Mantle cell lymphoma: correlation of clinical outcome and biologic features with three histologic variants.

PURPOSE: Clinical data and histologic material were retrospectively analyzed in 46 cases of previously untreated mantle cell lymphoma (MCL) to more fully characterize the clinical response pattern of these lymphomas and to determine whether growth pattern significantly affected clinical outcome. MATERIALS AND METHODS: The histologic pattern was classified as diffuse (61%), nodular (13%), and mantle zone (26%) in accordance with stated criteria. RESULTS: Bone marrow infiltration was detected in 69% of cases; the frequency of involvement correlated with histologic pattern, being most common in diffuse variants and least common in mantle zone variants. Other sites of extranodal involvement were observed in 50% of cases. Cyclin-D1 staining revealed nuclear positivity in 23 of 25 patients (92%) and no difference was observed between the various histologic patterns. Rearrangement at the bcl-1 major translocation cluster (MTC) was detected in seven of 21 cases, without regard for histologic pattern. Complete response rates to doxorubicin-based regimens showed a striking correlation with histologic pattern. Seventy-three percent of patients with a mantle zone pattern attained a complete response compared with only 25% of patients with a nodular pattern and 19% with a diffuse pattern. Three-year survival rates were 100%, 50%, and 55% for patients with mantle zone, nodular, and diffuse histologic patterns, respectively. CONCLUSION: We conclude that (1) diffuse and nodular MCL are associated with a poor treatment response and a poor overall survival rate; (2) the mantle zone variant exhibits the clinical attributes of a low-grade lymphoma; and (3) the poor survival rates of patients with nodular and diffuse MCL suggest that these variants be classified as intermediate-grade lymphomas. However, the trend of the time to treatment failure curve does not indicate that current regimens can cure MCL.

Hyper-CVAD and high-dose methotrexate/cytarabine followed by stem-cell transplantation: an active regimen for aggressive mantle-cell lymphoma.

PURPOSE: Diffuse and nodular forms of mantle-cell lymphoma (MCL) are consistently associated with poor prognosis. In an effort to improve the outcome, we adopted a treatment plan that consisted of four courses of fractionated cyclophosphamide (CY) 1,800 mg/m2 administered with doxorubicin (DOX), vincristine (VCR), and dexamethasone (Hyper-CVAD) that alternated with high-dose methotrexate (MTX) and cytarabine (Ara-C). After four courses, patients were consolidated with high-dose CY, total-body irradiation, and autologous or allogeneic blood or marrow stem-cell transplantation. PATIENTS AND METHODS: Forty-five patients were enrolled; 25 patients were previously untreated, 43 patients had Ann Arbor stage IV disease, and 42 patients had marrow involvement. Forty-one patients had diffuse histology, two patients had nodular, and two patients had blastic variants. RESULTS: Hyper-CVAD/MTX-Ara-C induced a response rate of 93.5% (complete response [CR], 38%; partial response [PR], 55.5%) after four cycles of pretransplantation induction chemotherapy. All patients who went on to undergo transplantation achieved CRs. For the 25 previously untreated patients, the overall survival (OS) and event-free survival (EFS) rates at 3 years were 92% (95% confidence interval [CI], 80 to 100) and 72% (95% CI, 45 to 98) compared with 25% (95% CI, 12 to 62; P = .005) and 17% (95% CI, 10 to 43; P = .007), respectively, for the previously treated patients. When compared with a historic control group who received a CY, DOX, VCR, and prednisone (CHOP)-like regimen, untreated patients in the study had a 3-year EFS rate of 72% versus 28% (P = .0001) and a better OS rate (92% v 56%; P = .05). Treatment-related death occurred in five patients: all were previously treated and two received allogeneic transplants. CONCLUSION: The Hyper-CVAD/MTX-Ara-C program followed by stem-cell transplantation is a promising new therapy for previously untreated patients with MCL.

Developmental and differential regulation of human MPO gene in leukemic cells.

