining was only rarely present in thymocytes but was found in the thymic epithelioreticular cells. Lymphocytes in the bone marrow were also typically TRAF-3 immunonegative, whereas myeloid progenitor cells and megakaryocytes were often TRAF-3 positive. Peripheral blood lymphocytes were mostly TRAF-3 immunonegative, while granulocytes were TRAF-3 immunopositive. Monocytes were strongly immunostained for TRAF-3, but macrophages in nodes typically contained little or no TRAF-3 immunoreactivity. Some lymphocytes within the germinal centers of secondary lymphoid follicles in normal and reactive nodes were TRAF-3 immunopositive, as were occasional interfollicular lymphocytes in the T cell regions of these organs, but most lymphocytes appeared to be TRAF-3 immunonegative or stained only weakly. Plasma cells, however, were strongly TRAF-3 positive. Stimulation of PBLs with anti-CD3 Ab induced marked increases in the steady state levels of TRAF-3 protein in vitro as determined by immunoblotting, while levels of TRAF-2 were unchanged, implying a dynamic regulation of TRAF-3 expression. The findings establish for the first time the cell type- and differentiation-specific patterns of expression of a member of the TRAF family of proteins.

Immunohistochemical analysis of in vivo patterns of TRAF-3 expression, a member of the TNF receptor-associated factor family

An immunohistochemical approach was used to explore the in vivo expression of TNF receptor-associated factor 3 (TRAF-3), a putative signaling protein that binds to the cytosolic domains of CD30, CD40, and lymphotoxin-beta receptors. TRAF-3 immunostaining was detected in many types of cells throughout the human body. TRAF-3 immunostaining was only rarely present in thymocytes but was found in the thymic epithelioreticular cells. Lymphocytes in the bone marrow were also typically TRAF-3 immunonegative, whereas myeloid progenitor cells and megakaryocytes were often TRAF-3 positive. Peripheral blood lymphocytes were mostly TRAF-3 immunonegative, while granulocytes were TRAF-3 immunopositive. Monocytes were strongly immunostained for TRAF-3, but macrophages in nodes typically contained little or no TRAF-3 immunoreactivity. Some lymphocytes within the germinal centers of secondary lymphoid follicles in normal and reactive nodes were TRAF-3 immunopositive, as were occasional interfollicular lymphocytes in the T cell regions of these organs, but most lymphocytes appeared to be TRAF-3 immunonegative or stained only weakly. Plasma cells, however, were strongly TRAF-3 positive. Stimulation of PBLs with anti-CD3 Ab induced marked increases in the steady state levels of TRAF-3 protein in vitro as determined by immunoblotting, while levels of TRAF-2 were unchanged, implying a dynamic regulation of TRAF-3 expression. The findings establish for the first time the cell type- and differentiation-specific patterns of expression of a member of the TRAF family of proteins.

Bone marrow involvement in T-cell-rich B-cell lymphoma

We describe the histologic and immunohistochemical findings in specimens from bone marrow (BM) biopsies performed for staging purposes in 13 patients with a previous tissue-based diagnosis of T-cell-rich B-cell lymphoma (TCRBCL). Bone marrow involvement was found in 8 (62%) of 13 cases and was often paratrabecular. The histologic appearance was not pathognomonic of TCRBCL, with the differential diagnosis including Hodgkin's disease and peripheral T-cell lymphoma. The infiltrates typically had a pale low-power appearance (due to histiocytic infiltration, relative hypocellularity, or both) that, in conjunction with the presence of a polymorphous infiltrate of scattered large atypical cells amid a mixed infiltrate of small lymphocytes and histiocytes, was suggestive of Hodgkin's disease. Immunohistochemistry revealed CD20 reactivity of the large atypical cells with the absence of CD15 and CD30 reactivity, supporting the diagnosis of TCRBCL. A prominent small T-cell infiltrate accompanying the large atypical cells was observed in all positive BM biopsy specimens. The increased incidence of BM involvement in TCRBCL is significantly higher than that found in de novo B-cell diffuse large cell lymphoma, suggesting a possible biologic difference between the two entities. Our cases share some similar clinicopathologic features with histiocyte-rich B-cell lymphoma and with diffuse lymphocyte-predominant Hodgkin's disease, paragranuloma type. We discuss the possible relationship to these two entities.

