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Results for “Immunophenotyping”

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PubMed1992

Acute leukemias with unusual immunophenotypes.

Over a two-year period, immunophenotypic patterns of 266 acute leukemia cases were analyzed using a panel of tests including TdT, SmIg and 9 surface antigens by the immunofluorescence stains for the assessment of the incidence and grade of phenotypic ambiguity (lineage infidelity) and the possible clinical significance of unusual immunophenotypes. Immunophenotypes were classified into four groups according to the degree of ectopic antigen expression. We classified as Group A (91.7%, 244 of 266 cases) those expressing conventional pattern without ectopic antigen. Group B (3.0%, 8 of 266 cases) was defined to have at least two lineage specific markers and single ectopic antigen. Such a "low grade deviation" did not prevent a definite immunodiagnosis. Group C (4.2%, 11 of 266 cases) revealed a promiscuous coexpression of markers related to different lineages, including two cases (0.8%, 2 cases) of biphenotypic leukemia. Group D (1.1%, 3 cases) included unclassifiable immunophenotypes with no antigen or HLA-DR only expression. Both patients with biphenotypic leukemia and one patient with unclassifiable immunophenotypes failed to respond to induction chemotherapy, suggesting a poor prognosis in these patients. The incidence of acute myelogenous leukemia (AML) cases with one or more ectopic surface antigens was 10 (8.1%) of the 124 AML cases. Ectopic antigen expression was seen in 5 (4%) of the 125 B-lineage acute lymphoblastic leukemia (ALL) cases and 3 (25%) of the 12 T-ALL cases. It is concluded that nearly 95% of cases of acute leukemia cases can be diagnosed accurately with immunophenotyping alone including patients with a mild degree of deviation from expected antigenic patterns.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗

PubMed1992

Histopathologic, immunophenotypic and genotypic analyses in ocular adnexal lymphoproliferative disorders.

This study reports on fourteen biopsies from patients presenting to our orbital and oncology service with ocular adnexal lymphoid proliferations between November 1988 to September 1991. The biopsies were studied using histologic, immunophenotypic and genotypic analyses. By histologic criteria, there were two reactive, five indeterminate and seven lymphomatous lesions. On immunophenotypic analysis, there were two monoclonal and 10 polyclonal lesions in the 12 specimens analysed. Genotypic analysis confirmed the histopathologic diagnoses for the reactive lesions by showing them to be germline. It also confirmed that both the histopathologic lymphomas and immunophenotypically monoclonal lesions were clonally rearranged. Genotypic analysis was able to separate the histologically indeterminate group into two subsets: clonally rearranged, of which there was one, and germline, of which there were four. In addition, it demonstrated that immunophenotypic polyclonality cannot always be equated with genotypic polyclonality as was the situation in four out of 10 lesions in our series. The significance of clonal arrangements in the histologically indeterminate and immunophenotypically polyclonal groups can only be determined by prospective study.

Adult↗

PubMed1991

Acute leukemia after a primary myelodysplastic syndrome: immunophenotypic, genotypic, and clinical characteristics.

We studied the nature of blast cells in 41 patients with acute leukemia following a previous primary myelodysplastic syndrome (MDS) by a combined multiparameter analysis including morphologic, immunophenotypic, and molecular genetic (Igs, T-cell receptor (TCR)-beta, -gamma, and -delta and the major breakpoint cluster region [M-bcr]) investigations. In addition, the clinical and hematologic characteristics according to the immunophenotype of blast cells were analyzed. Our results show that, although the granulocytic and/or monocytic lineages are those most commonly involved in these acute leukemias, other cell components, including the megakaryocytic and lymphoid, may be present (12% and 15% of the cases, respectively). Moreover, both morphologic and phenotypic studies show the frequent coexistence of two or three cell populations. Interestingly, in all cases the lymphoblastic component constantly displayed an early B phenotype (CD19+, CD10-, TdT+). Upon analyzing whether the type of MDS conditioned any differences in the immunophenotype of blast cells, we observed that, although the lymphoid lineage may be involved in all MDS subgroups, some differences emerge within the myeloid leukemic transformations. Thus, the refractory anemias with excess of blasts (RAEB) and RAEB in transformation displayed a significantly higher incidence of myeloblastic and megakaryoblastic transformations, while in the RA, RA with ring sideroblasts and chronic myelomonocytic leukemia, the granulo-monocytic phenotype predominated. In addition, our results show that the clinical and hematologic characteristics of these patients may be partially related to the immunophenotype of the blast cells. Ig heavy chain gene rearrangements were found in two of 19 patients analyzed (11%), one with a hybrid leukemia (lymphoid-myeloid) and the other with a granulo-monocytic phenotype. Two other hybrid transformations analyzed were in germline configuration. Gamma and delta gene rearrangements were found in 21% and 37% of these acute transformation, respectively. The TCR-beta and M-bcr were in germline configuration in all 19 cases studied. In summary, immunophenotype and molecular studies point to a pluripotent stem cell with preferential myeloid commitment as the target cell of leukemias following a primary MDS.

