Mantle cell lymphomas with concomitant MYC and CCND1 breakpoints are recurrently TdT positive and frequently show high-grade pathological and genetic features.

Chromosomal breakpoints involving the MYC gene locus, frequently referred to as MYC rearrangements (MYC - R+), are a diagnostic hallmark of Burkitt lymphoma and recurrent in many other subtypes of B-cell lymphomas including follicular lymphoma, diffuse large B-cell lymphoma and other high-grade B-cell lymphomas and are associated with an aggressive clinical course. In remarkable contrast, in MCL, only few MYC - R+ cases have yet been described. In the current study, we have retrospectively analysed 16 samples (MYC - R+, n = 15, MYC - R-, n = 1) from 13 patients and describe their morphological, immunophenotypic and (molecular) genetic features and clonal evolution patterns.

MYC expression and translocation analyses in low-grade and transformed follicular lymphoma.

Aims: Low-grade follicular lymphoma (FL) (grade 1/2, FL1/2) has an annual risk of transformation of ≈3%, which is associated with aberrations in CDKN2A/B, TP53, and MYC. As in diffuse large B-cell lymphoma, high MYC expression in transformed FL (tFL) might predict a MYC breakpoint.

Methods And Results: We quantified MYC expression by immunohistochemistry and digital analysis in 41 paired biopsies from 20 patients with FL1/2 with subsequent transformation and in four isolated biopsies of tFL.

JNK is constitutively active in mantle cell lymphoma: cell cycle deregulation and polyploidy by JNK inhibitor SP600125.

Mantle cell lymphoma (MCL) is characterized by genetic instability and a poor prognosis. Many blastoid variants are (hypo)tetraploid and have an even worse prognosis. We investigated the role of signalling by mitogen-activated protein kinases (MAPKs) in MCL.

Array comparative genomic hybridization reveals a very high frequency of deletions of the long arm of chromosome 6 in testicular lymphoma.

Despite the fact that numerous studies have been performed on diffuse large B-cell lymphoma (DLBCL), only few have concerned extranodal lymphomas occurring in the testis. We performed a cytogenetic and molecular study of 17 testicular non-Hodgkin lymphomas, of which 14 were proven primary DLBCL of the testis. Cytogenetic analysis revealed in 8 out of 11 evaluable cases a structural abnormality of the long arm of chromosome 6, with deletion or addition of material of unknown origin, and with breakpoints spanning the region 6q12-6q23.

Molecular, cytogenetic, and immunophenotypic characterization of follicular lymphoma grade 3B; a separate entity or part of the spectrum of diffuse large B-cell lymphoma or follicular lymphoma?

We studied a histological homogeneous group of 29 cases with the diagnosis of follicular lymphoma (FL) grade 3B (FL3Bs). In a previous study, we subdivided this group in 3 subgroups based on (1) aberrations of the 3q27 region, (2) lack of 3q27 and t(14;18), and (3) the presence of a t(14;18). In this study, we further characterized the FL3B lymphomas that are currently part of the spectrum of FL in the WHO classification, taking into account other cytogenetical aberrations, immunohistochemistry for P53, bcl2, bcl6, and CD10, rearrangement of the proto-oncogene myc, and mutation of the tumor suppressor gene TP53.