Northern blot analysis of RNA isolated from HL-60 cells before and after differentiation induction by TPA and DMSO showed that four MPO mRNA species (3.3, 3.1, 2.7, and 2.5 kb, respectively designated alpha 1, beta 1, alpha 2, and beta 2) are expressed in HL-60 cells. However, alpha 2 and beta 2 lack part of the 3' end sequence due to different polyadenylation sites. The steady state levels of alpha 2 and beta 2 MPO mRNA increase significantly after 1 hr of induction, while all four MPO mRNA species decrease dramatically after 10 hr of induction. Our results demonstrate that MPO gene expression is developmentally and differentially regulated. Northern blot analysis of RNA isolated from blast samples of acute myelogenous leukemia (M0-M5) and chronic lymphocytic leukemia (CLL) patients indicate that four MPO mRNA species are expressed in M1-M4 but are undetectable in M5 and CLL. Primer extension and S1 nuclease protection analysis of the MPO mRNA revealed a single transcription initiation site for the MPO gene.

Allogeneic bone marrow transplantation for poor-prognosis lymphoma: response, toxicity and survival depend on disease histology.

PURPOSE: To evaluate outcomes and identify prognostic factors in allogeneic bone marrow transplantation in patients with end-stage lymphoma. PATIENTS AND METHODS: Data were retrospectively analyzed of 64 patients (42 men and 22 women) 18 to 48 years of age with recurrent or refractory lymphoma who underwent allogeneic bone marrow transplantation from matched sibling donors (or in 1 case from a one antigen-mismatched relative) between May 1981 and July 1994. RESULTS: Twelve patients survived free of disease. They were 8 of 15 with low-grade lymphoma (disease-free survival at 2 years 59% +/- 13%); 3 of 25 with lymphoblastic lymphoma (disease-free survival 17% +/- 8%); and 1 of 10 with diffuse small non-cleaved cell lymphoma (disease-free (10% +/- 9%). Survival and disease-free survival of patients with low-grade lymphoma were significantly superior compared to any other subgroup of patients (P <0.01). Only 2 patients with low-grade lymphoma had disease progression (9% +/- 9% actuarial risk at 2 years) as opposed to 5 of 15 with intermediate-grade lymphoma (39% +/- 14%), 9 of 25 with lymphoblastic lymphoma (28% +/- 9%), and 8 of 10 (80% +/- 13%) with diffuse small non-cleaved lymphoma. The actuarial risk for disease progression was significantly lower for patients with low-grade lymphoma than for any other histologic subgroup (P <0.02). It was significantly higher for those with diffuse small non-cleaved cell lymphoma than for other histologic subgroups (P < or = 0.003). CONCLUSIONS: Allogeneic bone marrow transplantation is an effective procedure in patients with refractory low-grade lymphoma. It results in long-term remissions and should be considered in younger patients with recurrent disease who have a matched sibling donor. The late recurrence in 1 patient indicates the necessity of continued follow-up. A small fraction of patients with end-stage intermediate- and high-grade lymphoma can obtain prolonged disease-free survival, but recurrence and regimen-related toxicity remain major problems. The results could be improved by the development of conditioning regimens with less toxicity and by the use of bone marrow transplantation earlier in the course of the disease.

Apoptosis and the Bcl-2 gene family -- patterns of expression and prognostic value in stage I and II follicular center lymphoma.