Acute Disease↗

PubMed1992

Simultaneous fluorescence immunophenotyping and interphase cytogenetics: a contribution to the characterization of tumor cells.

In immunocytochemical studies, the phenotypic evaluation of tumor cells is often complicated by accompanying normal cells, representing the original tissue or infiltrating leukocytes. This holds particularly true for tissues with a great morphological and immunophenotypical variability, such as bone marrow. A method that identifies mitotic tumor cells by chromosomal aberrations and permits the subsequent immunophenotypical analysis was a first progress, demonstrated by Teerenhovi et al. However, the results are usually hampered by the low number of analyzable mitoses. We demonstrate here a method that simultaneously combines immunophenotyping and in situ hybridization with centromere-specific probes. Using our method, numerically aberrant tumor cells can be identified by interphase cytogenetics and subsequently analyzed immunophenotypically. Since all interphase cells can be analyzed, we are not limited by the number and banding quality of analyzable mitoses.

Antigens, CD↗

PubMed1992

Inconsistency of the immunophenotype of Reed-Sternberg cells in simultaneous and consecutive specimens from the same patients. A paraffin section evaluation in 56 patients.

Both immunophenotypic overlaps between Hodgkin's disease (HD) and non-Hodgkin's lymphoma (NHL), and evolution of one into the other have been reported. However, the underlying assumption that the antigenic expression of Reed-Sternberg (RS) cells is consistent in the same patient has not been evaluated. Such an evaluation was undertaken by immunophenotyping paraffin-embedded lymphoid tissue biopsies with HD from 56 patients in whom multiple specimens were obtained, either simultaneously from different sites or at different times. The panel of antibodies we used included: CD3 polyclonal antiserum, DAKO-M1 (CD15), L26 (CD20), BerH2 (CD30), MT1 (CD43), DAKO-LCA (CD45RB), UCHL1 (CD45R0), LN2 (CD74), and DAKO-EMA. The phenotype of RS cells was identical in simultaneous biopsies in only 11 of 39 patients (28%) and remained constant in consecutive biopsies in only 4 of 21 patients (19%). Major differences (relative to cell lineage specific antigens) were observed in 10 of 39 patients with simultaneous biopsies and in 10 of 21 patients over time; they mainly involved expression of T-cell antigens. Minor differences (relative to any other antigen) were observed in 22 of 39 patients with simultaneous biopsies and in 15 of 21 patients over time; these mainly involved CD15 or CD74. This striking variability of the immunophenotype of RS cells in the same patient may be due to aberrant marker expression, as a result of the neoplastic state, and/or to modulation of antigenic expression in relation to the host environment. This inconsistency suggests caution when interpreting the relationship between HD and NHL by paraffin immunophenotyping alone.

Antibodies↗

PubMed1991

Small lymphocytic lymphomas with predominant splenomegaly: a comparison of immunophenotypes with cases of predominant lymphadenopathy.

In this study, we compared small lymphocytic lymphomas with predominant lymphadenopathy with those with predominant splenomegaly and found differences in morphology and immunophenotype as well as clinical features. Cases with lymphadenopathy were characterized by widespread disease, CLL type morphology with proliferation centers, and a CD5, CD11c, CD23, CD43 positive, CD45Ro negative immunophenotype. Cases with predominant splenomegaly had more localized disease, a mantle zone pattern or a diffuse growth pattern without proliferation centers, and a CD5, CD11c, CD23, CD43 negative, and sometimes CD45Ro positive immunophenotype. CD45Ro (UCHL1) positivity and alkaline phosphatase staining were associated with a mantle zone growth pattern. Comparison with other small lymphocytic lymphoma subtypes indicated that each has its own specific immunophenotype.

