Significance of a Critical Set of 11q Chromosome Aberrations for Diagnosis of MYC Negative Burkitt Lymphoma

Abstract

Background: Burkitt lymphoma (BL) is characterized by a non-specific morphology and immunophenotype, a high proliferation rate, MYC rearrangements (MYC +), and by a simple karyotype. However, 5% of BL cases have no MYC rearrangements (MYC -) detectable by FISH. It is a matter of debate whether a true MYC (-) BL does exist.The WHO 2008 classification does not clearly define MYC (-) BL cases, and such cases are often misdiagnosed and treated as diffuse large B-cell lymphoma (DLBCL). We have previously described a provisional category of aggressive B-cell lymphoma unclassifiable (BCLU) with recurrent chromosome 11q aberrations, referred to as B-NHL(11q), with clinical, pathomorphological, and gene expression profile features typicalof BL,but MYC (-). B-NHLs(11q) carry proximal gains and telomeric losses of 11q. Karyotyping (CC) and FISH defined the gain region as dup(11)(q23q13) involving CCND1, ATM and KMT2A. As we have recently shown, BL and B-NHL(11q) express different levels of CD38 and CD16&CD56, and both have lower levels of miRNA-155, -21 and -26a than DLBCL. Here we describe a series of BL patients with a set of critical 11q aberrations and propose a diagnostic algorithm for a rapid work-up. Methods: Within a group of 82 BL cases diagnosed and treated with the BL protocol at our institution, we identified 15 cases of B-NHL(11q) with BL features and 11q aberrations: MYC (-) in 11(male/female 10/1, median age [range] 24 [18-62]) and MYC (+) in 4 cases (male/female 3/1, median age [range] 36.5 [20-82]). In MYC (-) pts, the disease was confined to a single site in 82%, was bulky (>7 cm) in 64% with diameter >20 cm in 45% of cases. BL, BCLU and DLBCL diagnosis according to WHO 2008 classification was based on histopathological/immunohistochemical examination (HP/IHC), CC, FISH, and clinical characteristics in all pts. For the final evaluation, the flow cytometry (FCM) immunophenotype, array comparative genomic hybridization (aCGH) data, and miRNA expression was assessed on samples obtained by the fine needle aspiration biopsy (FNAB). In the B-NHL(11q) cases we identified 11q duplication, dup(11q), with an inversion (inv) of the duplicated region and a deletion of its telomeric region, referred to as critical set of 11q aberrations, as opposed to non-critical aberration set that did not involve all three changes. B-NHL(11q) cells were evaluated with the panel of antibodies by IHC (CD20/CD10/BCL6/ BCL2/MUM1/MYC/Ki-67/CD43/CD44), and by FCM with CD (19, 20, 22, 23, 52, 79β, 81, 5, 25, 38, 43, 44, 45, 16&56, 56, 52, 62L, 71, 200), FMC7, HLADR, and BCL2. All B-NHL(11q) cases were evaluated by CC, FISH (MYC, BCL2, BCL6, CCND1, ATM, KMT2A and telomeric 11q) and aCGH. The relative positions of CCND1, ATM, and KMT2A within a duplicated region on the aberrant chromosome 11 were used to identify inversions. Results: A median follow-up of MYC (-) B-NHL(11q) pts treated with the BL regimen was 30 months, and 2-yr OS was 72% (95% CI: 45%, 99%). In 53% of B-NHL(11q) pts tingible body macrophages were less pronounced than in classic BL. All MYC (-) and MYC (+) B-NHLs(11q) cases presented the same phenotype and Ki-67 index of 100% and met the IHC criteria for BL. In MYC (-) and MYC (+) B-NHLs(11q) pts, all with a simple or less simple karyotype, we confirmed a critical or non-critical 11q aberrations in 10 and 5 pts, respectively. In 87% of pts we identified dup(11q), of two types: the larger part between 11q12.1 and 11q24.3 bands, and the smaller part between 11q22.3 and 11q24.1, with an additional multiplication of KMT2A inside the duplication region. In 13% of cases an inv without dup(11q) was detected. We found an inv of dup(11q) region in 73% of all cases, and no inv in dup(11q) in 2 MYC (+) cases only. Bulky tumors of >20 cm correlated with increased KMT2A copy number in B-NHLs(11q)cases. Conclusions: B-NHL(11q) cases are clinically homogenous while 11q aberrations are heterogeneous. We believe that BLs MYC (-) do exist. Combination of HP/IHC with FNAB/FCM/CC/FISH is a reliable method for credible diagnosis of BLMYC (-). BLMYC (-) should only be diagnosed in cases where critical 11q aberrations and a simple karyotype are identified. BCLU(11q) or DLBCL(11q) cases should be diagnosed if there are more complex karyotypes accompanied by 11q aberrations of any type. We hypothesize that in BLMYC (-) and other aggressive B-NHL(11q), 11q aberrations may determine clinical and pathomorphological features equivalent to those resulting from MYC rearrangements. Disclosures Walewski: Gilead: Consultancy, Honoraria, Other: travel, accommodation; Seattle: Other: travel, accommodation; GSK/Novartis: Research Funding; Genetics: Other: travel, accommodation; Celgene: Honoraria, Other: travel, accommodation, Research Funding; Teva: Consultancy, Honoraria; Servier: Consultancy; Karyopharm: Consultancy; Boehringer Ingelheim: Consultancy; Ariad: Consultancy; Takeda: Consultancy, Honoraria, Other; Roche: Consultancy, Honoraria, Other: travel, accommodation, Research Funding; Sanofi: Honoraria, Other: travel, accommodation; Mundipharma: Consultancy, Honoraria, Research Funding; Janssen-Cilag: Consultancy.

