Guidelines for subtyping small B-cell lymphomas in bone marrow biopsies

In this review, we summarise the patterns of bone marrow involvement by small B-cell lymphomas. Both our own experience and the literature reports on the subject show that each subtype of lymphoma can be recognised from a distinct combination of a suggestive growth pattern and a particular cytological composition. A predominantly paratrabecular infiltrate composed of centrocytes is characteristic of follicle centre cell lymphoma. In mantle cell lymphoma, prominent intertrabecular nodules, each consisting of a monotonous proliferation of small to intermediate-sized lymphoid cells with an irregular nucleus, are the most frequent finding. Marginal zone cell lymphoma displays similar intertrabecular nodules, but the infiltrates are rather loose and polymorphic, whereas the lymphoid cells exhibit monocytoid features. Diffuse infiltrates composed of small lymphocytes with clumped chromatin, of plasma cells with Dutcher bodies and of mast cells are observed in most cases of lymphoplasmacytoid lymphoma/immunocytoma. Although chronic lymphocytic leukaemia / small lymphocytic lymphoma can present with a comparable pattern of bone marrow involvement, an interstitial infiltrate of small lymphoid cells is usually observed. A comparable interstitial pattern also prevails in hairy cell leukaemia. This lymphoma subtype, however, can be readily identified by the abundant clear cytoplasm of the neoplastic cells, erythrocyte extravasation and associated abnormalities in the haematopoietic series.

Serum levels of tetranectin, intercellular adhesion molecule-1 and interleukin-10 in B-chronic lymphocytic leukemia

BACKGROUND AND OBJECTIVE

The fibrinolytic regulator tetranectin (TN), in association with the circulating intercellular adhesive molecule-1 (cICAM-1) and interleukin -10 (IL-10), may be involved in the metastatic cascade of B-chronic lymphocytic leukemia (B-CLL). Our aim was to investigate the potential usefulness of these molecules as prognostic markers in B-CLL.

DESIGN AND METHODS

Therefore, TN, cICAM-1, and IL-10 were assessed (ELISA) in the serum of 53 B-CLL patients, classified in Binet A, B, and C stages in comparison with those in 45 healthy subjects (HS).

RESULTS

TN was significantly lower in B-CLL patients than in HS (9.63 [8.75-11.51] mg/L, 13.75 [12.56-14.64] ng/mL, respectively, p<10(-5)), being lower (p = 0.05) in B and C stage patients (subgroup B+C) than in A stage ones (subgroup A). cICAM-1 levels were significantly higher in B-CLL patients than in HS (475.86 [355.86-593.79] ng/mL vs. 225.62 [118.49-312.83] ng/mL, respectively, p<10(-5)) with a tendency for higher levels in subgroup B+C than in subgroup A. A significant correlation of cICAM-1 with lactate dehydrogenase (LDH) (r(s) = 0.532, p = 0.049), and a significant increase in cICAM-1 in B-CLL with diffuse bone marrow infiltration (BMI) compared to that in B-CLL with nondiffuse BMI (624.48 [557.24-726.55] ng/mL vs. 480.34 [368.96-590.34] ng/mL, respectively, p = 0.0172) were found. A significant negative correlation between TN and cICAM-1 (r = -0.5017, p = 0.0001) was observed. IL-10 was detected in all B-CLL patients and in no HS (7.37 [5.30-10.55] pg/mL), being higher (p = 0.0153) in C than in A stage patients. A significant correlation of IL-10 with TN and cICAM-1 in subgroup B+C (r(s) = -0.659 [p = 0.014] and r = 0.679 [p = 0.011], respectively) was found.

CONCLUSIONS

The abovementioned findings and good performance characteristics of TN and cICAM-1 in B-CLL suggest the potential usefulness of these adhesive/recognition molecules as prognostic markers in B-CLL. The implication of these molecules along with IL-10 in the disease process deserves further study.