PURPOSE: The prognostic significance of spontaneous levels of apoptosis and Bcl-2, Bax, and Bcl-x protein expression in follicular center lymphoma (FCL) is unknown. The objectives of this retrospective study were (1) to investigate the relationship between pretreatment apoptosis levels and long-term treatment outcome in patients with Stage I and II FCL; (2) to define the incidence and patterns of Bax and Bcl-x protein expression in human FC; and (3) to determine the relationship of Bcl-2, Bax, and Bcl-x expression with spontaneous apoptosis levels and clinical outcome in localized FCL. METHODS AND MATERIALS: Between 1974 and 1988, 144 patients with Stage I or II FCL were treated. Hematoxylin and eosin (H & E) stained tissue sections of pretreatment specimens were retrieved for 96 patients. Treatment consisted of regional radiation therapy (XRT) for 25 patients, combined modality therapy (CMT) consisting of combination chemotherapy and XRT for 57 patients, and other treatments for 14 patients. Median follow-up for living patients was nearly 12 years. The apoptotic index (AI) was calculated by dividing the number of apoptotic cells by the total number of cells counted and multiplying by 100. Expression of Bcl-2, Bax, and Bcl-x proteins was assessed using immunohistochemistry. RESULTS: The mean and median AI values for the entire group were 0.53 and 0.4, respectively (range: 0-5.2). The AI strongly correlated with cytologic grade, with mean AI values of 0.25 for grade 1, 0.56 for grade 2, and 0.84 for grade 3 (p < 0.0005; Kendall correlation). A positive correlation was present between grouped AI and grouped mitotic index (MI) (p = 0.014). For patients treated with CMT, an AI < 0.4 correlated with improved freedom from relapse (FFR) p = 0.0145) and overall survival (OS) (p = 0.0081). An AI < 0.4 did not correlate with clinical outcome for the entire cohort or for patients receiving XRT only. Staining of tumor follicles for the Bcl-2 protein was positive, variable, and negative in 73%, 15%, and 12% of cases, respectively. Positive staining of tumor follicles was observed in 96% of cases for both the Bax and Bcl-x proteins. Expression of Bcl-2, Bax, or Bcl-x did not correlate with AI or clinical outcome. CONCLUSION: The level of spontaneous apoptosis in pretreatment specimens correlates with cytologic grade of FCL and is a significant predictor of FFR and OS for patients with localized FCL receiving CMT.

Practicality of molecular studies to evaluate small lymphocytic proliferations in endoscopic gastric biopsies.

Fifteen endoscopic gastric biopsies (GBx) from 12 patients with small lymphocytic infiltrates morphologically raising a differential of indeterminate lymphocytic infiltrate versus mucosa-associated lymphoid tissue (MALT) lymphoma were analyzed genotypically after frozen-section identification of the abnormal lymphocytic infiltrate. Frozen-section immunoperoxidase immunophenotyping was equivocal in each case. All patients had abdominal pain attributable to superficial gastric ulceration, most often antral, without peripheral lymphadenopathy or hepatosplenomegaly. Rearrangement of the immunoglobulin heavy-chain gene (JH-R, seven patients) or kappa light-chain gene (JK-R, eight patients), was found in eight GBx from eight (seven stage IAE; one stage IBE) of 12 patients, establishing, in conjunction with the histologic features, a diagnosis of low-grade B-cell lymphoma. This diagnosis had not been tenable on multiple prior GBx, ranging from one to five per patient, over intervals of 1 month to 6.5 years (median 4.5 months). The T-cell receptor beta-chain gene retained germline configuration in all cases. Insufficient DNA for molecular studies was extracted from the GBx of two patients, one with JK-R (JH-G) on subsequent GBx and one without further GBx. One patient had two GBx, each demonstrating a single additional band in HindIII digests hybridized with the JH probe. No rearrangements were detected in either the BamHI or the EcoRI digests. Uninvolved tissue from this patient was not available for the exclusion of restriction fragment length polymorphism. Three GBx (two patients) showed germline JH genes (JH-G). One had a partial gastrectomy (histology: MALT lymphoma) in 1981 followed by GBx in 1983 (histologically benign) and in 1990 (JH-G), and negative esophagogastroduodenoscopy (EGD) in 1991 without biopsy. The other patient (two GBx with JH-G) had multiple subsequent abnormal EGD, but no biopsies since December 18, 1990. Adequate DNA for gene rearrangement studies can be extracted from GBx samples weighing as little as 20 mg. The two samples with insufficient DNA weighed 1 and 16 mg, respectively. Practically speaking, the remainder of a frozen block from a single GBx is adequate, thus allowing the screening of multiple endoscopic GBx by sequential frozen sections to determine which one contains the most extensive lymphocytic infiltrate for molecular study. Consistent results are obtained on samples weighing 40 to 60 mg. This method is a suitable alternative to kappa/lambda frozen-section immunoperoxidase immunostaining, which can be uninterpretable on endoscopic biopsies or small biopsies from other sites.

