Nodal Follicular Lymphoma Research Articles

Bcl-2, Bcl-6 and CD10 expression in cutaneous B-cell lymphoma: further support for a follicle centre cell origin and differential diagnostic significance.

Primary cutaneous follicle centre cell lymphomas (PCFCCLs) are the most common type of cutaneous B-cell lymphoma. There is ongoing discussion on the origin of the neoplastic B cells in these PCFCCLs, and consequently on their relation to the groups of primary cutaneous marginal zone B-cell lymphomas (PCMZLs) and nodal follicular lymphomas. To define better the neoplastic B cells in PCFCCLs, and to find out if differences in the expression of the antiapoptopic protein Bcl-2, and Bcl-6 and CD10, molecules which are normally expressed by the neoplastic B cells in nodal follicular lymphomas, might have diagnostic or prognostic significance in cutaneous B-cell lymphoproliferative disorders. Pretreatment biopsies of well-defined groups of PCFCCL (n = 24), PCMZL (n = 14), primary cutaneous large B-cell lymphoma of the leg (PCLBCL-leg; n = 19), secondary cutaneous follicular lymphoma (n = 3) and cutaneous pseudo-B-cell lymphoma (n = 6) were investigated by immunohistochemistry for expression of Bcl-2, Bcl-6 and CD10. The PCFCCLs consistently expressed Bcl-6, whereas CD10 and Bcl-2 were expressed in only one and two of 24 cases, respectively. In contrast, PCMZLs were always negative for Bcl-6 and CD10, but were Bcl-2 positive, whereas skin and lymph node localizations of secondary cutaneous follicular lymphomas consistently expressed all of Bcl-2, Bcl-6 and CD10. Reactive follicle centre cells in pseudo-B-cell lymphomas expressed Bcl-6 (six of six cases) and CD10 (five of six cases), but not Bcl-2. PCLBCL-leg was Bcl-6 positive and CD10 negative in all cases, irrespective of clinical outcome, and strongly expressed Bcl-2 protein in all but two cases. The results of the present study provide further support for the follicle centre cell origin of both PCFCCL and PCLBCL-leg, and indicate that staining for Bcl-2, Bcl-6 and CD10 can serve as an important adjunct in the differential diagnosis of cutaneous B-cell lymphoproliferative disorders.

Primary follicular lymphoma of the gastrointestinal tract: a study of 25 cases and a literature review

To describe better the clinical, biological, endoscopic and pathological presentations, as well as the outcome, of primary follicular lymphoma (FL) of the gastrointestinal (GI) tract. From November 1983 to February 2001, 25 eligible patients with primary FL of the GI tract were retrieved from several French Departments of Pathology departments based on histological diagnosis and immunophenotype. Median age was 56 years (range 44-71) with a sex ratio female/male of 2 (17/8). Abdominal pain was the main presenting symptom followed by intestinal obstruction. The small intestine was the most common site of involvement. Lesions were unifocal in the majority of patients (15/25). A pattern similar to lymphomatous polyposis was observed in 50% (7/14) of patients. Twelve patients had stage I, 10 patients stage II and three patients stage IV disease, and there was minimal extra intestinal involvement. Lymphoma tissues were composed of neoplastic follicles, most of which were grade 1 according to the World Health Organization (WHO) classification. The immunophenotype of the lymphoma cells was CD20+, CD10+, bcl2+ and CD5-. In tissue samples, IgH/bcl2 rearrangement at the MBR locus was present in 11 of 14 patients tested. Seven patients did not receive any treatment; four of them progressed after a median follow-up of 37.5 months. Treatment was otherwise heterogeneous, and complete remission was obtained in 15 patients which lasted for a median of 31 months. Relapses were either in the GI tract (n = 3) or outside the GI tract (n = 3). After a median follow-up of 34 months (range 5-203), 22 patients were still alive (complete remission, 11; partial remission, three; stable disease, six; progressive disease, two). Primary FL of the GI tract is a predominantly female lymphoma that most frequently involves the small intestine. Since the endoscopic and clinical presentation may not be different from lymphomatous polyposis, which is often associated with mantle cell origin of tumor cells, it is mandatory to perform an immunohistological and, if possible, a molecular analysis of GI lymphoma. The course of the disease is indolent and does not differ from nodal FL. Thus, therapy may not be required unless significant clinical symptoms are present or until disease progression.

Primary and secondary cutaneous diffuse large B-cell lymphomas: a multiparameter analysis of 25 cases including fluorescence in situ hybridization for t(14;18) translocation.