Occurrence of both t(1;19) and t(8;14) in a patient with chronic lymphocytic leukemia

While t(1;19) and t(8;14) have been reported singly in pre-B-ALL and Burkitt's lymphoma, respectively, the occurrence of both translocations simultaneously in the same patient is rare. Indeed, a review of the English literature from 1966 to 1999 revealed no case reports with these findings. We report here an 88-year-old patient who was clinically diagnosed to have chronic lymphocytic leukemia and who carried both translocations in her peripheral blood cells. The patient refused to give consent for a bone marrow sample, the preferred tissue for study. The patient's clinical findings are discussed, although the relationship between the clinical information and cytogenetic findings, if any, is not known. Study of additional cases identical to ours will be helpful in determining the correlation, if any, between the patient's phenotype and the occurrence of the two translocations.

Malignancies of natural killer (NK) cell precursor: myeloid/NK cell precursor acute leukemia and blastic NK cell lymphoma/leukemia

Malignant hematolymphoid disorders arising from natural killer (NK) cells have become widely recognized in the past decade. Recently, we as well as others have drawn attention to some neoplasms of conceivable NK cell precursor origin that might represent two distinct entities, i.e. myeloid/NK cell precursor acute leukemia and blastic NK cell lymphoma/leukemia. Both of these diseases were characterized by remarkable extramedullary involvement and lymphoblastoid morphology, although the sites of involvement differed. Myeloid/NK cell precursor acute leukemia exhibited more frequent involvement of bone marrow (BM) and lymph nodes, whereas blastic NK cell lymphoma/leukemia affected extranodal sites, mainly the skin/subcutis. Tumor cells of these two diseases shared the CD16-, CD56+ and CD57- phenotype, but differed in other phenotypic profiles. Indeed, myeloid/NK cell precursor acute leukemia was immunophenotypically characterized by the expression of CD34 and blastic NK cell lymphoma/leukemia by that of CD4. On the theoretical level in the NK cell differentiation pathway, myeloid/NK cell precursor acute leukemia might be derived from a myeloid antigen-positive precursor preceding a NK cell committed precursor as a conceivable counterpart of blastic NK cell lymphoma/leukemia. Most cases with either disease lacked cytotoxic activities or molecules, a finding which seems to support their precursor origin. Notably, Epstein Barr virus (EBV) was negative in all cases, which contrasted with its high level associated with mature NK cell malignancies. Chemotherapy for acute myeloid leukemia was generally effective for myeloid/NK cell precursor acute leukemia, while the regimen for lymphoid malignancy was effective for blastic NK cell lymphoma/leukemia. These data suggests that each of these two diseases constitutes a distinct entity, which is also different from mature NK cell malignancies.

B-chronic lymphocytic leukemia, small lymphocytic lymphoma, and lymphoplasmacytic lymphoma, including Waldenström's macroglobulinemia: a clinical, morphologic, and biologic spectrum of similar disorders

Among small lymphocyte cell disorders, B-chronic lymphocytic leukemia (B-CLL), small lymphocytic lymphoma (SLL), and lymphoplasmacytic lymphoma/Waldenström's macroglobulinemia (LPL/MW) are included. B-CLL patients always have blood and bone marrow (BM) involvement by a CD5+ B lymphocyte. They frequently present with lymphadenopathy and/or hepatosplenomegaly, although in a considerable number of patients, no abnormal physical findings are found. They are prone to develop hypogammaglobulinemia, autoimmune hemolysis, or autoimmune thrombocytopenia. The typical immunophenotype of the malignant cell is CD5+, surface immunoglobulin (slg)+ (weak), CD23+, CD79b-, and FMC7-. Trisomy 12 and 13q deletions are frequent chromosomal abnormalities. The bcl-2 protein is usually overexpressed. SLL patients present with lymphadenopathy, usually generalized. Lymphocytosis is by definition absent and BM involvement, usually nodular, is found in 25% to 50% of patients. The lymph node lymphocytes are CD5+ and have a similar immunophenotype with CLL, but frequently express the LFA-1 adhesion molecule. Patients are at low risk to develop hypogammaglobulinemia, autoimmune hemolysis, or autoimmune thrombocytopenia. LPL/MW patients may present either with an accidental discovery of IgM gammopathy, symptoms related to paraproteinemia, or lymphadenopathy and/or splenomegaly. The BM is frequently involved and a leukemic picture may be found. A monoclonal gammopathy of IgM class is by definition present in MW and is frequently accompanied by hypogammaglobulinemia. Immunophenotypic studies usually reveal a CD5-, slg+ (moderate), cytoplasmic immunoglobulin (clg)+, FMC7+, and CD38+ cell. A significant proportion of cases carry the translocation t(9;14)(p13;q32) involving the PAX-5 gene. All of these disorders may potentially undergo transformation to large-cell lymphoma or Richter's syndrome. Prognostic factors have been extensively studied in B-CLL, but more studies are needed for SLL and LPL/MW. These entities should be differentiated from other B-chronic small lymphocyte cell disorders, particularly when the latter are leukemic.

