Clonal Epstein-Barr virus genome in T-cell-rich lymphomas of B or probable B lineage.

Seventeen nodal lymphomas (originally diagnosed as T-cell lymphomas based on histological features and immunohistochemical staining results) were studied for the presence of Epstein-Barr virus (EBV) genome, and the results correlated with immunoglobulin and T-cell receptor gene rearrangement analyses performed on the same tissue samples. All four EBV positive cases had clonal rearrangement of the joining region of the immunoglobulin heavy chain (IgJH) gene without clonal T-cell receptor beta-chain (TCR beta) gene rearrangement. Of these, two cases also showed clonally rearranged light chain gene, and they were reclassified as T-cell rich B-cell lymphomas (TRBL). The other two cases lacked clonal kappa or lambda light chain rearrangement and they were reclassified as T-cell rich lymphomas of probable B lineage, based on their isolated IgJH clonal rearrangement. These B-cell lymphomas may be easily misdiagnosed as T-cell lymphomas owing to the presence of an abundant reactive T-cell infiltrate masking the tumor population. The florid T-cell reaction may represent an unusual host response towards a clonal proliferation of EBV bearing B cells.     

Genotypic analysis in large cell lymphomas expressing a restricted set of differentiation antigens

Immunophenotyping and immunogenotyping were performed in a series of 8 large cell lymphomas exhibiting anaplastic or "histiocytic" morphology and displaying an uncertain phenotype due to a restricted number of differentiation antigens. 6 cases expressed the Ki-1 antigen. 4 cases expressed one or two B-cell markers and contained rearrangements of the immunoglobulin genes. One of them also exhibited a T-cell receptor (TCR) beta gene rearrangement. 3 cases expressed a single T-cell differentiation antigen. Among them, only 1 displayed both gamma and beta TCR gene rearrangement; 1 only contained a gamma TCR gene rearrangement and 1 completely lacked clonal rearrangements. The eight cases expressed an inconclusive immunophenotype due to an abundant population of reactive cells but showed an immunoglobulin gene rearrangement. In conclusion, 5 out of the 8 unusual lymphomas studied here could be characterized by immunogenotyping. This approach was, however, inconclusive in the 3 remaining cases, whose lineage and differentiation stage remain poorly defined.     

Rearrangement of immunoglobulin and T-cell receptor genes in Hodgkin''s disease.

The precise cellular origin of the malignant cell population in Hodgkin's disease (HD) is unknown. Recent application of Southern blotting techniques to detect clonal rearrangements of immunoglobulin (Ig) and T-cell receptor (TCR) genes has yielded conflicting results. The authors report the detailed analysis of tumor tissue DNA obtained from 18 cases of HD using Ig and TCR gene probes. The distribution of HD subtypes was similar to that in other series. Samples were examined for rearrangement by means of multiple restriction enzymes with specific probes for the Ig heavy chain, Ig kappa, Ig lambda, TCR beta, and TCR gamma loci. Only germline bands were detected in all 18 cases with the Ig gene probes and in 15 of 18 cases with the TCR probes. In 2 cases blot analysis suggested a predominance of polyclonal (or oligoclonal) T cells. In 1 case monoclonal rearrangement of the TCR beta gene was detected. Based on the intensity of the rearrangement and the small percentage of Reed-Sternberg (R-S) cells in this case, the clonal population detected was most likely not the R-S cell itself. The data do not support the frequent occurrence of Ig or TCR monoclonal gene rearrangement in HD.     

Chronic myelomonocytic leukaemia associated with T cell receptor delta gene rearrangement.