Advanced diffuse large-cell lymphoma treated with 12-week combination chemotherapy: natural history of relapse after initial complete response and prognostic variables defining outcome after relapse

PURPOSE

To define both the natural history of and prognostic factors affecting outcome post relapse from a complete response in advanced stage diffuse large-cell lymphoma.

PATIENTS AND METHODS

A total of 468 patients aged 17-74 years received the 12-week duration chemotherapy regimens MACOP-B, VACOP-B and ACOP-12 between 1 April 1981 and 31 December 1995 for advanced stage diffuse large, mixed or immunoblastic lymphoma. Of these 402 entered a complete remission, 97 (24%) of whom subsequently relapsed. Initial staging data, follow-up, and relapse information were analyzed to define the natural history of relapse and also subjected to univariate and multivariate correlation with overall (OS) and failure free survival (FFS).

RESULTS

Eleven percent of the relapses were low grade. All other relapses were of intermediate grade with 75% occurring within the first two years, the remainder up until the eleventh year. Median and five-year OS from the time of relapse for intermediate grade relapse were 12 months and 20%; for FFS they were eight months and 18% respectively. Adverse independent factors, for both OS and FFS were: less than one year to relapse, decreasing performance status at relapse, and more than three nodal sites at relapse.

CONCLUSIONS

Low-grade relapse is not uncommon in patients who initially presented with diffuse large cell lymphoma. As the management of low- and intermediate grade disease is so different biopsy proof of the nature of the relapse is of value. The prognostic factors identified need to be taken into consideration when analyzing results from trials of secondary treatment so as to avoid erroneous conclusions about comparative treatment efficacy.

Prognostic significance of Bax protein expression in diffuse aggressive non-Hodgkin's lymphoma

Bax is a proapoptotic member of the Bcl-2 protein family. The incidence and prognostic significance of Bax protein expression in diffuse non-Hodgkin's lymphomas with a large cell component (DLCL) was determined by an immunohistochemical method by using paraffin-embedded tumors from a cohort of patients treated uniformly with combination chemotherapy (n = 139). All patients were between 16 and 70 years of age and had advanced stage disease of diffuse large cell type (diffuse mixed, diffuse large cell, immunoblastic, or anaplastic large cell). Paraffin sections from diagnostic biopsies were successfully immunostained for Bax in 113 cases. Of these, 7 (6%) tumors were scored as Bax immunonegative (< 1% Bax-stained tumor cells), 42 (37%) as low (1% to 10%), 9 (8%) as low-intermediate (11% to 30%), 25 (22%) as high-intermediate (31% to 70%), and 30 specimens (27%) as high for Bax expression (> 70%). Of the 7 Bax-immunonegative lymphomas, all also scored low (< or = 10% immunostained tumor cells) for Bcl-2 expression, whereas 78 of the 106 (74%) Bax-immunopositive tumors had low Bcl-2 expression. By itself, Bax expression was not of prognostic significance in univariate analysis, although there was a clear trend for patients with Bax-immunonegative lymphomas (n = 7) to relapse sooner and to die faster than patients whose tumors contained Bax-immunopositive malignant cells (n = 106; 8-year overall survival 29% versus 55%; P = .06). When combined with Bcl-2 immunostaining data, Bax provided additional prognostic information. Among patients with Bcl-2 low-expressing DLCLs, for example, Bax immunonegativity was associated with lower 8-year relapse-free survival (RFS; 29% v 61%; P < .01) and lower 8-year overall survival (OS; 29% v 63%; P < .05), suggesting that absence of Bax protein connotes a more aggressive phenotype when Bcl-2 protein is also not expressed at high levels. In contrast, low Bax expression was associated with improved 8-year disease-free survival (52% v 16%; P < .02), RFS (47% v 11%; P < .02), and OS (64% v 11%; P < .01) in patients whose tumors expressed Bcl-2 at high levels, suggesting that the combination of high levels of Bax and Bcl-2 expression is more deleterious than high levels of Bcl-2 expression alone. Bax expression failed to provide additional prognostic information beyond Bcl-2 expression in multivariate analysis that included the clinical International Prognostic Index factors (age, stage, lactate dehydrogenase, performance status, and number of extranodal sites) and immunophenotype. Taken together, the results suggest that Bax expression is not a major prognostic marker in DLCL. However, the interactions of the Bcl-2 and Bax expression data with respect to clinical outcome may shed new insights into the biological significance of Bcl-2/Bax protein heterodimerization.