Although primary cutaneous diffuse large B-cell lymphomas (DLBCLs) except for those of the leg are grouped together with primary cutaneous follicle center cell lymphoma in the European Organization for Research and Treatment of Cancer classification of primary cutaneous lymphomas, they typically lack the usual phenotypic profile of follicular lymphoma. Whether they are truly of follicular center cell origin, have a molecular pathogenesis similar to nodal follicular lymphoma, or have any biologic features that distinguish them from secondary DLBCL involving skin remains uncertain. To address these issues, a retrospective multiparameter study of 25 patients including clinical, histologic, immunophenotypic, and cytogenetic analyses was performed. A classic CD10+, bcl-6+ follicular center cell profile was found in 10 (40%) cutaneous DLBCL (2 of 11 primary, 5 of 8 secondary, 3 of 6 unclassified) with bcl-2 expression seen only in the nonprimary cases. Of the remaining cases, 14 cases (56%) were CD10-, bcl-6+, bcl-2+/- (9 primary) and one case (4%) was CD10-, bcl-6-, bcl-2+ (0 primary). Fluorescence in situ hybridization analysis showed a t(14;18) in 0 of 9 primary and 3 of 5 secondary cases. Primary cases were frequently found in the head/neck region, whereas secondary cases were more common on the trunk and extremities. Patients with primary disease were all alive, usually having received only local therapy, at a median follow-up of 19 months. Most secondary cases were treated with chemotherapy with only one untreated patient dead of disease at a median follow-up of 5 months. Primary cutaneous DLBCLs therefore appear to be distinctive as they have fewer features of follicular lymphoma than do secondary cases. Nevertheless, some appear to be of follicular center cell origin, even though they probably have a different molecular pathogenesis than most nodal follicular lymphomas.

Primary Cutaneous Follicular Lymphoma

Primary cutaneous B-cell lymphomas displaying a prominent follicular growth pattern are rare and remain poorly defined, particularly in terms of the frequency of detection of t(14;18) and whether or not, as a group, they represent an entity distinct from follicular lymphoma arising in lymph nodes. The morphologic, immunophenotypic, and clinical features of 16 cases of primary cutaneous follicular lymphoma, identified during a review of all PCBCL in the Scotland and Newcastle Lymphoma Group database, were studied and the number of cases harboring t(14;18) assessed by polymerase chain reaction using primers to the major breakpoint cluster region. Comparisons were made with stage I follicular lymphoma arising in lymph nodes and follicular lymphoma secondarily involving the skin. All cases of primary cutaneous follicular lymphoma had undergone thorough staging, including physical examination and CT scans of chest and abdomen, with 15 of 16 cases also having bone marrow aspiration and/or trephine performed. The morphology and immunophenotype of the lesions were similar to that expected in lymph nodes. All cases displayed a follicular architecture complete with follicular dendritic cell networks and comprised an admixture of CD10 and/or bcl-6-positive neoplastic centrocytes and centroblasts with 13 of 16 cases also expressing bcl-2 protein. None harbored t(14;18), a significantly different finding compared with cases of stage I nodal follicular lymphoma (p <0.001) and secondary cutaneous follicular lymphoma (p <0.039). Relapses occurred in five of 15 patients with a median time to first relapse of 20 months (range 1-73 months; mean 27.2 months). These were multiple in two patients and involved extracutaneous sites in two patients. The propensity for relapse was similar to that in a comparative cohort of stage I nodal follicular lymphoma, but the group of primary cutaneous follicular lymphoma were significantly more likely to attain complete remission; all cases of primary cutaneous follicular lymphoma were in complete remission when last seen compared with 49 of 87 patients with stage I nodal follicular lymphoma (p <0.005). No lymphoma-related deaths were encountered in 15 cases with a mean follow-up >60 months (range 5-119 months). These results support the concept of a subtype of follicular lymphoma lacking t(14;18) involving the major breakpoint cluster region, and with a propensity to arise in the skin. Despite a high relapse rate patients with primary cutaneous follicular lymphoma are more likely to achieve complete remission and may ultimately have a more favorable long-term prognosis than those with equivalent nodal disease.

Primary cutaneous follicular lymphoma: an assessment of clinical, histopathologic, immunophenotypic, and molecular features.

