t(14;18)(q32;q21) in chronic lymphocytic leukemia patients: Report of two cases and a literature review

Novel identification of t(14;18)(q32;q21)/IGH::MALT1 in chronic lymphocytic leukaemia

Chronic lymphocytic leukaemia (CLL) is a clonal B-cell malignancy and remains a chronic disease despite improvements in clinical outcomes since the use of targeted therapies. Both clinical and biological parameters are important for determining prognosis. Unlike other mature B-cell lymphomas, translocations involving the immunoglobulin heavy chain (IGH) locus are uncommon in CLL. There have been few case reports of CLL harbouring t(14;18)/IGH::BCL2 and t(14;19)/IGH::BCL3. Here we describe the first two cases of patients with CLL with documented t(14;18)(q32;q21)/IGH::MALT1. Both cases in this report were associated with lower-risk biological parameters. Thus, FISH testing for MALT1 in cases with unknown IGH translocation partners in the setting of CLL should be implemented in clinical practice to better define such cases.

The spectrum of chromosomal translocations in the Arab world: ethnic-specific chromosomal translocations and their relevance to diseases

Chromosomal translocations (CTs) are the most common type of structural chromosomal abnormalities in humans. CTs have been reported in several studies in the Arab world, but the frequency and spectrum of these translocations are not well characterized. The aim of this study is to conduct a systematic review to estimate the frequency and spectrum of CTs in the 22 Arab countries. Four literature databases were searched: PubMed, Science Direct, Scopus, and Web of Science, from the time of inception until July 2021. A combination of broad search terms was used to collect all possible CTs reported in the Arab world. In addition to the literature databases, all captured CTs were searched in three chromosomal rearrangement databases (Mitelman Database, CytoD 1.0 Database, and the Atlas of Genetics and Cytogenetics in Oncology and Hematology), along with PubMed and Google Scholar, to check whether the CTs are unique to the Arabs or shared between Arabs and non-Arabs. A total of 9,053 titles and abstracts were screened, of which 168 studies met our inclusion criteria, and 378 CTs were identified in 15 Arab countries, of which 57 CTs were unique to Arab patients. Approximately 89% of the identified CTs involved autosomal chromosomes. Three CTs, t(9;22), t(13;14), and t(14;18), showed the highest frequency, which were associated with hematological malignancies, recurrent pregnancy loss, and follicular lymphoma, respectively. Complex CTs were commonly reported among Arabs, with a total of 44 CTs, of which 12 were unique to Arabs. This is the first study to focus on the spectrum of CTs in the Arab world and compressively map the ethnic-specific CTs relevant to cancer. It seems that there is a distinctive genotype of Arabs with CTs, of which some manifested with unique clinical phenotypes. Although ethnic-specific CTs are highly relevant to disease mechanism, they are understudied and need to be thoroughly addressed.

Chromosomal aberrations after induced pluripotent stem cells reprogramming

Induced pluripotent stem cells (iPSCs) are generated from adult cells that have been reprogrammed to pluripotency. However, in vitro cultivation and genetic reprogramming increase genetic instability, which could result in chromosomal abnormalities. Maintenance of genetic stability after reprogramming is required for possible experimental and clinical applications. The aim of this study was to analyze chromosomal alterations by using the G-banding karyotyping method applied to 97 samples from 38 iPSC cell lines generated from peripheral blood or Wharton’s jelly. Samples from patients with long QT syndrome, Jervell and Lange-Nielsen syndrome and amyotrophic lateral sclerosis and from normal individuals revealed the following chromosomal alterations: acentric fragments, chromosomal fusions, premature centromere divisions, double minutes, radial figures, ring chromosomes, polyploidies, inversions and trisomies. An analysis of two samples generated from Wharton’s jelly before and after reprogramming showed that abnormal clones can emerge or be selected and generate an altered lineage. IPSC lines may show clonal and nonclonal chromosomal aberrations in several passages (from P6 to P34), but these aberrations are more common in later passages. Many important chromosomal aberrations were detected, showing that G-banding is very useful for evaluating genetic instability with important repercussions for the application of iPSC lines.

[Chronic lymphocytic leukemia with t (14;18) (q32;q21) : report of eight cases and a literature review]

目的

分析伴t(14;18)(q32;q21)的慢性淋巴细胞白血病（CLL）患者的临床特征及预后，并进行相关文献复习。

方法

收集并分析2009年11月至2019年11月于江苏省人民医院就诊的8例伴t(14;18)(q32;q21)的CLL患者的临床资料。

结果

8例患者中7例男性，1例女性，诊断时中位年龄70岁，3例免疫表型积分5分，4例积分4分，1例积分3分。所有患者的骨髓组织病理学均为典型CLL表现。染色体核型示所有患者的t(14;18)(q32;q21)均为干系，3例仅携带t(14;18)(q32;q21)异常，4例为t(14;18)(q32;q21)伴+12，1例为t(14;18)(q32;q21)伴13q−。通过FISH在另外3例患者中发现了13q−。6例检测了免疫球蛋白重链可变区（IGHV）突变状态且均为有突变，未见IGHV3-21片段使用。进行相关检测的患者中，仅1例携带TP53突变，其余患者未见TP53、SF3B1、NOTCH1、MYD88突变。中位随访30.9个月时，1例死亡，7例存活，其中3例尚未达到治疗指征，4例接受化疗或免疫治疗的患者病情均稳定。

