Follicular large cell lymphoma. An immunophenotype study.

The authors investigated 17 cases of follicular large cell lymphoma using monoclonal antibodies applied to frozen sections. The neoplastic cells in 11 cases (65%) showed evidence of immunoglobulin expression similar to the reported percentage of immunoglobulin expressing diffuse large cell lymphomas and lower than seen in low grade follicular lymphomas. All cases showed expression of the B lineage markers T015, B1, and 4G7, and HLA-DR. CALLA was present in all but 1 case, similar to that reported for follicular lymphomas, and much higher than reported for diffuse large cell lymphoma. Approximately one-half of the cases showed weak expression of Tac, 5 cases expressed B2 (C3d), and 3 cases expressed T05 (C3b). Variable expression was seen for the Ki-67 antigen. A CR4/23+, B2+, T05+ dendritic population was identified in all cases. An interfollicular host T-cell infiltrate was noted, mainly phenotypic helper cells. This study demonstrates that follicular large cell lymphoma has immunologic similarities to both diffuse large cell lymphoma and the low grade follicular lymphomas.     

HLA-DR expression in B-cell non-Hodgkin's malignant lymphomas: a multiparameter flow cytometry study

Ten cases of reactive follicular hyperplasia and 31 cases of B-cell non-Hodgkin's malignant lymphoma were studied using multiparameter flow cytometry. A bimodal distribution for HLA-DR expression, but not for surface immunoglobulin or B cell-specific antigens CD19 and CD20, was observed commonly in mixed cell type and infrequently in non-mixed cell type B-cell malignant lymphomas. On the basis of HLA-DR distribution alone, 31 cases of B-cell malignant lymphomas of low, intermediate, and high grades could be separated into mixed and non-mixed cell types, with only two misclassifications (P = 0.0001). Exceptionally, one case of malignant lymphoma, follicular and diffuse, mixed-cell type had a unimodal HLA-DR distribution, and one case of malignant lymphoma, diffuse, large noncleaved cell type had a bimodal HLA-DR distribution. In all cases of malignant lymphoma, follicular, mixed-cell type studied, low HLA-DR was correlated with small cells, and high HLA-DR was correlated with large cells. In contrast, HLA-DR expression and cell size were not as directly correlated in cases of malignant lymphoma, diffuse, mixed-cell type. These observations suggest that most, but not all, cases of B-cell malignant lymphomas of the mixed cell type can be separated from other B-cell lymphomas on the basis of HLA-DR distribution.     

IMMUNOHISTOCHEMICAL STUDIES ON B CELL LYMPHOMAS WITH SPECIAL REFERENCE TO T CELL INFILTRATION AND ITS SIGNIFICANCE AS A PROGNOSTIC FACTOR

Twenty-eight cases of B cell lymphoma were studied immunohistochemically utilizing a panel of monoclonal antibodies. Of 27 cases tested, 26 were B-1-positive and 22 of 24 cases were HLA-DR positive. There were eight BA-1-positive cases, including one follicular lymphoma, and 10 J-5-positive cases including five diffuse large cell lymphomas. Some of the J-5-positive diffuse large cell lymphomas were considered to be of follicular center cell origin. Infiltration and distribution of non-neoplastic T cell subsets, BA-1-positive B cells, dendritic reticulum cells, Langerhans cells and HNK cells showed close similarity between the structure of follicular lymphomas and that of the reactive follicles. Such similarity to the normal counterpart structure was less apparent in diffuse lymphomas, especially in the large cell type. These findings were interpreted to be an expression of different degrees of neoplastic deviation. There was evidence to suggest that, regardless of the histological classification, a large number of infiltrating non-neoplastic T cells was related to good prognosis. ACT A PATHOL JPN 38: 47–58, 1988.     