t(11;18)(q21;q21) is the most common translocation in MALT lymphomas

BACKGROUND

Low grade malignant lymphomas arising from mucosa associated lymphoid tissue (MALT) represent a distinct clinicopathological entity. The cytogenetic findings and molecular genetics of MALT lymphomas remain minimally defined. Cytogenetic studies infrequently constitute part of the diagnostic work-up of MALT lymphomas, most commonly due to small biopsy size and their extranodal localization. Only 28 MALT cases with a clonal karyotype have been published to date. A number of chromosomal abnormalities have been observed with the majority of the cases featuring trisomy of chromosome 3 which is present in up to 78% of the cases.

MATERIALS AND METHODS

A total of 116 cases of MALT lymphoma were diagnosed at BCCA between 1988 and 1997. Eleven cases of pathologically confirmed MALT lymphomas were subjected to cytogenetic analysis at the time of the initial evaluation. Eight of 11 cases yielded successful cultures and the presence of a clonal karyotype using standard cytogenetic methodology. In addition, a single case of orbital MALT lymphoma with a clonal karyotype has been obtained through our consultative practice from University of Nebraska Medical Center. These nine cases of MALT lymphoma with a clonal karyotype are the subject of this report.

RESULTS AND CONCLUSION

In this study we report nine cytogenetically studied MALT lymphomas, three of which feature a novel t(11;18)(q21;q21) translocation which has also been observed in five other MALT cases described in the literature. This recurrent translocation is the most common translocation associated with MALT lymphomas being present in 33% (three of nine) of our cases and 18% (five of 28) of the previously published cases. The results suggest that a potentially important gene located at one of these breakpoints may be involved in the pathogenesis of MALT lymphomas.

Pathologic prognostic factors in diffuse aggressive non-Hodgkin's lymphoma

Recent advances in understanding the immunophenotypic, molecular genetic, and cytogenetic heterogeneity of diffuse large-cell lymphomas (DLCL) have provided new insights into the diversity of these disorders. Clinical prognostic factors are useful for predicting outcome in DLCL, but are surrogates of the underlying biology. The role of pathologic prognostic factors as the biologic correlates of clinical behavior in DLCL should allow the development of new prognostic models that incorporate both clinical and pathological data, and lead to improved outcome for those patients not cured by modern-day treatment regimens.

Immunohistochemical analysis of interleukin-1beta-converting enzyme/Ced-3 family protease, CPP32/Yama/Caspase-3, in Hodgkin's disease

The Caenorhabditis elegans cell death gene, Ced-3, encodes a protein homologous to mammalian interleukin-1beta-converting enzyme (ICE), a cysteine protease implicated in programmed cell death (PCD). CPP32, also known as Yama, apopain, and Caspase-3, is a member of this family, has substrate specificities similar to Ced-3, and has been shown to have an active role in PCD. Evidence suggests that these proteases act downstream of inhibitors of PCD such as Bcl-2 and Bcl-x(L), which are frequently expressed in Reed-Sternberg (RS) cells of Hodgkin's disease (HD). To date there have been no studies examining the role of the ICE/Ced-3 family of proteins, in particular CPP32, in HD. We examined 24 cases of HD with a classical immunophenotype and 6 cases of nodular lymphocyte predominant HD (NLPHD) for the expression of CPP32 in the RS cells and lymphohistiocytic (L&H) cells as detected by immunohistochemistry. Twenty two of 24 cases (92%) of HD expressed the protein in the RS cells, whereas the L&H cells in all 6 cases of NLPHD lacked expression of CPP32. These results provide further evidence that NLPHD is a phenotypically different disease distinct from classical forms of HD. The differential expression of the cell death protein CPP32 may be an important factor contributing to the apparently different clinical behaviour of NLPHD in contrast to classical HD. The lack of expression of CPP32 in NLPHD shares similarities with low-grade B-cell non-Hodgkin's lymphomas and may explain their common clinical course. Further studies are required to elucidate the significance of CPP32 in HD.