Aged↗

PubMed1990

Characteristics of CD11c+CD5+ chronic B-cell leukemias and the identification of novel peripheral blood B-cell subsets with chronic lymphoid leukemia immunophenotypes.

Previous studies have indicated that chronic lymphocytic leukemias (CLL) are characterized by the coexpression of CD5 and B-cell antigens, while hairy cell leukemias (HCL) typically express CD11c+CD5- B-cell immunophenotypes. In this report we describe the features of B-cell leukemias with CD11c+CD5+ immunophenotypes and the identification of novel circulating B-cell subsets defined by the expression of CD20, CD5, and CD11c antigens. Morphologic evaluation of 14CD11c+CD5+ B-cell leukemias showed that they generally had larger cellular diameters (14 to 21 microns) and lower nuclear:cytoplasm ratios than typical small lymphocyte CLL. These cases did not exhibit the well-defined nucleoli characteristic of prolymphocytic leukemia (PLL). The presenting clinical features of CD11c+CD5+ B-cell leukemias were most consistent with CLL or PLL, and none of the evaluated cases had pancytopenia, splenomegaly, and cytoplasmic villi characteristic of HCL. Examination of normal peripheral blood (n = 6) by three-color flow cytometry identified four novel B-cell subsets with the following immunophenotypes (mean percent of total CD20+ B cells +/- SE): CD20+CD5+CD11c+ (8.0 +/- 1.6); CD20+CD5-CD11c+ (12.0 +/- 2.0); CD20+CD5+CD11c- (35.0 +/- 4.9); and CD20+CD5-CD11c- (44.0 +/- 5.0). Our findings suggest that CD11c+CD5+ B-cell leukemias with atypical morphologic features represent forms of CLL or PLL rather than HCL. In addition, we have identified novel subsets of circulating B cells defined by patterns of CD20, CD5, and CD11c expression that correspond to the immunophenotypes of chronic B-cell leukemias.

Adult↗

PubMed1992

Non-Hodgkin's lymphomas arising in patients successfully treated for Hodgkin's disease. A clinical, histologic, and immunophenotypic study of 14 cases.

We report on 14 patients who developed Hodgkin's disease (HD), were successfully treated, and subsequently developed non-Hodgkin's lymphoma (NHL). The median interval between the diagnosis of HD and the diagnosis of NHL was 136 months (range 11-336). The clinical features of the patients with HD were similar to other patients with HD. Results of biopsies showed 12 nodular sclerosis and one mixed cellularity; one was not further classified. Immunophenotypic studies in nine cases showed that the Reed-Sternberg (RS) and Hodgkin's (H) cells were LeuM1+ LCA-. The patients were treated for HD in a nonuniform manner: two received radiation therapy, four received chemotherapy, and eight received both modalities. The NHLs were usually extranodal (79%) with frequent presentation as an abdominal mass. According to the Working Formulation, six lymphomas were small noncleaved cell (four non-Burkitt's, two Burkitt's), three were diffuse large cell, and two were follicular and diffuse large cell. Three neoplasms were not classified: two lymphomas with plasmacytoid differentiation were placed in the intermediate and low-grade categories, respectively, and one neoplasm was a plasmacytoma. All 14 neoplasms had an immunophenotype typical of NHL of B-cell lineage and were LeuM1-. Seven of the 12 patients treated with combination chemotherapy experienced a complete remission of their NHL. We conclude that the clinical, histologic, and immunophenotypic findings of the NHLs in these patients are analogous to those of NHLs that occur in immunosuppressed patients, suggesting that immunodeficiency plays a role in the pathogenesis of NHLs arising after HD.

Adolescent↗

PubMed2026

To unveil the causal relationship between immunophenotypes and colorectal cancer using two-sample bidirectional Mendelian randomization and mediation analyses.