Testicular diffuse large cell lymphoma with tubule preservation – molecular genetic evidence of transformation from previous follicular lymphoma

Testicular lymphomas usually occur in older men and are mostly diffuse large B-cell lymphomas (DLBL). They may be primary manifestation of lymphoma or represent a relapse of a previous non-Hodgkin’s lymphoma. This report details a testicular large cell lymphoma, which was proven to be large cell transformation of a low-grade follicular lymphoma biopsied 8 years earlier. Initially, a 38-year old man was diagnosed with cervical lymphadenopathy, and biopsy was interpreted as reactive follicular hyperplasia; no treatment was given, and the lymphadenopathy resolved spontaneously. Eight years later, the patient underwent surgery for a left testicular mass and gastroscopy for gastric symptoms. The patient died 7 months later with evidence for intra-abdominal and central nervous system lymphoma after a brief but temporary response to M-BACOD chemotherapy. Orchiectomy specimen and gastroscopic biopsy showed diffuse large B-cell lymphoma (CD20+), which infiltrated between well-preserved tubules in the testis. Histological comparison with 20 testicular lymphomas without previous lymphoma showed tubule infiltration in all cases, suggesting that the tubule-preserving infiltration pattern could be a histological marker for secondary lymphoma involvement in testis. On re-examination, the lymph node 8 years prior was verified as follicular, predominantly small, cleaved cell lymphoma with bcl2-positive follicles. The earlier follicular lymphoma and the subsequent diffuse large cell lymphoma were analyzed using polymerase chain reaction and showed identical sequences of the t(14;18) translocation and immunoglobulin heavy chain gene rearrangement. Analysis of the VH-gene sequences from the follicular lymphoma revealed sequence heterogeneity consistent with ongoing mutation. However, the transformed diffuse large cell lymphoma had no intraclonal variation, with the sequence matching with one of the subclones from the low-grade follicular lymphoma. These results confirm that the large cell transformation of follicular lymphoma occurs in a single follicular lymphoma cell. This case also indicates that the selection of the transformed clone can be part of the natural history of disease and can occur without exposure to chemotherapy. Received: 4 May 1999 / Accepted: 6 September 1999     

Combination of Hodgkin's disease and diffuse large cell lymphoma: an in situ hybridization study for immunoglobulin light chain messenger RNA

It is not clear whether the rare combination of Hodgkin's disease with non-Hodgkin lymphomas are true composite lymphomas or differentiation stages of one tumour cell clone. We used in situ hybridization and immunohistochemistry for the demonstration of immunoglobulin light chains in order to investigate the relationship between the two lymphoma components. In three cases of nodular lymphocyte predominance Hodgkin's disease combined with diffuse large B-cell lymphoma the Hodgkin cells, as well as the tumour cells in the diffuse large B-cell lymphoma, showed the same messenger RNA for one light chain. Thus, using in situ hybridization in nodular lymphocyte predominance Hodgkin's disease combined with diffuse large B-cell lymphoma in a small number of cases a possible genetic relationship between the two components could be shown. In nodular sclerosis combined with diffuse large B-cell lymphoma, in situ hybridization did not support a common clonal origin of both tumour parts. However, a unique clonal derivation cannot be excluded by the techniques applied.     

Primary lymphomas of the liver. Report of six cases and review of the literature

Six cases of diffuse large cell lymphoma (DLCL) of the liver were studied with immunohistochemistry for common leukocyte antigen (CLA), lysozyme, alpha-1-antitrypsin (AAT), and kappa and lambda light chains on paraffin-embedded tissues. All six cases were positive for CLA. Four of the six cases showed staining for lysozyme and AAT (three focal and one diffuse staining). In three cases, frozen tissue for monoclonal antibodies and glutaraldehyde-fixed tissue for electron microscopic examination were available. Two of these showed B-cell phenotypes with monoclonal antibody studies. Electron microscopic examination on these two B-cell lymphomas showed scant cytoplasm and a paucity of cytoplasmic organelles. The third case did not show definite B- or T-cell surface markers but did show strong Leu-M1 and OKM1 staining. Electron microscopic examination of the tumor cells showed a prominent Golgi apparatus, abundant cytoplasm with numerous cytoplasmic organelles and phagolysosomes. However, DNA hybridization studies on this tumor showed immunoglobulin heavy and kappa light chain gene rearrangements typical of a B-cell lymphoma. All six lymphomas were solitary liver masses without evidence of disease elsewhere. The mean age for the six patients was 56.2 years (four males, two females).     