The concept of typical and atypical chronic lymphocytic leukaemia

Subdivision of CLL into typical and atypical subtypes, as proposed by the FAB group in 1989, is not yet widely accepted and its clinical significance is still debated. In recent years, however, a strong correlation was found between atypical morphology trisomy 12 and an aberrant immunophenotype. In the first part of this review we discuss current concepts and generally accepted data on morphology, immunophenotype, genetic abnormalities, clinical features and prognostic factors in CLL. Subsequently, based on our own series and other recently published data, we analyse the validity and clinical impact of classifying CLL into typical and atypical entities and demonstrate that they may represent two closely related but different entities.

Plasmablastic lymphoma: a new subcategory of human immunodeficiency virus-related non-Hodgkin's lymphoma

A patient with human immunodeficiency virus-related non-Hodgkin's lymphoma arising in the oral cavity is reported. The tumour had an unusual immunohistochemical profile that was negative for leucocyte common antigen and the B-cell antigen CD20 but positive for the plasma cell-reactive antibody VS38c. The features of this type of tumour, which has recently been categorized, are presented and discussed.

Deficiency of the ATM protein expression defines an aggressive subgroup of B-cell chronic lymphocytic leukemia

The gene mutated in ataxia telangiectasia, ATM, on human chromosome 11q22-q23 is implicated in cell cycle control and DNA repair. Ataxia telangiectasia patients as well as ATM-deficient mice are immune deficient and develop lymphoproliferative disease. Abnormalities in 11q22.3-q23.1 have also been described in B-cell chronic lymphocytic leukemia (B-CLL). We analyzed B-CLL samples for loss of heterozygosity (LOH) using microsatellite markers located at the ATM (D11S2179), mixed-lineage leukemia (MLL; D11S1356), and BCL1 (D11S987) loci, all of which are located around 11q23. Five (14%) of 36 informative cases showed LOH at the ATM gene, and two of these five cases had LOH at the MLL gene. No LOH was detected at the BCL1 locus, and none of the cases showed LOH at the MLL gene without LOH at the ATM gene. Four of these five cases with LOH at the ATM gene were studied for ATM protein expression by Western blot analysis. All four cases lacked ATM protein. An additional 111 cases of B-CLL were studied for expression of ATM protein by Western blot analysis and RIA. Thirty-eight (34%) of these cases showed ATM levels <50% of that seen in normal lymphoid cells. No morphological or immunophenotypic difference was observed between ATM-deficient B-CLL cases and cases with normal ATM expression. However, patients with ATM deficiency had significantly shorter survival times (35.66 versus 97.3 months; P = 0.003) and more aggressive disease, suggesting that ATM is involved in the leukemogenesis of B-CLL. These data also suggest that the ATM gene may play a role in the reported 11q23 abnormality in B-CLL, which also characterizes an aggressive disease.

Low number of DNA copy number changes in small lymphocytic lymphoma

BACKGROUND AND OBJECTIVE

Small lymphocytic lymphoma (SLL) is morphologically and immunologically similar to chronic lymphocytic leukemia (CLL), and the new REAL classification refers to them as a single disease termed SLL/CLL. Recently, frequent losses in 6q, 11q and/or 13q were observed in CLL using comparative genomic hybridization (CGH). We performed CGH analyses in order to find out whether these two entities contain the same DNA copy number changes.