Morphological, immunophenotypic, and genetic analyses were carried out on peripheral blood, bone marrow, and pharyngeal biopsy material from a patient with chronic myelomonocytic leukaemia (CMML). Morphological analysis of bone marrow was diagnostic of CMML; immunophenotypic analysis of peripheral blood and bone marrow were negative for B and T cell antigens, and immunochemistry performed on the pharyngeal extramedullary infiltrate showed the presence of large monocytoid cells which stained positively for muramidase. Genotypic analysis, however, showed clonal rearrangement of the T cell receptor (TCR) delta chain gene, a marker of T cell or, less commonly, B cell lymphoid neoplasms. Other TCR genes, beta and gamma, were germline in all tissues examined. TCR delta is rearranged in precursor B cell and most T lymphoid neoplasms. A small proportion of cases (10%) of acute myeloid leukaemia (AML) also show rearrangement of the TCR delta gene. To date TCR delta rearrangement has not been described in CMML. The aberrant TCR delta rearrangement shown in this patient with CMML provides further evidence of the clonal nature of this disorder.     

Immunohistochemistry and gene rearrangement studies in the diagnosis of malignant lymphomas: a comparison of 152 cases.

One hundred fifty-two cases (155 specimens) of lymphoproliferative disorders were studied by immunohistochemistry and gene rearrangement analysis. Ninety-five of 96 B-cell lymphomas (99%) showed genotypic B-cell monoclonality. Of these, five cases had rearranged T-cell receptor (TCR) beta chain gene in addition to immunoglobulin heavy chain (IgH) and kappa light chain (Ig-K), one case had rearranged IgH and TCR-gamma chain but not Ig-K or TCR-beta, and two cases had only Ig-K rearrangement. One exceptional case in the B-cell lymphoma group had unrearranged, germline genotypes. In contrast, only 10 of 19 (53%) phenotypic T-cell lymphomas had rearranged TCR-beta, eight with concurrent TCR-gamma rearrangement. Of the remaining nine cases, six had germline configuration, two had rearranged Ig-K only, and one had both IgH and Ig-K rearrangement. This last case was reclassified as T-cell predominant, B-cell lymphoma. Thirteen of 16 cases of Hodgkin's disease had germline configuration; three cases had rearranged IgH and Ig-K, of which two were lymphocyte predominant with light chain monoclonality and one was a recurrence. Among 21 reactive lesions, 17 had germline configuration and four had rearranged IgH and Ig-K genes. Of these four cases, two were orbital lesions, one was a partially involved lymph node, and one developed a nodular lymphoma 9 months later. Our results indicate that almost all B-cell lymphomas have IgH and/or Ig-K rearrangement. In contrast, peripheral T-cell lymphomas have greater genotypic heterogeneity, and germline patterns for TCR genes are not uncommon. Reactive lesions and Hodgkin's disease tend to retain germline configuration, and any exception is often associated with an unusual clinical setting and/or histology. Genotypic analysis is thus most indicated in B-cell lymphomas with equivocal immunohistochemistry findings, T-cell lymphomas, and atypical cases of Hodgkin's disease and reactive lesions.     

The application of antigen receptor gene rearrangement of BIOMED-2 in the pathologic diagnosis of 348 cases with non-Hodgkin lymphoma in a single institution in Southwest of China