Combined analysis of T cell receptor gamma and immunoglobulin heavy chain gene rearrangements at the single-cell level in lymphomas with dual genotype

By prospectively studying immunoglobulin heavy chain gene (IgH) and T cell receptor gamma (TCRgamma) gene rearrangements in 398 lymphoma cases, a dual genotype was observed in 13% of B cell and 11% of T cell lymphomas. According to histological subtype, the highest incidence was observed for mantle cell lymphomas (32%) and lymphoplasmacytic lymphoma (21%) among B cell lymphomas, and for angioimmunoblastic lymphoma (AILT) (46%) and Sézary syndrome (SS) (50%) among T cell lymphomas. To determine whether the dual genotype corresponds to the presence of two distinct monoclonal populations or to the presence of both rearrangements within the same lymphoma cells, single-cell microdissection was used after immunohistochemistry and a single-cell combined IgH and TCRgamma gene analysis was designed after a whole-genome amplification step. This protocol was applied to the study of two nodal B cell lymphomas (one diffuse large B cell lymphoma and one mantle cell lymphoma) and two cutaneous T cell lymphomas (one AILT and one SS). Two cases (SS and mantle cell lymphoma) were true bigenotypic lymphomas, as both IgH and TCRgamma monoclonal rearrangements were detected in the same cells. Conversely, in the diffuse large B cell lymphoma and AILT cases, large CD22+ single cells exhibited only the monoclonal IgH rearrangement but not the TCRgamma gene that was detected in CD3+ single cells. Such an approach allows the identification of true bigenotypic lymphoma among dual genotypic lymphoma. Specific genetic alterations may be further amplified from microdissected cryopreserved material, such as the t(11;14) breakpoint detected in bigenotypic B cells of the mantle cell lymphoma case.     

Lack of surface immunoglobulin light chain expression by flow cytometric immunophenotyping can help diagnose peripheral B-cell lymphoma

We determined the prevalence and significance of finding B cells without surface immunoglobulin (SIg) light chain expression. The flow cytometry database at Johns Hopkins Medical Institutions was searched for cases in which immunoglobulin light chain staining was performed to rule out a B-cell malignant neoplasm between January 1994 and February 2000. We excluded plasma cell dyscrasias, precursor B-cell acute lymphoblastic leukemia/lymphomas, and hematogones. Cases with more than 25% of B cells lacking SIg light chain expression were retrieved. Polymerase chain reaction assays for immunoglobulin heavy chain gene rearrangements were performed in SIg-negative cases with available tissue blocks. We identified 36 cases; all represented lymphoma. Their diagnoses included diffuse large B-cell lymphoma (20), HIV-related lymphoma (5), follicular lymphoma (5), Burkitt lymphoma (2), monomorphic posttransplant lymphoproliferative disorder (1), chronic lymphocytic leukemia/small lymphocytic lymphoma (1), marginal zone B-cell lymphoma (1), and low grade B-cell lymphoma (1). Of the 17 SIg-negative cases with amplifiable DNAs, 12 (71%) showed a clonal immunoglobulin heavy chain gene rearrangement. SIg-negative B-cell lymphomas are rare. Complete absence of SIg light chain expression in a mature B cell proliferation can be used as a surrogate marker to help diagnose peripheral B-cell lymphoma.     