DESIGN AND METHODS

Seventeen patients with stage IV disease and one with stage III disease were studied by CGH. CGH is based on quantitation of the fluorescence intensity of differentially labeled DNAs. For this purpose tumor DNA labeled with FITC-12dUTP and normal DNA labeled with Texas red-5dUTP were hybridized to normal metaphase chromosomes. The ratio of fluorescence intensity of hybridized tumor and normal DNA was measured using computerized image microscopy to identify over- or under-represented regions in the tumor genome. All findings were confirmed using a confidence interval of 99% with a 1% error probability.

RESULTS

The most consistent finding was a gain of the entire chromosome 12 observed in three patients and a loss in 14q24 in one patient. No other changes were detected. All abnormal cases presented with stage IV disease and had bone marrow infiltration. Two 12+ cases had a leukemic disease.

INTERPRETATION AND CONCLUSIONS

Our results indicate that trisomy 12 is one of the most frequent chromosomal aberrations in SLL. Losses regarded as typical of CLL were not present in SLL. This may indicate that the genetic pathways in the development of SLL/CLL in patients presenting with enlarged lymph nodes (SLL) with or without leukemia are different from those in patients presenting with leukemia (CLL) without enlarged lymph nodes.

Trisomy 12 in chronic lymphocytic leukemia--geographical variation

Incidence of trisomy 12 was studied in 60 cases of chronic lymphocytic leukemia (CLL) with chromosome 12 specific alpha-satellite DNA probe by fluorescence in situ hybridization (FISH). Trisomy 12 was observed in 37 (61.8%) patients. Cells with trisomy 12 were detected in a varying proportion, ranging from > 2% to 86%. Patients with trisomy 12 were predominantly observed with total white blood cell (WBC) count > 80 x 10(9) l(-1) (P < 0.001). In addition, the percentage of trisomy 12 positive lymphocytes correlated with the high WBC counts. Trisomy 12 was observed equally in typical and atypical CLL. 90% of our patients were in the intermediate and high risk groups. It was seen that there was significantly higher percentage of trisomy 12 positive lymphocytes ( > 10%) in the high risk groups (P < 0.05). A higher incidence of FMC7 positivity in atypical CLL was seen in our study. However, there was no significant relationship found between trisomy 12 positivity and expression of either FMC7 or CD23 in our cases. It appears that the CLL that we see at our centre is at a different phase of evolution and perhaps biologically different compared to the CLL seen in the West.

Cyclin D1 overexpression detected by a simple competitive reverse transcription-polymerase chain reaction assay for lymphoid malignancies

t(11;14)(q13;q32) observed in B-cell malignancies is associated with cyclin D1 (bcl-1, PRAD1, CCND1) overexpression. We devised a simple competitive reverse transcription-polymerase chain reaction (RT-PCR) assay for rapid detection of cyclin D1 overexpression. Sharing a single upstream primer derived from a homologous sequence in cyclins D1, D2 and D3, each PCR product serves as a competitor and cyclin D1 overexpression is determined by comparing the intensities of the three amplified products. We analyzed cyclin D1 in clinical specimens from 104 patients with lymphoid malignancies. Cyclin D1 overexpression was evident in 13 of 104 (7/72 non-Hodgkin's lymphomas, 0/6 adult T-cell lymphoma/leukemias, 0/4 Hodgkin's diseases, 0/11 acute lymphoblastic leukemias, 3/4 multiple myelomas, 1/2 Waldenström's macroglobulinemias, 1/2 prolymphocytic leukemias and 1/3 chronic lymphocytic leukemias). Among 72 patients for whom cytogenetic studies had been done, all 7 patients with t(11;14) were positive. The relative expression levels of D-type cyclins altered dramatically in the presence of t(11;14). Thus, this RT-PCR assay can identify tumors with cyclin D1 overexpression. Cyclin D1 overexpression was frequent in extranodal specimens (11 out of 32 vs. 2 of 72 lymph nodes) and was restricted to specific types of lymphoid malignancies, as observed using other methods. This reliable assay should be suitable to provide clinical guidance for the diagnosis and management of lymphoid malignancies, especially in the case of extranodal involvement.