Colorectal cancer (CRC) is a leading cause of cancer-related death worldwide. The mechanisms underlying this trend are not yet fully understood. This study aimed to examine the potential role of genetically predicted immunophenotypes in the development of CRC. A two-sample bidirectional Mendelian randomization study was conducted to explore the relationship between 731 genetically predicted immune cells and CRC. Furthermore, a two-step Mendelian randomization approach was employed to assess the possible mediating effect of immune cells on CRC. The inverse-variance weighted method identified 5 immunophenotypes as significantly inversely associated with CRC risk: the odds ratios for CRC risk associated with activated CD4 regulatory T cells (%CD4 regulatory T cells), CD25++ CD45RA- CD4 nonregulatory T cells (%CD4 + T cells), CD25++ CD45RA- CD4 nonregulatory T cells (%T cells), CD25++ CD8 + T cells (%T cells), and CD64 + CD16 + monocytes were 0.925 (95% CI = 0.874-0.978, P = 6.516 × 10-3), 0.935 (95% CI = 0.878-0.995, P = .035), 0.936 (95% CI = 0.889-0.985, P = .011), 0.863 (95% CI = 0.786-0.948, P = 2.142 × 10-3), and 0.636 (95% CI = 0.519-0.778, P = 1.18 × 10-5), respectively. The mediation analysis indicated that the absolute count of CD25++ CD8 + T cells led to a 33.9% decrease in the risk associated with the percentage of activated CD4 regulatory T cells within CD4 regulatory T cells and CRC. Our analysis revealed that 5 immunophenotypes may be risk factors for CRC. Since other complementary methods have yielded inconsistent results, however, further investigation is necessary.

Colorectal Neoplasms↗

PubMed2026

Machine learning-guided risk stratification in elderly AML based on genomic, immunophenotypic and therapeutic profiles.

BACKGROUND: Elderly patients with acute myeloid leukemia (AML) exhibit considerable biological and clinical heterogeneity, hindering precise prognosis. Existing prognostic systems inadequately capture the complexity of elderly AML due to their reliance on data from younger cohorts and omission of key factors like immunophenotypic markers and therapeutic profiles. This study aimed to develop and internally validate a machine learning-based prognostic model specifically tailored to elderly AML patients. METHODS: A total of 156 patients were analyzed using a two-stage modeling strategy. Clinical and genomic variables were modeled first, followed by independent analysis of immunophenotypic features. Feature selection was performed using multilayer perceptron (MLP) and random forest (RF), while multivariate Cox regression was used for final model construction. Internal validation was conducted using 1000 bootstrap iterations to assess model stability and performance. RESULTS: The model demonstrated strong predictive performance, with a concordance index (C-index) of 0.702. Time-dependent area under the curve (AUC) and calibration plots confirmed accurate prediction of 1-, 3-, and 5-year overall survival. Decision curve analysis indicated favorable net benefit across a range of threshold probabilities. Key independent prognostic factors identified included TP53 mutations, high CD13 expression, and IDH2 mutations. CONCLUSION: This model provides a robust and interpretable tool for individualized risk stratification in elderly AML. By integrating genomic, immunophenotypic, and therapeutic variables, it may help optimize treatment decisions and improve outcomes for this vulnerable population. Future efforts should focus on external validation and integration of dynamic biomarkers.

Humans↗

PubMed1992

Molecular and immunophenotypic characterization of AIDS-associated, Epstein-Barr virus-negative, polyclonal lymphoma.

PURPOSE: A molecular analysis of non-Hodgkin's lymphomas (NHLs) from patients with AIDS was undertaken to determine the prevalence and immunophenotype of polyclonal B-cell lymphoma. MATERIALS AND METHODS: DNA was extracted from 40 diagnostic biopsy specimens obtained from patients seen at University of California, San Francisco (UCSF) between 1986 and 1990. Clonality, infection with Epstein-Barr virus (EBV), and presence of a rearranged c-myc gene were determined by Southern blot analysis. Lymphoma immunophenotypes were determined by frozen-section immunohistochemical analysis. RESULTS: The most prevalent genotype of lymphoma in this study was that of polyclonal, EBV-negative tumors with no evidence of c-myc rearrangement (14 of 40; 35%). Monoclonal, EBV-positive tumors with no evidence of c-myc rearrangement comprised the second most prevalent class (10 of 40; 25%), and polyclonal, EBV-positive tumors similar to those seen in transplant patients were observed in only a small subset (three of 40; 8%) of specimens analyzed. The immunophenotype of B cells in the polyclonal EBV-negative subset was equally divided into B-cell-predominant and mixed-phenotype lymphomas, with the latter category containing numerous infiltrating T cells. The B cells in each category were immunoglobulin M-positive (IgM+), CD20+, CD21-. All but one of the polyclonal NHLs had large-cell histology. CONCLUSIONS: EBV-negative, AIDS-associated, polyclonal B-cell lymphoma appears to be a new class of human immunodeficiency virus (HIV)-associated disease more prevalent in the current study than any other molecular subclass. The absence of CD21, the EBV receptor, may explain in part the absence of EBV within this polyclonal B-cell population.