Unlike nodal follicular lymphoma (NFL), Primary cutaneous follicular lymphomas (PCFLs) rarely express Bcl-2 protein or t(14;18)(q32;q21) (Bcl-2/IgH). The aim of this study was to further characterize PCFL in a large series from North America. Clinical data and archival formalin-fixed, paraffin-embedded tissue were obtained from 32 patients. PCFL was defined as follicular lymphoma limited to the skin at the time of diagnosis and within the first 6 months after diagnosis. Specimens were analyzed for the expression of CD3, CD10, CD20, Bcl-2, and Bcl-6 proteins by immunohistochemistry as well as for the presence of t(14;18)(q32;q21) by polymerase chain reaction. The male-to-female ratio was 1.5:1, with a median age of 60 years. Twenty-four patients had lesions on the head and neck, five had lesions on the trunk, and three had lesions on both head and trunk. Follow-up data were available in all cases, with a mean length of 35.8 months. The majority of the patients were treated with radiation therapy. All patients were alive at last follow-up except one. Recurrence was noted in seven patients (22%), after a mean disease-free survival time of 17.7 months. CD10 and Bcl-6 expression were seen in 29 (91%) of 32 and 31 (97%) of 32 cases, respectively. Bcl-2 expression was noted in 13 (41%) of 32 cases. PCR results for t(14;18)(q32;q21) were positive in 11 (34%) of 32 patients and showed correlation with Bcl-2 protein expression. The sequencing of the t(14;18)(q32;q21) amplicons confirmed unique breakpoints in each of the seven tested cases. Comparison between the Bcl-2 and/or t(14;18)(q32;q21)-positive and t(14;18)(q32;q21)-negative cases revealed no significant difference in age, site, clinical course, or outcome. We demonstrated Bcl-2 protein expression and t(14;18)(q32;q21) in a significant minority of cases, suggesting a relationship with NFL. It remains to be seen whether, on longer follow-up, there is any clinical difference in cases with and without t(14;18)(q32;q21).

Primary Cutaneous Follicular Lymphoma: An Assessment of Clinical, Histopathologic, Immunophenotypic, and Molecular Features

PURPOSE: Unlike nodal follicular lymphoma (NFL), Primary cutaneous follicular lymphomas (PCFLs) rarely express Bcl-2 protein or t(14;18)(q32;q21) (Bcl-2/IgH). The aim of this study was to further characterize PCFL in a large series from North America. PATIENTS AND METHODS: Clinical data and archival formalin-fixed, paraffin-embedded tissue were obtained from 32 patients. PCFL was defined as follicular lymphoma limited to the skin at the time of diagnosis and within the first 6 months after diagnosis. Specimens were analyzed for the expression of CD3, CD10, CD20, Bcl-2, and Bcl-6 proteins by immunohistochemistry as well as for the presence of t(14;18)(q32;q21) by polymerase chain reaction. RESULTS: The male-to-female ratio was 1.5:1, with a median age of 60 years. Twenty-four patients had lesions on the head and neck, five had lesions on the trunk, and three had lesions on both head and trunk. Follow-up data were available in all cases, with a mean length of 35.8 months. The majority of the patients were treated with radiation therapy. All patients were alive at last follow-up except one. Recurrence was noted in seven patients (22%), after a mean disease-free survival time of 17.7 months. CD10 and Bcl-6 expression were seen in 29 (91%) of 32 and 31 (97%) of 32 cases, respectively. Bcl-2 expression was noted in 13 (41%) of 32 cases. PCR results for t(14;18)(q32;q21) were positive in 11 (34%) of 32 patients and showed correlation with Bcl-2 protein expression. The sequencing of the t(14;18)(q32;q21) amplicons confirmed unique breakpoints in each of the seven tested cases. Comparison between the Bcl-2 and/or t(14;18)(q32;q21)-positive and t(14;18)(q32;q21)-negative cases revealed no significant difference in age, site, clinical course, or outcome. CONCLUSION: We demonstrated Bcl-2 protein expression and t(14;18)(q32;q21) in a significant minority of cases, suggesting a relationship with NFL. It remains to be seen whether, on longer follow-up, there is any clinical difference in cases with and without t(14;18)(q32;q21).

Primary Cutaneous Follicle Center Cell Lymphoma and Limited Stage Follicular Non-Hodgkin's Lymphoma: A Comparison of Clinical and Biological Features