Clinical utility of heteroduplex analysis of TCR gamma gene rearrangements in the diagnosis of T-cell lymphoproliferative disorders

We conducted this study to assess the clinical utility of heteroduplex analysis of polymerase chain reaction (PCR) products for Tgamma gene rearrangements in the diagnosis of T-cell lymphoproliferative disorders (LPDs) using a single set of consensus primers. This method was used to study 103 cases using fresh or frozen tissue. These included 62 cases of T-cell LPDs, 25 cases of B-cell LPDs, 3 cases of anaplastic large cell lymphomas of undefined lineage, and 13 cases of reactive disorders. The latter group served as the negative control group. For all cases of T-cell LPDs, the results of Tbeta Southern analysis (SA) and heteroduplex PCR analysis were compared. We also studied 10 cases of postthymic T-cell lymphoma using paraffin-embedded tissue. Heteroduplex Tgamma PCR was positive in 51 (89%) of 57 cases that were rearranged by Tbeta SA. Eight of the 10 cases of T-cell lymphoma analyzed using paraffin-embedded tissue were positive. There were no false-positive results. These results demonstrate that this method is an effective screening test in the clinical laboratory. A positive result obviates the need to perform SA. Preliminary results suggest this method is useful using paraffin-embedded tissue.

Bcl-6 and lymphoproliferative disorders

We report a series of 37 cases of lymphoproliferative disorders with 3q27 structural chromosomal abnormalities. Breakpoints at 3q27, the site of the bcl-6 gene, appear in a broad range of B cell lymphoma histologies but are most frequently detected in follicular lymphomas lacking a t(14;18) and diffuse large cell lymphomas. The majority of 3q27 rearrangements result from translocations involving the immunoglobulin heavy or light chain genes, however, involvement of other partner chromosomes is also observed. Molecular rearrangement of bcl-6 is demonstrable in a subset of cases. Bcl-6 is a recently identified gene encoding a zinc-finger protein. It is normally expressed in germinal center B cells where it is believed to have a developmental or differentiation function. Transcriptional deregulation of bcl-6 through translocations, submicroscopic molecular rearrangements or point mutations may be responsible for this gene's putative lymphomagenic potential.

Massive bleeding from multiple gastric ulcerations in a patient with lymphocytic gastritis and celiac sprue

Uncontrolled hemorrhage and multisystem organ failure developed in a patient with celiac sprue, lymphocytic gastritis, and diffuse gastric ulceration. A proximal small bowel biopsy showed villous atrophy and lymphoplasmacytic infiltration consistent with celiac sprue. At autopsy, there were no gross or histologic findings to suggest lymphoma. The intestinal lymphocytic infiltrate was not monoclonal, and gene rearrangements were not detected. Lymphocytic gastritis is a rare cause of upper gastrointestinal hemorrhage, which may be the result of sensitivity to gluten or other luminal antigens. This diagnosis should be considered in cases of diffuse gastric ulceration with bleeding in which the endoscopic appearances are not typical of peptic ulcer disease or drug-induced erosions. Ideally, biopsies of gastric and duodenal mucosa should be performed to establish the diagnosis.