Paraimmunoblastic variant of small lymphocytic lymphoma/leukemia.

We report 16 cases of a distinctive, biologically aggressive variant of small lymphocytic lymphoma/leukemia (SLL/L) that is characterized by the diffuse proliferation of cells normally comprising the pseudoproliferation centers (so-called paraimmunoblasts). Demographically, the patients differed in no significant regard from patients with SLL/L of usual type. Rapidly progressive, generalized lymphadenopathy was the dominant clinical finding in 15 of the 16 patients; one patient presented with symptoms related to lymphomatous involvement of the stomach and regional lymph nodes. Splenomegaly was observed in five patients. Seven patients, two of whom had a history of indolent-phase chronic lymphocytic leukemia, had an absolute lymphocytosis at diagnosis. In most patients, bone marrow involvement was noted at diagnosis. It consisted predominantly of small lymphocytic infiltrates indistinguishable from those observed in SLL/L of usual type; significant paraimmunoblastic infiltration was infrequent and generally occurred late in the disease course. Immunohistochemical and cytogenetic study further substantiated the hypothesized relationship of these cases to SLL/L. Findings included (a) coexpression of sIg and Leu-1 antigen in the majority of cases and (b) the presence of a t(11;14) (q13;q32) chromosome translocation in two of three cases with analyzable metaphases. Although treatment protocols were not uniform, follow-up data indicated an accelerated clinical course. Eleven patients have died of their disease between 3 and 39 months after diagnosis; the median survival was 28 months.

The value of immunophenotyping on paraffin sections in the identification of T-cell rich B-cell large-cell lymphomas: lineage confirmed by JH rearrangement.

Immunophenotyping of lymphomas using paraffin-embedded lymphoid tissue, not previously distorted by frozen section, is useful in identifying the large neoplastic B cells that may be in the minority in T-cell rich B-cell lymphoma (TCRBCL). Even in cases in which frozen tissue sections are available, the improved morphology in unfrozen sections allows the proper classification of these lymphomas as large cell and identifies their B-cell lineage, which is important for clinical therapeutic studies. Seven cases initially believed to be diffuse mixed cell lymphoma of possible peripheral T-cell lineage showed the large cells to be immunoreactive with L-26 (pan B-cell marker) with the majority of smaller lymphocytes immunoreactive for UCHL-1 and Leu-22 (pan T-cell markers). K/lambda immunostaining on frozen sections was equivocal. In these cases, the diagnosis of large-cell lymphoma of B-cell lineage was confirmed by detection of immunoglobulin heavy- (all seven cases) and light- (six of seven cases) chain gene rearrangements, with germ-line configuration of the T-cell receptor beta-chain gene (all cases). Some cases of TCRBCL may not show detectable rearrangement of the immunoglobulin genes because of the low concentration of neoplastic cells in the samples submitted. The presence of rearrangements in these seven cases, however, supports the diagnosis of TCRBCL based on paraffin immunophenotyping when frozen tissue is not available or when molecular studies are not feasible. Although these seven cases are classified as large-cell lymphoma, an intermediate-grade lymphoma, the influence of the reactive T-cell population on the clinical behavior will require follow-up studies.

T-cell-rich B large-cell lymphoma simulating lymphocyte-rich Hodgkin's disease.