Primary cutaneous follicular lymphoma (PCFL) and nodal follicular lymphoma (NFL) are different entities, which, nevertheless, exhibit common features. The aim of this study was to compare the clinico-biological characteristics and the outcome of patients with PCFL and with limited stage NFL. A group of 22 consecutive patients with PCFL presenting with single or multiple cutaneous lesions was compared to a group of 21 patients with limited stage NFL. The median age was 56 and 55 years, respectively. The histologic features were compared, as well as treatment modalities and response. Treatment of PCFL consisted of restricted field radiotherapy (RT), chemotherapy (CHT) and combined modalities (CM) in 12, 5 and 5 cases, respectively. Among the 21 patients with NFL, RT was employed in 13, CHT in 7 and the CM in one patient. The response to treatment was: 17 complete responses, CR (12 RT, 2 CHT, 3 CM), 3 partial responses, PR (1 CHT, 2 CM) and 2 non-responses, NR (2 CHT) in the PCFL group, while in the NFL group 18 patients attained CR (13 RT, 4 CHT, 1 CM) and 3 PR (3 CHT). The relapse rate was 22.7 and 28.5% in PCFL and NFL, respectively (median follow up of 48 and 50 months). The estimated 4 years event free survival (EFS) in the PCFL and NFL patients were 68 and 70%, respectively, (P =0.83). The estimated 4 years overall survival (OS) in the PCFL and NFL groups were 90% and 100% respectively, (P =0.254). Among the 22 patients with PCFL, there was a higher incidence of large cells than in NFL, although the differences were not significant (P =0.08). In conclusion, despite histologic (higher proportion of large cells) and biologic differences, cutaneous and limited stage NFL show similar responses to treatment, with similar relapse rates, EFS and OS.

Coexpression of Bcl-6 and CD10 in diffuse large B-cell lymphomas: Significance of Bcl-6 expression patterns in identifying germinal center B-cell lymphoma

Most follicular lymphomas (FLs) transform to diffuse lymphoma eventually, comprising a significant proportion of diffuse large B-cell lymphoma (DLBCL). Judging by bcl-2 rearrangement (bcl-2R), one third of DLBCLs are believed to be of FL derivation in the Western population. However, bcl-2R is not specific and is not detectable in every case of FL. In East Asia, FL is uncommon but DLBCL is not. The proportion of tumors of FL origin in DLBCL is not known in this region. The coexpression of Bcl-6 and CD10 proteins, a reliable marker to identify germinal center (GC) B-cell lymphoma including FL, was analyzed in primary nodal DLBCLs (n = 104) diagnosed at major hospitals in Seoul during a recent 2-year period, along with well-defined cases (n = 17) of nodal FL as controls. Bcl-2 protein expression (n = 77) was also studied along with bcl-2R (n = 64), by polymerase chain reaction. Formalin-fixed archival specimens were used in all these assays. The Bcl-6/CD10 coexpression was observed in 35 DLBCLs (34%) and 14 FLs (82%), and most of them showed a pattern of Bcl-6 expression similar to that of the GC. Bcl-2 expression or bcl-2R did not correlate with Bcl-6/CD10 coexpression. Histologically, compartmentalizing sclerosis was associated with a high rate of the coexpression (8 of 10). In conclusion, to detect GC B-cell lymphoma in routine biopsy specimens, a pattern of Bcl-6 staining similar to the GC must be identified. Bcl-6+/CD10+ GC B-cell lymphomas thus defined comprised one third of primary nodal DLBCLs in Korea. The incidence rate is similar to that in the West. The reasons for the discrepancy between the incidence of GC B-cell lymphoma and the paucity of the follicular pattern in East Asian subjects warrant further studies. HUM PATHOL 32:954-962. Copyright © 2001 by W.B. Saunders Company

Cutaneous Presentation of Follicular Lymphomas

The description of primary cutaneous follicular lymphoma has raised interest in the differential diagnosis of this versus disseminated follicular lymphoma involving the skin. We report here on four cases of Stage IV follicular lymphoma, diagnosed in skin biopsy, in which cutaneous lesion was the most noticeable feature of clinical presentation. In all cases, the morphological features were superimposed over typical nodal follicular lymphoma. Apart from classic B-cell markers, they were characterized by CD10 and bcl6 positivity, markers of follicle germinal center cells; and bcl2 expression, with a corresponding t(14;18) translocation in three of three cases examined. In all four cases, bone marrow study and clinical staging revealed disease that had disseminated since diagnosis. Follow-up showed relapsing cutaneous and nodal disease in two cases. The only difference observed with a control group of 10 cases of primary cutaneous follicular lymphoma was the absence in this group of t(14; 18). Disseminated classical follicular lymphoma has to be considered in the differential diagnosis of follicular lymphoma presenting in the skin. This series of cases suggests that the presence of t(14;18) could imply the existence of disease that has disseminated beyond the skin and that cases harboring this translocation could be candidates for systemic polychemotherapy.

Cutaneous b-cell lymphomas of follicular and marginal zone types: use of Bcl-6, CD10, Bcl-2, and CD21 in differential diagnosis and classification.