Malignant lymphoma of the urinary bladder: a clinicopathological study of 11 cases

AIM: To report the clinical and histological features and outcome of primary and secondary malignant lymphomas of the urinary bladder. METHODS: Eleven cases of malignant lymphoma of the urinary bladder were obtained from the registry of cases at St Bartholomews and the Royal London Hospitals. The lymphomas were classified on the basis of their morphology and immunophenotype, and the clinical records were reviewed. RESULTS: There were six primary lymphomas: three extranodal marginal zone lymphomas of mucosa associated lymphoid tissue (MALT) type and three diffuse large B cell lymphomas. Of the five secondary cases, four were diffuse large B cell lymphomas, one secondary to a systemic follicular follicle centre lymphoma, and one nodular sclerosis Hodgkins disease. Four patients with secondary lymphoma for whom follow up was available had died of disease within 13 months of diagnosis. Primary lymphomas followed a more indolent course. In one case, there was evidence of transformation from low grade MALT-type to diffuse large B cell lymphoma. The most common presenting symptom was haematuria. Cystoscopic appearances were of solid, sometimes necrotic tumours resembling transitional cell carcinoma, and in one case the tumours were multiple. These cases represented 0.2% of all bladder neoplasms. CONCLUSIONS: Diffuse large B cell lymphoma and MALT-type lymphoma are the most common primary malignant lymphomas of the bladder. Lymphoepithelial lesions in MALT-type lymphoma involve transitional epithelium, and their presence in high grade lymphoma suggests a primary origin owing to transformation of low grade MALT-type lymphoma. Primary and secondary diffuse large B cell lymphomas of the bladder are histologically similar, but the prognosis of the former is favourable.     

Chromosomal abnormalities in lymphoma and their correlations with nucleic acid flow cytometry

Cytogenetic studies were performed on 25 samples obtained from 25 patients with lymphoma. Fourteen of these were also simultaneously studied with nucleic acid flow cytometry to determine percent S-phase and DNA content (ploidy). In 17 cases (68%), evaluable metaphases were obtained. The evaluable metaphase rate was higher in previously untreated patients (15/19 or 79%). All but two cases showed abnormal karyotype. All five cases showing either the t(8;14) or t(8;22) abnormality were associated with extremely high percent S-phase values, ranging from 36% to 47%, which is in the range of high-grade lymphomas according to our previous experience. Four of these cases were diagnosed as Burkitt's lymphoma and one as diffuse large cell lymphoma. Further review of this latter case resulted in the pathologic diagnosis being changed to Burkitt's lymphoma. Three patients had either numerical or structural abnormalities of chromosome #21 [two cases of extra chromosomes and one i(21q)]. All three cases were diagnosed as diffuse large cell lymphoma. Four instances of trisomy 12 were identified. Only one of these was diagnosed as diffuse well-differentiated lymphocytic lymphoma. The remaining three were Burkitt's lymphoma in two and diffuse large cell lymphoma in one. Two instances of t(14;18) were observed. This is the characteristic abnormality of follicular lymphomas. One of these cases was a follicular large cell lymphoma. The second case had possibly originated from a follicular mixed lymphoma and had evolved into a diffuse mixed cell type. Both of these cases had low S-phase values in the range of low-grade lymphomas. The correlation between ploidy as determined by flow cytometry and cytogenetic analysis was good whenever the DNA index was elevated. However, when the DNA index was 1.0 (diploid), concordant measurements were observed in only five of eight cases. Flow cytometry detected one instance of clearly abnormal ploidy, which was thought to be diploid by cytogenetics. This case most likely represents a "false negative" cytogenetic determination.     

Characterization of Non-Hodgkin''s Lymphomas Using Multiple Cell Markers: Immunologic, Morphologic, and Cytochemical Studies of 72 Cases