Blotting, Southern↗

PubMed1992

Availability of flow cytometric immunophenotyping of lymphocytes to hospital patients--United States, 1990.

The pathogenesis of disease caused by human immunodeficiency virus (HIV) is largely attributable to the decrease in T-lymphocytes bearing the CD4 cell-surface molecule (CD4 + T-lymphocytes) (1). The percentage of CD4 + T-lymphocytes among total lymphocytes and the percentages of other lymphocyte subpopulations (e.g., CD8 + T-lymphocytes) are generally measured by flow cytometric immunophenotyping (FCl) (also called immunophenotyping by flow cytometry [2], T-lymphocyte immunophenotyping [3], and fluorescence-activated cell sorting). FCl results are frequently used to guide the treatment of HIV-infected persons. To assess the availability of FCl to hospital patients, in 1990, the National Public Health and Hospital Institute (NPHHI), a private, nonprofit research institute, surveyed hospitals about their provision of FCl to patients. This report presents findings from the survey.

Acquired Immunodeficiency Syndrome↗

PubMed1992

Simultaneous genotypic and immunophenotypic analysis of interphase cells using dual-color fluorescence: a demonstration of lineage involvement in polycythemia vera.

Fluorescent in situ hybridization has become a useful technique by which chromosomal abnormalities may be shown in interphase cells. We present a dual-fluorescence method whereby a chromosomal and immunophenotypic marker can be visualized simultaneously in the same interphase cell. Two patients with the myeloproliferative disorder polycythemia vera and trisomy for chromosome 8 have been studied using this technique and selective involvement of the myeloid and erythrocyte lineages has been shown by the detection of the trisomy in immunophenotyped cells. Simultaneous analysis of genotype and immunophenotype in individual cells from patients with myeloproliferative disorders or leukemia may help identify the developmental and lineage status of cells in which molecular alterations have resulted in clonal advantage.

Aged↗

PubMed1991

Lymphocyte immunophenotypes among anti-HTLV-I/II-positive blood donors and recipients. The Transfusion Safety Study Group.

The Transfusion Safety Study retrospectively screened a repository of serum specimens collected in late 1984-early 1985 to identify blood donors with antibody to human T-cell lymphotropic virus (HTLV) at that time. They and their recipients have been traced for additional HTLV studies. Immunophenotypic analyses of peripheral blood lymphocytes from nine anti-HTLV-positive recipients, assumed to be infected during or since late 1984, showed no significant changes from healthy controls. Evaluation of the immunophenotypes of the 48 donors, however, showed significant elevations in the absolute counts of the T-cell (CD2) and natural killer (CD56) populations, the T helper/inducer and suppressor/inducer subsets (CD4+ CD29+ and CD4+ CD45RA+), and changes in T-cell activation markers. Long-term but not recent HTLV infection appears to alter the T-cell immunophenotypic pattern. Both infection with HTLV and human immunodeficiency virus type 1 are associated with a decreased CD2+ CD26+ count.

Blood Donors↗

PubMed1991

Immunophenotyping of 515 cases of acute lymphoblastic leukemia in China.

Using cell surface markers and a panel of monoclonal antibodies, 515 cases of acute lymphoblastic leukemia (ALL) were immunophenotyped. T cell type ALL (T-ALL), non-T cell type ALL (Non-T-ALL) including common ALL (C-ALL), Null-ALL and B cell type ALL (B-ALL) were found. These major subtypes of ALL were further divided according to their phenotypes in detail. It was noticed that the phenotypes of these subtypes of ALL reflected basically the phenotypes of normal T or B cells at various differentiation stages or certain population of lymphocytes. The diagnosis of cell lineage was more precise when based on immunophenotyping than morphological description. The combination of morphological and immunological classification can improve the diagnosis of acute leukemias. In addition, it was observed that the immunophenotyping was relevant to clinicopathologic features, responses to therapy and prognosis of ALL patients. The incidences of major subtypes of ALL, the age distribution of ALL subsets and male sex bias with T-ALL in Chinese are discussed.

Adolescent↗

PubMed1991

Gastrointestinal stromal tumours: correlation of immunophenotype with clinicopathological features.