Immunophenotypic analysis of 50 cases fulfilling the histologic criteria for mixed cellularity Hodgkin's disease disclosed nine cases with a B-cell, non-Hodgkin's phenotype (CD20+, CD15-, CD30-, EMA-). The cases were characterized by a diffuse small lymphocytic milieu, interspersed atypical large cells including classic Reed-Sternberg cells, and infrequent plasma cells, eosinophils, and L&H cells. The male:female ratio was 7:2 (aged 22-65 years, median 39 years). Three patients were Ann Arbor stage II, two stage III, and four stage IV. The patients presented with generalized lymphadenopathy (four), mesenteric lymph node involvement (two), splenomegaly (four), and bone marrow involvement (three). Four patients were treated with standard Hodgkin's disease protocols. Two attained a complete response and two a partial response; all relapsed and died. Four of five patients treated for large-cell lymphoma achieved a complete response and are currently alive without evidence of disease. The one patient with an initial partial response relapsed and died. We conclude that immunophenotypic analysis is essential in cases of histologic mixed cellularity Hodgkin's disease, especially in those with lymphocyte-rich morphology. Cases with a B-cell phenotype should be diagnosed and treated as T-cell-rich B large-cell lymphoma.

Cell kinetic analysis of interleukin-2 receptor-tested chronic lymphocytic leukemia using the AgNOR silver stain.

B-cell chronic lymphocytic leukemia (B-CLL) is typically a low-grade neoplasm with a diploid DNA index and low proliferative activity. Interleukin-2 receptor (IL-2R/CD25) positivity often indicates increased proliferative activity and activation in both T and B lymphocytes. The argyrophilic nucleolar organizer regions (AgNORs) are loops of DNA identified by a silver staining technique and have been correlated with ploidy and proliferative activity. Two distinct AgNOR counting methods have been previously shown to correlate with DNA ploidy and proliferative activity, respectively: the mean AgNOR count (mAgNOR) correlates more with ploidy, and the percentage of nuclei with > or = 5 AgNORs/nucleus (pAgNOR) reflects proliferative activity. We studied bone marrow specimens from 32 patients with B-CLL using both anti-IL-2R on the marrow aspirates and the AgNOR silver stain on marrow biopsy specimens, applying both AgNOR counts. All tumors were CD5+, CD19+, and CD19/CD20+. Sixteen tumors were IL-2R- (< 20% IL-2+ B cells), and 16 were IL-2R+ (> or = 20% IL-2R+ B-cells). No significant difference in morphology of bone marrow involvement was noted in the two groups. A male predominance was noted in the IL-2R+ group of patients (3:1). There was also a preponderance of lambda light chain expression in the IL-2R+ tumors (11/16) compared with the IL-2R- cases (5/16). Except for two cases, all tumors had mAgNOR counts within the diploid range (< 2.4). The 16 IL-2R- tumors had pAgNOR in the range of 0% to 7% (mean, 2.31 +/- 2.18 standard deviation), whereas the IL-2R+ tumors had pAgNOR ranging from 6% to 15% (mean, 10.20 +/- 2.70 standard deviation; P < .0001). This finding suggests that IL-2R+ B-CLL might represent a subgroup of tumors with higher proliferative activity.

Detection of subgroups of chronic B-cell leukemias by FMC7 monoclonal antibody.