Prognostic significance of Bcl-2 protein expression and Bcl-2 gene rearrangement in diffuse aggressive non-Hodgkin's lymphoma

The prognostic significance of Bcl-2 protein expression and bcl-2 gene rearrangement in diffuse large cell lymphomas (DLCL) is controversial. Bcl-2 protein expression prevents apoptosis and may have an important role in clinical drug resistance. The presence of a bcl-2 gene rearrangement in de novo DLCL suggests a possible follicle center cell origin and perhaps a distinct clinical behavior more akin to low-grade non-Hodgkin's lymphoma (NHL). The purpose of this study was to determine the impact of Bcl-2 protein expression and bcl-2 gene rearrangement (mbr and mcr) on survival of a cohort of patients with DLCL who were uniformly evaluated and treated with effective chemotherapy. Patients included the original MACOP-B cohort (n = 121) and the initial 18 patients treated with the VACOP-B regimen (total = 139). All patients had advanced-stage disease, were 16 to 70 years old, and corresponded to Working Formulation categories F, G, or H. No patients had prior treatment, discordant lymphoma, or human immunodeficiency virus seropositivity. Paraffin sections from diagnostic biopsies were analyzed for bcl-2 gene rearrangement including mbr and mcr breakpoints by polymerase chain reaction and Bcl-2 protein expression by immunohistochemistry. With a median follow-up of 81 months, overall (OS), disease-free (DFS), and relapse-free survival (RFS) were measured to determine the prognostic significance of these parameters. Analyzable DNA was present in 118 of 139 (85%) cases, with 14 demonstrating a bcl-2 rearrangement (11 mbr, 3 mcr). All 14 of these bcl-2 gene rearrangement-positive cases were found in the 102 patients with a B-cell immunophenotype, but the presence of this rearrangement had no significant influence on survival. Bcl-2 protein expression was interpretable in 116 of 139 (83%) cases, with immunopositivity detected in 54 of 116 (47%). Using a cut-off of greater than 10% Bcl-2 immunopositive tumor cells for analysis, positive Bcl-2 protein expression was seen in 28 of 116 (24%) patients and the presence of this expression correlated with decreased 8-year OS (34% v 60%, P < .01), DFS (32% v 66%, P < .001), and RFS (25% v 59%, P < .001). Bcl-2 protein expression remained significant in multivariate analysis that included the clinical international prognostic index factors and immunophenotype (P < .02). In conclusion, although bcl-2 gene rearrangement status could not be shown to have an impact on outcome, Bcl-2 protein expression is a strong significant predictor of OS, DFS, and RFS in DLCLs.

Immunolocalization of the ICE/Ced-3-family protease, CPP32 (Caspase-3), in non-Hodgkin's lymphomas, chronic lymphocytic leukemias, and reactive lymph nodes

Immunohistochemical analysis of the apoptosis-effector protease CPP32 (Caspase-3) in normal lymph nodes, tonsils, and nodes affected with reactive hyperplasia (n = 22) showed strong immunoreactivity in the apoptosis-prone germinal center B-lymphocytes of secondary follicles, but little or no reactivity in the surrounding long-lived mantle zone lymphocytes. Immunoblot analysis of fluorescence-activated cell sorted germinal center and mantle zone B cells supported the immunohistochemical results. In 22 of 27 (81%) follicular small cleaved cell non-Hodgkin's B-cell lymphomas, the CPP32-immunopositive germinal center lymphocytes were replaced by CPP32-negative tumor cells. In contrast, the large cell component of follicular mixed cells (FMs) and follicular large cell lymphomas (FLCLs) was strongly CPP32 immunopositive in 12 of 17 (71%) and in 8 of 14 (57%) cases, respectively, whereas the residual small-cleaved cells were poorly stained for CPP32 in all FLCLs and in 12 of 17 (71%) FMs, suggesting that an upregulation of CPP32 immunoreactivity occurred during progression. Similarly, cytosolic immunostaining for CPP32 was present in 10 of 12 (83%) diffuse large cell lymphomas (DLCLs) and 2 of 3 diffuse mixed B-cell lymphomas (DMs). Immunopositivity for CPP32 was also found in the majority of other types of non-Hodgkin's lymphomas studied. Plasmacytomas were CPP32 immunonegative in 4 of 12 (33%) cases, in contrast to normal plasma cells, which uniformly contained intense CPP32 immunoreactivity, implying downregulation of CPP32 in a subset of these malignancies. All 12 peripheral blood B-cell chronic lymphocyte leukemia specimens examined were CPP32 immunopositive, whereas 3 of 3 small lymphocytic lymphomas were CPP32 negative, suggesting that CPP32 expression may vary depending on the tissue compartment in which these neoplastic B cells reside. The results show dynamic regulation of CPP32 expression in normal and malignant lymphocytes.