结论

t(14;18)(q32;q21)在CLL中少见，往往与+12、有突变的IGHV伴随出现。伴t(14;18)(q32;q21)的CLL可能预后良好。

An unusual case of chronic lymphocytic leukemia with trisomy 12 and t(14;18) and a favorable response to ibrutinib

Chronic lymphocytic leukemia (CLL) is the most common type of adult leukemia. Chromosomal abnormalities are reported to play important roles in CLL pathogenesis and evolution, including deletions of 11q, 13q, 17p, and trisomy12, that are frequently observed and have a known prognostic value. Furthermore, the mutational status of the IGHV gene was reported as an independent prognostic marker in CLL impacting the choice of therapy. We herein, report an unusual presentation of a Lebanese CLL patient with two cytogenetic abnormalities: trisomy 12 and t(14;18)(q32;q21), along with an unmutated IGHV, displaying a favorable response to ibrutinib with a maintained complete remission.

TP53 mutations are common in mantle cell lymphoma, including the indolent leukemic non-nodal variant

INTRODUCTION

Mantle cell lymphoma (MCL) is an aggressive B-cell neoplasm, but clinically indolent subtypes are also recognized. Data on the utility of mutation profiling in the context of routine workup and its role in risk-stratification of MCL patients are limited. In this study, we describe the mutational landscape and clinicopathologic correlates of a series of MCL cases at a single-institution setting.

METHODS

Samples from 26 patients with MCL were evaluated by NGS using DNA extracted from peripheral blood (PB) or bone marrow (BM). Evaluation of extent of PB or BM involvement was performed using flow cytometry immunophenotyping.

RESULTS

The study group included 17 (65%) men and 9 (35%) women with a median age of 65 years (range, 50-94). Twenty-one (81%) patients had nodal MCL (N-MCL) and 5 (19%) had the "leukemic variant" (L-MCL). Mutated genesincluded TP53 (35%), ATM (27%), CARD11 (10%); and FBXW7, NOTCH1, SPEN, BIRC3 (~5% each). Most mutations were clonal in nature. Ten unique TP53 mutations were identified in 9 samples, including 3 L-MCL cases. There was no difference in the frequency of TP53 mutations between L-MCL and N-MCL groups (p = 0.3), but TP53 mutations were subclonal in 2/3 L-MCL cases. Identification of clonal TP53 alterations in L-MCL patients prompted initiation of therapy despite low tumor burden.

CONCLUSIONS

TP53 is commonly mutated in MCL. TP53 mutations may be clonal or subclonal. Seemingly indolent L-MCL may harbor subclonal TP53 mutations which may serve as a useful biomarker for prognostication, therapeutic planning, follow-up monitoring, and early detection of clonal expansion.

The expanding role of venetoclax in chronic lymphocytic leukemia and small lymphocytic lymphoma

The BCL-2 protein family members inhibit cellular apoptosis, and their overexpression represents a common survival adaption in cancer. Recently, a selective BCL-2 inhibitor ABT-199, venetoclax, has demonstrated remarkable activity in relapsed/refractory chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL), both as a single agent and in combination with anti-CD20 immunotherapies, such as rituximab. In this article, we review the development and latest clinical data that have led to the expanded approval of venetoclax with rituximab in relapsed/refractory CLL/SLL. We also discuss ongoing and future clinical trials designed to evaluate the efficacy of venetoclax in previously untreated patients and to investigate venetoclax combinations with inhibitors of B-cell receptor signaling pathway. These studies hope to offer an expanded list of chemotherapy-free regimens for patients with CLL/SLL.

Composite Lymphoma as Co-occurrence of Advanced Chronic Lymphocytic Leukemia/Small Lymphocytic Lymphoma Carrying Trisomy 12 and t(14;18) and Peripheral T-cell Lymphoma

Composite lymphoma is defined as the co-occurrence of two types of lymphoma, comprising 1-4% of lymphomas, and the association of B-cell-type chronic lymphocytic leukemia (B-CLL)/small lymphocytic lymphoma and peripheral T-cell lymphoma (PTCL) is rare. Here, we report a case (77-year-old woman) of advanced B-CLL complicated by newly appearing PTCL. Two years after the onset of B-CLL, CLL cells acquired CD38 antigen expression and the disease entity became CLL/prolymphocytic leukemia. Trisomy 12 and t(14;18) karyotypes were observed. Five years after the onset of B-CLL, large abnormal cells with convoluted nuclei appeared in the peripheral blood and rapidly increased in number. These cells were positive for CD3, CD4, CD5, CD30 (partially), CD56, and αβ-type T-cell receptor (TCR), in which PCR demonstrated monoclonal TCR-γ gene rearrangement. An additional diagnosis of PTCL, not otherwise specified was made. We treated her with an R-CHOP regimen, resulting in the marked reduction of B-CLL cells but progressive PTCL. Brentuximab vedotin had a transient effect, but the patient died of sepsis due to residual PTCL and pancytopenia. This case is highly informative for tumor biology of B-CLL in terms of emergence of both chromosomal abnormalities and PTCL with progression of this leukemia.