Monoclonal antibody FMC7 detects subgroups of B-cell leukemias that have arisen from cells in late stages of B-cell maturation. FMC7 was studied by flow cytometry on cell samples from 192 patients with a diagnosis of chronic lymphocytic leukemia (CLL) or lymphoma. The leukemic cells from 16 patients were reactive with this antibody. These 16 cases were evaluated for other surface markers, morphology of cells, and clinical characteristics. Of the 16 patients, 14 had cells that strongly expressed surface immunoglobulin (SIg). This is atypical of CLL cells, which characteristically show weak expression of SIg. Eleven cases had kappa and five had lambda light chain. All patients' cells had consistently brighter CD20 expression than that of CD19. Fourteen patients had expression of CD5 on their leukemic cells. One patient had more than 55% prolymphocytes, meeting the criteria of prolymphocytic leukemia (PLL), two patients had CLL in prolymphocytic transformation (CLL/PL), and two other patients were classified as having a paraimmunoblastic variant of small lymphocytic lymphoma based on a high number of paraimmunoblasts and on the histologic features. Another nine patients had immature lymphoid cells distinct from prolymphocytes or paraimmunoblasts on morphologic study. The immature cells were variable in size, and the nuclear chromatin was less clumped than that of prolymphocytes. The histologic diagnoses in four of these cases were consistent with mantle cell lymphoma. Splenomegaly was observed in 11 patients (69%), and 11 patients had advanced Rai 3 or 4 disease. Among 10 patients treated with fludarabine, five responded to therapy. Monoclonal antibody FMC7 is useful for identifying a group of atypical variants of CLL, PLL, and other B-cell lymphomas in leukemic phase that can be easily confused with CLL. Careful attention to the cell morphology and histologic features is important for the differential diagnosis of FMC7-positive, B-cell lymphoproliferative diseases.

Polymerase chain reaction detection of the t(11;14) translocation involving the bcl-1 major translocation cluster in mantle cell lymphoma.

The utility of polymerase-mediated assays in the detection of the t(11;14) involving the bcl-1 major translocation cluster (bcl-1 MTC) was evaluated by analyzing DNA from 33 patients with mantle cell lymphoma, 14 patients with other non-Hodgkin's lymphomas, and five patients with reactive lymphoid hyperplasia. The polymerase chain reaction (PCR) assay was performed using a consensus immunoglobin heavy-chain joining region primer in conjunction with a chromosome 11 specific oligonucleotide primer flanking the translocation site. The sensitivity and specificity of the assay were confirmed by correlation of the (PCR) assay data with restriction analysis. Rearrangements at the bcl-1 MTC were detected in 13 (39%) of 33 cases of mantle cell lymphoma by PCR and in 13 (48%) of 27 cases by restriction analysis. Amplicons were detectable by PCR in 85% (11 of 13) of the cases shown to be bcl-1 rearranged by restriction analysis. Failure to detect amplification products in DNA samples from non-mantle cell lymphomas and reactive follicular hyperplasia further confirmed the specificity of the assay. Sequential hybridization of the PCR products with oligonucleotide probes 3' to the bcl-1 MTC primer revealed that the breakpoints in the bcl-1 MTC were clustered around an Sst I restriction site over a range of 170 base pairs. The study demonstrates that PCR-mediated assay for the detection of the t(11;14) at the bcl-1 MTC is specific and sensitive and can be used as an adjunct to restriction analysis in routine diagnostics.

The application of fluorescence-based PCR and PCR-SSCP to monitor the clonal relationship of cells bearing the t(14;18)(q32;q21) in sequential biopsy specimens from patients with follicle center cell lymphoma.

This study evaluates the utility of fluorescence-based polymerase chain reaction (PCR) and PCR-SSCP methodologies to monitor the clonal relatedness of cells with bcl-2 major break point region (mbr)/JR fusion sequences in sequential samples from patients with follicular lymphoma (FL). Fluorescence-tagged PCR products from 2-4 sequential samples from seven FL patients were resolved in acrylamide gels and analyzed on an Applied Biosystems' automated DNA sequencer equipped with Genescan software. The amplicons were sequenced directly using automated DNA sequencing to obtain the precise amplicon size and base sequence. Fluorescence-based PCR-single-strand conformation polymorphism (SSCP) analysis performed to distinguish amplicons of similar size but of different base sequence. Amplification products differing by as few as 5 bp resolved clearly under fluorescent PCR assay conditions making possible by visual inspection alone the distinction of two products that otherwise appeared to be of similar size by conventional gel electrophoretic methods. The size of the amplicons as determined by Genescan software correlated exactly with the sizes generated by sequence analysis confirming the precision and accuracy of the fluorescent PCR assay. Under nondenaturing conditions, the mobility profiles of the amplicons from sequential samples with identical base sequence remained indistinguishable, whereas amplicons of similar size but of dissimilar base sequence from different patients exhibited distinct migration patterns. Thus, this study demonstrates that a combination of fluorescent PCR and PCR-SSCP assays for the detection of the t(14;18) provides an accurate measure of clonal relationship based on molecular size and sequence similarities without involving radiolabeling and sequencing strategies. Furthermore, the demonstrated preservation of junctional sequences across sequential biopsy specimens validates the use of PCR in the monitoring of minimal residual disease and eliminates concern about the detection of secondary, non-tumor-related translocations.