Tissues from 72 cases (87 specimens) of various non-Hodgkin's lymphomas were analyzed for cell markers using multiple techniques. Cell suspensions were evaluated for E, EAC, and IgGEA rosette forming cells; Fc receptor cells; and surface immunoglobulin bearing cells. Cryostat section studies topographically defined EAC binding cells. Cytochemical determinations and immunoperoxidase methods for detection of intracellular immunoglobulin and lysozyme complemented other techniques in evaluating infiltrates containing large neoplastic cells. B-cell malignancies comprised 58 cases (80%) of this series and included well and moderately well differentiated lymphocytic lymphomas (10/10); nodular (23/23) and diffuse (10/18) poorly differentiated lymphocytic lymphomas; and lymphomas of mixed lymphocytic-“histiocytic” (3/3), “undifferentiated” (3/3), and “histiocytic” (9/13) types. Nodular lymphomas were characterized as B-cell neoplasms but also revealed a prominent population of T lymphocytes (39 ± 12%). Alkaline phosphatase activity, a cytochemical marker for lymphoid cells of follicular cuffs, was most consistently observed in B-cell lymphomas of moderately well differentiated lymphocytic type (4/6 cases). In some diffuse lymphomas, cryostat section studies (EAC rosettes) suggested a pre-existing nodular proliferation. One unusual B-cell lymphoma of large cell type exhibited IgGEA rosette formation and a strong receptor for the Fc portion of IgG. Ten lymphomas (14%) were of T-cell type and were represented by cases of diffuse poorly differentiated lymphocytic lymphoma (5/18, including 3 lymphoblastic lymphomas), Sézary syndrome (1), mycosis fungoides (1), and a cytologically distinctive large cell (“histiocytic”) lymphoma (3/13). Acid phosphatase activity was a consistent marker for the T-cell malignancies, some of which also revealed α-naphthyl butyrate esterase activity. No true histiocytic lymphomas were detected. Three cases of diffuse poorly differentiated lymphocytic lymphoma and one “histiocytic” lymphoma were null.     

Expression of the Leu-8 antigen by B-cell lymphomas

The Leu-8 antigen is found on the surface of many hematologic cells, including many T- and B-lymphocytes. With the use of a frozen-section immunoperoxidase technic, 152 B-cell non-Hodgkin's lymphomas were examined for Leu-8 expression. Of these lymphomas, 53% expressed Leu-8. Subclassification of the lymphomas with the use of the International Working Formulation showed that most small lymphocytic, intermediate lymphocytic, and diffuse large cell lymphomas and about half of diffuse small cleaved, diffuse mixed, and follicular lymphomas expressed Leu-8. In contrast, all 17 cases of small noncleaved cell (Burkitt's) lymphoma and 9 of 10 cases of multiple myeloma/plasmacytoma were Leu-8 negative. These results indicate that Leu-8 is expressed on a wide variety of B-cell lymphomas and that differences in Leu-8 expression may be useful in the diagnostic separation of small lymphocytic lymphoma with plasmacytoid features from multiple myeloma/plasmacytoma, and diffuse large cell lymphoma from Burkitt's lymphoma.     

Primary gastric lymphomas: Morphologic, immunohistochemical and immunogenetic analyses

Morphologic, lmmunohistochemical and lmmunogenetic studies were performed on 28 cases of primary gastric lymphoma from fresh frozen tissue. Eight cases were diagnosed as diffuse large B-cell lymphoma, four as follicular center lymphoma (follicular), five as mucosa-associated lymphoid tissue (MALT) lymphoma, three as plasmacytoma, and three as T-cell lymphoma, two as mantle cell lymphoma, one as follicular center lymphoma (diffuse, predominantly small cell), and one as lymphoplasmacytoid lymphoma, and one as Hodgkin's disease.
From lmmunohistochemical studies, four types of morphologically similar low-grade lymphomas can be differentiated by a combination of various monoclonal antibodies. Cases of diffuse large B-cell lymphoma may have a germinal center origin. We observed lympho-epithelial lesions in cases of non-MALT lymphomas. We therefore consider that the current diagnostic criterion for MALT lymphoma may not always be valid.
Except for cases of T-cell lymphoma and Hodgkin's disease, 17 out of 22 cases revealed clonal rearrangement bands of the JH gene. In situ hybridization (ISH) and polymerase chain reaction (PCR) studies revealed the presence of Epstein-Barr (EB) virus genomes in two and three cases, respectively. Epstein-Barr virus may play a role in lympho-magenesis, although on relatively rare occasions.     