ObjectiveTo explore the clinical value of immunoglobulin (Ig) and T cell receptor (TCR) gene rearrangement in the diagnosis of non-Hodgkin lymphoma.MethodsUsing the standardized BIOMED-2 multiplex PCR strategy to detect IgH, IgK and TCR in 272 cases of mature B-cell lymphoma, 55 cases of mature T-cell lymphoma, 21 cases of extranodal NK/ T-cell lymphoma, nasal type, and 20 cases of lymphoid tissue reactive hyperplasia.ResultsAmong all mature B-cell lymphomas, the sensitivity of Ig gene rearrangement was 91.18% (248/272), IgH and IgK gene rearrangement was 76.47% (208/272) and 75.00% (204/272), respectively, meanwhile the sensitivity of TCRγ rearrangement was 3.68% (10/272). In the 55 cases of mature T-cell lymphoma, the sensitivity of the detection of TCRγ was 76.36% (44/55), at the same time the sensitivity of Ig gene rearrangement was 14.55% (8/55), IgH and IgK gene rearrangement was 7.27% (4/55) and 12.73% (7/55), respectively. In 21 cases of extranodal NK/T cell lymphoma, nasal type, and 20 cases of reactive lymphoid hyperplasia, no gene rearrangement was found in the samples of IgH, IgK and TCR. The sensitivity of gene rearrangement in Ig/TCR in B and T-cell lymphoma was significantly different from that in the control group (P < 0.05).ConclusionThe Ig/TCR gene rearrangement of BIOMED-2 multiplex PCR strategy has important auxiliary value in the diagnosis of B/T-cell non-Hodgkin lymphoma respectively, however, a few B-cell lymphomas may company TCR gene rearrangement as well as a few T-cell lymphomas may accompany Ig gene rearrangement, it must be comprehensively judged with the combination of morphology, immunohistochemistry and clinical features.     

Semireannealing, single-stranded conformational polymorphism: a novel and effective tool for the diagnosis of T-cell clonality.

Single-stranded conformational polymorphism (SSCP) is often used for the diagnosis of T-cell clonality in lymphoproliferative disorders. We introduce a semireannealing SSCP (SR-SSCP) protocol that is rapid, reproducible, and effective. By denaturing and reannealing the polymerase chain reaction (PCR) product before high-resolution polyacrylamide gel electrophoresis, it is possible to generate a diagnostic fingerprint for each case with clonal T-cell receptor-gamma (TCR-gamma) gene rearrangement detected after PCR with TCR-gamma specific consensus primers. Discrete and distinct denatured single-stranded DNA band profiles characterize the rearranged TCR-gamma clones. In the same gel, the clone size may be estimated in the reannealed double-stranded PCR DNA and can be assessed down to the 2% clonal T-cell population level. Eighty-four cases, including 37 T-cell neoplasms, 29 B-cell neoplasms, and 18 reactive lymph node samples were analyzed by SR-SSCP. Clonal TCR-gamma rearrangement was diagnosed in 32 out of 37 T-cell neoplasms but in none of the B-cell tumors or reactive lymph node samples corresponding to sensitivity and specificity of 86.5% and 100%, respectively. We compare the results of SR-SSCP to those obtained by capillary electrophoresis and direct sequence analysis with 100% correlation. This novel method is applicable to any system for identification and quantitation of microheterogeneity in PCR products.     

Peripheral T-cell lymphoma complicated by a proliferation of large B cells

We studied 14 cases that showed a morphologic appearance of peripheral T-cell lymphoma and contained substantial numbers of CD20+ large B cells. In all but 2 cases, the CD20+ large cells showed a mix of kappa and lambda light chain expression. Two cases showed a focal predominance of kappa expression. In situ hybridization using the EBER1 probe for detection of Epstein-Barr virus (EBV) RNA was performed on every case. EBV RNA was present in 10 cases. Of 8 cases with EBV RNA stained by immunohistochemistry for the latent membrane protein of EBV, 6 were positive. Double-labeling immunohistochemistry and in situ hybridization confirmed that EBV was present in the large B cells. Polymerase chain reaction (PCR) analysis showed a clonal rearrangement of the T-cell receptor (TCR)-gamma chain gene in 12 of 13 cases tested. One additional case showed a clonal rearrangement of the TCR-beta chain gene by Southern blot hybridization. PCR analysis showed a clonal immunoglobulin gene rearrangement in 5 cases, a suggestion of a clonal rearrangement in 1, an oligoclonal pattern in 4, and a polyclonal pattern in 4. The finding of large B and T cells may result in a misdiagnosis of a reactive process or of T-cell-rich B-cell lymphoma. The presence of EBV in some cases could cause further confusion with the reactive T- and B-immunoblastic proliferation of infectious mononucleosis.     