Extended en bloc resection of a primary mediastinal parathyroid carcinoma.

Parathyroid carcinoma is a rare endocrine tumor infrequently seen in the mediastinum. This report describes a patient who underwent en bloc resection of a primary mediastinal parathyroid carcinoma. The tumor originated from the thymus and extended from the aortic arch to the thyroid; local invasion suggested malignancy. En bloc resection of this carcinoma with all surrounding tissue provided local control of the tumor and relief of symptomatic hypercalcemia.

Genomic DNA amplification and the detection of t(2;5)(p23;q35) in lymphoid neoplasms.

Anaplastic large cell lymphoma (ALCL) is an intermediate grade Non-Hodgkin's lymphoma (NHL) characterized by the frequent presence of the t(2;5)(p23;q35). This translocation fuses the nucleophosmin (NPM) gene on chromosome 5q35 to a protein kinase gene (Anaplastic Lymphoma Kinase, ALK) on chromosome 2p23. In order to determine the frequency of t(2;5) we used a DNA polymerase chain reaction (PCR) amplification using genomic DNA, 5'-primers derived from the NPM gene, and 3'-primers derived from the ALK gene. The presence of amplifiable DNA in the samples was established with PCR and oligonucleotide primers designed to amplify a 3,016 bp fragment from the beta-globin locus. The t(2;5) PCR assay was established using DNA isolated from three t(2;5)-positive ALCL cell lines. Its ability to amplify genomic DNA prepared for routine molecular diagnostic use was validated using archival DNA from four ALCL tumors known to be t(2;5)-positive. Its sensitivity was established by serially diluting t(2;5)-positive DNA in normal DNA: amplicons were generated in 100% of reactions diluted 10(4)-fold (6-8 cells per tube) and in 30% of those diluted 10(5)-fold (0.6-0.8 cells per tube.) We subsequently analyzed archival genomic DNA extracted from 38 ALCL, 77 NHLs, 37 Hodgkin's lymphomas, and 9 lymphomatoid papuloses. The t(2;5) was detected in 6 ALCLs (16%, 95% confidence intervals 6%-31%), but not in any other lymphoma, or in lymphomatoid papulosis. By using the published sequence of the fourth NPM intron that is involved in t(2;5) and by sequencing the individual tumor amplicons and also the normal ALK intron that is involved in t(2;5), we established that all breakpoints involve the same introns in the ALK and NPM loci. Detailed analysis demonstrated that each translocation generates a unique breakpoint sequence, and suggested that sequence homology between the ALK and NPM intron sequences may be involved in the translocation. We conclude that genomic DNA-PCR is useful for the detection of t(2;5) that in our patient population is restricted to ALCL and is not detectable in other NHL, Hodgkin's disease, or lymphomatoid papulosis. More work is needed to determine the prognostic significance of t(2;5), and to establish the utility of the genomic DNA PCR in monitoring minimal residual disease.

Mantle cell lymphomas.