De novo CD5 positive diffuse large B-cell lymphomas with bone marrow involvement in Korean

In CD5 positive (CD5+) mature B-cell lymphomas, newly recognized CD5+ diffuse large B-cell lymphoma (DLBCL) has been characterized by aggressive features. We studied twenty-five cases with CD5+ lymphomas involving bone marrow. Eleven cases were diagnosed as chronic lymphocytic leukemia, six cases were diagnosed as mantle cell lymphoma (MCL), and three cases with morphologic characteristics of MCL and without both the cyclin D1 expression and IGH/CCND1 rearrangement were unclassifiable. The remaining five cases, showing large to medium-sized lymphoid cells with prominent nucleoli and a moderate amount of cytoplasm, were diagnosed as DLBCL. Five DLBCL cases were positive for CD5, CD20, surface immunoglobulin, but negative for CD23. Patients with CD5+ DLBCL showed a high age of onset (median, 68 yr) and two patients expired one month after the diagnosis. Since CD5+ DLBCL forms a distinct subgroup of DLBCL, a study of CD5 expression in DLBCL would be helpful to predict prognosis and to determine future therapeutic strategy. To the best of our knowledge, this is the first report on de novo CD5+ DLBCL in Koreans.     

MALT1 gene rearrangements and NF-kappaB activation involving p65 and p50 are absent or rare in primary MALT lymphomas of the breast.

Mucosa associated lymphoid tissue (MALT) lymphomas arising in the breast are uncommon and few cases have been assessed for MALT lymphoma-associated translocations, BCL-10 expression, or NF-kappaB activation. In this study, we analyzed eight cases of primary breast MALT lymphoma. We also included 14 cases of primary breast diffuse large B-cell lymphoma since some of these may represent transformation of MALT lymphoma, known to occur at extra-mammary MALT sites. All cases were assessed for MALT1 gene rearrangements by fluorescence in situ hybridization (FISH). Using immunohistochemical methods, all cases were assessed for BCL-10, and subsets were assessed for NF-kappaB p65 and p50. None of the cases had MALT1 gene rearrangements by FISH. Of eight MALT lymphomas, BCL-10 was positive in seven (88%), with moderate nuclear and cytoplasmic staining in six, and a weak cytoplasmic staining in one. NF-kappaB p65 (n=8) and p50 (n=5) were negative or showed only cytoplasmic staining (ie inactivated) in all cases. Of 14 diffuse large B-cell lymphoma cases, BCL-10 was positive in 12 (87%), with weak-to-moderate cytoplasmic staining in 10, weak cytoplasmic and focally nuclear staining in one, and a moderate-to-strong nuclear and cytoplasmic staining in one. NF-kappaB p65 (n=11) showed cytoplasmic staining in all cases, whereas p50 (n=8) showed nuclear positivity (ie activated) in two (25%) cases. We conclude that MALT1 gene rearrangements are absent or rare in primary breast MALT lymphoma and diffuse large B-cell lymphoma. In MALT lymphomas, the moderate BCL-10 nuclear expression in six neoplasms is inconsistent with the FISH results, suggesting that BCL-10 immunostaining overestimates the frequency of MALT1 gene rearrangements. We also could not demonstrate NF-kappaB activation using nuclear staining for p65 and p50. In contrast, breast diffuse large B-cell lymphomas are heterogeneous. Weak cytoplasmic BCL-10 staining in most cases and evidence of NF-kappaB p50 activation in a subset differs from breast MALT lymphomas.     

Common acute lymphoblastic leukemia-associated antigen (CALLA)-positive B cell lymphoma

We analyzed the expression of common acute lymphoblastic leukemia-associated antigen (CALLA) in 134 cases of non-Hodgkin's lymphoma of the B cell type using an immunohistochemical method. The incidence of CALLA expression in B cell lymphomas was higher in follicular lymphomas (29%) than in diffuse lymphomas (15%). Malignant lymphoma (ML), follicular small cleaved cell (FSC) according to the histologic type, showed a considerably high incidence of CALLA (43%), whereas ML, diffuse small cleaved cell (DSC) displayed a very low incidence (5%). These findings suggest the possibility that these two morphologically similar lymphomas may be derived from distinct populations of B cells [CALLA+-germinal center (GC) cells, CALLA- -germinal center (GC) cells or mantle zone (MZ) cells]. In addition, one case of DSC expressed surface immunoglobulin D (SIgD) and alkaline phosphatase (ALPase) as well as CALLA. This indicates that CALLA-positive small cleaved cell lymphoma expressing SIgD or ALPase may represent neoplastic proliferation of CALLA-positive MZ cells of secondary follicles in lymph nodes.     