Bone marrow trephines containing lymphoid aggregates from patients with rheumatoid and other autoimmune disorders frequently show clonal B-cell infiltrates

In bone marrow trephines, morphological and immunohistochemical criteria may not be sufficient to discriminate reactive from malignant lymphoid infiltrates. The aim of this study was to determine whether the detection of clonal immunoglobulin heavy chain (IGH) gene rearrangements is a reliable and specific marker for malignant B-cell clones in bone marrow biopsies. Bone marrow trephines with infiltration by different types of low-grade B-cell non-Hodgkin lymphoma (n = 32), reactive lymphoid hyperplasia (n = 18), and reactive lymphoid aggregates (n = 15), including 5 patients with rheumatoid or other autoimmune disorders, were analyzed by morphology, immunohistochemistry, IGH gene rearrangement (polymerase chain reaction), and DNA sequence analysis in selected cases. In 22 (68.8%) of 32 patients with B-cell non-Hodgkin lymphoma, a clonal IGH gene rearrangement was detected. Of the reactive cases, 1 of 18 patients with lymphoid hyperplasia demonstrated clonality, and 9 (60%) of 15 patients with reactive lymphoid aggregates gave a clonal result (GeneScan analysis). DNA sequence analysis was performed in 7 of the latter patients confirming clonality in 6. Four of the patients with B-cell clonality had an autoimmune disorder. None of these patients developed a malignant lymphoma during follow-up. Thus, the molecular detection of a clonal rearrangement of the IGH gene may support the diagnosis of a malignant lymphoma infiltrating the bone marrow. However, morphologically and immunohistochemically benign lymphoid aggregates might also harbor B-cell clones especially in patients with autoimmune disorders. Therefore, the detection of clonality has to be interpreted with utmost care and does not qualify for the unequivocal diagnosis of a malignant B-cell lymphoma.     

Immunophenotypic and genotypic characterization of primary non-Hodgkin's lymphoma of the gastrointestinal tract

Antigen receptor gene rearrangement studies have been applied to gastrointestinal (GI) lymphoid proliferations in only a limited number of cases, and their use and contribution to the diagnosis and characterization of GI lymphomas is unknown. We retrospectively studied 17 cases of primary GI lymphoma using fresh/frozen tissue with a combination of immunophenotypic and genotypic techniques. The vast majority of the neoplasms were B-cell lymphomas (88%) with rare T-cell tumors. The most common B-cell immunophenotype was IgM-kappa (40%), while five of the B-cell lymphomas (33%) lacked surface light chain immunoglobulin. Immunophenotypic evidence of histiocytic differentiation was not identified. Clonality was confirmed in 59% (10/17) of the neoplasms by immunophenotyping and 88% (15/17) by antigen receptor gene rearrangement studies. All of the 15 B-cell lymphomas (100%) demonstrated clonally rearranged immunoglobulin gene rearrangement. The two lymphomas with T-cell immunophenotypes did not demonstrate T-cell receptor beta-chain gene rearrangement. Antigen receptor gene rearrangement data can be useful and may even be necessary in certain cases for the proper classification and/or diagnosis of GI lymphoid proliferations.     

Angioimmunoblastic T-cell lymphoma with cutaneous involvement: a case report with subtle histologic changes and clonal T-cell proliferation

Angioimmunoblastic T-cell lymphoma is a nodal peripheral T-cell lymphoma that rarely involves the skin. We describe a 62-year-old Taiwanese man who developed a second relapse of angioimmunoblastic T-cell lymphoma with generalized erythroderma and numerous plaquelike and nodular lesions. Biopsy of the erythematous skin lesion demonstrated mild infiltrate of atypical small lymphocytes, some with clear cytoplasm. The lymphoid infiltrate was located mainly around skin appendages and in the upper dermis without epidermotropism. Immunohistochemically, these atypical lymphocytes expressed CD3. Polymerase chain reaction analysis for T-cell receptor gamma-chain gene rearrangement using paraffin section showed the same-sized monoclonal bands in the skin and 2 previous nodal biopsies. We conclude that the histologic features of angioimmunoblastic T-cell lymphoma involving skin may be very subtle, showing only mild lymphoid infiltrate. Awareness of the history of angioimmunoblastic T-cell lymphoma with ancillary studies, including clonality testing for T-cell receptor gene rearrangement, is crucial for reaching an accurate diagnosis.     