MCLs are thought to arise from a subset of B cells that normally express the CD5 antigen and that reside in the mantle zone of secondary lymphoid follicles. Although expression of the CD5 antigen is also seen in small lymphocytic lymphoma and chronic lymphocytic leukemia, MCL differs from SLL/ CLL in several ways. Whereas trisomy of chromosome 12 is the hallmark cytogenetic abnormality of SLL/CLL, the translocation (11;14) (q13q32) is the most frequent karyotypic abnormality in MCL. The histologic pattern of MCL is most frequently diffuse. However, this lymphoma can grow in a unique pattern called 'mantle zone MCL,' indicating that the malignant cells expand the mantle of the follicle and grow around a normal germinal center. If the germinal center is also replaced by the malignant cells, but the follicular architecture remains, the pattern appears nodular. The clinical presentation of MCL is usually only seen with advanced disease stage, particularly in patients with diffuse MCL. The bone marrow is the most frequently affected extranodal site, followed by the gastrointestinal tract. The histologic pattern of disease in the lymph nodes correlates with clinical outcome. Patients with diffuse MCL have poor response to frontline combination chemotherapy including doxorubicin, whereas patients with mantle zone MCL have excellent complete remission rates. The therapeutic response correlates in turn with worse survival outcome for patients with diffuse MCL compared to mantle zone MCL. The few patients with nodular MCL had clinical behavior similar to diffuse MCL. The chemotherapeutic response of diffuse and nodular MCL, however, is quite poor, and we would propose that new investigational approaches be considered in the front-line therapy of these disorders.

Immunoglobulin gene rearrangement and its implications for the study of B-cell neoplasia.

Molecular biologic investigation of the process of immunoglobulin gene rearrangement has elucidated the mechanism of immunologic diversification and has provided essential tools for the study of B-cell neoplasia. The use of immunoglobulin gene probes has permitted a clearer understanding of B-cell malignancies, but has also raised new questions and pointed out new directions for ultimately clarifying the mechanism of B-cell transformation. Thus, we have a difficult challenge ahead, but with our present knowledge, we are in a better position than ever to address critical issues relating to the genesis of lymphoid neoplasia.

T-cell-rich B-cell lymphoma.

We analyzed 23 cases of T-cell-rich B-cell lymphomas (BCL) to determine if the clinical features are characteristic of a discrete entity. Cases encoded as T-cell-rich BCL in the hematopathology archives of the University of Texas M.D. Anderson Cancer Center between 1988 and 1991 formed the basis of this study. At least 50% of the total population of cells were required to be of T-cell phenotype. Actually, all but one patient had more than 70% T cells in the total population. Sixty-five percent of all cases were referred with other diagnosis such as Hodgkin's mixed cellularity, peripheral T-cell lymphoma (PTCL), or diffuse mixed lymphoma, and had received therapy accordingly. With the exception of splenomegaly, which occurred in 35% of cases, the other clinical characteristics and the response to therapy did not indicate that this entity represents a distinct type of lymphoma. Ann Arbor stage I-II presentations were seen in 10 of 23 (43%) T-cell-rich BCLs. Serum lactate dehydrogenase (LDH) was elevated in eight of 19 patients. Age, sex, and beta 2-microglobulin were not significantly different from classical B-cell large cell lymphoma. The clinical presentation and clinical outcome of T-cell-rich BCL did not differ from that of common B-cell large cell lymphoma, except for the higher proportion of splenomegaly seen in patients with T-cell-rich BCL. The presence of the T-cell-rich infiltrate varied: it frequently was not seen at relapse or at other sites of disease at presentation. It was thus considered an unstable parameter. The major importance of identifying this entity is to distinguish it pathologically from other disorders such as Hodgkin's disease and PTCL, which would be treated in a different manner.

Keratin-positive, epithelial membrane antigen-positive solitary pelvic tumor with ultrastructural features of large cell lymphoma.

A case of an unusual malignant solitary pelvic tumor is presented. The neoplastic cells were positive for keratin and epithelial membrane antigen. Although ultrastructural features (prominent nuclear pleomorphism, abundant polyribosomes, and absence of cell junctions) were those typically seen in large cell lymphomas, lymphoid markers were not detected, and immunoglobulin heavy-chain gene and T-cell receptor beta-chain gene rearrangements were not identified. Combination chemotherapy resulted in complete remission.