Automated classification of patients with chronic lymphocytic leukemia and immunocytoma from flow cytometric three-color immunophenotypes

The goal of this study was the discrimination between chronic lymphocytic leukemia (B-CLL), clinically more aggressive lymphoplasmocytoid immunocytoma (LP-IC) and other low-grade non-Hodgkin's lymphomas (NHL) of the B-cell type by automated analysis of flow cytometric immunophenotypes CD45/14/20, CD4/8/3, kappa/CD19/5, lambda/CD19/5 and CD10/23/19 from peripheral blood and bone marrow aspirate leukocytes using the multiparameter classification program CLASSIF1. The immunophenotype list mode files were exhaustively evaluated by combined lymphocyte, monocyte, and granulocyte (LMG) analysis. The results were introduced into databases and automatically classified in a standardized way. The resulting triple matrix classifiers are laboratory and instrument independent, error tolerant, and robust in the classification of unknown test samples. Practically 100% correct individual patient classification was achievable, and most manually unclassifiable patients were unambiguously classified. It is of interest that the single lambda/CD19/5 antibody triplet provided practically the same information as the full set of the five antibody triplets. This demonstrates that standardized classification can be used to optimize immunophenotype panels. On-line classification of test samples is accessible on the Internet: http://www.biochem.mpg.de/valet/leukaem1.html Immunophenotype panels are usually devised for the detection of the frequency of abnormal cell populations. As shown by computer classification, most the highly discriminant information is, however, not contained in percentage frequency values of cell populations, but rather in total antibody binding, antibody binding ratios, and relative antibody surface density parameters of various lymphocyte, monocyte, and granulocyte cell populations.

Cell proliferation, bcl-2, c-myc, p53 and apoptosis as indicators of different aggressiveness in small lymphocytic lymphoma (SLL)

Cell proliferation activity, by MIB1 mAb, expression of bcl-2, c-myc and p53 gene proteins and apoptotic index (AI) were assessed in 54 cases of SLL and compared to the morphological subtypes of this disorder, defined by Lennert on the basis of amount and distribution of small and larger activated lymphocytes as diffuse, tumor-forming and pseudofollicular subtypes (DS, TFS, PFS). MIB1 scores showed significant differences between DS, PFS and TFS (5.5%, 16.61% and 24.14%, respectively; p < 0.0001). Worth noting, the MIB1 score did not differ significantly when comparing DS with the diffuse areas of PFS, or TFS with the pseudofollicles of PFS. The mean bcl-2 gene protein score was displayed to a high extent in all subtypes, but less extensively by larger activated lymphocytes that, conversely, expressed c-myc. MIB1 score correlated negatively with bcl-2 and positively with c-myc protein scores. These findings suggest that lymphocytes protected from apoptosis by bcl-2 would be exponed to cell activation and growth acceleration provided by c-myc. This condition would account for a different aggressiveness of morphologically activated subtypes, such as TFS and PFS with larger pseudofollicles. The survival analysis, performed in 23 cases, showed a trend of association of cell proliferation and c-myc expression with a more aggressive progression of the disease. Overexpression of p53 and apoptosis were found only in a minority of cases, unrelated to the subtypes. In conclusion, cell growth fraction, bcl-2 and c-myc assessment may be of help in predicting the aggressiveness of different subtypes of SLL. This approach should be most conveniently applied to PFS, which represents a continuum between DS and TFS, in order to distinguish, in this heterogeneous subtype, more indolent from more aggressive disorders.