Monoclonal analysis of immunoglobulin heavy chain and T-cell receptor gamma chain gene rearrangements in paraffin-embedded tissues from non-Hodgkin lymphoma patients

Gene rearrangement is an important diagnostic marker of malignant lymphoma, and rearrangements of the immunoglobulin heavy chain (IgH) and T-cell receptor gamma chain (TCRgamma) genes are useful markers for Band T-cell lymphoma, respectively. A polymerase chain reaction (PCR) can be used to analyze clonality in formalin-fixed paraffin-embedded specimens. We performed 73 monoclonal analyses of such specimens of lymphoma tissues and examined the ability to diagnose malignant lymphoma by this method. Monoclonality of lymphoma cells was found in 71.9% and 78.9% of specimens with IgH and TCRgamma gene rearrangements, respectively. Therefore, in diagnosing cases of non-Hodgkin lymphoma in which neoplasms and reactive lymphoid tissues are difficult to identify by morphological and immunohistochemical findings, PCR-based monoclonal analysis may allow confirmation of a pathological diagnosis of malignant lymphoma.     

Eosinophil-rich CD30+ lymphoproliferative disorder of the oral mucosa. A form of "traumatic eosinophilic granuloma"

We describe 3 patients who had oral mucosal lesions with features of traumatic eosinophilic granuloma (TEG) and containing CD30+ atypical cells. In 1 patient, the oral lesion was followed by skin nodules. All lesions were evaluated histologically, by immunohistochemical analysis, and by polymerase chain reaction (PCR) analysis of the T-cell receptor (TCR) gamma chain gene. All oral lesions were characterized by a dense and deeply infiltrative lymphoproliferation, showing epitheliotropism and massive eosinophilia. They contained atypical large lymphoid cells, which expressed T-cell markers and CD30. PCR analysis showed a monoclonal rearrangement of the TCR gamma chain gene in all lesions and, in 1 patient, the same rearrangement in the oral and cutaneous specimens. The lesions in these patients seem to be the oral counterpart of the spectrum of primary cutaneous CD30+ lymphoproliferative disorders and should be recognized as such to avoid a diagnosis of large T-cell lymphoma and possible consequent overtreatment. However, they represent only a subset among several others within the complex and heterogeneous category of disorders referred to as TEG.     

Evaluation of biotinylated DNA probes for the detection of gene rearrangements in clinical specimens

To determine whether a nonisotopic procedure is suitable for analyzing clinical specimens for gene rearrangements, the authors hybridized DNA from 15 specimens of lymphoid tissue with biotinylated DNA probes directed to J beta I + J beta II (T-cell receptor beta chain gene), JH (immunoglobulin gene heavy chain J region), and J kappa (immunoglobulin gene kappa light chain J region). Five cases of benign lymphoid hyperplasia, one case of dermatopathic lymphadenopathy, and one case of small noncleaved follicular center cell lymphoma had germline hybridization patterns when digested with Bam HI, Eco RI, and Hind III restriction endonucleases. Four cases of B-cell lymphoma and three cases of T-cell lymphoma had clearly detectable rearrangements of the genes for immunoglobulin or the T-cell receptor or both. One case of dermatopathic lymphadenopathy had a faint, clonal rearrangement of the T-cell receptor after digestion with Eco RI and Bam III. The authors conclude that biotinylated DNA probes can be useful for analyzing gene rearrangements in clinical specimens.     