Cutaneous follicular lymphomas (FLs) and cutaneous B-cell lymphomas of extranodal marginal zone (MZL)/mucosal-associated lymphoid tissue (MALT) type may have morphologic overlap, despite the fact that they are thought to be of distinct derivation (germinal center vs. postgerminal center). The problem is compounded by the reported absence of bcl-2 expression by many cutaneous FLs, leading to speculation that cutaneous FL may be unrelated to nodal FL. The authors analyzed the expression of the germinal center-associated antigens bcl-6 and CD10 and of bcl-2 in 18 cutaneous B-cell lymphomas (10 FLs and eight MZLs), in relationship to CD21+ follicular structures, to clarify the relationship of nodal to cutaneous FLs and to explore the value of these antigens in differential diagnosis. The authors studied 10 cutaneous FLs (seven primary and three secondary) and eight MZLs (six primary and two secondary). The FLs (found in six men and four women age 45-75 years) involved the trunk (n = 3) and scalp, face and neck (n = 7). The MZLs (found in five women and three men age 34-81 years) involved the trunk (n = 4), face and neck (n = 2), and arm (n = 2). Immunostaining for CD21, bcl-6, CD10, and bcl-2 allowed the delineation of compartments within the tumors and yielded distinct patterns of staining in FL and MZL. In both follicular and interfollicular/diffuse areas of FL the neoplastic cells were bcl-6+ (10 of 10), often CD10+ (seven of 10, four of seven primary), and bcl-2+ (nine of 10, six of seven primary). Only three of seven cases (one of five primary) had bcl-2 rearrangement detectable by polymerase chain reaction. In the MZLs, the neoplastic B-cells were bcl-6-, CD10-, and bcl-2+ (eight of eight). Three patterns of CD21+ follicles were identified in MZL: reactive germinal centers, uniformly bcl-6+, CD10+, and bcl-2- (five of eight MZLs); colonized follicles, both bcl-6-, bcl-2+, and L26+ cells, and bcl-6+ and bcl-2- cells (five of eight MZLs); and expanded/colonized follicular dendritic cell meshworks, bcl-6- and bcl-2+ B cells with rare residual bcl-6+ and bcl-2- cells (four of eight MZLs). The authors conclude that cutaneous FLs express bcl-6 uniformly, usually express CD10 and bcl-2, and have a follicular pattern similar to nodal FL and consistent with a germinal center origin. The immunophenotype of cutaneous FL is distinct from that of cutaneous MZL, which is negative for bcl-6 and CD10. Colonized follicles in MZL, identified by CD21+ follicular dendritic cell meshworks, contained numerous bcl-6- and bcl-2+ B cells, and were readily distinguished from neoplastic follicles in FL. Conversely, CD21- interfollicular and diffuse areas in FLs contained bcl-6+ and CD10+ cells, which were not seen in diffuse areas of MZLs. Thus, the combination of bcl-2, bcl-6, and CD21 staining is useful for the distinction of cutaneous MZL from cutaneous FL.

Absence of the t(14;18) chromosomal translocation in primary cutaneous B-cell lymphoma.

The t(14;18)(q32;q21) chromosomal translocation is found in the majority of nodal follicular lymphomas and in a lower percentage of systemic high-grade diffuse large B-cell lymphomas. The translocation results in the juxtaposition of the bcl-2 gene on chromosome 18 with the immunoglobulin heavy chain joining region on chromosome 14. Bcl-2 protein prevents apoptosis and the translocation leads to overexpression of a functionally normal Bcl-2 protein that prevents apoptosis of neoplastic cells. The purpose of our study was to analyse cases of primary cutaneous B-cell lymphoma (PCBCL) for the presence of the t(14;18) translocation and to correlate the results with Bcl-2 expression and histological subtype. Forty-four cutaneous B-cell lymphoid proliferations (36 PCBCL, four follicular B-cell lymphomas with cutaneous presentation and four reactive B-cell infiltrates) were analysed by polymerase chain reaction amplification and polyacrylamide gel electrophoresis using consensus primers for the joining region on the immunoglobulin heavy chain gene in combination with either a primer for the major breakpoint region (MBR) or the minor cluster region (mcr) on chromosome 18. None of 36 PCBCL analysed demonstrated a t(14;18) translocation; however, three of four systemic follicular B-cell lymphomas presenting in the skin were found to have a translocation in the MBR, which was confirmed by sequence analysis. Correlation with Bcl-2 immunostaining showed that of seven patients with high-grade cutaneous diffuse large B-cell lymphoma, four were Bcl-2 positive but had no evidence of a t(14;18) translocation. In the five cases classified as primary cutaneous follicle centre cell lymphoma, the neoplastic cells within the germinal centres failed to express Bcl-2. However, Bcl-2-positive neoplastic cells were present in all four cases of systemic follicular lymphoma, including the case that did not show a t(14;18) translocation. In all cases of marginal zone lymphoma the marginal zone lymphocytes were Bcl-2 positive. These findings indicate that the t(14;18) translocation does not occur in PCBCL, which suggests the involvement of different pathogenetic mechanisms compared with their nodal counterparts. Furthermore, the detection of a t(14;18) translocation in cutaneous B-cell lymphoma should suggest the presence of systemic disease, which underlies the need for exhaustive staging procedures.