Stromal tumours of the gastrointestinal tract remain a persistent source of controversy with regard to both their proposed lines of differentiation and the difficulty in predicting their biological behaviour. We have examined 60 cases with a panel of seven antibodies directed at the identification of smooth muscular or neural differentiation. In our hands, 36 per cent of cases showed neural differentiation (although only 6.6 per cent expressed S-100 protein); 31 per cent appeared smooth muscular; 20 per cent manifested bidirectional differentiation; and 13 per cent were negative for all the markers used. Histological appearances do not reliably reflect immunophenotype. We have attempted to correlate immunophenotype with the site of the lesions and with their clinical behaviour. Mean follow-up of 5 years was obtained in 42 cases. Tumours with a neural phenotype have the best prognosis. Gastric tumours expressing both desmin and smooth muscle actin (in the absence of other markers) with up to 4 mitoses per 30 HPF behave in a benign fashion. Larger studies are required to substantiate the value of immunophenotyping this complex group of tumours.

Adult↗

PubMed2025

Well-differentiated systemic mastocytosis: Genetics, mast cell immunophenotypes, and KIT autophosphorylation.

BACKGROUND: Well-differentiated systemic mastocytosis (WDSM) is a rare myeloid neoplasm where the genetic etiology is often unknown. OBJECTIVE: We aimed to assess WDSM patients for novel KIT variants, mast cell (MC) aberrant immunophenotypes, and KIT autophosphorylation patterns. METHODS: Next-generation sequencing, MC immunophenotyping, and KIT autophosphorylation studies were performed. RESULTS: Among 454 SM patients, there were 432 with KIT p.D816V+ SM and 4 with KIT p.D816Y+ SM-notably, none of these patients had WDSM. Of the remaining patients, we identified 7 with WDSM (1.5%) and 2 relatives with mastocytosis in skin. Next-generation sequencing revealed that 6 of 9 subjects carried known or novel germline KIT variants corresponding to regions outside of codon 816. Three patients had germline KIT p.K509I; 2 had germline KIT p.A533D; 1 had two germline KIT variants p.F681L and p.M541L; and 3 had no KIT mutation. Intracellular expression of CD2 and CD25 and less robust expression of CD30 was observed in MCs from WDSM patients. By developing a novel transient transfection assay in 293T cells, we found that unlike KIT p.D816F/V/Y variants that exhibit nearly exclusive intracellular localization and strong ligand-independent autophosphorylation (class II), WDSM-associated KIT variants showed enhanced ligand-dependent autophosphorylation relative to wild type (class I). CONCLUSIONS: Our study doubles the number of KIT variants identified in WDSM patients. No KIT p.D816V+ SM patient had WDSM. Intracellular CD2 and CD25 expression was more robustly detected in MCs from WDSM patients compared to CD30.

Humans↗

PubMed1991

Histomorphologic and immunophenotypic spectrum of primary gastro-intestinal B-cell lymphomas.

In order to compare primary gastro-intestinal (GI) B-cell lymphomas histomorphologically and immunophenotypically with orthologous steps of B-cell differentiation within the mucosa-associated lymphoid tissue (MALT) of the GI tract, a comprehensive panel of well characterized leucocyte differentiation antigens was composed. It comprised immunoglobulin constituents CD5, CD10, CD11c, CD20, CD23, CD24, CD30, CDw32, CD38, CD39, CDw75, CD76, and vimentin. These antigens yield characteristic immunoprofiles for the following B-cell compartments of the MALT, per se closely linked to cytologically distinct B-cell phenotypes: mantle zone (MZ), extrafollicular compartment (EF), follicle center (FC), and plasma-cell compartment (PC). An unselected series of 31 MALT B lymphomas (13 of low and 18 of high grade malignancy) was classified histologically in routine preparations and subsequently characterized immunohistochemically using fresh frozen tissue, monoclonal antibodies (MAbs) against the antigen panel listed above, and an indirect immunoperoxidase method. The final classification considered both morphology and immunoprofile of tumor cells. Ten tumors were "typical" in both respects: 2 closely corresponded to MZ, 5 to EF, 2 to FC and 1 to PC. The remaining 21 cases were characterized as "atypical" because of anaplastic cytology and/or abnormal co-expression and/or loss of antigens. A hybrid EF/FC phenotype was most frequently observed together with centrocyte-like or centrocytic anaplastic cytology of tumor cells. We conclude that MALT B-cell neoplasia comprises a broad spectrum of histo- and immunophenotypes ranging from well differentiated forms closely mimicking normal B-cell development to highly abnormal tumors which cannot be subclassified.

Antibodies, Monoclonal↗