Configuration of immunoglobulin and T cell receptor beta and gamma genes in acute myeloid leukaemia: pitfalls in the analysis of 40 cases.

AIMS: To evaluate the overall incidence of immunoglobulin (Ig) and T cell receptor (TCR) beta and gamma gene rearrangements in a series of 40 cases of acute myeloid leukaemia (AML) and to determine whether structural modifications of these genes could be correlated with the abnormal expression of lymphoid markers in malignant cells. METHODS: All cases were classified according to the criteria of the FAB group and immunophenotyped with a panel of monoclonal antibodies reactive with myeloid and lymphoid differentiation antigens. DNA analysis was performed by the method of Southern using probes for the Ig JH, TCR-C beta 1, and TCR-J tau 1 regions. RESULTS: Phenotypic analysis showed that in addition to myeloid markers, 10 cases expressed lymphoid antigens: CD7 in seven (of which three were TdT positive, one CD2 positive, and one CD19 positive) and CD19 in three. Southern blot analysis showed that bands with sizes different from the germ line control were present in the TCR beta genes in 11 cases: in six of 30 with pure myeloid phenotype and in five of 10 of those expressing lymphoid markers. A close observation of the size and patterns of those bands, however, showed that they could be artefactual. Indeed, further analysis showed that they were either due to resistant Eco RI/Hind III sites at the beta locus or to plasmid contamination. Rearranged genes were eventually found in only two of the 40 cases: at the Ig JH region in one of the 30 with pure myeloid phenotype (3.3%) and at the TCR gamma genes in one of 10 with lymphoid markers (10%). CONCLUSIONS: These observations showed that Ig/TCR gene rearrangements were rare in this AML series (overall incidence of 5%) and that they were not significantly more common in cases with aberrant expression of lymphoid markers. The size and pattern of the potential non-germline bands that can be found in these loci must be carefully evaluated.     

Rearrangement of the T-cell receptor delta chain gene in T-cell lymphomas with a mature phenotype.

The configuration of the T-cell receptor (TCR) delta chain gene was assessed using restriction fragment analysis and the Southern blot technique in 39 T-cell lymphomas with a mature immunophenotype. The TCR delta gene was rearranged in four lymphomas although the gamma/delta TCR was not expressed in two cases studied. The TCR delta gene was the only TCR gene rearranged in two cases. Each lymphoma with TCR delta gene rearrangement had an aberrant T-cell immunophenotype and three cases were of the large cell anaplastic type. The TCR delta gene was deleted in 22 cases and was in the germline configuration in 13 lymphomas. Deletion of the TCR delta gene was characteristic of mycosis fungoides, adult T-cell leukemia/lymphoma (human T cell leukemia-lymphoma virus positive), and Lennert's lymphoma, and was not identified in angiocentric lymphomas. In eight cases with TCR delta deletion, however, a large number of polyclonal (presumably reactive) T cells were present and, in these lymphomas, the authors could not determine if TCR delta gene deletion occurred in the polyclonal T cells, the neoplastic cells, or both cell populations. The authors conclude that the TCR delta gene is usually deleted in mature T-cell lymphomas, as would be expected in alpha/beta TCR T cells. However, TCR delta gene rearrangement is detectable in approximately 10% of cases. Analysis of this locus may be useful diagnostically, as it occasionally may be the only molecular marker of clonality in mature T-cell lymphomas T-cell receptor delta chain gene rearrangement also is found most often in lymphomas of the large cell anaplastic type.     

Comparison of capillary electrophoresis and polyacrylamide gel electrophoresis for the evaluation of T and B cell clonality by polymerase chain reaction.