Bcl‐2 and p53 protein expression in follicular lymphoma

Recent studies have shown bcl-2 to be regulated by p53. Other studies have suggested an inverse relationship between p53 and bcl-2 protein expression in breast and colonic cancers and in a variety of subtypes of non-Hodgkin's lymphoma. This study investigates the relationship between bcl-2 and p53 protein expression and the correlation between these findings and the grade and cell type of follicular lymphomas according to the REAL classification. Paraffin-embedded nodal follicular lymphomas (n=37) were subjected to bcl-2 and p53 immunohistochemistry on tissue sections using a three-step ABC system. Positive immunostaining for both oncoproteins was scored using a three-tiered scale: +, <10 per cent cells; ++, 10–50 per cent cells; and +++, >50 per cent cells (<10 per cent was used as a cut-off to define negative tumours). Ninety-seven per cent (36/37) of follicular lymphomas expressed bcl-2 protein in all three grades, manifesting in the small cell (grade 1) through to the large cell (grade 3). p53 protein expression showed a pattern of increasing immunostaining with progression towards the high-grade follicular lymphoma: grade 1=6 per cent (1/16); grade 2=48 per cent (10/21); grade 3=100 per cent (6/6). Five cases comprised varying combinations of grades. This latter finding suggests a role for p53 mutation in the progression/transformation of follicular lymphoma. The mechanism, however, differs from that suggested in breast and colonic cancers, since an inverse relationship between bcl-2 and p53 was not demonstrated in the present study. © 1997 John Wiley & Sons, Ltd.

Bcl-2 and p53 protein expression in follicular lymphoma.

Recent studies have shown bcl-2 to be regulated by p53. Other studies have suggested an inverse relationship between p53 and bcl-2 protein expression in breast and colonic cancers and in a variety of subtypes of non-Hodgkin's lymphoma. This study investigates the relationship between bcl-2 and p53 protein expression and the correlation between these findings and the grade and cell type of follicular lymphomas according to the REAL classification. Paraffin-embedded nodal follicular lymphomas (n = 37) were subjected to bcl-2 and p53 immunohistochemistry on tissue sections using a three-step ABC system. Positive immunostaining for both oncoproteins was scored using a three-tiered scale: +, < 10 per cent cells; ++, 10-50 per cent cells; and ++(+), > 50 per cent cells (< 10 per cent was used as a cut-off to define negative tumours). Ninety-seven per cent (36/37) of follicular lymphomas expressed bcl-2 protein in all three grades, manifesting in the small cell (grade 1) through to the large cell (grade 3). p53 protein expression showed a pattern of increasing immunostaining with progression towards the high-grade follicular lymphoma: grade 1 = 6 per cent (1/16); grade 2 = 48 per cent (10/21); grade 3 = 100 per cent (6/6). Five cases comprised varying combinations of grades. This latter finding suggests a role for p53 mutation in the progression/transformation of follicular lymphoma. The mechanism, however, differs from that suggested in breast and colonic cancers, since an inverse relationship between bcl-2 and p53 was not demonstrated in the present study.

Immunohistochemistry in apparently normal bone marrow trephine specimens from patients with nodal follicular lymphoma.

To establish the role of immunohistochemistry (using a limited panel of antibodies) in detecting minimal involvement by follicular lymphoma in routinely processed bone marrow trephine specimens, which show no obvious morphological (light microscopic) evidence of lymphoma; to determine whether bcl-2 immunostaining in bone marrow distinguishes between benign and malignant infiltrates in a patient with nodal follicular lymphoma. Twenty seven consecutively selected paraffin wax embedded, formalin fixed bone marrow trephine specimens were stained with the following antibodies: anti-bcl-2, anti-CD79a, anti-CD3, and kappa and lambda light chains, using the Streptavidin biotin complex technique. Five of the 27 cases, which showed no evidence of involvement by follicular lymphoma on routine stains, showed monotypic B cells on immunohistochemistry. Two of the cases were diffuse, while the remaining three showed mini-aggregates around bony trabeculae. In all five cases the lymphomatous infiltrates were strongly bcl-2 positive. Reactive B lymphoid nodules did not show the same degree of bcl-2 positivity, and negative cells could be discerned within the reactive nodules. There is merit in studying so-called negative bone marrows immunohistochemically in order to detect minimal involvement by follicular lymphoma. A limited panel of antibodies including anti-bcl-2, anti-CD79a and anti-CD3 is usually adequate to accomplish this. Strongly bcl-2 positive lymphoid aggregates in the bone marrow of patients with nodal follicular lymphoma are indicative of lymphoma.