Late relapse in patients with diffuse large-cell lymphoma treated with MACOP-B

PURPOSE

To examine the clinical course of patients who experienced a late relapse after initial curative chemotherapy for advanced-stage diffuse large-cell lymphoma.

PATIENTS AND METHODS

Between April 1981 and June 1986, 127 patients with de novo advanced-stage diffuse large-cell lymphoma were treated with a 12-week chemotherapy program (methotrexate, doxorubicin, cyclophosphamide, vincristine, prednisone, and bleomycin [MACOP-B]). The overall survival rate at 10 years is 52%. One hundred six patients (83%) entered a complete remission (CR) and 43 of them relapsed. With a median follow-up duration of 146 months, 26 patients relapsed early and 17 relapsed late, ie, after a continuous CR (cCR) of greater than 24 months. All late relapses occurred in patients with B-cell lymphoma.

RESULTS

After 24 months from diagnosis, the rate of late relapse averaged 2.2% per year and reached a projected 22% actuarial risk of late relapse after 10 years. The median time to late relapse was 69 months (range, 38 to 141). Ten patients relapsed with aggressive histologic subtypes and were treated with curative intent using anthracycline-based chemotherapy. Four remain in second CR, one is alive with disease, and five died of disease or while on treatment. The 6-year overall survival rate from the time of relapse (SFR) for these 10 patients is 42%. Six patients relapsed with low-grade follicular lymphoma. These patients received various treatments intended to control, but not necessarily cure disease. One is in second CR, one is alive with disease, and four died of disease or while on treatment. The 6-year overall SFR rate for these six patients is 40%. bcl-2 translocation and Bcl-2 protein expression at diagnosis did not predict for the type of late relapse. One patient did not undergo repeat biopsy at relapse and died 9 months later despite aggressive therapy.

CONCLUSION

Curative therapy should be attempted in patients who relapse late with aggressive-histology lymphoma and those who relapse with follicular histology may benefit from palliative treatment. The behavior of late-relapse lymphoma is similar to de novo lymphoma, with outcome dictated by the histologic subtype at relapse.

Mantle cell lymphoma: a clinicopathologic study of 80 cases

Mantle cell lymphoma (MCL) is a relatively uncommon yet distinct type of malignant lymphoma whose clinical and pathological characterization has been limited by the small numbers of cases published to date. We studied 80 cases of MCL seen at a single institution over 7 years to determine both clinical and pathological prognostic factors. The patients in this study were predominantly male (70%) and older (mean age, 63 years) and presented with advanced-stage disease (88%). Extranodal involvement was common. Median overall survival (OS) was 43 months. Except for performance status, prognosis was not significantly influenced by clinical prognostic factors. Histologically, MCL architecture was classified as diffuse (78%), nodular (16%), or mantle zone (6%); the OS among these groups was identical. Increased mitotic activity (>20 mitotic figures per 10 high power fields), blastic transformation, and peripheral blood involvement at diagnosis also predicted for a worse outcome, but bone marrow involvement did not. The presence or absence of a translocation t(11; 14) by cytogenetic analysis or a bcl-1 rearrangement by Southern analysis did not significantly predict outcome. In summary, this study of 80 cases of MCL highlights its distinctive clinicopathologic features and shows that increased mitotic activity, blastic morphology, and peripheral blood involvement at diagnosis are prognostically important factors.