Polymerase chain reaction (PCR) technique is widely used in the diagnosis of lymphoma, and PCR amplification products are typically detected by polyacrylamide gel electrophoresis (PAGE). However, the identification of small clonal populations, or the distinction of clonal PCR products in a polyclonal milieu remains difficult, requiring technically demanding alterations to gel analysis. This study describes an alternative approach using a capillary electrophoresis (CE) system to produce an accurately sized electropherogram. A variety of patient samples were examined, including solid tissue, peripheral blood, bone marrow aspirates, and paraffin-embedded tissue. A total of 28 samples were evaluated by PCR for B-cell clonality by detection of immunoglobulin heavy chain gene rearrangement and 29 samples for T-cell clonality by detection of T-cell gamma locus gene rearrangement. Standard 10% PAGE analysis of PCR products was compared with CE. There was a 100% concordance in the assessment of both B-cell and T-cell clonality. Dilution studies with the SUP-B15 cell line showed a detection limit of 0.03% for B-cell clonality and 0.05% for T-cell clonality using CE, versus 0.2% to 1%, respectively for PAGE. Automated, fluorescent analysis of PCR products by CE seems to be at least equally as effective as gel-based analysis for the detection of clonal B-cell and T-cell populations. Moreover. CE offers superior resolution and improved sensitivity, thus representing a significant improvement over traditional gel electrophoretic techniques in these regards.     

Immunoglobulin and T-cell receptor gene rearrangement analysis in malignant lymphoid neoplasms.

Gene rearrangement analysis using Southern-blot hybridization technique is a standard method for evaluating clonal receptor gene rearrangement. Both clonality and lineage can be identified in lymphoid neoplasms by the demonstration of one or more rearranged antigen receptor genes of the immunoglobulin supergene family-immunoglobulin and T-cell receptor genes. To evaluate the diagnostic applicability of antigen receptor gene rearrangements in the diagnosis of malignant lymphomas and leukemias, the authors performed a gene rearrangement analysis of 54 cases by southern blot hybridization technique. One or two clonally rearranged bands were detected in the malignant lymphomas and in the lymphoblastic leukemias with a false-negative rate of 13.8%. No clonal, rearranged band was detected in benign reactive hyperplasias, carcinomas or non-lymphocytic leukemias. Rearrangement analysis could resolve the lineage, clonality and stage of differentiation of malignant lymphoid neoplasms.     

Identification of monoclonal B-cell populations by rapid cycle polymerase chain reaction. A practical screening method for the detection of immunoglobulin gene rearrangements.

Alternatives to Southern blot hybridization for gene rearrangement analysis are being studied because of the time, labor, cost, and radioisotopes required for this technique. We have utilized a rapid, hot air, thermocycling polymerase chain reaction (PCR) system to examine various lymphoproliferative disorders for immunoglobulin heavy chain (IgH) gene rearrangements. This unique system amplifies DNA from 10 microliters samples placed in glass capillary tubes, over a total cycle time of about 30 minutes. Amplified bands are easily visualized on ethidium bromide-stained agarose gels. Forty-one monoclonal B-cell proliferations, 27 reactive lymphoid hyperplasias, 17 T-cell lymphomas and 3 cases of Hodgkin's disease were studied. All 88 cases were fully characterized by morphologic, immunophenotypic, and genotypic (Southern blot) analyses. Each case was separately evaluated by PCR with two primer pairs: 1) IgH variable region (VH) and IgH joining region (JH) and 2) bcl-2 and JH. Thirty-four of 41 monoclonal B-cell proliferations revealed a distinct band (within an expected base pair range) with 1 or both primer combinations supporting B-cell monoclonality; the other 7 cases were considered false negatives. The 47 entities without IgH gene rearrangements detectable by Southern analysis demonstrated no amplified product or a smear of amplified DNA with no distinct band. The overall specificity of PCR was 100%, and the sensitivity was 83% when directly compared with Southern blot analysis. Although its sensitivity is currently less than optimal, PCR is a rapid and practical screening method for the detection of IgH gene rearrangements. If a positive result is obtained no further analysis is required; however, if there is a negative result, standard Southern blot analysis should be performed to definitively exclude the presence of a monoclonal B-cell population in the sample.