Katarzyna Blachnio

Cytogenetic and Flow Cytometry Evaluation of Richter Syndrome Reveals MYC, CDKN2A, IGH Alterations With Loss of CD52, CD62L and Increase of CD71 Antigen Expression as the Most Frequent Recurrent Abnormalities

OBJECTIVES Richter syndrome (RS) is a transformation of chronic lymphocytic leukemia (CLL) or small lymphocytic lymphoma (SLL) into high-grade lymphoma. There are only limited data on flow cytometry (FCM) and cytogenetics in RS. METHODS In this study, FCM, classic cytogenetics (CC), and fluorescence in situ hybridization (FISH) were performed in eight RS cases. RESULTS Most cases of RS were characterized by a loss/decrease of CD52 and CD62L and increased CD71 expression. CC identified complex karyotypes, with losses of 9/9p and 17/17p as the most frequent in four of seven cases. Seven RS cases demonstrated MYC abnormalities. Disruptions of CDKN2A and IGH were identified in five of seven and four of seven RS cases, respectively. CONCLUSIONS Newly diagnosed RS is an oncologic emergency, and a quick diagnostic decision is crucial in clinical practice. Therefore, in patients with CLL/SLL and rapidly enlarging asymmetric lymphadenopathy and/or extranodal tumors, we strongly advise FCM of fine-needle aspiration biopsy (FNAB) material, including CD62L, CD52, and CD71 analysis as well as assessment of karyotype and at least MYC abnormalities by FISH of the same FNAB material. Loss of CD52 expression in RS most likely predicts resistance to alemtuzumab therapy, which is frequently used in CLL.

miR expression in MYC-negative DLBCL/BL with partial trisomy 11 is similar to classical Burkitt lymphoma and different from diffuse large B–cell lymphoma

Fast and reliable differential diagnosis of Burkitt lymphoma (BL) vs. diffuse large B cell lymphoma (DLBCL) is of major importance for therapeutic decisions and patient outcome. Aggressive B cell non-Hodgkin lymphomas (B-NHLs) that do not belong to the abovementioned entities were categorized by the current WHO lymphoma classification as “B-cell lymphoma, unclassifiable, with features intermediate between DLBCL and BL” (DLBCL/BL). We have recently described a DLBCL/BL subgroup with recurrent chromosome 11q aberrations, resembling BL (B-NHLs[11q]). Here, we analyzed 102 prospectively collected fine needle aspirates from patients with aggressive B-NHLs in order to investigate the potential of microRNA (miR)-155, its precursor BIC, as well as miR-21 and miR-26a to differentiate BL from DLBCL, and from DLBCL/BL that include B-NHLs[11q]. Both BL and DLBCL/BL cases, including B-NHLs[11q], demonstrated significantly lower expression levels of miR-155/BIC, miR-21, and miR-26a compared to primary DLBCL. In conclusion, the miRs expression in B-NHLs[11q] provides a new suggestion, in addition to pathomorphological and clinical similarities between classical, i.e., MYC translocation-positive BL, and B-NHLs[11q], to recognize the B-NHLs[11q] subgroup of DLBCL/BL category as a MYC translocation-negative variant of BL in most cases, and points to the potential utility of miR-155/BIC/miR-21/miR-26a for the differential diagnosis of a heterogeneous category of DLBCL/BL.

Unusual cyclin D1 positive marginal zone lymphoma of mediastinum.

We report a case of 43-yr-old Caucasian female with an unusual, cyclin D1 positive marginal zone lymphoma (MZL) of mucosa-associated lymphoid tissue (MALT) type of the mediastinum. To date, only about 30 cases of this entity have been published. They occur mainly in Asian females with a history of coexisung autoimmune disease. To our knowledge, this is the first case of medistinal MZL with cyclin D1 expression. In the span of 6 yr this patients tumor recurred three times, was surgically treated, and initially diagnosed as paraganglioma. The diagnosis was based on histopathological examination only. Our final diagnosis of MZL was made by combined evaluation of histopathology (HP), immunohistochemistry (IH), flow cytometry (FCM), fluorescence in situ hybridization (FISH), and molecular biology studies. We found a positive cyclin D1 reaction by IH and cyclin D1 mRNA (CCND1) overexpression by reverse transcription polymerase chain reaction (RT-PCR). Very high cyclin D1 to β-actin mRNA ratio in this case was comparable with the ratio, characteristic for mantle cell lymphoma (MCL). However, there was no translocation t(11;14) found by FISH and an immunophenotype by IH and FCM was consistent with MZL ruling out MCL diagnosis. In addition, our case differs from other, previously reported thymic MZL lymphoma cases by no autoimmune disease association, Caucasian origin, and the absence of the plasmacytic differentiation on both HP/IH.