Immunoreactivity for bcl‐2 protein in cutaneous lymphomas and lymphoid hyperplasias*

The B-cell leukemia/lymphoma gene (bcl-2) produces a unique protein product (BCLP) that is believed to protect lymphoid cells from apoptosis. The bcl-2 gene is frequently rearranged in nodal follicular lymphomas as well as in diffuse lymphoproliferations, but has generally been regarded as most useful in the recognition of the former of these lesions. However, little is known regarding BCLP expression in cutaneous lymphoid infiltrates. Using an immunohistochemical technique and a monoclonal antibody (clone no. 124) the authors examined 67 examples of cutaneous lymphoid infiltrates--31 cases of malignant lymphoma of the skin (MLS) and 36 examples of cutaneous lymphoid hyperplasias (CLH)--to determine if patterns of BCLP reactivity could distinguish CLH from MLS or primary from secondary involvement of the skin by malignant lymphoma. Fifty-eight per cent of MLS cases were BCL-positive, as were 33% of CLH. Three of four cases of follicular cutaneous lymphoma showed BCLP-positivity in neoplastic follicles, whereas similar structures in cases of CLH with a follicular pattern were BCLP-negative. Sixty per cent of primary MLSs and 57% of secondary lymphomas were reactive for BCLP. These data suggest that immunostains for BCLP are of little help in the separation of benign from malignant cutaneous lymphoid infiltrates, and that they are likewise incapable of separating primary from secondary MLS. BCLP immunostains may have a limited adjuvant diagnostic role in distinguishing reactive from neoplastic follicular lymphoid lesions of the skin.

A PCR ANALYSIS OF BCL-2 GENE REARRANGEMENT IN NODAL AND EXTRANODAL NON-HODGKINS-LYMPHOMA (NHL) - SOME UNUSUAL OBSERVATIONS IN SAUDI PATIENTS

Non-Hodgkin's lymphoma (NHL) is the most common malignancy referred to our institute which is the largest tertiary referral cancer centre in Saudi Arabia, The proportion of follicular low grade NHL appears to be extremely small in this population (<5% of all NHL). To date, there is no data available regarding any correlation between bcl-2 gene rearrangement and different cell types of nodal and extranodal NHLs in Saudi patients. We used a sequential polymerase chain reaction (PCR) technique to determine the frequency of bcl-2/J(H) recombination occurring via the major breakpoint region (mbr) in 16 GI tract NHLs including 4 MALT lymphomas and 13 follicular (nodal) NHLs. The results showed only 2/13 (15%) nodal follicular NHLs with bcl-2/J(H) fusion DNA whereas 9/16 (56%) of the extranodal NHLs with at least 2 of them exhibiting MALT characteristics were positive for the bcl-2 gene rearrangement. A breakdown of the proportion of extranodal NHLs of different cell types showing bcl-2 rearrangement via mbr was as follows: 5/8 diffuse large non-cleaved cell (DLNCC), 1/3 diffuse small cleaved cell (DSCC), 1/1 follicular small cleaved cell (FSCC) and 2/4 MALTs. The PCR amplified bcl-2/J(H) fusion DNA from 5 randomly selected tumors (2 MALTs, 1 DLNCC, 1 DSCC and 1 nodal follicular lymphoma) were cloned and sequenced. All 5 of them showed different bcl-2/J(H) N-regions confirming the clonality of each tumor sample. The data indicating a very low incidence of bcl-2 translocation in nodal follicular NHLs and a surprisingly high incidence of it in extranodal NHLs are intriguing, and quite contrary to the findings in Western patients. These unusual observations warrant further studies and may suggest that different genetic events are involved in the development of extranodal NHLs including MALT and follicular center-cell NHLs in Saudi patients.

Expression of a lymphocyte adhesion molecule (CD44) in malignant lymphomas: relevance to primary site, histological subtype and clinical stage.