CD43 expression in B cell lymphoma.

AIMS: To determine the expression of CD43 in frozen sections in a range of B cell lymphomas. METHODS: The monoclonal antibody WR14, clustered provisionally in the Fourth Leucocyte Typing Workshop as a CD43 reagent, was investigated by epitope blocking studies on formalin fixed reactive lymph node tissue, using the established CD43 antibody MT1, to validate its use as a CD43 reagent. CD43 expression was studied in 131 immunophenotypically defined B cell lymphomas, including lymphocytic lymphoma (Lc, n = 13), centrocytic lymphoma (Cc, n = 14), and a range of follicle centre cell lymphomas (FCC) including centroblastic/centrocytic follicular (CbCcF, n = 48), centroblastic diffuse (CbD, n = 39), centroblastic/centrocytic diffuse (CbCcD, n = 4), centroblastic follicular and diffuse (Cb FD, n = 3) and centroblastic/centrocytic follicular and diffuse (CbCc FD, n = 1). Nine lymphomas of mucosa associated lymphoid tissue (MALT) were also examined. RESULTS: Epitope blocking studies showed that WR14 is a CD43 reagent that binds to an epitope identical with or close to that recognised by MT1. Eleven of 13 (84%) cases of Lc and 11 of 14 (78%) cases of Cc expressed CD43; 87 of 95 (91%) cases of FCC did not. All eight low grade lymphomas of MALT were negative. One high grade lymphoma, transformed from a low grade MALT lymphoma, was positive for CD43. The expression of CD43 by tumours of B cell lineage was associated with the expression of CD5 (p < 0.001) although either antigen could occasionally be found in the absence of the other. CONCLUSION: CD43 reagents can be used in conjunction with CD5 antibodies for the immunophenotypic discrimination of follicle centre cell lymphomas from non-follicle centre cell lymphomas.     

CD30 (Ki-1) expression in adult T-cell leukaemia/lymphoma is associated with distinctive immunohistological and clinical characteristics

Twenty-one patients with CD30 (Ki-1) positive lymphoma were studied from a group of 91 patients with adult T-cell leukaemia/lymphoma. The patients were grouped into three types: diffuse CD30 positive anaplastic large cell lymphoma in 11 patients (group 1); pleomorphic type lymphoma with diffuse CD30 expression in five patients (group 2); and pleomorphic type lymphoma with positive CD30 expression in large cells but negative in medium-sized and small cells in five patients (group 3). The patients with diffuse CD30 positive lymphomas (groups 1, 2) frequently presented with extranodal tumours (68.8%) and lymph node enlargement greater than 2 cm in diameter (50%), and rarely with leukaemic changes, bone marrow involvement and hypercalcaemia (one case of each). Patients in group 3 rarely had extranodal tumours, but had frequent leukaemic changes. Expression of intercellular adhesion molecule (ICAM-1; CD54) by the lymphoma cells in 13 patients (81.3%) with diffuse CD30 positive lymphomas, was significantly higher than that in 33 patients (9.1%) with CD30 negative adult T-cell leukaemia/lymphomas. No positive reaction for epithelial membrane antigen (EMA) was found in the lymphoma cells of CD30 positive cases. The overall survival in patients with diffuse CD30 positive lymphomas was better than that of CD30 negative adult T-cell leukaemia/lymphoma patients, but showed no significant difference. These findings suggest that diffuse CD30 positive adult T-cell leukaemia/lymphoma has unusual clinical and immunohistological findings. It is also speculated that local tumour formation and leukaemic changes in such diffuse CD30 positive cases are influenced by CD54 (ICAM-1) expression by the lymphoma cells.