Unusual IgD+/CD38-follicular lymphoma with leukemic presentation

Follicular lymphoma (FL) is a low-grade lymphoma, with rare presentation of leukemic phase in peripheral blood at the diagnosis. We describe a 49-yr-old woman who developed leukemic phase of FL in a 3 mo period after histological diagnosis of peripheral lymph node. To confirm the final diagnosis, flow cytometry (FCM) of peripheral blood, nested PCR with bcl-2 rearrangement, and cytogenetic analysis of peripheral blood and bone marrow cells were done. Lymphoma cells were negative for CD38 and expressed monoclonal surface immunoglobulins with relatively strong and “bright” IgD and “dim” kappa-chain by FCM analysis. Although the patient presented with generalized lymphadenopathy, massive peripheral blood and bone marrow involvement, she achieved complete clinical response after first-line chemotherapy COP and rituximab. She is still in a good condition with follow up over 2 yr.

Mantle cell lymphoma presenting with paraproteinemia.

Mantle cell lymphoma (MCL) is most frequently diagnosed by the routine histological (HP) and immunohistochemical (IH) examination. Herein we present a case of 47-yr-old female with general lymphadenopathy and leukemic blood picture. She was initially diagnosed with marginal zone lymphoma (MZL). This diagnosis was based not only on the HP/IH examination but also on the presence of IgM paraproteinemia. Flow cytometry (FCM) examination was helpful in making of the final diagnosis of MCL. Fluorescence in situ hybridization and cyclin D1 mRNA detection by RT-PCR additionally confirmed the MCL diagnosis. The IgM paraproteinemia is rare in MCL, although is a common feature of lymphoplasmacytoid lymphomas (LPL) and is considered a major characteristic of Waldenström’s macroglobulinemia (WM).

The 11q-Gain/Loss Aberration Occurs Recurrently in MYC-Negative Burkitt-like Lymphoma With 11q Aberration, as Well as MYC-Positive Burkitt Lymphoma and MYC-Positive High-Grade B-Cell Lymphoma, NOS

Abstract Objectives The latest revision of lymphoma’s World Health Organization classification describes the new provisional entity “Burkitt-like lymphoma with 11q aberration” (BLL, 11q) as lacking MYC rearrangement, but harboring the specific11q-gain/loss aberration. We report genetic characteristics of 11 lymphoma cases with this aberration. Methods Classical cytogenetics, fluorescence in situ hybridization (FISH), and single nucleotide polymorphism/array comparative genomic hybridization. Results The 11q aberrations were described as duplication, inversion, and deletion. Array comparative genomic hybridization showed two types of duplication: bigger than 50 megabase pairs (Mbp) and smaller than 20 Mbp, which were associated with bulky tumor larger than 20 cm and amplification of the 11q23.3 region, including KMT2A. Six cases revealed a normal FISH status of MYC and were diagnosed as BLL,11q. Five cases showed MYC rearrangement and were diagnosed as Burkitt lymphoma (BL) or high-grade B-cell lymphoma, not otherwise specified (HGBL, NOS). Conclusions The 11q-gain/loss is not specific for BLL, 11q, but occurs recurrently in MYC-positive BL and MYC-positive HGBL.

Lenalidomide potentiates CD4 + CD25 + Treg-related suppression of lymphoma B-cell proliferation

We have previously found that ex vivo expanded human CD4+CD25+Treg cells suppress proliferation of lymphoma B-cell lines. Here we demonstrate that the immunomodulatory drug lenalidomide potentiates suppression of lymphoma B-cell proliferation by freshly isolated CD4+CD25+Tregs, as well as suppression by Tregs expanded polyclonally in the presence of rapamycin from CD4+CD25+T cells or CD4+CD25+CD127loT cells. The regulation of lymphoma cell proliferation by Tregs pre-expanded with “third-party” allogeneic MoDCs in the presence of rapamycin was also potentiated by lenalidomide. Lenalidomide contributed to the suppression exerted by Tregs despite concomitant downregulation of Treg proliferation. Lenalidomide did not reduce the suppression of conventional T cells by expanded Tregs. The exposure of polyclonally expanded Tregs to lenalidomide did not significantly alter their phenotype. There was no uniform pattern of lenalidomide effect on Treg-mediated regulation of lymphoma B cells freshly isolated from patients. Freshly isolated lymphoma cells activated with multimeric CD40L and IL-4 to support their survival in vitro varied in their sensitivity to lenalidomide, and the regulatory effect of Tregs on such lymphoma cells ranged from suppression to help in individual patients. Lenalidomide potentiated or attenuated Treg effects on the survival of freshly isolated lymphoma cells. A combination of lenalidomide treatment with adoptive transfer of CD4+CD25+Tregs or CD4+CD25+CD127loTregs expanded ex vivo could be used to suppress proliferation of residual lymphoma in select patients with lymphoma responsive to the regulation by Tregs and sensitive to lenalidomide.