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

“…Burkitt-like lymphoma with 11q aberration shows a number of clinicopathological and molecular similarities to MYC-positive Burkitt lymphoma. [1][2][3][4]18 Typical of Burkitt-like lymphoma with 11q aberration, as we have shown here and previously, 1,2,4 was one peak incidence in HIV/EBV-negative young adult males. The typical presentation, predominantly nodal/tonsilar, was a single bulky lymph node/tumor, or less frequently, with a few contiguous lymph nodes/tumors involved, without bone marrow and central nervous system involvement, while in the Salaverria series, 2 there were children with bone marrow involvement.…”

“…In the current study, we confirm a pattern of an inverted duplication of a part of the long arm of chromosome 11 1 with mono-or biallelic telomeric loss of 11q, 2,4 which we have previously referred to as a critical set of 11q aberrations, 18 as a recurrent 11q abnormality. One case that presented no 11q deletion detected by single-nucleotide polymorphism analysis/array-comparative genomic hybridization and FISH showed a uniparental disomy in the critical 11q24.1q25 deletion region.…”

“…We have previously described flow cytometry immunophenotype of Burkitt lymphoma. 18,20,22 In the current study, antigen expression patterns in all Burkitt-like lymphomas with 11q aberration are similar to that of Burkitt lymphoma, but with some statistically significant differences. First, we found CD16/CD56 expression in 60% of Burkitt-like lymphomas with 11q aberration and in none of Burkitt lymphomas carrying both MYC rearrangement and 11q aberration, or MYC-positive Burkitt lymphoma.…”

“…Burkitt-like lymphoma with 11q aberration approaches is a reliable method for credible diagnosis of Burkitt-like lymphoma with 11q aberration and Burkitt lymphoma. Considering these results, as well as previous data, 9,18,20,22 we propose a practical flow cytometry and immunohistochemistry-based approach to the diagnosis of Burkitt-like lymphoma with 11q aberration and Burkitt lymphoma, as summarized in Table 2.…”

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

“…This finding was preliminarily published, describing cytogenetic data of four out of five cases presented in this article. 19 Simultaneous presence of these two aberrations indicate that 11q-gain/loss is not specifically associated with MYC -negative BLL,11q, but may be present also in the classic BL and HGBL, NOS, with MYC rearrangement. Our results are in accordance with recently published data.…”