Lymphocyte adhesion molecules defined by anti-CD44 antibody (Hermes-3) may be involved in lymphocyte binding to high endothelial venules at sites where lymphocytes exist the blood. CD44 expression was immunohistochemically examined in 167 well characterized cases of malignant lymphomas (MLs). None of 12 nodal follicular lymphomas (FLs) were CD44+, whereas 3 of 4 extranodal ones showed distinct CD44 expression. In contrast to nodal FLs, 28 of the 38 (74%) nodal diffuse B-cell lymphomas were CD44+ (p < 0.0001). T-cell lymphomas showed a significantly higher expression of CD44 antigen than diffuse B-cell lymphomas in the nodal cases (p < 0.04), but not in the extranodal ones. In nodal diffuse lymphomas, 3 of 5 stage I lymphomas (60%) were CD44+ in contrast to 53 of 63 stage II-IV lymphomas (84%), but the difference was not statistically significant. Of 14 Hodgkin's diseases, 9 cases were CD44+ with no significant correlation with clinical stage. The data of flow cytometric analysis confirmed the results of immunohistochemical analysis. In conclusion, CD44 expression is relevant to primary sites of distinctive MLs originating in the mucosal regions (MALToma) and some histological subtypes, but the relation with clinical stage was not defined. Some other adhesion molecules or different mechanisms must also be taken into account concerning the genesis and the expansion of MLs.

Breast Lymphoma

We studied the morphologic, immunologic, and clinical features of 31 cases of malignant lymphoma involving the breast. Primary breast lymphoma occurred in nine women with a median age of 69 years (range, 51-87 years); median follow-up was 31 months (range, 9-67 months). Eight cases were low grade, one was high grade, and all expressed B-lineage antigens. Four cases had features of lymphoma of mucosa-associated lymphoid tissue (MALT); three were free of disease after excision alone at 10, 12, and 48 months, whereas the fourth relapsed with transition to immunoblastic lymphoma and died at 25 months. Four patients had follicular lymphomas, three of which relapsed, causing death from active disease at a median of 55 months (range, 25-67 months). One case of small noncleaved cell lymphoma relapsed, causing death at 31 months. Lymphoma secondarily involved the breast in 22 patients (21 women, one man) with a median age of 60 years (range, 39-83 years) at breast relapse; these patients were followed for a median of 88 months (range, 2-271 months) from primary diagnosis and 4 months (range, 0-116 months) from breast relapse. Nineteen patients had prior documented lymphomas (10 nodal or splenic, nine extranodal), and breast involvement most commonly occurred as part of widespread, predominantly nodal disease. Three patients had breast involvement by lymphomas that were generalized at diagnosis or staging. Thirteen cases were low grade (nine follicular), seven intermediate grade, and one high grade; 19 of 20 cases expressed B-lineage antigens, and one expressed T-lineage antigens. Four cases had features of MALT-type lymphoma; in these patients, isolated breast relapses were interspersed with other extranodal relapses, with interim resolution of disease after local or systemic therapy; two were free of disease and two were alive with localized disease on treatment at median follow-up of 60 months (range, 9-91 months). In contrast, 15 of 18 nonMALT lymphomas had widespread disease at breast relapse (median, 29 months; range, 0-259 months); 16 of 18 received systemic therapy, 10 died with active disease, and five of eight had disseminated active disease at last follow-up. Primary breast lymphomas were commonly low grade. The follicular lymphomas had clinical behavior similar to nodal follicular lymphoma. Primary MALT-type lymphomas were a distinct subset with a potential for disease-free survival after local therapy. Secondary breast lymphomas were heterogeneous and more commonly higher grade, although follicular lymphoma was the most common subtype.(ABSTRACT TRUNCATED AT 400 WORDS)

Changes in Clinico‐pathological Features of Hodgkin's Disease and Follicular Lymphoma in Nagoya, Japan, over a 21‐year Period (1965‐85)

To study changes in the clinico-pathological features of malignant lymphomas in Japan, the histopathological and clinical features of 71 cases of Hodgkin's disease and 49 cases of nodal follicular lymphoma occurring in Nagoya were compared in three different periods (1965-71, 1972-78 and 1979-85). The proportional frequency of Hodgkin's disease among total lymphomas (10%) and that of follicular lymphoma among non-Hodgkin's nodal lymphomas (18%) did not vary over the study period. As to the histological patterns of Hodgkin's disease, the relative frequency of the nodular sclerosis (NS) type, which is relatively common in young women, increased, but that of other types decreased in the more recent periods. For follicular lymphoma, the relative frequency of the completely follicular type, which is more common in the United States than in Japan, increased. The five-year survival rate in patients with follicular lymphoma improved more recently even after adjusting for the effects of other prognostic factors. This recent increase in survival rates may be due partly to the recent improvement in cancer treatment, but is also related to the recent increase in patients with better prognostic features, i.e. the NS type of Hodgkin's disease. These variations over time suggest that the patterns of malignant lymphomas in Japan might be gradually changing, probably because of westernization, as seen in cancers of other organs.