[Monoclonal plasmacytic differentiation in small-cell lymphomas of B-cell origin: immunocytoma versus other types]

We have studied the morphological and immunohistochemical features of monoclonal cytoplasmic Ig (c-Ig) production in the biopsy material of 161 small B-cell non-Hodgkin's lymphomas to verify a frequency of the plasmacytic/plasmacytoid differentiation of tumor cells for the aims of their differential diagnosis. The analyzed differentiation was identified in all the cases of immunocytoma (n = 20/20), in 2/3 of MALT-lymphomas (n = 24/38) and 1/2 of monocytoid B-cell lymphoma cases (n = 4/7), in 1/5 of centroblastic-centrocytic lymphoma cases (n = 12/60) and rarely in centrocytoma (n = 4/36). We conclude that a plasmacytic differentiation is not an unique feature of the immunocytoma. For the differential diagnosis, a histological analysis and not a proof of monoclonal c-Ig itself seems to be decisive. The obtained results are discussed in relation to the histogenesis of small B-cell lymphomas, which represent a neoplastic counterpart of the reactive B-cells at different stages of their maturation and differentiation.

The Revised European-American Classification of Lymphoid Neoplasms (REAL): a new perspective for the classification of cutaneous lymphomas

Differing classification schemes for malignant lymphomas have been used in Europe and the United States. Attempts to translate between the principle classifications have been unsuccessful and historically it has been difficult to arrive at an unified approach. In addition, many new lymphoma entities have been recognized in recent years that are not delineated in any of the existing classification schemes. To provide a unified international basis for clinical and investigative work in this field, in 1994 the International Lymphoma Study Group (ILSG) proposed a new classification termed Revised European-American Classification of Lymphoid Neoplasms (REAL). This review discusses the REAL classification, especially as it pertains to cutaneous lymphomas, and provides insight into the clinicopathologic features of lymphoproliferative disease involving the skin. The premise of the REAL classification is that a classification scheme should be based on the delineation of disease entities, utilizing pathologic, immunophenotypic, genetic, and clinical features. Therefore, if cutaneous involvement is an integral aspect of any lymphoma subtype, this clinical information is included in the definition of that neoplasm. We conclude that the principles of the REAL classification are applicable to cutaneous lymphomas, as well as lymphomas involving other anatomic sites.

11q deletions identify a new subset of B-cell chronic lymphocytic leukemia characterized by extensive nodal involvement and inferior prognosis

Deletions of the long arm of chromosome 11 (11q) are one of the most frequent structural chromosome aberrations in various types of lymphoproliferative disorders. However, in most conventional chromosome banding studies of B-cell chronic lymphocytic leukemia (B-CLL), 11q deletions were not identified as a frequent aberration. The objective of this study was to analyze the frequency and clinical impact of 11q deletions in B-CLL by interphase cytogenetics using fluorescence in situ hybridization (FISH). Mononuclear cells from 214 patients with B-CLL were studied by FISH using the yeast artificial chromosome (YAC) clone 755b11 from chromosome region 11q22.3-q23.1; we previously showed that this clone was contained within a 2- to 3-Mb sized segment of 11q commonly deleted in lymphoproliferative disorders. Forty-three of the 214 (20%) tumors exhibited 11q deletions; 11q deletions were the second most frequent chromosome aberration following 13q14 (RB1 and/or D13S25) deletions (45%); they were more frequent than trisomy 12 (15%) or deletion of 17p (TP53 gene) (10%). Patients with 11q deletions were younger (P = .01) and had more advanced clinical stages (P = .01). 11q deletions were associated with extensive peripheral, abdominal, and mediastinal lymphadenopathy (P < .001). Patients with 11q deletions had a more rapid disease progression as shown by a shorter treatment-free interval (9 months v 43 months; P < .001). The prognostic effect of 11q deletion on survival strongly depended on the age: in patients less than 55 years old, the median survival time was significantly shorter in the deletion group (64 months v 209 months; P < .001), whereas in patients > or = 55 years old there was no significant difference (94 months v 111 months; P = .82). 11q deletions identify a new clinical subset of B-CLL characterized by extensive lymph node involvement. In younger B-CLL patients, this aberration is an important predictor of survival.