Expression of CD52 in B-cell and T-cell lymphomas compared to normal T-cells as a potential guide for antibody therapy

6720 Background: Despite expanding use of anti-CD52 monoclonal antibody in the treatment of lymphoma/leukemia little is known about possible impact of antigen expression on therapeutic response. The purpose of this study was to evaluate degree of CD52 expression on lymphoma cells from new patients referred to the MSCM Cancer Center in Warsaw. METHODS Fine needle aspiration from lymph nodes, peripheral blood or bone marrow mononuclear cells were analyzed by flow cytometry for CD52 expression and mean fluorescence intensity (MFI) was calculated and compared to normal T lymphocytes from the same sample (MFI ratio). RESULTS Samples from 48 patients with the following lymphoma histology were analysed: small lymphomcytic lymphoma/chronic lymphocytic leukemia (SLL/CLL) - 17, hairy cell leukemia (HCL) -1, splenic marginal zone lymphoma (SMZL) - 5, mucosa associated lymphoid tissue (MALT) lymphoma - 2, diffuse large B-cell lymphoma (DLBCL) - 2, Burkitts lymphoma - 4, mantle cell lymphoma (MCL) - 3, follicular lymphoma (FL) - 4, T/NK cell precursor lymphoma (T/NK-LBL) - 6, B-cell precursor lymphoma (B-LBL) - 1, plasma cell myeloma (MM) - 3, reactive lymph node hyperplasia (RLNH) -1. Relative CD52 expression on SLL/CLL cells was highly variable with a range of MFI ratio from 1.4 to 13. Among other lymphoma subtypes the highest CD52 MFI was found in SMZL and HCL, followed by DLBCL and BL, and was relatively low in MCL and FL patients. In T/NK-LBL samples only a proportion of lymphoma cell population expressed CD52 antigen and MFI on positive cells was uniformly lower than MFI of normal T cells from the same sample with a MFI ratio range of 0-14. CONCLUSIONS These data indicate marked variability of CD52 expression in SLL/CLL cells, consistently high expression in SMZL, and a substantial decrease of CD52 expression in T/NK lymphoma cells. This may suggest caution in using anti-CD52 antibody in the novel treatment protocols for T/NK cell lymphoma/leukemia and a promising indication for its use in SMZL. Both will need a closer look at corelation of clinical response to anti-CD52 antibody with antigen expression on neoplastic cells. [Table: see text].

A comprehensive flow-cytometry-based immunophenotypic characterization of Burkitt-like lymphoma with 11q aberration

We previously described a subset of MYC translocation-negative aggressive B-cell lymphomas resembling Burkitt lymphoma, characterized by proximal gains and distal losses in chromosome 11. In the 2016 WHO classification, these MYC-negative lymphomas were recognized as a new provisional entity, ‘Burkitt-like lymphoma with 11q aberration’. Here we present an immunophenotype analysis of Burkitt-like lymphomas with 11q aberration. Cells were acquired by fine needle aspiration biopsy from 10 young adult patients, 80% of whom presented recurrence-free 5-year survival. Twenty-three MYC-positive Burkitt lymphomas, including three carrying both MYC rearrangement and 11q aberration, served as controls. By immunohistochemistry, all Burkitt-like lymphomas with 11q aberration were CD20+/CD10+/BCL6+/BCL2−/MUM1−/MYC+/EBV−, usually LMO2+/CD44−/CD43− and sometimes CD56+, and showed high proliferation rate. By flow cytometry, Burkitt-like lymphoma with 11q aberration immunophenotypically resembled MYC-positive Burkitt lymphoma, except for significantly (adjusted P<0.001) more frequent CD38higher expression in Burkitt lymphoma (91% MYC-positive Burkitt lymphoma vs 10% Burkitt-like lymphoma with 11q aberration), more frequently diminished CD45 expression in Burkitt lymphoma (74% vs 10%), an exclusive CD16/CD56 and highly restricted CD8 expression in Burkitt-like lymphoma with 11q aberration (60% vs 0% and 40% vs 4%, respectively). We showed high diagnostic accuracy and effectiveness of flow cytometry in Burkitt lymphoma. CD16/CD56 expression without CD38higher and the lack of CD16/CD56 with CD38higher expression proves to be a reliable, fast, and cost-effective method for diagnosing 11q aberration and MYC rearrangements in CD10(+) aggressive lymphomas, respectively. In addition, we confirmed a pattern of an inverted duplication with telomeric loss of 11q, as a recurrent 11q abnormality, but one case presented alternative changes, possibly resulting in an equivalent molecular effect. Our findings reveal similarities along with subtle but essential differences in the immunophenotype of Burkitt-like lymphoma with 11q aberration and MYC-positive Burkitt lymphoma, important for the differential diagnosis, but also for understanding the pathogenesis of Burkitt-like lymphoma with 11q aberration.